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2024-01-18Merge tag 'iommu-updates-v6.8' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu Pull iommu updates from Joerg Roedel: "Core changes: - Fix race conditions in device probe path - Retire IOMMU bus_ops - Support for passing custom allocators to page table drivers - Clean up Kconfig around IOMMU_SVA - Support for sharing SVA domains with all devices bound to a mm - Firmware data parsing cleanup - Tracing improvements for iommu-dma code - Some smaller fixes and cleanups ARM-SMMU drivers: - Device-tree binding updates: - Add additional compatible strings for Qualcomm SoCs - Document Adreno clocks for Qualcomm's SM8350 SoC - SMMUv2: - Implement support for the ->domain_alloc_paging() callback - Ensure Secure context is restored following suspend of Qualcomm SMMU implementation - SMMUv3: - Disable stalling mode for the "quiet" context descriptor - Minor refactoring and driver cleanups Intel VT-d driver: - Cleanup and refactoring AMD IOMMU driver: - Improve IO TLB invalidation logic - Small cleanups and improvements Rockchip IOMMU driver: - DT binding update to add Rockchip RK3588 Apple DART driver: - Apple M1 USB4/Thunderbolt DART support - Cleanups Virtio IOMMU driver: - Add support for iotlb_sync_map - Enable deferred IO TLB flushes" * tag 'iommu-updates-v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (66 commits) iommu: Don't reserve 0-length IOVA region iommu/vt-d: Move inline helpers to header files iommu/vt-d: Remove unused vcmd interfaces iommu/vt-d: Remove unused parameter of intel_pasid_setup_pass_through() iommu/vt-d: Refactor device_to_iommu() to retrieve iommu directly iommu/sva: Fix memory leak in iommu_sva_bind_device() dt-bindings: iommu: rockchip: Add Rockchip RK3588 iommu/dma: Trace bounce buffer usage when mapping buffers iommu/arm-smmu: Convert to domain_alloc_paging() iommu/arm-smmu: Pass arm_smmu_domain to internal functions iommu/arm-smmu: Implement IOMMU_DOMAIN_BLOCKED iommu/arm-smmu: Convert to a global static identity domain iommu/arm-smmu: Reorganize arm_smmu_domain_add_master() iommu/arm-smmu-v3: Remove ARM_SMMU_DOMAIN_NESTED iommu/arm-smmu-v3: Master cannot be NULL in arm_smmu_write_strtab_ent() iommu/arm-smmu-v3: Add a type for the STE iommu/arm-smmu-v3: disable stall for quiet_cd iommu/qcom: restore IOMMU state if needed iommu/arm-smmu-qcom: Add QCM2290 MDSS compatible iommu/arm-smmu-qcom: Add missing GMU entry to match table ...
2024-01-09Merge tag 'mm-stable-2024-01-08-15-31' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: "Many singleton patches against the MM code. The patch series which are included in this merge do the following: - Peng Zhang has done some mapletree maintainance work in the series 'maple_tree: add mt_free_one() and mt_attr() helpers' 'Some cleanups of maple tree' - In the series 'mm: use memmap_on_memory semantics for dax/kmem' Vishal Verma has altered the interworking between memory-hotplug and dax/kmem so that newly added 'device memory' can more easily have its memmap placed within that newly added memory. - Matthew Wilcox continues folio-related work (including a few fixes) in the patch series 'Add folio_zero_tail() and folio_fill_tail()' 'Make folio_start_writeback return void' 'Fix fault handler's handling of poisoned tail pages' 'Convert aops->error_remove_page to ->error_remove_folio' 'Finish two folio conversions' 'More swap folio conversions' - Kefeng Wang has also contributed folio-related work in the series 'mm: cleanup and use more folio in page fault' - Jim Cromie has improved the kmemleak reporting output in the series 'tweak kmemleak report format'. - In the series 'stackdepot: allow evicting stack traces' Andrey Konovalov to permits clients (in this case KASAN) to cause eviction of no longer needed stack traces. - Charan Teja Kalla has fixed some accounting issues in the page allocator's atomic reserve calculations in the series 'mm: page_alloc: fixes for high atomic reserve caluculations'. - Dmitry Rokosov has added to the samples/ dorectory some sample code for a userspace memcg event listener application. See the series 'samples: introduce cgroup events listeners'. - Some mapletree maintanance work from Liam Howlett in the series 'maple_tree: iterator state changes'. - Nhat Pham has improved zswap's approach to writeback in the series 'workload-specific and memory pressure-driven zswap writeback'. - DAMON/DAMOS feature and maintenance work from SeongJae Park in the series 'mm/damon: let users feed and tame/auto-tune DAMOS' 'selftests/damon: add Python-written DAMON functionality tests' 'mm/damon: misc updates for 6.8' - Yosry Ahmed has improved memcg's stats flushing in the series 'mm: memcg: subtree stats flushing and thresholds'. - In the series 'Multi-size THP for anonymous memory' Ryan Roberts has added a runtime opt-in feature to transparent hugepages which improves performance by allocating larger chunks of memory during anonymous page faults. - Matthew Wilcox has also contributed some cleanup and maintenance work against eh buffer_head code int he series 'More buffer_head cleanups'. - Suren Baghdasaryan has done work on Andrea Arcangeli's series 'userfaultfd move option'. UFFDIO_MOVE permits userspace heap compaction algorithms to move userspace's pages around rather than UFFDIO_COPY'a alloc/copy/free. - Stefan Roesch has developed a 'KSM Advisor', in the series 'mm/ksm: Add ksm advisor'. This is a governor which tunes KSM's scanning aggressiveness in response to userspace's current needs. - Chengming Zhou has optimized zswap's temporary working memory use in the series 'mm/zswap: dstmem reuse optimizations and cleanups'. - Matthew Wilcox has performed some maintenance work on the writeback code, both code and within filesystems. The series is 'Clean up the writeback paths'. - Andrey Konovalov has optimized KASAN's handling of alloc and free stack traces for secondary-level allocators, in the series 'kasan: save mempool stack traces'. - Andrey also performed some KASAN maintenance work in the series 'kasan: assorted clean-ups'. - David Hildenbrand has gone to town on the rmap code. Cleanups, more pte batching, folio conversions and more. See the series 'mm/rmap: interface overhaul'. - Kinsey Ho has contributed some maintenance work on the MGLRU code in the series 'mm/mglru: Kconfig cleanup'. - Matthew Wilcox has contributed lruvec page accounting code cleanups in the series 'Remove some lruvec page accounting functions'" * tag 'mm-stable-2024-01-08-15-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (361 commits) mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDER mm, treewide: introduce NR_PAGE_ORDERS selftests/mm: add separate UFFDIO_MOVE test for PMD splitting selftests/mm: skip test if application doesn't has root privileges selftests/mm: conform test to TAP format output selftests: mm: hugepage-mmap: conform to TAP format output selftests/mm: gup_test: conform test to TAP format output mm/selftests: hugepage-mremap: conform test to TAP format output mm/vmstat: move pgdemote_* out of CONFIG_NUMA_BALANCING mm: zsmalloc: return -ENOSPC rather than -EINVAL in zs_malloc while size is too large mm/memcontrol: remove __mod_lruvec_page_state() mm/khugepaged: use a folio more in collapse_file() slub: use a folio in __kmalloc_large_node slub: use folio APIs in free_large_kmalloc() slub: use alloc_pages_node() in alloc_slab_page() mm: remove inc/dec lruvec page state functions mm: ratelimit stat flush from workingset shrinker kasan: stop leaking stack trace handles mm/mglru: remove CONFIG_TRANSPARENT_HUGEPAGE mm/mglru: add dummy pmd_dirty() ...
2024-01-09Merge tag 'slab-for-6.8' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab Pull slab updates from Vlastimil Babka: - SLUB: delayed freezing of CPU partial slabs (Chengming Zhou) Freezing is an operation involving double_cmpxchg() that makes a slab exclusive for a particular CPU. Chengming noticed that we use it also in situations where we are not yet installing the slab as the CPU slab, because freezing also indicates that the slab is not on the shared list. This results in redundant freeze/unfreeze operation and can be avoided by marking separately the shared list presence by reusing the PG_workingset flag. This approach neatly avoids the issues described in 9b1ea29bc0d7 ("Revert "mm, slub: consider rest of partial list if acquire_slab() fails"") as we can now grab a slab from the shared list in a quick and guaranteed way without the cmpxchg_double() operation that amplifies the lock contention and can fail. As a result, lkp has reported 34.2% improvement of stress-ng.rawudp.ops_per_sec - SLAB removal and SLUB cleanups (Vlastimil Babka) The SLAB allocator has been deprecated since 6.5 and nobody has objected so far. We agreed at LSF/MM to wait until the next LTS, which is 6.6, so we should be good to go now. This doesn't yet erase all traces of SLAB outside of mm/ so some dead code, comments or documentation remain, and will be cleaned up gradually (some series are already in the works). Removing the choice of allocators has already allowed to simplify and optimize the code wiring up the kmalloc APIs to the SLUB implementation. * tag 'slab-for-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: (34 commits) mm/slub: free KFENCE objects in slab_free_hook() mm/slub: handle bulk and single object freeing separately mm/slub: introduce __kmem_cache_free_bulk() without free hooks mm/slub: fix bulk alloc and free stats mm/slub: optimize free fast path code layout mm/slub: optimize alloc fastpath code layout mm/slub: remove slab_alloc() and __kmem_cache_alloc_lru() wrappers mm/slab: move kmalloc() functions from slab_common.c to slub.c mm/slab: move kmalloc_slab() to mm/slab.h mm/slab: move kfree() from slab_common.c to slub.c mm/slab: move struct kmem_cache_node from slab.h to slub.c mm/slab: move memcg related functions from slab.h to slub.c mm/slab: move pre/post-alloc hooks from slab.h to slub.c mm/slab: consolidate includes in the internal mm/slab.h mm/slab: move the rest of slub_def.h to mm/slab.h mm/slab: move struct kmem_cache_cpu declaration to slub.c mm/slab: remove mm/slab.c and slab_def.h mm/mempool/dmapool: remove CONFIG_DEBUG_SLAB ifdefs mm/slab: remove CONFIG_SLAB code from slab common code cpu/hotplug: remove CPUHP_SLAB_PREPARE hooks ...
2024-01-08mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDERKirill A. Shutemov
commit 23baf831a32c ("mm, treewide: redefine MAX_ORDER sanely") has changed the definition of MAX_ORDER to be inclusive. This has caused issues with code that was not yet upstream and depended on the previous definition. To draw attention to the altered meaning of the define, rename MAX_ORDER to MAX_PAGE_ORDER. Link: https://lkml.kernel.org/r/20231228144704.14033-2-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-01-05mm/mglru: add CONFIG_LRU_GEN_WALKS_MMUKinsey Ho
Add CONFIG_LRU_GEN_WALKS_MMU such that if disabled, the code that walks page tables to promote pages into the youngest generation will not be built. Also improves code readability by adding two helper functions get_mm_state() and get_next_mm(). Link: https://lkml.kernel.org/r/20231227141205.2200125-3-kinseyho@google.com Signed-off-by: Kinsey Ho <kinseyho@google.com> Co-developed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Tested-by: Donet Tom <donettom@linux.vnet.ibm.com> Acked-by: Yu Zhao <yuzhao@google.com> Cc: kernel test robot <lkp@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-01-03Merge branches 'apple/dart', 'arm/rockchip', 'arm/smmu', 'virtio', ↵Joerg Roedel
'x86/vt-d', 'x86/amd' and 'core' into next
2023-12-29mm: remove unnecessary ia64 code and commentKefeng Wang
IA64 has gone with commit cf8e8658100d ("arch: Remove Itanium (IA-64) architecture"), remove unnecessary ia64 special mm code and comment too. Link: https://lkml.kernel.org/r/20231222070203.2966980-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-12mm/thp: add CONFIG_TRANSPARENT_HUGEPAGE_NEVER optionDmytro Maluka
Currently enabling THP support (CONFIG_TRANSPARENT_HUGEPAGE) requires enabling either CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS or CONFIG_TRANSPARENT_HUGEPAGE_MADVISE, which both cause khugepaged starting by default at kernel bootup. Add the third choice CONFIG_TRANSPARENT_HUGEPAGE_NEVER, in line with the existing kernel command line setting transparent_hugepage=never, to disable THP by default (in particular, to prevent starting khugepaged by default) but still allow enabling it at runtime via sysfs. Rationale: khugepaged has its own non-negligible memory cost even if it is not used by any applications, since it bumps up vm.min_free_kbytes to its own required minimum in set_recommended_min_free_kbytes(). For example, on a machine with 4GB RAM, with 3 mm zones and pageblock_order == MAX_ORDER, starting khugepaged causes vm.min_free_kbytes increase from 8MB to 132MB. So if we use THP on machines with e.g. >=8GB of memory for better performance, but avoid using it on lower-memory machines to avoid its memory overhead, then for the same reason we also want to avoid even starting khugepaged on those <8GB machines. So with CONFIG_TRANSPARENT_HUGEPAGE_NEVER we can use the same kernel image on both >=8GB and <8GB machines, with THP support enabled but khugepaged not started by default. The userspace can then decide to enable THP via sysfs if needed, based on the total amount of memory. This could also be achieved with the existing transparent_hugepage=never setting in the kernel command line instead. But it seems cleaner to avoid tweaking the command line for such a basic setting. P.S. I see that CONFIG_TRANSPARENT_HUGEPAGE_NEVER was already proposed in the past [1] but without an explanation of the purpose. [1] https://lore.kernel.org/all/202211301651462590168@zte.com.cn/ Link: https://lkml.kernel.org/r/20231205170244.2746210-1-dmaluka@chromium.org Link: https://lore.kernel.org/all/20231204163254.2636289-1-dmaluka@chromium.org/ Signed-off-by: Dmytro Maluka <dmaluka@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-12zswap: shrink zswap pool based on memory pressureNhat Pham
Currently, we only shrink the zswap pool when the user-defined limit is hit. This means that if we set the limit too high, cold data that are unlikely to be used again will reside in the pool, wasting precious memory. It is hard to predict how much zswap space will be needed ahead of time, as this depends on the workload (specifically, on factors such as memory access patterns and compressibility of the memory pages). This patch implements a memcg- and NUMA-aware shrinker for zswap, that is initiated when there is memory pressure. The shrinker does not have any parameter that must be tuned by the user, and can be opted in or out on a per-memcg basis. Furthermore, to make it more robust for many workloads and prevent overshrinking (i.e evicting warm pages that might be refaulted into memory), we build in the following heuristics: * Estimate the number of warm pages residing in zswap, and attempt to protect this region of the zswap LRU. * Scale the number of freeable objects by an estimate of the memory saving factor. The better zswap compresses the data, the fewer pages we will evict to swap (as we will otherwise incur IO for relatively small memory saving). * During reclaim, if the shrinker encounters a page that is also being brought into memory, the shrinker will cautiously terminate its shrinking action, as this is a sign that it is touching the warmer region of the zswap LRU. As a proof of concept, we ran the following synthetic benchmark: build the linux kernel in a memory-limited cgroup, and allocate some cold data in tmpfs to see if the shrinker could write them out and improved the overall performance. Depending on the amount of cold data generated, we observe from 14% to 35% reduction in kernel CPU time used in the kernel builds. [nphamcs@gmail.com: check shrinker enablement early, use less costly stat flushing] Link: https://lkml.kernel.org/r/20231206194456.3234203-1-nphamcs@gmail.com Link: https://lkml.kernel.org/r/20231130194023.4102148-7-nphamcs@gmail.com Signed-off-by: Nhat Pham <nphamcs@gmail.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Tested-by: Bagas Sanjaya <bagasdotme@gmail.com> Cc: Chris Li <chrisl@kernel.org> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Seth Jennings <sjenning@redhat.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Vitaly Wool <vitaly.wool@konsulko.com> Cc: Yosry Ahmed <yosryahmed@google.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-12iommu: Change kconfig around IOMMU_SVAJason Gunthorpe
Linus suggested that the kconfig here is confusing: https://lore.kernel.org/all/CAHk-=wgUiAtiszwseM1p2fCJ+sC4XWQ+YN4TanFhUgvUqjr9Xw@mail.gmail.com/ Let's break it into three kconfigs controlling distinct things: - CONFIG_IOMMU_MM_DATA controls if the mm_struct has the additional fields for the IOMMU. Currently only PASID, but later patches store a struct iommu_mm_data * - CONFIG_ARCH_HAS_CPU_PASID controls if the arch needs the scheduling bit for keeping track of the ENQCMD instruction. x86 will select this if IOMMU_SVA is enabled - IOMMU_SVA controls if the IOMMU core compiles in the SVA support code for iommu driver use and the IOMMU exported API This way ARM will not enable CONFIG_ARCH_HAS_CPU_PASID Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/20231027000525.1278806-2-tina.zhang@intel.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
2023-12-06mm/Kconfig: make userfaultfd a menuconfigPeter Xu
PTE_MARKER_UFFD_WP is a subconfig for userfaultfd. To make it clear, switch to use menuconfig for userfaultfd. Link: https://lkml.kernel.org/r/20231123224204.1060152-1-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-05mm/slab: remove CONFIG_SLAB from all Kconfig and MakefileVlastimil Babka
Remove CONFIG_SLAB, CONFIG_DEBUG_SLAB, CONFIG_SLAB_DEPRECATED and everything in Kconfig files and mm/Makefile that depends on those. Since SLUB is the only remaining allocator, remove the allocator choice, make CONFIG_SLUB a "def_bool y" for now and remove all explicit dependencies on SLUB or SLAB as it's now always enabled. Make every option's verbose name and description refer to "the slab allocator" without refering to the specific implementation. Do not rename the CONFIG_ option names yet. Everything under #ifdef CONFIG_SLAB, and mm/slab.c is now dead code, all code under #ifdef CONFIG_SLUB is now always compiled. Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Christoph Lameter <cl@linux.com> Acked-by: David Rientjes <rientjes@google.com> Tested-by: David Rientjes <rientjes@google.com> Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2023-10-25mm: restrict the pcp batch scale factor to avoid too long latencyHuang Ying
In page allocator, PCP (Per-CPU Pageset) is refilled and drained in batches to increase page allocation throughput, reduce page allocation/freeing latency per page, and reduce zone lock contention. But too large batch size will cause too long maximal allocation/freeing latency, which may punish arbitrary users. So the default batch size is chosen carefully (in zone_batchsize(), the value is 63 for zone > 1GB) to avoid that. In commit 3b12e7e97938 ("mm/page_alloc: scale the number of pages that are batch freed"), the batch size will be scaled for large number of page freeing to improve page freeing performance and reduce zone lock contention. Similar optimization can be used for large number of pages allocation too. To find out a suitable max batch scale factor (that is, max effective batch size), some tests and measurement on some machines were done as follows. A set of debug patches are implemented as follows, - Set PCP high to be 2 * batch to reduce the effect of PCP high - Disable free batch size scaling to get the raw performance. - The code with zone lock held is extracted from rmqueue_bulk() and free_pcppages_bulk() to 2 separate functions to make it easy to measure the function run time with ftrace function_graph tracer. - The batch size is hard coded to be 63 (default), 127, 255, 511, 1023, 2047, 4095. Then will-it-scale/page_fault1 is used to generate the page allocation/freeing workload. The page allocation/freeing throughput (page/s) is measured via will-it-scale. The page allocation/freeing average latency (alloc/free latency avg, in us) and allocation/freeing latency at 99 percentile (alloc/free latency 99%, in us) are measured with ftrace function_graph tracer. The test results are as follows, Sapphire Rapids Server ====================== Batch throughput free latency free latency alloc latency alloc latency page/s avg / us 99% / us avg / us 99% / us ----- ---------- ------------ ------------ ------------- ------------- 63 513633.4 2.33 3.57 2.67 6.83 127 517616.7 4.35 6.65 4.22 13.03 255 520822.8 8.29 13.32 7.52 25.24 511 524122.0 15.79 23.42 14.02 49.35 1023 525980.5 30.25 44.19 25.36 94.88 2047 526793.6 59.39 84.50 45.22 140.81 Ice Lake Server =============== Batch throughput free latency free latency alloc latency alloc latency page/s avg / us 99% / us avg / us 99% / us ----- ---------- ------------ ------------ ------------- ------------- 63 620210.3 2.21 3.68 2.02 4.35 127 627003.0 4.09 6.86 3.51 8.28 255 630777.5 7.70 13.50 6.17 15.97 511 633651.5 14.85 22.62 11.66 31.08 1023 637071.1 28.55 42.02 20.81 54.36 2047 638089.7 56.54 84.06 39.28 91.68 Cascade Lake Server =================== Batch throughput free latency free latency alloc latency alloc latency page/s avg / us 99% / us avg / us 99% / us ----- ---------- ------------ ------------ ------------- ------------- 63 404706.7 3.29 5.03 3.53 4.75 127 422475.2 6.12 9.09 6.36 8.76 255 411522.2 11.68 16.97 10.90 16.39 511 428124.1 22.54 31.28 19.86 32.25 1023 414718.4 43.39 62.52 40.00 66.33 2047 429848.7 86.64 120.34 71.14 106.08 Commet Lake Desktop =================== Batch throughput free latency free latency alloc latency alloc latency page/s avg / us 99% / us avg / us 99% / us ----- ---------- ------------ ------------ ------------- ------------- 63 795183.13 2.18 3.55 2.03 3.05 127 803067.85 3.91 6.56 3.85 5.52 255 812771.10 7.35 10.80 7.14 10.20 511 817723.48 14.17 27.54 13.43 30.31 1023 818870.19 27.72 40.10 27.89 46.28 Coffee Lake Desktop =================== Batch throughput free latency free latency alloc latency alloc latency page/s avg / us 99% / us avg / us 99% / us ----- ---------- ------------ ------------ ------------- ------------- 63 510542.8 3.13 4.40 2.48 3.43 127 514288.6 5.97 7.89 4.65 6.04 255 516889.7 11.86 15.58 8.96 12.55 511 519802.4 23.10 28.81 16.95 26.19 1023 520802.7 45.30 52.51 33.19 45.95 2047 519997.1 90.63 104.00 65.26 81.74 From the above data, to restrict the allocation/freeing latency to be less than 100 us in most times, the max batch scale factor needs to be less than or equal to 5. Although it is reasonable to use 5 as max batch scale factor for the systems tested, there are also slower systems. Where smaller value should be used to constrain the page allocation/freeing latency. So, in this patch, a new kconfig option (PCP_BATCH_SCALE_MAX) is added to set the max batch scale factor. Whose default value is 5, and users can reduce it when necessary. Link: https://lkml.kernel.org/r/20231016053002.756205-5-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: David Hildenbrand <david@redhat.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Christoph Lameter <cl@linux.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04zswap: change zswap's default allocator to zsmallocNhat Pham
Out of zswap's 3 allocators, zsmalloc is the clear superior in terms of memory utilization, both in theory and as observed in practice, with its high storage density and low internal fragmentation. zsmalloc is also more actively developed and maintained, since it is the allocator of choice for zswap for many users, as well as the only allocator for zram. A historical objection to the selection of zsmalloc as the default allocator for zswap is its lack of writeback capability. However, this has changed, with the zsmalloc writeback patchset, and the subsequent zswap LRU refactor. With this, there is not a lot of good reasons to keep zbud, an otherwise inferior allocator, as the default instead of zswap. This patch changes the default allocator to zsmalloc. The only exception is on settings without MMU, in which case zbud will remain as the default. Link: https://lkml.kernel.org/r/20230908235115.2943486-1-nphamcs@gmail.com Signed-off-by: Nhat Pham <nphamcs@gmail.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Yosry Ahmed <yosryahmed@google.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Cc: Seth Jennings <sjenning@redhat.com> Cc: Vitaly Wool <vitaly.wool@konsulko.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-29Merge tag 'mm-stable-2023-08-28-18-26' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - Some swap cleanups from Ma Wupeng ("fix WARN_ON in add_to_avail_list") - Peter Xu has a series (mm/gup: Unify hugetlb, speed up thp") which reduces the special-case code for handling hugetlb pages in GUP. It also speeds up GUP handling of transparent hugepages. - Peng Zhang provides some maple tree speedups ("Optimize the fast path of mas_store()"). - Sergey Senozhatsky has improved te performance of zsmalloc during compaction (zsmalloc: small compaction improvements"). - Domenico Cerasuolo has developed additional selftest code for zswap ("selftests: cgroup: add zswap test program"). - xu xin has doe some work on KSM's handling of zero pages. These changes are mainly to enable the user to better understand the effectiveness of KSM's treatment of zero pages ("ksm: support tracking KSM-placed zero-pages"). - Jeff Xu has fixes the behaviour of memfd's MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED sysctl ("mm/memfd: fix sysctl MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED"). - David Howells has fixed an fscache optimization ("mm, netfs, fscache: Stop read optimisation when folio removed from pagecache"). - Axel Rasmussen has given userfaultfd the ability to simulate memory poisoning ("add UFFDIO_POISON to simulate memory poisoning with UFFD"). - Miaohe Lin has contributed some routine maintenance work on the memory-failure code ("mm: memory-failure: remove unneeded PageHuge() check"). - Peng Zhang has contributed some maintenance work on the maple tree code ("Improve the validation for maple tree and some cleanup"). - Hugh Dickins has optimized the collapsing of shmem or file pages into THPs ("mm: free retracted page table by RCU"). - Jiaqi Yan has a patch series which permits us to use the healthy subpages within a hardware poisoned huge page for general purposes ("Improve hugetlbfs read on HWPOISON hugepages"). - Kemeng Shi has done some maintenance work on the pagetable-check code ("Remove unused parameters in page_table_check"). - More folioification work from Matthew Wilcox ("More filesystem folio conversions for 6.6"), ("Followup folio conversions for zswap"). And from ZhangPeng ("Convert several functions in page_io.c to use a folio"). - page_ext cleanups from Kemeng Shi ("minor cleanups for page_ext"). - Baoquan He has converted some architectures to use the GENERIC_IOREMAP ioremap()/iounmap() code ("mm: ioremap: Convert architectures to take GENERIC_IOREMAP way"). - Anshuman Khandual has optimized arm64 tlb shootdown ("arm64: support batched/deferred tlb shootdown during page reclamation/migration"). - Better maple tree lockdep checking from Liam Howlett ("More strict maple tree lockdep"). Liam also developed some efficiency improvements ("Reduce preallocations for maple tree"). - Cleanup and optimization to the secondary IOMMU TLB invalidation, from Alistair Popple ("Invalidate secondary IOMMU TLB on permission upgrade"). - Ryan Roberts fixes some arm64 MM selftest issues ("selftests/mm fixes for arm64"). - Kemeng Shi provides some maintenance work on the compaction code ("Two minor cleanups for compaction"). - Some reduction in mmap_lock pressure from Matthew Wilcox ("Handle most file-backed faults under the VMA lock"). - Aneesh Kumar contributes code to use the vmemmap optimization for DAX on ppc64, under some circumstances ("Add support for DAX vmemmap optimization for ppc64"). - page-ext cleanups from Kemeng Shi ("add page_ext_data to get client data in page_ext"), ("minor cleanups to page_ext header"). - Some zswap cleanups from Johannes Weiner ("mm: zswap: three cleanups"). - kmsan cleanups from ZhangPeng ("minor cleanups for kmsan"). - VMA handling cleanups from Kefeng Wang ("mm: convert to vma_is_initial_heap/stack()"). - DAMON feature work from SeongJae Park ("mm/damon/sysfs-schemes: implement DAMOS tried total bytes file"), ("Extend DAMOS filters for address ranges and DAMON monitoring targets"). - Compaction work from Kemeng Shi ("Fixes and cleanups to compaction"). - Liam Howlett has improved the maple tree node replacement code ("maple_tree: Change replacement strategy"). - ZhangPeng has a general code cleanup - use the K() macro more widely ("cleanup with helper macro K()"). - Aneesh Kumar brings memmap-on-memory to ppc64 ("Add support for memmap on memory feature on ppc64"). - pagealloc cleanups from Kemeng Shi ("Two minor cleanups for pcp list in page_alloc"), ("Two minor cleanups for get pageblock migratetype"). - Vishal Moola introduces a memory descriptor for page table tracking, "struct ptdesc" ("Split ptdesc from struct page"). - memfd selftest maintenance work from Aleksa Sarai ("memfd: cleanups for vm.memfd_noexec"). - MM include file rationalization from Hugh Dickins ("arch: include asm/cacheflush.h in asm/hugetlb.h"). - THP debug output fixes from Hugh Dickins ("mm,thp: fix sloppy text output"). - kmemleak improvements from Xiaolei Wang ("mm/kmemleak: use object_cache instead of kmemleak_initialized"). - More folio-related cleanups from Matthew Wilcox ("Remove _folio_dtor and _folio_order"). - A VMA locking scalability improvement from Suren Baghdasaryan ("Per-VMA lock support for swap and userfaults"). - pagetable handling cleanups from Matthew Wilcox ("New page table range API"). - A batch of swap/thp cleanups from David Hildenbrand ("mm/swap: stop using page->private on tail pages for THP_SWAP + cleanups"). - Cleanups and speedups to the hugetlb fault handling from Matthew Wilcox ("Change calling convention for ->huge_fault"). - Matthew Wilcox has also done some maintenance work on the MM subsystem documentation ("Improve mm documentation"). * tag 'mm-stable-2023-08-28-18-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (489 commits) maple_tree: shrink struct maple_tree maple_tree: clean up mas_wr_append() secretmem: convert page_is_secretmem() to folio_is_secretmem() nios2: fix flush_dcache_page() for usage from irq context hugetlb: add documentation for vma_kernel_pagesize() mm: add orphaned kernel-doc to the rst files. mm: fix clean_record_shared_mapping_range kernel-doc mm: fix get_mctgt_type() kernel-doc mm: fix kernel-doc warning from tlb_flush_rmaps() mm: remove enum page_entry_size mm: allow ->huge_fault() to be called without the mmap_lock held mm: move PMD_ORDER to pgtable.h mm: remove checks for pte_index memcg: remove duplication detection for mem_cgroup_uncharge_swap mm/huge_memory: work on folio->swap instead of page->private when splitting folio mm/swap: inline folio_set_swap_entry() and folio_swap_entry() mm/swap: use dedicated entry for swap in folio mm/swap: stop using page->private on tail pages for THP_SWAP selftests/mm: fix WARNING comparing pointer to 0 selftests: cgroup: fix test_kmem_memcg_deletion kernel mem check ...
2023-08-21mm/memory_hotplug: simplify ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE kconfigAneesh Kumar K.V
Patch series "Add support for memmap on memory feature on ppc64", v8. This patch series update memmap on memory feature to fall back to memmap allocation outside the memory block if the alignment rules are not met. This makes the feature more useful on architectures like ppc64 where alignment rules are different with 64K page size. This patch (of 6): Instead of adding menu entry with all supported architectures, add mm/Kconfig variable and select the same from supported architectures. No functional change in this patch. Link: https://lkml.kernel.org/r/20230808091501.287660-1-aneesh.kumar@linux.ibm.com Link: https://lkml.kernel.org/r/20230808091501.287660-2-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21mm: kill frontswapJohannes Weiner
The only user of frontswap is zswap, and has been for a long time. Have swap call into zswap directly and remove the indirection. [hannes@cmpxchg.org: remove obsolete comment, per Yosry] Link: https://lkml.kernel.org/r/20230719142832.GA932528@cmpxchg.org [fengwei.yin@intel.com: don't warn if none swapcache folio is passed to zswap_load] Link: https://lkml.kernel.org/r/20230810095652.3905184-1-fengwei.yin@intel.com Link: https://lkml.kernel.org/r/20230717160227.GA867137@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Yin Fengwei <fengwei.yin@intel.com> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Acked-by: Nhat Pham <nphamcs@gmail.com> Acked-by: Yosry Ahmed <yosryahmed@google.com> Acked-by: Christoph Hellwig <hch@lst.de> Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Vitaly Wool <vitaly.wool@konsulko.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-18mm/vmemmap optimization: split hugetlb and devdax vmemmap optimizationAneesh Kumar K.V
Arm disabled hugetlb vmemmap optimization [1] because hugetlb vmemmap optimization includes an update of both the permissions (writeable to read-only) and the output address (pfn) of the vmemmap ptes. That is not supported without unmapping of pte(marking it invalid) by some architectures. With DAX vmemmap optimization we don't require such pte updates and architectures can enable DAX vmemmap optimization while having hugetlb vmemmap optimization disabled. Hence split DAX optimization support into a different config. s390, loongarch and riscv don't have devdax support. So the DAX config is not enabled for them. With this change, arm64 should be able to select DAX optimization [1] commit 060a2c92d1b6 ("arm64: mm: hugetlb: Disable HUGETLB_PAGE_OPTIMIZE_VMEMMAP") Link: https://lkml.kernel.org/r/20230724190759.483013-8-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-18mm: make MEMFD_CREATE into a selectable config optionThomas Weißschuh
The memfd_create() syscall, enabled by CONFIG_MEMFD_CREATE, is useful on its own even when not required by CONFIG_TMPFS or CONFIG_HUGETLBFS. Split it into its own proper bool option that can be enabled by users. Move that option into mm/ where the code itself also lies. Also add "select" statements to CONFIG_TMPFS and CONFIG_HUGETLBFS so they automatically enable CONFIG_MEMFD_CREATE as before. Link: https://lkml.kernel.org/r/20230630-config-memfd-v1-1-9acc3ae38b5a@weissschuh.net Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Tested-by: Zhangjin Wu <falcon@tinylab.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-07-18Randomized slab caches for kmalloc()GONG, Ruiqi
When exploiting memory vulnerabilities, "heap spraying" is a common technique targeting those related to dynamic memory allocation (i.e. the "heap"), and it plays an important role in a successful exploitation. Basically, it is to overwrite the memory area of vulnerable object by triggering allocation in other subsystems or modules and therefore getting a reference to the targeted memory location. It's usable on various types of vulnerablity including use after free (UAF), heap out- of-bound write and etc. There are (at least) two reasons why the heap can be sprayed: 1) generic slab caches are shared among different subsystems and modules, and 2) dedicated slab caches could be merged with the generic ones. Currently these two factors cannot be prevented at a low cost: the first one is a widely used memory allocation mechanism, and shutting down slab merging completely via `slub_nomerge` would be overkill. To efficiently prevent heap spraying, we propose the following approach: to create multiple copies of generic slab caches that will never be merged, and random one of them will be used at allocation. The random selection is based on the address of code that calls `kmalloc()`, which means it is static at runtime (rather than dynamically determined at each time of allocation, which could be bypassed by repeatedly spraying in brute force). In other words, the randomness of cache selection will be with respect to the code address rather than time, i.e. allocations in different code paths would most likely pick different caches, although kmalloc() at each place would use the same cache copy whenever it is executed. In this way, the vulnerable object and memory allocated in other subsystems and modules will (most probably) be on different slab caches, which prevents the object from being sprayed. Meanwhile, the static random selection is further enhanced with a per-boot random seed, which prevents the attacker from finding a usable kmalloc that happens to pick the same cache with the vulnerable subsystem/module by analyzing the open source code. In other words, with the per-boot seed, the random selection is static during each time the system starts and runs, but not across different system startups. The overhead of performance has been tested on a 40-core x86 server by comparing the results of `perf bench all` between the kernels with and without this patch based on the latest linux-next kernel, which shows minor difference. A subset of benchmarks are listed below: sched/ sched/ syscall/ mem/ mem/ messaging pipe basic memcpy memset (sec) (sec) (sec) (GB/sec) (GB/sec) control1 0.019 5.459 0.733 15.258789 51.398026 control2 0.019 5.439 0.730 16.009221 48.828125 control3 0.019 5.282 0.735 16.009221 48.828125 control_avg 0.019 5.393 0.733 15.759077 49.684759 experiment1 0.019 5.374 0.741 15.500992 46.502976 experiment2 0.019 5.440 0.746 16.276042 51.398026 experiment3 0.019 5.242 0.752 15.258789 51.398026 experiment_avg 0.019 5.352 0.746 15.678608 49.766343 The overhead of memory usage was measured by executing `free` after boot on a QEMU VM with 1GB total memory, and as expected, it's positively correlated with # of cache copies: control 4 copies 8 copies 16 copies total 969.8M 968.2M 968.2M 968.2M used 20.0M 21.9M 24.1M 26.7M free 936.9M 933.6M 931.4M 928.6M available 932.2M 928.8M 926.6M 923.9M Co-developed-by: Xiu Jianfeng <xiujianfeng@huawei.com> Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> Signed-off-by: GONG, Ruiqi <gongruiqi@huaweicloud.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Acked-by: Dennis Zhou <dennis@kernel.org> # percpu Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2023-06-29Merge tag 'slab-for-6.5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab Pull slab updates from Vlastimil Babka: - SLAB deprecation: Following the discussion at LSF/MM 2023 [1] and no objections, the SLAB allocator is deprecated by renaming the config option (to make its users notice) to CONFIG_SLAB_DEPRECATED with updated help text. SLUB should be used instead. Existing defconfigs with CONFIG_SLAB are also updated. - SLAB_NO_MERGE kmem_cache flag (Jesper Dangaard Brouer): There are (very limited) cases where kmem_cache merging is undesirable, and existing ways to prevent it are hacky. Introduce a new flag to do that cleanly and convert the existing hacky users. Btrfs plans to use this for debug kernel builds (that use case is always fine), networking for performance reasons (that should be very rare). - Replace the usage of weak PRNGs (David Keisar Schmidt): In addition to using stronger RNGs for the security related features, the code is a bit cleaner. - Misc code cleanups (SeongJae Parki, Xiongwei Song, Zhen Lei, and zhaoxinchao) Link: https://lwn.net/Articles/932201/ [1] * tag 'slab-for-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: mm/slab_common: use SLAB_NO_MERGE instead of negative refcount mm/slab: break up RCU readers on SLAB_TYPESAFE_BY_RCU example code mm/slab: add a missing semicolon on SLAB_TYPESAFE_BY_RCU example code mm/slab_common: reduce an if statement in create_cache() mm/slab: introduce kmem_cache flag SLAB_NO_MERGE mm/slab: rename CONFIG_SLAB to CONFIG_SLAB_DEPRECATED mm/slab: remove HAVE_HARDENED_USERCOPY_ALLOCATOR mm/slab_common: Replace invocation of weak PRNG mm/slab: Replace invocation of weak PRNG slub: Don't read nr_slabs and total_objects directly slub: Remove slabs_node() function slub: Remove CONFIG_SMP defined check slub: Put objects_show() into CONFIG_SLUB_DEBUG enabled block slub: Correct the error code when slab_kset is NULL mm/slab: correct return values in comment for _kmem_cache_create()
2023-06-28Merge branch 'expand-stack'Linus Torvalds
This modifies our user mode stack expansion code to always take the mmap_lock for writing before modifying the VM layout. It's actually something we always technically should have done, but because we didn't strictly need it, we were being lazy ("opportunistic" sounds so much better, doesn't it?) about things, and had this hack in place where we would extend the stack vma in-place without doing the proper locking. And it worked fine. We just needed to change vm_start (or, in the case of grow-up stacks, vm_end) and together with some special ad-hoc locking using the anon_vma lock and the mm->page_table_lock, it all was fairly straightforward. That is, it was all fine until Ruihan Li pointed out that now that the vma layout uses the maple tree code, we *really* don't just change vm_start and vm_end any more, and the locking really is broken. Oops. It's not actually all _that_ horrible to fix this once and for all, and do proper locking, but it's a bit painful. We have basically three different cases of stack expansion, and they all work just a bit differently: - the common and obvious case is the page fault handling. It's actually fairly simple and straightforward, except for the fact that we have something like 24 different versions of it, and you end up in a maze of twisty little passages, all alike. - the simplest case is the execve() code that creates a new stack. There are no real locking concerns because it's all in a private new VM that hasn't been exposed to anybody, but lockdep still can end up unhappy if you get it wrong. - and finally, we have GUP and page pinning, which shouldn't really be expanding the stack in the first place, but in addition to execve() we also use it for ptrace(). And debuggers do want to possibly access memory under the stack pointer and thus need to be able to expand the stack as a special case. None of these cases are exactly complicated, but the page fault case in particular is just repeated slightly differently many many times. And ia64 in particular has a fairly complicated situation where you can have both a regular grow-down stack _and_ a special grow-up stack for the register backing store. So to make this slightly more manageable, the bulk of this series is to first create a helper function for the most common page fault case, and convert all the straightforward architectures to it. Thus the new 'lock_mm_and_find_vma()' helper function, which ends up being used by x86, arm, powerpc, mips, riscv, alpha, arc, csky, hexagon, loongarch, nios2, sh, sparc32, and xtensa. So we not only convert more than half the architectures, we now have more shared code and avoid some of those twisty little passages. And largely due to this common helper function, the full diffstat of this series ends up deleting more lines than it adds. That still leaves eight architectures (ia64, m68k, microblaze, openrisc, parisc, s390, sparc64 and um) that end up doing 'expand_stack()' manually because they are doing something slightly different from the normal pattern. Along with the couple of special cases in execve() and GUP. So there's a couple of patches that first create 'locked' helper versions of the stack expansion functions, so that there's a obvious path forward in the conversion. The execve() case is then actually pretty simple, and is a nice cleanup from our old "grow-up stackls are special, because at execve time even they grow down". The #ifdef CONFIG_STACK_GROWSUP in that code just goes away, because it's just more straightforward to write out the stack expansion there manually, instead od having get_user_pages_remote() do it for us in some situations but not others and have to worry about locking rules for GUP. And the final step is then to just convert the remaining odd cases to a new world order where 'expand_stack()' is called with the mmap_lock held for reading, but where it might drop it and upgrade it to a write, only to return with it held for reading (in the success case) or with it completely dropped (in the failure case). In the process, we remove all the stack expansion from GUP (where dropping the lock wouldn't be ok without special rules anyway), and add it in manually to __access_remote_vm() for ptrace(). Thanks to Adrian Glaubitz and Frank Scheiner who tested the ia64 cases. Everything else here felt pretty straightforward, but the ia64 rules for stack expansion are really quite odd and very different from everything else. Also thanks to Vegard Nossum who caught me getting one of those odd conditions entirely the wrong way around. Anyway, I think I want to actually move all the stack expansion code to a whole new file of its own, rather than have it split up between mm/mmap.c and mm/memory.c, but since this will have to be backported to the initial maple tree vma introduction anyway, I tried to keep the patches _fairly_ minimal. Also, while I don't think it's valid to expand the stack from GUP, the final patch in here is a "warn if some crazy GUP user wants to try to expand the stack" patch. That one will be reverted before the final release, but it's left to catch any odd cases during the merge window and release candidates. Reported-by: Ruihan Li <lrh2000@pku.edu.cn> * branch 'expand-stack': gup: add warning if some caller would seem to want stack expansion mm: always expand the stack with the mmap write lock held execve: expand new process stack manually ahead of time mm: make find_extend_vma() fail if write lock not held powerpc/mm: convert coprocessor fault to lock_mm_and_find_vma() mm/fault: convert remaining simple cases to lock_mm_and_find_vma() arm/mm: Convert to using lock_mm_and_find_vma() riscv/mm: Convert to using lock_mm_and_find_vma() mips/mm: Convert to using lock_mm_and_find_vma() powerpc/mm: Convert to using lock_mm_and_find_vma() arm64/mm: Convert to using lock_mm_and_find_vma() mm: make the page fault mmap locking killable mm: introduce new 'lock_mm_and_find_vma()' page fault helper
2023-06-24mm: introduce new 'lock_mm_and_find_vma()' page fault helperLinus Torvalds
.. and make x86 use it. This basically extracts the existing x86 "find and expand faulting vma" code, but extends it to also take the mmap lock for writing in case we actually do need to expand the vma. We've historically short-circuited that case, and have some rather ugly special logic to serialize the stack segment expansion (since we only hold the mmap lock for reading) that doesn't match the normal VM locking. That slight violation of locking worked well, right up until it didn't: the maple tree code really does want proper locking even for simple extension of an existing vma. So extract the code for "look up the vma of the fault" from x86, fix it up to do the necessary write locking, and make it available as a helper function for other architectures that can use the common helper. Note: I say "common helper", but it really only handles the normal stack-grows-down case. Which is all architectures except for PA-RISC and IA64. So some rare architectures can't use the helper, but if they care they'll just need to open-code this logic. It's also worth pointing out that this code really would like to have an optimistic "mmap_upgrade_trylock()" to make it quicker to go from a read-lock (for the common case) to taking the write lock (for having to extend the vma) in the normal single-threaded situation where there is no other locking activity. But that _is_ all the very uncommon special case, so while it would be nice to have such an operation, it probably doesn't matter in reality. I did put in the skeleton code for such a possible future expansion, even if it only acts as pseudo-documentation for what we're doing. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-06-19mm: zswap: support exclusive loadsYosry Ahmed
Commit 71024cb4a0bf ("frontswap: remove frontswap_tmem_exclusive_gets") removed support for exclusive loads from frontswap as it was not used. Bring back exclusive loads support to frontswap by adding an "exclusive" output parameter to frontswap_ops->load. On the zswap side, add a module parameter to enable/disable exclusive loads, and a config option to control the boot default value. Refactor zswap entry invalidation in zswap_frontswap_invalidate_page() into zswap_invalidate_entry() to reuse it in zswap_frontswap_load() if exclusive loads are enabled. With exclusive loads, we avoid having two copies of the same page in memory (compressed & uncompressed) after faulting it in from zswap. On the other hand, if the page is to be reclaimed again without being dirtied, it will be re-compressed. Compression is not usually slow, and a page that was just faulted in is less likely to be reclaimed again soon. Link: https://lkml.kernel.org/r/20230607195143.1473802-1-yosryahmed@google.com Signed-off-by: Yosry Ahmed <yosryahmed@google.com> Suggested-by: Yu Zhao <yuzhao@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Seth Jennings <sjenning@redhat.com> Cc: Vitaly Wool <vitaly.wool@konsulko.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-16Merge branches 'slab/for-6.5/prandom', 'slab/for-6.5/slab_no_merge' and ↵Vlastimil Babka
'slab/for-6.5/slab-deprecate' into slab/for-next Merge the feature branches scheduled for 6.5: - replace the usage of weak PRNGs, by David Keisar Schmidt - introduce the SLAB_NO_MERGE kmem_cache flag, by Jesper Dangaard Brouer - deprecate CONFIG_SLAB, with a planned removal, by myself
2023-05-26mm/slab: rename CONFIG_SLAB to CONFIG_SLAB_DEPRECATEDVlastimil Babka
As discussed at LSF/MM [1] [2] and with no objections raised there, deprecate the SLAB allocator. Rename the user-visible option so that users with CONFIG_SLAB=y get a new prompt with explanation during make oldconfig, while make olddefconfig will just switch to SLUB. In all defconfigs with CONFIG_SLAB=y remove the line so those also switch to SLUB. Regressions due to the switch should be reported to linux-mm and slab maintainers. [1] https://lore.kernel.org/all/4b9fc9c6-b48c-198f-5f80-811a44737e5f@suse.cz/ [2] https://lwn.net/Articles/932201/ Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k Acked-by: Helge Deller <deller@gmx.de> # parisc
2023-05-24mm/slab: remove HAVE_HARDENED_USERCOPY_ALLOCATORVlastimil Babka
With SLOB removed, both remaining allocators support hardened usercopy, so remove the config and associated #ifdef. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
2023-04-27Merge tag 'mm-stable-2023-04-27-15-30' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of switching from a user process to a kernel thread. - More folio conversions from Kefeng Wang, Zhang Peng and Pankaj Raghav. - zsmalloc performance improvements from Sergey Senozhatsky. - Yue Zhao has found and fixed some data race issues around the alteration of memcg userspace tunables. - VFS rationalizations from Christoph Hellwig: - removal of most of the callers of write_one_page() - make __filemap_get_folio()'s return value more useful - Luis Chamberlain has changed tmpfs so it no longer requires swap backing. Use `mount -o noswap'. - Qi Zheng has made the slab shrinkers operate locklessly, providing some scalability benefits. - Keith Busch has improved dmapool's performance, making part of its operations O(1) rather than O(n). - Peter Xu adds the UFFD_FEATURE_WP_UNPOPULATED feature to userfaultd, permitting userspace to wr-protect anon memory unpopulated ptes. - Kirill Shutemov has changed MAX_ORDER's meaning to be inclusive rather than exclusive, and has fixed a bunch of errors which were caused by its unintuitive meaning. - Axel Rasmussen give userfaultfd the UFFDIO_CONTINUE_MODE_WP feature, which causes minor faults to install a write-protected pte. - Vlastimil Babka has done some maintenance work on vma_merge(): cleanups to the kernel code and improvements to our userspace test harness. - Cleanups to do_fault_around() by Lorenzo Stoakes. - Mike Rapoport has moved a lot of initialization code out of various mm/ files and into mm/mm_init.c. - Lorenzo Stoakes removd vmf_insert_mixed_prot(), which was added for DRM, but DRM doesn't use it any more. - Lorenzo has also coverted read_kcore() and vread() to use iterators and has thereby removed the use of bounce buffers in some cases. - Lorenzo has also contributed further cleanups of vma_merge(). - Chaitanya Prakash provides some fixes to the mmap selftesting code. - Matthew Wilcox changes xfs and afs so they no longer take sleeping locks in ->map_page(), a step towards RCUification of pagefaults. - Suren Baghdasaryan has improved mmap_lock scalability by switching to per-VMA locking. - Frederic Weisbecker has reworked the percpu cache draining so that it no longer causes latency glitches on cpu isolated workloads. - Mike Rapoport cleans up and corrects the ARCH_FORCE_MAX_ORDER Kconfig logic. - Liu Shixin has changed zswap's initialization so we no longer waste a chunk of memory if zswap is not being used. - Yosry Ahmed has improved the performance of memcg statistics flushing. - David Stevens has fixed several issues involving khugepaged, userfaultfd and shmem. - Christoph Hellwig has provided some cleanup work to zram's IO-related code paths. - David Hildenbrand has fixed up some issues in the selftest code's testing of our pte state changing. - Pankaj Raghav has made page_endio() unneeded and has removed it. - Peter Xu contributed some rationalizations of the userfaultfd selftests. - Yosry Ahmed has fixed an issue around memcg's page recalim accounting. - Chaitanya Prakash has fixed some arm-related issues in the selftests/mm code. - Longlong Xia has improved the way in which KSM handles hwpoisoned pages. - Peter Xu fixes a few issues with uffd-wp at fork() time. - Stefan Roesch has changed KSM so that it may now be used on a per-process and per-cgroup basis. * tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits) mm,unmap: avoid flushing TLB in batch if PTE is inaccessible shmem: restrict noswap option to initial user namespace mm/khugepaged: fix conflicting mods to collapse_file() sparse: remove unnecessary 0 values from rc mm: move 'mmap_min_addr' logic from callers into vm_unmapped_area() hugetlb: pte_alloc_huge() to replace huge pte_alloc_map() maple_tree: fix allocation in mas_sparse_area() mm: do not increment pgfault stats when page fault handler retries zsmalloc: allow only one active pool compaction context selftests/mm: add new selftests for KSM mm: add new KSM process and sysfs knobs mm: add new api to enable ksm per process mm: shrinkers: fix debugfs file permissions mm: don't check VMA write permissions if the PTE/PMD indicates write permissions migrate_pages_batch: fix statistics for longterm pin retry userfaultfd: use helper function range_in_vma() lib/show_mem.c: use for_each_populated_zone() simplify code mm: correct arg in reclaim_pages()/reclaim_clean_pages_from_list() fs/buffer: convert create_page_buffers to folio_create_buffers fs/buffer: add folio_create_empty_buffers helper ...
2023-04-25Merge tag 'slab-for-6.4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab Pull slab updates from Vlastimil Babka: "The main change is naturally the SLOB removal. Since its deprecation in 6.2 I've seen no complaints so hopefully SLUB_(TINY) works well for everyone and we can proceed. Besides the code cleanup, the main immediate benefit will be allowing kfree() family of function to work on kmem_cache_alloc() objects, which was incompatible with SLOB. This includes kfree_rcu() which had no kmem_cache_free_rcu() counterpart yet and now it shouldn't be necessary anymore. Besides that, there are several small code and comment improvements from Thomas, Thorsten and Vernon" * tag 'slab-for-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: mm/slab: document kfree() as allowed for kmem_cache_alloc() objects mm/slob: remove slob.c mm/slab: remove CONFIG_SLOB code from slab common code mm, pagemap: remove SLOB and SLQB from comments and documentation mm, page_flags: remove PG_slob_free mm/slob: remove CONFIG_SLOB mm/slub: fix help comment of SLUB_DEBUG mm: slub: make kobj_type structure constant slab: Adjust comment after refactoring of gfp.h
2023-04-18mm/hugetlb_vmemmap: rename ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAPAneesh Kumar K.V
Now we use ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP config option to indicate devdax and hugetlb vmemmap optimization support. Hence rename that to a generic ARCH_WANT_OPTIMIZE_VMEMMAP Link: https://lkml.kernel.org/r/20230412050025.84346-2-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Tarun Sahu <tsahu@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05mm: introduce CONFIG_PER_VMA_LOCKSuren Baghdasaryan
Patch series "Per-VMA locks", v4. LWN article describing the feature: https://lwn.net/Articles/906852/ Per-vma locks idea that was discussed during SPF [1] discussion at LSF/MM last year [2], which concluded with suggestion that “a reader/writer semaphore could be put into the VMA itself; that would have the effect of using the VMA as a sort of range lock. There would still be contention at the VMA level, but it would be an improvement.” This patchset implements this suggested approach. When handling page faults we lookup the VMA that contains the faulting page under RCU protection and try to acquire its lock. If that fails we fall back to using mmap_lock, similar to how SPF handled this situation. One notable way the implementation deviates from the proposal is the way VMAs are read-locked. During some of mm updates, multiple VMAs need to be locked until the end of the update (e.g. vma_merge, split_vma, etc). Tracking all the locked VMAs, avoiding recursive locks, figuring out when it's safe to unlock previously locked VMAs would make the code more complex. So, instead of the usual lock/unlock pattern, the proposed solution marks a VMA as locked and provides an efficient way to: 1. Identify locked VMAs. 2. Unlock all locked VMAs in bulk. We also postpone unlocking the locked VMAs until the end of the update, when we do mmap_write_unlock. Potentially this keeps a VMA locked for longer than is absolutely necessary but it results in a big reduction of code complexity. Read-locking a VMA is done using two sequence numbers - one in the vm_area_struct and one in the mm_struct. VMA is considered read-locked when these sequence numbers are equal. To read-lock a VMA we set the sequence number in vm_area_struct to be equal to the sequence number in mm_struct. To unlock all VMAs we increment mm_struct's seq number. This allows for an efficient way to track locked VMAs and to drop the locks on all VMAs at the end of the update. The patchset implements per-VMA locking only for anonymous pages which are not in swap and avoids userfaultfs as their implementation is more complex. Additional support for file-back page faults, swapped and user pages can be added incrementally. Performance benchmarks show similar although slightly smaller benefits as with SPF patchset (~75% of SPF benefits). Still, with lower complexity this approach might be more desirable. Since RFC was posted in September 2022, two separate Google teams outside of Android evaluated the patchset and confirmed positive results. Here are the known usecases when per-VMA locks show benefits: Android: Apps with high number of threads (~100) launch times improve by up to 20%. Each thread mmaps several areas upon startup (Stack and Thread-local storage (TLS), thread signal stack, indirect ref table), which requires taking mmap_lock in write mode. Page faults take mmap_lock in read mode. During app launch, both thread creation and page faults establishing the active workinget are happening in parallel and that causes lock contention between mm writers and readers even if updates and page faults are happening in different VMAs. Per-vma locks prevent this contention by providing more granular lock. Google Fibers: We have several dynamically sized thread pools that spawn new threads under increased load and reduce their number when idling. For example, Google's in-process scheduling/threading framework, UMCG/Fibers, is backed by such a thread pool. When idling, only a small number of idle worker threads are available; when a spike of incoming requests arrive, each request is handled in its own "fiber", which is a work item posted onto a UMCG worker thread; quite often these spikes lead to a number of new threads spawning. Each new thread needs to allocate and register an RSEQ section on its TLS, then register itself with the kernel as a UMCG worker thread, and only after that it can be considered by the in-process UMCG/Fiber scheduler as available to do useful work. In short, during an incoming workload spike new threads have to be spawned, and they perform several syscalls (RSEQ registration, UMCG worker registration, memory allocations) before they can actually start doing useful work. Removing any bottlenecks on this thread startup path will greatly improve our services' latencies when faced with request/workload spikes. At high scale, mmap_lock contention during thread creation and stack page faults leads to user-visible multi-second serving latencies in a similar pattern to Android app startup. Per-VMA locking patchset has been run successfully in limited experiments with user-facing production workloads. In these experiments, we observed that the peak thread creation rate was high enough that thread creation is no longer a bottleneck. TCP zerocopy receive: From the point of view of TCP zerocopy receive, the per-vma lock patch is massively beneficial. In today's implementation, a process with N threads where N - 1 are performing zerocopy receive and 1 thread is performing madvise() with the write lock taken (e.g. needs to change vm_flags) will result in all N -1 receive threads blocking until the madvise is done. Conversely, on a busy process receiving a lot of data, an madvise operation that does need to take the mmap lock in write mode will need to wait for all of the receives to be done - a lose:lose proposition. Per-VMA locking _removes_ by definition this source of contention entirely. There are other benefits for receive as well, chiefly a reduction in cacheline bouncing across receiving threads for locking/unlocking the single mmap lock. On an RPC style synthetic workload with 4KB RPCs: 1a) The find+lock+unlock VMA path in the base case, without the per-vma lock patchset, is about 0.7% of cycles as measured by perf. 1b) mmap_read_lock + mmap_read_unlock in the base case is about 0.5% cycles overall - most of this is within the TCP read hotpath (a small fraction is 'other' usage in the system). 2a) The find+lock+unlock VMA path, with the per-vma patchset and a trivial patch written to take advantage of it in TCP, is about 0.4% of cycles (down from 0.7% above) 2b) mmap_read_lock + mmap_read_unlock in the per-vma patchset is < 0.1% cycles and is out of the TCP read hotpath entirely (down from 0.5% before, the remaining usage is the 'other' usage in the system). So, in addition to entirely removing an onerous source of contention, it also reduces the CPU cycles of TCP receive zerocopy by about 0.5%+ (compared to overall cycles in perf) for the 'small' RPC scenario. In https://lkml.kernel.org/r/87fsaqouyd.fsf_-_@stealth, Punit demonstrated throughput improvements of as much as 188% from this patchset. This patch (of 25): This configuration variable will be used to build the support for VMA locking during page fault handling. This is enabled on supported architectures with SMP and MMU set. The architecture support is needed since the page fault handler is called from the architecture's page faulting code which needs modifications to handle faults under VMA lock. Link: https://lkml.kernel.org/r/20230227173632.3292573-1-surenb@google.com Link: https://lkml.kernel.org/r/20230227173632.3292573-10-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05mm, treewide: redefine MAX_ORDER sanelyKirill A. Shutemov
MAX_ORDER currently defined as number of orders page allocator supports: user can ask buddy allocator for page order between 0 and MAX_ORDER-1. This definition is counter-intuitive and lead to number of bugs all over the kernel. Change the definition of MAX_ORDER to be inclusive: the range of orders user can ask from buddy allocator is 0..MAX_ORDER now. [kirill@shutemov.name: fix min() warning] Link: https://lkml.kernel.org/r/20230315153800.32wib3n5rickolvh@box [akpm@linux-foundation.org: fix another min_t warning] [kirill@shutemov.name: fixups per Zi Yan] Link: https://lkml.kernel.org/r/20230316232144.b7ic4cif4kjiabws@box.shutemov.name [akpm@linux-foundation.org: fix underlining in docs] Link: https://lore.kernel.org/oe-kbuild-all/202303191025.VRCTk6mP-lkp@intel.com/ Link: https://lkml.kernel.org/r/20230315113133.11326-11-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc] Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05dmapool: add alloc/free performance testKeith Busch
Patch series "dmapool enhancements", v4. Time spent in dma_pool alloc/free increases linearly with the number of pages backing the pool. We can reduce this to constant time with minor changes to how free pages are tracked. This patch (of 12): Provide a module that allocates and frees many blocks of various sizes and report how long it takes. This is intended to provide a consistent way to measure how changes to the dma_pool_alloc/free routines affect timing. Link: https://lkml.kernel.org/r/20230126215125.4069751-1-kbusch@meta.com Link: https://lkml.kernel.org/r/20230126215125.4069751-2-kbusch@meta.com Signed-off-by: Keith Busch <kbusch@kernel.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Matthew Wilcox <willy@infradead.org> Cc: Tony Battersby <tonyb@cybernetics.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05mm: Remove "select SRCU"Paul E. McKenney
Now that the SRCU Kconfig option is unconditionally selected, there is no longer any point in selecting it. Therefore, remove the "select SRCU" Kconfig statements. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: <linux-mm@kvack.org> Reviewed-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
2023-03-29mm/slob: remove CONFIG_SLOBVlastimil Babka
Remove SLOB from Kconfig and Makefile. Everything under #ifdef CONFIG_SLOB, and mm/slob.c is now dead code. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Acked-by: Lorenzo Stoakes <lstoakes@gmail.com> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
2023-02-02zsmalloc: set default zspage chain size to 8Sergey Senozhatsky
This changes key characteristics (pages per-zspage and objects per-zspage) of a number of size classes which in results in different pool configuration. With zspage chain size of 8 we have more size clases clusters (123) and higher huge size class watermark (3632 bytes). Please read zsmalloc documentation for more details. Link: https://lkml.kernel.org/r/20230118005210.2814763-5-senozhatsky@chromium.org Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02zsmalloc: make zspage chain size configurableSergey Senozhatsky
Remove hard coded limit on the maximum number of physical pages per-zspage. This will allow tuning of zsmalloc pool as zspage chain size changes `pages per-zspage` and `objects per-zspage` characteristics of size classes which also affects size classes clustering (the way size classes are merged). Link: https://lkml.kernel.org/r/20230118005210.2814763-4-senozhatsky@chromium.org Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18selftests/vm: rename selftests/vm to selftests/mmSeongJae Park
Rename selftets/vm to selftests/mm for being more consistent with the code, documentation, and tools directories, and won't be confused with virtual machines. [sj@kernel.org: convert missing vm->mm changes] Link: https://lkml.kernel.org/r/20230107230643.252273-1-sj@kernel.org Link: https://lkml.kernel.org/r/20230103180754.129637-5-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-12-17Merge tag 'x86_mm_for_6.2_v2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mm updates from Dave Hansen: "New Feature: - Randomize the per-cpu entry areas Cleanups: - Have CR3_ADDR_MASK use PHYSICAL_PAGE_MASK instead of open coding it - Move to "native" set_memory_rox() helper - Clean up pmd_get_atomic() and i386-PAE - Remove some unused page table size macros" * tag 'x86_mm_for_6.2_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (35 commits) x86/mm: Ensure forced page table splitting x86/kasan: Populate shadow for shared chunk of the CPU entry area x86/kasan: Add helpers to align shadow addresses up and down x86/kasan: Rename local CPU_ENTRY_AREA variables to shorten names x86/mm: Populate KASAN shadow for entire per-CPU range of CPU entry area x86/mm: Recompute physical address for every page of per-CPU CEA mapping x86/mm: Rename __change_page_attr_set_clr(.checkalias) x86/mm: Inhibit _PAGE_NX changes from cpa_process_alias() x86/mm: Untangle __change_page_attr_set_clr(.checkalias) x86/mm: Add a few comments x86/mm: Fix CR3_ADDR_MASK x86/mm: Remove P*D_PAGE_MASK and P*D_PAGE_SIZE macros mm: Convert __HAVE_ARCH_P..P_GET to the new style mm: Remove pointless barrier() after pmdp_get_lockless() x86/mm/pae: Get rid of set_64bit() x86_64: Remove pointless set_64bit() usage x86/mm/pae: Be consistent with pXXp_get_and_clear() x86/mm/pae: Use WRITE_ONCE() x86/mm/pae: Don't (ab)use atomic64 mm/gup: Fix the lockless PMD access ...
2022-12-15Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm updates from Paolo Bonzini: "ARM64: - Enable the per-vcpu dirty-ring tracking mechanism, together with an option to keep the good old dirty log around for pages that are dirtied by something other than a vcpu. - Switch to the relaxed parallel fault handling, using RCU to delay page table reclaim and giving better performance under load. - Relax the MTE ABI, allowing a VMM to use the MAP_SHARED mapping option, which multi-process VMMs such as crosvm rely on (see merge commit 382b5b87a97d: "Fix a number of issues with MTE, such as races on the tags being initialised vs the PG_mte_tagged flag as well as the lack of support for VM_SHARED when KVM is involved. Patches from Catalin Marinas and Peter Collingbourne"). - Merge the pKVM shadow vcpu state tracking that allows the hypervisor to have its own view of a vcpu, keeping that state private. - Add support for the PMUv3p5 architecture revision, bringing support for 64bit counters on systems that support it, and fix the no-quite-compliant CHAIN-ed counter support for the machines that actually exist out there. - Fix a handful of minor issues around 52bit VA/PA support (64kB pages only) as a prefix of the oncoming support for 4kB and 16kB pages. - Pick a small set of documentation and spelling fixes, because no good merge window would be complete without those. s390: - Second batch of the lazy destroy patches - First batch of KVM changes for kernel virtual != physical address support - Removal of a unused function x86: - Allow compiling out SMM support - Cleanup and documentation of SMM state save area format - Preserve interrupt shadow in SMM state save area - Respond to generic signals during slow page faults - Fixes and optimizations for the non-executable huge page errata fix. - Reprogram all performance counters on PMU filter change - Cleanups to Hyper-V emulation and tests - Process Hyper-V TLB flushes from a nested guest (i.e. from a L2 guest running on top of a L1 Hyper-V hypervisor) - Advertise several new Intel features - x86 Xen-for-KVM: - Allow the Xen runstate information to cross a page boundary - Allow XEN_RUNSTATE_UPDATE flag behaviour to be configured - Add support for 32-bit guests in SCHEDOP_poll - Notable x86 fixes and cleanups: - One-off fixes for various emulation flows (SGX, VMXON, NRIPS=0). - Reinstate IBPB on emulated VM-Exit that was incorrectly dropped a few years back when eliminating unnecessary barriers when switching between vmcs01 and vmcs02. - Clean up vmread_error_trampoline() to make it more obvious that params must be passed on the stack, even for x86-64. - Let userspace set all supported bits in MSR_IA32_FEAT_CTL irrespective of the current guest CPUID. - Fudge around a race with TSC refinement that results in KVM incorrectly thinking a guest needs TSC scaling when running on a CPU with a constant TSC, but no hardware-enumerated TSC frequency. - Advertise (on AMD) that the SMM_CTL MSR is not supported - Remove unnecessary exports Generic: - Support for responding to signals during page faults; introduces new FOLL_INTERRUPTIBLE flag that was reviewed by mm folks Selftests: - Fix an inverted check in the access tracking perf test, and restore support for asserting that there aren't too many idle pages when running on bare metal. - Fix build errors that occur in certain setups (unsure exactly what is unique about the problematic setup) due to glibc overriding static_assert() to a variant that requires a custom message. - Introduce actual atomics for clear/set_bit() in selftests - Add support for pinning vCPUs in dirty_log_perf_test. - Rename the so called "perf_util" framework to "memstress". - Add a lightweight psuedo RNG for guest use, and use it to randomize the access pattern and write vs. read percentage in the memstress tests. - Add a common ucall implementation; code dedup and pre-work for running SEV (and beyond) guests in selftests. - Provide a common constructor and arch hook, which will eventually be used by x86 to automatically select the right hypercall (AMD vs. Intel). - A bunch of added/enabled/fixed selftests for ARM64, covering memslots, breakpoints, stage-2 faults and access tracking. - x86-specific selftest changes: - Clean up x86's page table management. - Clean up and enhance the "smaller maxphyaddr" test, and add a related test to cover generic emulation failure. - Clean up the nEPT support checks. - Add X86_PROPERTY_* framework to retrieve multi-bit CPUID values. - Fix an ordering issue in the AMX test introduced by recent conversions to use kvm_cpu_has(), and harden the code to guard against similar bugs in the future. Anything that tiggers caching of KVM's supported CPUID, kvm_cpu_has() in this case, effectively hides opt-in XSAVE features if the caching occurs before the test opts in via prctl(). Documentation: - Remove deleted ioctls from documentation - Clean up the docs for the x86 MSR filter. - Various fixes" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (361 commits) KVM: x86: Add proper ReST tables for userspace MSR exits/flags KVM: selftests: Allocate ucall pool from MEM_REGION_DATA KVM: arm64: selftests: Align VA space allocator with TTBR0 KVM: arm64: Fix benign bug with incorrect use of VA_BITS KVM: arm64: PMU: Fix period computation for 64bit counters with 32bit overflow KVM: x86: Advertise that the SMM_CTL MSR is not supported KVM: x86: remove unnecessary exports KVM: selftests: Fix spelling mistake "probabalistic" -> "probabilistic" tools: KVM: selftests: Convert clear/set_bit() to actual atomics tools: Drop "atomic_" prefix from atomic test_and_set_bit() tools: Drop conflicting non-atomic test_and_{clear,set}_bit() helpers KVM: selftests: Use non-atomic clear/set bit helpers in KVM tests perf tools: Use dedicated non-atomic clear/set bit helpers tools: Take @bit as an "unsigned long" in {clear,set}_bit() helpers KVM: arm64: selftests: Enable single-step without a "full" ucall() KVM: x86: fix APICv/x2AVIC disabled when vm reboot by itself KVM: Remove stale comment about KVM_REQ_UNHALT KVM: Add missing arch for KVM_CREATE_DEVICE and KVM_{SET,GET}_DEVICE_ATTR KVM: Reference to kvm_userspace_memory_region in doc and comments KVM: Delete all references to removed KVM_SET_MEMORY_ALIAS ioctl ...
2022-12-15mm: Rename GUP_GET_PTE_LOW_HIGHPeter Zijlstra
Since it no longer applies to only PTEs, rename it to PXX. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20221022114424.776404066%40infradead.org
2022-12-13Merge tag 'mm-stable-2022-12-13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - More userfaultfs work from Peter Xu - Several convert-to-folios series from Sidhartha Kumar and Huang Ying - Some filemap cleanups from Vishal Moola - David Hildenbrand added the ability to selftest anon memory COW handling - Some cpuset simplifications from Liu Shixin - Addition of vmalloc tracing support by Uladzislau Rezki - Some pagecache folioifications and simplifications from Matthew Wilcox - A pagemap cleanup from Kefeng Wang: we have VM_ACCESS_FLAGS, so use it - Miguel Ojeda contributed some cleanups for our use of the __no_sanitize_thread__ gcc keyword. This series should have been in the non-MM tree, my bad - Naoya Horiguchi improved the interaction between memory poisoning and memory section removal for huge pages - DAMON cleanups and tuneups from SeongJae Park - Tony Luck fixed the handling of COW faults against poisoned pages - Peter Xu utilized the PTE marker code for handling swapin errors - Hugh Dickins reworked compound page mapcount handling, simplifying it and making it more efficient - Removal of the autonuma savedwrite infrastructure from Nadav Amit and David Hildenbrand - zram support for multiple compression streams from Sergey Senozhatsky - David Hildenbrand reworked the GUP code's R/O long-term pinning so that drivers no longer need to use the FOLL_FORCE workaround which didn't work very well anyway - Mel Gorman altered the page allocator so that local IRQs can remnain enabled during per-cpu page allocations - Vishal Moola removed the try_to_release_page() wrapper - Stefan Roesch added some per-BDI sysfs tunables which are used to prevent network block devices from dirtying excessive amounts of pagecache - David Hildenbrand did some cleanup and repair work on KSM COW breaking - Nhat Pham and Johannes Weiner have implemented writeback in zswap's zsmalloc backend - Brian Foster has fixed a longstanding corner-case oddity in file[map]_write_and_wait_range() - sparse-vmemmap changes for MIPS, LoongArch and NIOS2 from Feiyang Chen - Shiyang Ruan has done some work on fsdax, to make its reflink mode work better under xfstests. Better, but still not perfect - Christoph Hellwig has removed the .writepage() method from several filesystems. They only need .writepages() - Yosry Ahmed wrote a series which fixes the memcg reclaim target beancounting - David Hildenbrand has fixed some of our MM selftests for 32-bit machines - Many singleton patches, as usual * tag 'mm-stable-2022-12-13' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (313 commits) mm/hugetlb: set head flag before setting compound_order in __prep_compound_gigantic_folio mm: mmu_gather: allow more than one batch of delayed rmaps mm: fix typo in struct pglist_data code comment kmsan: fix memcpy tests mm: add cond_resched() in swapin_walk_pmd_entry() mm: do not show fs mm pc for VM_LOCKONFAULT pages selftests/vm: ksm_functional_tests: fixes for 32bit selftests/vm: cow: fix compile warning on 32bit selftests/vm: madv_populate: fix missing MADV_POPULATE_(READ|WRITE) definitions mm/gup_test: fix PIN_LONGTERM_TEST_READ with highmem mm,thp,rmap: fix races between updates of subpages_mapcount mm: memcg: fix swapcached stat accounting mm: add nodes= arg to memory.reclaim mm: disable top-tier fallback to reclaim on proactive reclaim selftests: cgroup: make sure reclaim target memcg is unprotected selftests: cgroup: refactor proactive reclaim code to reclaim_until() mm: memcg: fix stale protection of reclaim target memcg mm/mmap: properly unaccount memory on mas_preallocate() failure omfs: remove ->writepage jfs: remove ->writepage ...
2022-11-30mm: Kconfig: make config SECRETMEM visible with EXPERTLukas Bulwahn
Commit 6a108a14fa35 ("kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT") introduces CONFIG_EXPERT to carry the previous intent of CONFIG_EMBEDDED and just gives that intent a much better name. That has been clearly a good and long overdue renaming, and it is clearly an improvement to the kernel build configuration that has shown to help managing the kernel build configuration in the last decade. However, rather than bravely and radically just deleting CONFIG_EMBEDDED, this commit gives CONFIG_EMBEDDED a new intended semantics, but keeps it open for future contributors to implement that intended semantics: A new CONFIG_EMBEDDED option is added that automatically selects CONFIG_EXPERT when enabled and can be used in the future to isolate options that should only be considered for embedded systems (RISC architectures, SLOB, etc). Since then, this CONFIG_EMBEDDED implicitly had two purposes: - It can make even more options visible beyond what CONFIG_EXPERT makes visible. In other words, it may introduce another level of enabling the visibility of configuration options: always visible, visible with CONFIG_EXPERT and visible with CONFIG_EMBEDDED. - Set certain default values of some configurations differently, following the assumption that configuring a kernel build for an embedded system generally starts with a different set of default values compared to kernel builds for all other kind of systems. Considering the second purpose, note that already probably arguing that a kernel build for an embedded system would choose some values differently is already tricky: the set of embedded systems with Linux kernels is already quite diverse. Many embedded system have powerful CPUs and it would not be clear that all embedded systems just optimize towards one specific aspect, e.g., a smaller kernel image size. So, it is unclear if starting with "one set of default configuration" that is induced by CONFIG_EMBEDDED is a good offer for developers configuring their kernels. Also, the differences of needed user-space features in an embedded system compared to a non-embedded system are probably difficult or even impossible to name in some generic way. So it is not surprising that in the last decade hardly anyone has contributed changes to make something default differently in case of CONFIG_EMBEDDED=y. Currently, in v6.0-rc4, SECRETMEM is the only config switched off if CONFIG_EMBEDDED=y. As long as that is actually the only option that currently is selected or deselected, it is better to just make SECRETMEM configurable at build time by experts using menuconfig instead. Make SECRETMEM configurable when EXPERT is set and otherwise default to yes. Further, SECRETMEM needs ARCH_HAS_SET_DIRECT_MAP. This allows us to remove CONFIG_EMBEDDED in the close future. Link: https://lkml.kernel.org/r/20221116131922.25533-1-lukas.bulwahn@gmail.com Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-30mm,hugetlb: use folio fields in second tail pageHugh Dickins
Patch series "mm,huge,rmap: unify and speed up compound mapcounts". This patch (of 3): We want to declare one more int in the first tail of a compound page: that first tail page being valuable property, since every compound page has a first tail, but perhaps no more than that. No problem on 64-bit: there is already space for it. No problem with 32-bit THPs: 5.18 commit 5232c63f46fd ("mm: Make compound_pincount always available") kindly cleared the space for it, apparently not realizing that only 64-bit architectures enable CONFIG_THP_SWAP (whose use of tail page->private might conflict) - but make sure of that in its Kconfig. But hugetlb pages use tail page->private of the first tail page for a subpool pointer, which will conflict; and they also use page->private of the 2nd, 3rd and 4th tails. Undo "mm: add private field of first tail to struct page and struct folio"'s recent addition of private_1 to the folio tail: instead add hugetlb_subpool, hugetlb_cgroup, hugetlb_cgroup_rsvd, hugetlb_hwpoison to a second tail page of the folio: THP has long been using several fields of that tail, so make better use of it for hugetlb too. This is not how a generic folio should be declared in future, but it is an effective transitional way to make use of it. Delete the SUBPAGE_INDEX stuff, but keep __NR_USED_SUBPAGE: now 3. [hughd@google.com: prefix folio's page_1 and page_2 with double underscore, give folio's _flags_2 and _head_2 a line documentation each] Link: https://lkml.kernel.org/r/9e2cb6b-5b58-d3f2-b5ee-5f8a14e8f10@google.com Link: https://lkml.kernel.org/r/5f52de70-975-e94f-f141-543765736181@google.com Link: https://lkml.kernel.org/r/3818cc9a-9999-d064-d778-9c94c5911e6@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: James Houghton <jthoughton@google.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mina Almasry <almasrymina@google.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev> Cc: Peter Xu <peterx@redhat.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yang Shi <shy828301@gmail.com> Cc: Zach O'Keefe <zokeefe@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-30mm: always compile in pte markersPeter Xu
Patch series "mm: Use pte marker for swapin errors". This series uses the pte marker to replace the swapin error swap entry, then we save one more swap entry slot for swap devices. A new pte marker bit is defined. This patch (of 2): The PTE markers code is tiny and now it's enabled for most of the distributions. It's fine to keep it as-is, but to make a broader use of it (e.g. replacing read error swap entry) it needs to be there always otherwise we need special code path to take care of !PTE_MARKER case. It'll be easier just make pte marker always exist. Use this chance to extend its usage to anonymous too by simply touching up some of the old comments, because it'll be used for anonymous pages in the follow up patches. Link: https://lkml.kernel.org/r/20221030214151.402274-1-peterx@redhat.com Link: https://lkml.kernel.org/r/20221030214151.402274-2-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: Huang Ying <ying.huang@intel.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-12-01mm, slob: rename CONFIG_SLOB to CONFIG_SLOB_DEPRECATEDVlastimil Babka
As explained in [1], we would like to remove SLOB if possible. - There are no known users that need its somewhat lower memory footprint so much that they cannot handle SLUB (after some modifications by the previous patches) instead. - It is an extra maintenance burden, and a number of features are incompatible with it. - It blocks the API improvement of allowing kfree() on objects allocated via kmem_cache_alloc(). As the first step, rename the CONFIG_SLOB option in the slab allocator configuration choice to CONFIG_SLOB_DEPRECATED. Add CONFIG_SLOB depending on CONFIG_SLOB_DEPRECATED as an internal option to avoid code churn. This will cause existing .config files and defconfigs with CONFIG_SLOB=y to silently switch to the default (and recommended replacement) SLUB, while still allowing SLOB to be configured by anyone that notices and needs it. But those should contact the slab maintainers and linux-mm@kvack.org as explained in the updated help. With no valid objections, the plan is to update the existing defconfigs to SLUB and remove SLOB in a few cycles. To make SLUB more suitable replacement for SLOB, a CONFIG_SLUB_TINY option was introduced to limit SLUB's memory overhead. There is a number of defconfigs specifying CONFIG_SLOB=y. As part of this patch, update them to select CONFIG_SLUB and CONFIG_SLUB_TINY. [1] https://lore.kernel.org/all/b35c3f82-f67b-2103-7d82-7a7ba7521439@suse.cz/ Cc: Russell King <linux@armlinux.org.uk> Cc: Aaro Koskinen <aaro.koskinen@iki.fi> Cc: Janusz Krzysztofik <jmkrzyszt@gmail.com> Cc: Tony Lindgren <tony@atomide.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Stafford Horne <shorne@gmail.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Conor Dooley <conor@kernel.org> Cc: Damien Le Moal <damien.lemoal@opensource.wdc.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Aaro Koskinen <aaro.koskinen@iki.fi> # OMAP1 Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> # riscv k210 Acked-by: Arnd Bergmann <arnd@arndb.de> # arm Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Christoph Lameter <cl@linux.com>
2022-11-29mm: Do not enable PG_arch_2 for all 64-bit architecturesCatalin Marinas
Commit 4beba9486abd ("mm: Add PG_arch_2 page flag") introduced a new page flag for all 64-bit architectures. However, even if an architecture is 64-bit, it may still have limited spare bits in the 'flags' member of 'struct page'. This may happen if an architecture enables SPARSEMEM without SPARSEMEM_VMEMMAP as is the case with the newly added loongarch. This architecture port needs 19 more bits for the sparsemem section information and, while it is currently fine with PG_arch_2, adding any more PG_arch_* flags will trigger build-time warnings. Add a new CONFIG_ARCH_USES_PG_ARCH_X option which can be selected by architectures that need more PG_arch_* flags beyond PG_arch_1. Select it on arm64. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> [pcc@google.com: fix build with CONFIG_ARM64_MTE disabled] Signed-off-by: Peter Collingbourne <pcc@google.com> Reported-by: kernel test robot <lkp@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Steven Price <steven.price@arm.com> Reviewed-by: Steven Price <steven.price@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20221104011041.290951-2-pcc@google.com
2022-11-27mm, slub: add CONFIG_SLUB_TINYVlastimil Babka
For tiny systems that have used SLOB until now, SLUB might be impractical due to its higher memory usage. To help with that, introduce an option CONFIG_SLUB_TINY that modifies SLUB to use less memory. This is done by sacrificing scalability, security and debugging features, therefore not recommended for any system with more than 16MB RAM. This commit introduces the option and uses it to set other related options in a way that reduces memory usage. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Christoph Lameter <cl@linux.com>
2022-10-10Merge tag 'mm-stable-2022-10-08' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in linux-next for a couple of months without, to my knowledge, any negative reports (or any positive ones, come to that). - Also the Maple Tree from Liam Howlett. An overlapping range-based tree for vmas. It it apparently slightly more efficient in its own right, but is mainly targeted at enabling work to reduce mmap_lock contention. Liam has identified a number of other tree users in the kernel which could be beneficially onverted to mapletrees. Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat at [1]. This has yet to be addressed due to Liam's unfortunately timed vacation. He is now back and we'll get this fixed up. - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses clang-generated instrumentation to detect used-unintialized bugs down to the single bit level. KMSAN keeps finding bugs. New ones, as well as the legacy ones. - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of memory into THPs. - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to support file/shmem-backed pages. - userfaultfd updates from Axel Rasmussen - zsmalloc cleanups from Alexey Romanov - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and memory-failure - Huang Ying adds enhancements to NUMA balancing memory tiering mode's page promotion, with a new way of detecting hot pages. - memcg updates from Shakeel Butt: charging optimizations and reduced memory consumption. - memcg cleanups from Kairui Song. - memcg fixes and cleanups from Johannes Weiner. - Vishal Moola provides more folio conversions - Zhang Yi removed ll_rw_block() :( - migration enhancements from Peter Xu - migration error-path bugfixes from Huang Ying - Aneesh Kumar added ability for a device driver to alter the memory tiering promotion paths. For optimizations by PMEM drivers, DRM drivers, etc. - vma merging improvements from Jakub Matěn. - NUMA hinting cleanups from David Hildenbrand. - xu xin added aditional userspace visibility into KSM merging activity. - THP & KSM code consolidation from Qi Zheng. - more folio work from Matthew Wilcox. - KASAN updates from Andrey Konovalov. - DAMON cleanups from Kaixu Xia. - DAMON work from SeongJae Park: fixes, cleanups. - hugetlb sysfs cleanups from Muchun Song. - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core. Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1] * tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits) hugetlb: allocate vma lock for all sharable vmas hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer hugetlb: fix vma lock handling during split vma and range unmapping mglru: mm/vmscan.c: fix imprecise comments mm/mglru: don't sync disk for each aging cycle mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol mm: memcontrol: use do_memsw_account() in a few more places mm: memcontrol: deprecate swapaccounting=0 mode mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled mm/secretmem: remove reduntant return value mm/hugetlb: add available_huge_pages() func mm: remove unused inline functions from include/linux/mm_inline.h selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd selftests/vm: add thp collapse shmem testing selftests/vm: add thp collapse file and tmpfs testing selftests/vm: modularize thp collapse memory operations selftests/vm: dedup THP helpers mm/khugepaged: add tracepoint to hpage_collapse_scan_file() mm/madvise: add file and shmem support to MADV_COLLAPSE ...
2022-09-26mm: multi-gen LRU: admin guideYu Zhao
Add an admin guide. Link: https://lkml.kernel.org/r/20220918080010.2920238-14-yuzhao@google.com Signed-off-by: Yu Zhao <yuzhao@google.com> Acked-by: Brian Geffon <bgeffon@google.com> Acked-by: Jan Alexander Steffens (heftig) <heftig@archlinux.org> Acked-by: Oleksandr Natalenko <oleksandr@natalenko.name> Acked-by: Steven Barrett <steven@liquorix.net> Acked-by: Suleiman Souhlal <suleiman@google.com> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Tested-by: Daniel Byrne <djbyrne@mtu.edu> Tested-by: Donald Carr <d@chaos-reins.com> Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com> Tested-by: Konstantin Kharlamov <Hi-Angel@yandex.ru> Tested-by: Shuang Zhai <szhai2@cs.rochester.edu> Tested-by: Sofia Trinh <sofia.trinh@edi.works> Tested-by: Vaibhav Jain <vaibhav@linux.ibm.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Barry Song <baohua@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Larabel <Michael@MichaelLarabel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>