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2024-07-17mm/gup: clear the LRU flag of a page before adding to LRU batchyangge
If a large number of CMA memory are configured in system (for example, the CMA memory accounts for 50% of the system memory), starting a virtual virtual machine with device passthrough, it will call pin_user_pages_remote(..., FOLL_LONGTERM, ...) to pin memory. Normally if a page is present and in CMA area, pin_user_pages_remote() will migrate the page from CMA area to non-CMA area because of FOLL_LONGTERM flag. But the current code will cause the migration failure due to unexpected page refcounts, and eventually cause the virtual machine fail to start. If a page is added in LRU batch, its refcount increases one, remove the page from LRU batch decreases one. Page migration requires the page is not referenced by others except page mapping. Before migrating a page, we should try to drain the page from LRU batch in case the page is in it, however, folio_test_lru() is not sufficient to tell whether the page is in LRU batch or not, if the page is in LRU batch, the migration will fail. To solve the problem above, we modify the logic of adding to LRU batch. Before adding a page to LRU batch, we clear the LRU flag of the page so that we can check whether the page is in LRU batch by folio_test_lru(page). It's quite valuable, because likely we don't want to blindly drain the LRU batch simply because there is some unexpected reference on a page, as described above. This change makes the LRU flag of a page invisible for longer, which may impact some programs. For example, as long as a page is on a LRU batch, we cannot isolate it, and we cannot check if it's an LRU page. Further, a page can now only be on exactly one LRU batch. This doesn't seem to matter much, because a new page is allocated from buddy and added to the lru batch, or be isolated, it's LRU flag may also be invisible for a long time. Link: https://lkml.kernel.org/r/1720075944-27201-1-git-send-email-yangge1116@126.com Link: https://lkml.kernel.org/r/1720008153-16035-1-git-send-email-yangge1116@126.com Fixes: 9a4e9f3b2d73 ("mm: update get_user_pages_longterm to migrate pages allocated from CMA region") Signed-off-by: yangge <yangge1116@126.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: David Hildenbrand <david@redhat.com> Cc: Barry Song <21cnbao@gmail.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-17mm/numa_balancing: teach mpol_to_str about the balancing modeTvrtko Ursulin
Since balancing mode was added in bda420b98505 ("numa balancing: migrate on fault among multiple bound nodes"), it was possible to set this mode but it wouldn't be shown in /proc/<pid>/numa_maps since there was no support for it in the mpol_to_str() helper. Furthermore, because the balancing mode sets the MPOL_F_MORON flag, it would be displayed as 'default' due a workaround introduced a few years earlier in 8790c71a18e5 ("mm/mempolicy.c: fix mempolicy printing in numa_maps"). To tidy this up we implement two changes: Replace the MPOL_F_MORON check by pointer comparison against the preferred_node_policy array. By doing this we generalise the current special casing and replace the incorrect 'default' with the correct 'bind' for the mode. Secondly, we add a string representation and corresponding handling for the MPOL_F_NUMA_BALANCING flag. With the two changes together we start showing the balancing flag when it is set and therefore complete the fix. Representation format chosen is to separate multiple flags with vertical bars, following what existed long time ago in kernel 2.6.25. But as between then and now there wasn't a way to display multiple flags, this patch does not change the format in practice. Some /proc/<pid>/numa_maps output examples: 555559580000 bind=balancing:0-1,3 file=... 555585800000 bind=balancing|static:0,2 file=... 555635240000 prefer=relative:0 file= Link: https://lkml.kernel.org/r/20240708075632.95857-1-tursulin@igalia.com Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com> Fixes: bda420b98505 ("numa balancing: migrate on fault among multiple bound nodes") References: 8790c71a18e5 ("mm/mempolicy.c: fix mempolicy printing in numa_maps") Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: David Rientjes <rientjes@google.com> Cc: <stable@vger.kernel.org> [5.12+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-17mm: memcg1: convert charge move flags to unsigned long longRoman Gushchin
Currently MOVE_ANON and MOVE_FILE flags are defined as integers and it leads to the following Smatch static checker warning: mm/memcontrol-v1.c:609 mem_cgroup_move_charge_write() warn: was expecting a 64 bit value instead of '~(1 | 2)' Fix this be redefining them as unsigned long long. Even though the issue allows to set high 32 bits of mc.flags to an arbitrary number, these bits are never used, so it doesn't have any significant consequences. Link: https://lkml.kernel.org/r/ZpF8Q9zBsIY7d2P9@google.com Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-17mm/mglru: fix overshooting shrinker memoryYu Zhao
set_initial_priority() tries to jump-start global reclaim by estimating the priority based on cold/hot LRU pages. The estimation does not account for shrinker objects, and it cannot do so because their sizes can be in different units other than page. If shrinker objects are the majority, e.g., on TrueNAS SCALE 24.04.0 where ZFS ARC can use almost all system memory, set_initial_priority() can vastly underestimate how much memory ARC shrinker can evict and assign extreme low values to scan_control->priority, resulting in overshoots of shrinker objects. To reproduce the problem, using TrueNAS SCALE 24.04.0 with 32GB DRAM, a test ZFS pool and the following commands: fio --name=mglru.file --numjobs=36 --ioengine=io_uring \ --directory=/root/test-zfs-pool/ --size=1024m --buffered=1 \ --rw=randread --random_distribution=random \ --time_based --runtime=1h & for ((i = 0; i < 20; i++)) do sleep 120 fio --name=mglru.anon --numjobs=16 --ioengine=mmap \ --filename=/dev/zero --size=1024m --fadvise_hint=0 \ --rw=randrw --random_distribution=random \ --time_based --runtime=1m done To fix the problem: 1. Cap scan_control->priority at or above DEF_PRIORITY/2, to prevent the jump-start from being overly aggressive. 2. Account for the progress from mm_account_reclaimed_pages(), to prevent kswapd_shrink_node() from raising the priority unnecessarily. Link: https://lkml.kernel.org/r/20240711191957.939105-2-yuzhao@google.com Fixes: e4dde56cd208 ("mm: multi-gen LRU: per-node lru_gen_folio lists") Signed-off-by: Yu Zhao <yuzhao@google.com> Reported-by: Alexander Motin <mav@ixsystems.com> Cc: Wei Xu <weixugc@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-17mm/mglru: fix div-by-zero in vmpressure_calc_level()Yu Zhao
evict_folios() uses a second pass to reclaim folios that have gone through page writeback and become clean before it finishes the first pass, since folio_rotate_reclaimable() cannot handle those folios due to the isolation. The second pass tries to avoid potential double counting by deducting scan_control->nr_scanned. However, this can result in underflow of nr_scanned, under a condition where shrink_folio_list() does not increment nr_scanned, i.e., when folio_trylock() fails. The underflow can cause the divisor, i.e., scale=scanned+reclaimed in vmpressure_calc_level(), to become zero, resulting in the following crash: [exception RIP: vmpressure_work_fn+101] process_one_work at ffffffffa3313f2b Since scan_control->nr_scanned has no established semantics, the potential double counting has minimal risks. Therefore, fix the problem by not deducting scan_control->nr_scanned in evict_folios(). Link: https://lkml.kernel.org/r/20240711191957.939105-1-yuzhao@google.com Fixes: 359a5e1416ca ("mm: multi-gen LRU: retry folios written back while isolated") Reported-by: Wei Xu <weixugc@google.com> Signed-off-by: Yu Zhao <yuzhao@google.com> Cc: Alexander Motin <mav@ixsystems.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-17mm/kmemleak: replace strncpy() with strscpy()Kees Cook
Replace the depreciated[1] strncpy() calls with strscpy(). Uses of object->comm do not depend on the padding side-effect. Link: https://github.com/KSPP/linux/issues/90 [1] Link: https://lkml.kernel.org/r/20240710001300.work.004-kees@kernel.org Signed-off-by: Kees Cook <kees@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-17mm, page_alloc: put should_fail_alloc_page() back behing CONFIG_FAIL_PAGE_ALLOCVlastimil Babka
This mostly reverts commit af3b854492f3 ("mm/page_alloc.c: allow error injection"). The commit made should_fail_alloc_page() a noinline function that's always called from the page allocation hotpath, even if it's empty because CONFIG_FAIL_PAGE_ALLOC is not enabled, and there is no option to disable it and prevent the associated function call overhead. As with the preceding patch "mm, slab: put should_failslab back behind CONFIG_SHOULD_FAILSLAB" and for the same reasons, put the should_fail_alloc_page() back behind the config option. When enabled, the ALLOW_ERROR_INJECTION and BTF_ID records are preserved so it's not a complete revert. Link: https://lkml.kernel.org/r/20240711-b4-fault-injection-reverts-v1-2-9e2651945d68@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Cc: Akinobu Mita <akinobu.mita@gmail.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andrii Nakryiko <andrii@kernel.org> Cc: Christoph Lameter <cl@linux.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David Rientjes <rientjes@google.com> Cc: Eduard Zingerman <eddyz87@gmail.com> Cc: Hao Luo <haoluo@google.com> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Fastabend <john.fastabend@gmail.com> Cc: KP Singh <kpsingh@kernel.org> Cc: Martin KaFai Lau <martin.lau@linux.dev> Cc: Mateusz Guzik <mjguzik@gmail.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Song Liu <song@kernel.org> Cc: Stanislav Fomichev <sdf@fomichev.me> Cc: Yonghong Song <yonghong.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-17mm, slab: put should_failslab() back behind CONFIG_SHOULD_FAILSLABVlastimil Babka
Patch series "revert unconditional slab and page allocator fault injection calls". These two patches largely revert commits that added function call overhead into slab and page allocation hotpaths and that cannot be currently disabled even though related CONFIG_ options do exist. A much more involved solution that can keep the callsites always existing but hidden behind a static key if unused, is possible [1] and can be pursued by anyone who believes it's necessary. Meanwhile the fact the should_failslab() error injection is already not functional on kernels built with current gcc without anyone noticing [2], and lukewarm response to [1] suggests the need is not there. I believe it will be more fair to have the state after this series as a baseline for possible further optimisation, instead of the unconditional overhead. For example a possible compromise for anyone who's fine with an empty function call overhead but not the full CONFIG_FAILSLAB / CONFIG_FAIL_PAGE_ALLOC overhead is to reuse patch 1 from [1] but insert a static key check only inside should_failslab() and should_fail_alloc_page() before performing the more expensive checks. [1] https://lore.kernel.org/all/20240620-fault-injection-statickeys-v2-0-e23947d3d84b@suse.cz/#t [2] https://github.com/bpftrace/bpftrace/issues/3258 This patch (of 2): This mostly reverts commit 4f6923fbb352 ("mm: make should_failslab always available for fault injection"). The commit made should_failslab() a noinline function that's always called from the slab allocation hotpath, even if it's empty because CONFIG_SHOULD_FAILSLAB is not enabled, and there is no option to disable that call. This is visible in profiles and the function call overhead can be noticeable especially with cpu mitigations. Meanwhile the bpftrace program example in the commit silently does not work without CONFIG_SHOULD_FAILSLAB anyway with a recent gcc, because the empty function gets a .constprop clone that is actually being called (uselessly) from the slab hotpath, while the error injection is hooked to the original function that's not being called at all [1]. Thus put the whole should_failslab() function back behind CONFIG_SHOULD_FAILSLAB. It's not a complete revert of 4f6923fbb352 - the int return type that returns -ENOMEM on failure is preserved, as well ALLOW_ERROR_INJECTION annotation. The BTF_ID() record that was meanwhile added is also guarded by CONFIG_SHOULD_FAILSLAB. [1] https://github.com/bpftrace/bpftrace/issues/3258 Link: https://lkml.kernel.org/r/20240711-b4-fault-injection-reverts-v1-0-9e2651945d68@suse.cz Link: https://lkml.kernel.org/r/20240711-b4-fault-injection-reverts-v1-1-9e2651945d68@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Cc: Akinobu Mita <akinobu.mita@gmail.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andrii Nakryiko <andrii@kernel.org> Cc: Christoph Lameter <cl@linux.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David Rientjes <rientjes@google.com> Cc: Eduard Zingerman <eddyz87@gmail.com> Cc: Hao Luo <haoluo@google.com> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Fastabend <john.fastabend@gmail.com> Cc: KP Singh <kpsingh@kernel.org> Cc: Martin KaFai Lau <martin.lau@linux.dev> Cc: Mateusz Guzik <mjguzik@gmail.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Song Liu <song@kernel.org> Cc: Stanislav Fomichev <sdf@fomichev.me> Cc: Yonghong Song <yonghong.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-17mm: ignore data-race in __swap_writepagePei Li
Syzbot reported a possible data race: BUG: KCSAN: data-race in __swap_writepage / scan_swap_map_slots read-write to 0xffff888102fca610 of 8 bytes by task 7106 on cpu 1. read to 0xffff888102fca610 of 8 bytes by task 7080 on cpu 0. While we are in __swap_writepage to read sis->flags, scan_swap_map_slots is trying to update it with SWP_SCANNING. value changed: 0x0000000000008083 -> 0x0000000000004083. While this can be updated non-atomicially, this won't affect SWP_SYNCHRONOUS_IO, so we consider this data-race safe. This is possibly introduced by commit 3222d8c2a7f8 ("block: remove ->rw_page"), where this if branch is introduced. Link: https://lkml.kernel.org/r/20240711-bug13-v1-1-cea2b8ae8d76@gmail.com Fixes: 3222d8c2a7f8 ("block: remove ->rw_page") Signed-off-by: Pei Li <peili.dev@gmail.com> Reported-by: syzbot+da25887cc13da6bf3b8c@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=da25887cc13da6bf3b8c Cc: Dan Williams <dan.j.williams@intel.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-16Merge tag 'linux_kselftest-kunit-6.11-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest Pull KUnit updates from Shuah Khan: - add vm_mmap() allocation resource manager - convert usercopy kselftest to KUnit - disable usercopy testing on !CONFIG_MMU - add MODULE_DESCRIPTION() to core, list, and usercopy tests - add tests for assertion formatting functions - assert.c - introduce KUNIT_ASSERT_MEMEQ and KUNIT_ASSERT_MEMNEQ macros - fix KUNIT_ASSERT_STRNEQ comments to make it clear that it is an assertion - rename KUNIT_ASSERT_FAILURE to KUNIT_FAIL_AND_ABORT * tag 'linux_kselftest-kunit-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: kunit: Introduce KUNIT_ASSERT_MEMEQ and KUNIT_ASSERT_MEMNEQ macros kunit: Rename KUNIT_ASSERT_FAILURE to KUNIT_FAIL_AND_ABORT for readability kunit: Fix the comment of KUNIT_ASSERT_STRNEQ as assertion kunit: executor: Simplify string allocation handling kunit/usercopy: Add missing MODULE_DESCRIPTION() kunit/usercopy: Disable testing on !CONFIG_MMU usercopy: Convert test_user_copy to KUnit test kunit: test: Add vm_mmap() allocation resource manager list: test: add the missing MODULE_DESCRIPTION() macro kunit: add missing MODULE_DESCRIPTION() macros to core modules list: test: remove unused struct 'klist_test_struct' kunit: Cover 'assert.c' with tests
2024-07-15Merge tag 'vfs-6.11.mount.api' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs mount API updates from Christian Brauner: - Add a generic helper to parse uid and gid mount options. Currently we open-code the same logic in various filesystems which is error prone, especially since the verification of uid and gid mount options is a sensitive operation in the face of idmappings. Add a generic helper and convert all filesystems over to it. Make sure that filesystems that are mountable in unprivileged containers verify that the specified uid and gid can be represented in the owning namespace of the filesystem. - Convert hostfs to the new mount api. * tag 'vfs-6.11.mount.api' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: fuse: Convert to new uid/gid option parsing helpers fuse: verify {g,u}id mount options correctly fat: Convert to new uid/gid option parsing helpers fat: Convert to new mount api fat: move debug into fat_mount_options vboxsf: Convert to new uid/gid option parsing helpers tracefs: Convert to new uid/gid option parsing helpers smb: client: Convert to new uid/gid option parsing helpers tmpfs: Convert to new uid/gid option parsing helpers ntfs3: Convert to new uid/gid option parsing helpers isofs: Convert to new uid/gid option parsing helpers hugetlbfs: Convert to new uid/gid option parsing helpers ext4: Convert to new uid/gid option parsing helpers exfat: Convert to new uid/gid option parsing helpers efivarfs: Convert to new uid/gid option parsing helpers debugfs: Convert to new uid/gid option parsing helpers autofs: Convert to new uid/gid option parsing helpers fs_parse: add uid & gid option option parsing helpers hostfs: Add const qualifier to host_root in hostfs_fill_super() hostfs: convert hostfs to use the new mount API
2024-07-15Merge tag 'vfs-6.11.misc' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull misc vfs updates from Christian Brauner: "Features: - Support passing NULL along AT_EMPTY_PATH for statx(). NULL paths with any flag value other than AT_EMPTY_PATH go the usual route and end up with -EFAULT to retain compatibility (Rust is abusing calls of the sort to detect availability of statx) This avoids path lookup code, lockref management, memory allocation and in case of NULL path userspace memory access (which can be quite expensive with SMAP on x86_64) - Don't block i_writecount during exec. Remove the deny_write_access() mechanism for executables - Relax open_by_handle_at() permissions in specific cases where we can prove that the caller had sufficient privileges to open a file - Switch timespec64 fields in struct inode to discrete integers freeing up 4 bytes Fixes: - Fix false positive circular locking warning in hfsplus - Initialize hfs_inode_info after hfs_alloc_inode() in hfs - Avoid accidental overflows in vfs_fallocate() - Don't interrupt fallocate with EINTR in tmpfs to avoid constantly restarting shmem_fallocate() - Add missing quote in comment in fs/readdir Cleanups: - Don't assign and test in an if statement in mqueue. Move the assignment out of the if statement - Reflow the logic in may_create_in_sticky() - Remove the usage of the deprecated ida_simple_xx() API from procfs - Reject FSCONFIG_CMD_CREATE_EXCL requets that depend on the new mount api early - Rename variables in copy_tree() to make it easier to understand - Replace WARN(down_read_trylock, ...) abuse with proper asserts in various places in the VFS - Get rid of user_path_at_empty() and drop the empty argument from getname_flags() - Check for error while copying and no path in one branch in getname_flags() - Avoid redundant smp_mb() for THP handling in do_dentry_open() - Rename parent_ino to d_parent_ino and make it use RCU - Remove unused header include in fs/readdir - Export in_group_capable() helper and switch f2fs and fuse over to it instead of open-coding the logic in both places" * tag 'vfs-6.11.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (27 commits) ipc: mqueue: remove assignment from IS_ERR argument vfs: rename parent_ino to d_parent_ino and make it use RCU vfs: support statx(..., NULL, AT_EMPTY_PATH, ...) stat: use vfs_empty_path() helper fs: new helper vfs_empty_path() fs: reflow may_create_in_sticky() vfs: remove redundant smp_mb for thp handling in do_dentry_open fuse: Use in_group_or_capable() helper f2fs: Use in_group_or_capable() helper fs: Export in_group_or_capable() vfs: reorder checks in may_create_in_sticky hfs: fix to initialize fields of hfs_inode_info after hfs_alloc_inode() proc: Remove usage of the deprecated ida_simple_xx() API hfsplus: fix to avoid false alarm of circular locking Improve readability of copy_tree vfs: shave a branch in getname_flags vfs: retire user_path_at_empty and drop empty arg from getname_flags vfs: stop using user_path_at_empty in do_readlinkat tmpfs: don't interrupt fallocate with EINTR fs: don't block i_writecount during exec ...
2024-07-15Merge branch 'slab/for-6.11/buckets' into slab/for-nextVlastimil Babka
Merge all the slab patches previously collected on top of v6.10-rc1, over cleanups/fixes that had to be based on rc6.
2024-07-15mm/memcg: alignment memcg_data define conditionAlex Shi (Tencent)
commit 21c690a349ba ("mm: introduce slabobj_ext to support slab object extensions") changed the folio/page->memcg_data define condition from MEMCG to SLAB_OBJ_EXT. This action make memcg_data exposed while !MEMCG. As Vlastimil Babka suggested, let's add _unused_slab_obj_exts for SLAB_MATCH for slab.obj_exts while !MEMCG. That could resolve the match issue, clean up the feature logical. Signed-off-by: Alex Shi (Tencent) <alexs@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Yoann Congal <yoann.congal@smile.fr> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-07-12mm: shmem: rename mTHP shmem countersRyan Roberts
The legacy PMD-sized THP counters at /proc/vmstat include thp_file_alloc, thp_file_fallback and thp_file_fallback_charge, which rather confusingly refer to shmem THP and do not include any other types of file pages. This is inconsistent since in most other places in the kernel, THP counters are explicitly separated for anon, shmem and file flavours. However, we are stuck with it since it constitutes a user ABI. Recently, commit 66f44583f9b6 ("mm: shmem: add mTHP counters for anonymous shmem") added equivalent mTHP stats for shmem, keeping the same "file_" prefix in the names. But in future, we may want to add extra stats to cover actual file pages, at which point, it would all become very confusing. So let's take the opportunity to rename these new counters "shmem_" before the change makes it upstream and the ABI becomes immutable. While we are at it, let's improve the documentation for the legacy counters to make it clear that they count shmem pages only. Link: https://lkml.kernel.org/r/20240710095503.3193901-1-ryan.roberts@arm.com Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Lance Yang <ioworker0@gmail.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Barry Song <baohua@kernel.org> Acked-by: David Hildenbrand <david@redhat.com> Cc: Daniel Gomez <da.gomez@samsung.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12mm: swap_state: use folio_alloc_mpol() in __read_swap_cache_async()Kefeng Wang
Convert to use folio_alloc_mpol() helper() in __read_swap_cache_async(). Link: https://lkml.kernel.org/r/20240709105508.3933823-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12mm/migrate: putback split folios when numa hint migration failsPeter Xu
This issue is not from any report yet, but by code observation only. This is yet another fix besides Hugh's patch [1] but on relevant code path, where eager split of folio can happen if the folio is already on deferred list during a folio migration. Here the issue is NUMA path (migrate_misplaced_folio()) may start to encounter such folio split now even with MR_NUMA_MISPLACED hint applied. Then when migrate_pages() didn't migrate all the folios, it's possible the split small folios be put onto the list instead of the original folio. Then putting back only the head page won't be enough. Fix it by putting back all the folios on the list. [1] https://lore.kernel.org/all/46c948b4-4dd8-6e03-4c7b-ce4e81cfa536@google.com/ [akpm@linux-foundation.org: remove now unused local `nr_pages'] Link: https://lkml.kernel.org/r/20240708215537.2630610-1-peterx@redhat.com Fixes: 7262f208ca68 ("mm/migrate: split source folio if it is on deferred split list") Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Hugh Dickins <hughd@google.com> Cc: Huang Ying <ying.huang@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12mm/truncate: batch-clear shadow entriesYu Zhao
Make clear_shadow_entry() clear shadow entries in `struct folio_batch` so that it can reduce contention on i_lock and i_pages locks, e.g., watchdog: BUG: soft lockup - CPU#29 stuck for 11s! [fio:2701649] clear_shadow_entry+0x3d/0x100 mapping_try_invalidate+0x117/0x1d0 invalidate_mapping_pages+0x10/0x20 invalidate_bdev+0x3c/0x50 blkdev_common_ioctl+0x5f7/0xa90 blkdev_ioctl+0x109/0x270 Also, rename clear_shadow_entry() to clear_shadow_entries() accordingly. [yuzhao@google.com: v2] Link: https://lkml.kernel.org/r/20240710060933.3979380-1-yuzhao@google.com Link: https://lkml.kernel.org/r/20240708212753.3120511-1-yuzhao@google.com Reported-by: Bharata B Rao <bharata@amd.com> Closes: https://lore.kernel.org/d2841226-e27b-4d3d-a578-63587a3aa4f3@amd.com/ Signed-off-by: Yu Zhao <yuzhao@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12mm/memory-failure: remove obsolete MF_MSG_DIFFERENT_COMPOUNDMiaohe Lin
The page cannot become compound pages again just after a folio is split as an extra refcnt is held. So the MF_MSG_DIFFERENT_COMPOUND case is obsolete and can be removed to get rid of this false assumption and code burden. But add one WARN_ON() here to keep the situation clear. Link: https://lkml.kernel.org/r/20240708030544.196919-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12mm: simplify folio_migrate_mapping()Hugh Dickins
Now that folio_undo_large_rmappable() is an inline function checking order and large_rmappable for itself (and __folio_undo_large_rmappable() is now declared even when CONFIG_TRANASPARENT_HUGEPAGE is off) there is no need for folio_migrate_mapping() to check large and large_rmappable first (in the mapping case when it has had to freeze anyway). Link: https://lkml.kernel.org/r/68feee73-050e-8e98-7a3a-abf78738d92c@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12mm/page_alloc: put __free_pages_core() in __meminit sectionWei Yang
__free_pages_core() is only used in bootmem init and hot-add memory init path. Let's put it in __meminit section. Link: https://lkml.kernel.org/r/20240706061615.30322-1-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12mm: thp: support "THPeligible" semantics for mTHP with anonymous shmemBang Li
After the commit 7fb1b252afb5 ("mm: shmem: add mTHP support for anonymous shmem"), we can configure different policies through the multi-size THP sysfs interface for anonymous shmem. But currently "THPeligible" indicates only whether the mapping is eligible for allocating THP-pages as well as the THP is PMD mappable or not for anonymous shmem, we need to support semantics for mTHP with anonymous shmem similar to those for mTHP with anonymous memory. Link: https://lkml.kernel.org/r/20240705032309.24933-1-libang.li@antgroup.com Signed-off-by: Bang Li <libang.li@antgroup.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Lance Yang <ioworker0@gmail.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12mm: fix khugepaged activation policyRyan Roberts
Since the introduction of mTHP, the docuementation has stated that khugepaged would be enabled when any mTHP size is enabled, and disabled when all mTHP sizes are disabled. There are 2 problems with this; 1. this is not what was implemented by the code and 2. this is not the desirable behavior. Desirable behavior is for khugepaged to be enabled when any PMD-sized THP is enabled, anon or file. (Note that file THP is still controlled by the top-level control so we must always consider that, as well as the PMD-size mTHP control for anon). khugepaged only supports collapsing to PMD-sized THP so there is no value in enabling it when PMD-sized THP is disabled. So let's change the code and documentation to reflect this policy. Further, per-size enabled control modification events were not previously forwarded to khugepaged to give it an opportunity to start or stop. Consequently the following was resulting in khugepaged eroneously not being activated: echo never > /sys/kernel/mm/transparent_hugepage/enabled echo always > /sys/kernel/mm/transparent_hugepage/hugepages-2048kB/enabled [ryan.roberts@arm.com: v3] Link: https://lkml.kernel.org/r/20240705102849.2479686-1-ryan.roberts@arm.com Link: https://lkml.kernel.org/r/20240705102849.2479686-1-ryan.roberts@arm.com Link: https://lkml.kernel.org/r/20240704091051.2411934-1-ryan.roberts@arm.com Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Fixes: 3485b88390b0 ("mm: thp: introduce multi-size THP sysfs interface") Closes: https://lore.kernel.org/linux-mm/7a0bbe69-1e3d-4263-b206-da007791a5c4@redhat.com/ Acked-by: David Hildenbrand <david@redhat.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Lance Yang <ioworker0@gmail.com> Cc: Yang Shi <shy828301@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12memory tier: consolidate the initialization of memory tiersHo-Ren (Jack) Chuang
The current memory tier initialization process is distributed across two different functions, memory_tier_init() and memory_tier_late_init(). This design is hard to maintain. Thus, this patch is proposed to reduce the possible code paths by consolidating different initialization patches into one. The earlier discussion with Jonathan and Ying is listed here: https://lore.kernel.org/lkml/20240405150244.00004b49@Huawei.com/ If we want to put these two initializations together, they must be placed together in the later function. Because only at that time, the HMAT information will be ready, adist between nodes can be calculated, and memory tiering can be established based on the adist. So we position the initialization at memory_tier_init() to the memory_tier_late_init() call. Moreover, it's natural to keep memory_tier initialization in drivers at device_initcall() level. If we simply move the set_node_memory_tier() from memory_tier_init() to late_initcall(), it will result in HMAT not registering the mt_adistance_algorithm callback function, because set_node_memory_tier() is not performed during the memory tiering initialization phase, leading to a lack of correct default_dram information. Therefore, we introduced a nodemask to pass the information of the default DRAM nodes. The reason for not choosing to reuse default_dram_type->nodes is that it is not clean enough. So in the end, we use a __initdata variable, which is a variable that is released once initialization is complete, including both CPU and memory nodes for HMAT to iterate through. Link: https://lkml.kernel.org/r/20240704072646.437579-1-horen.chuang@linux.dev Signed-off-by: Ho-Ren (Jack) Chuang <horenchuang@bytedance.com> Suggested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Gregory Price <gourry.memverge@gmail.com> Cc: Len Brown <lenb@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: Ravi Jonnalagadda <ravis.opensrc@micron.com> Cc: SeongJae Park <sj@kernel.org> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12mm/page_counter: move calculating protection values to page_counterMaarten Lankhorst
It's a lot of math, and there is nothing memcontrol specific about it. This makes it easier to use inside of the drm cgroup controller. [akpm@linux-foundation.org: fix kerneldoc, per Jeff Johnson] Link: https://lkml.kernel.org/r/20240703112510.36424-1-maarten.lankhorst@linux.intel.com Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Jeff Johnson <quic_jjohnson@quicinc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12mm: unexport vmf_insert_mixed_mkwriteChristoph Hellwig
vmf_insert_mixed_mkwrite is only used by the built-in DAX code. Link: https://lkml.kernel.org/r/20240702072327.1640911-1-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alistair Popple <apopple@nvidia.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12mm: remove CONFIG_ARCH_HAS_HUGEPDChristophe Leroy
powerpc was the only user of CONFIG_ARCH_HAS_HUGEPD and doesn't use it anymore, so remove all related code. Link: https://lkml.kernel.org/r/4b10c54c794780b955f3ad6c657d0199dd792146.1719928057.git.christophe.leroy@csgroup.eu Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Acked-by: Oscar Salvador <osalvador@suse.de> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12mm: provide mm_struct and address to huge_ptep_get()Christophe Leroy
On powerpc 8xx huge_ptep_get() will need to know whether the given ptep is a PTE entry or a PMD entry. This cannot be known with the PMD entry itself because there is no easy way to know it from the content of the entry. So huge_ptep_get() will need to know either the size of the page or get the pmd. In order to be consistent with huge_ptep_get_and_clear(), give mm and address to huge_ptep_get(). Link: https://lkml.kernel.org/r/cc00c70dd384298796a4e1b25d6c4eb306d3af85.1719928057.git.christophe.leroy@csgroup.eu Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12zsmalloc: rename class stat mutatorsSergey Senozhatsky
A cosmetic change. o Rename class_stat_inc() and class_stat_dec() to class_stat_add() and class_stat_sub() correspondingly. inc/dec are usually associated with +1/-1 modifications, while zsmlloc can modify stats by up to ->objs_per_zspage. Use add/sub (follow atomics naming). o Rename zs_stat_get() to class_stat_read() get() is usually associated with ref-counting and is paired with put(). zs_stat_get() simply reads class stat so rename to reflect it. (This also follows atomics naming). Link: https://lkml.kernel.org/r/20240701031140.3756345-1-senozhatsky@chromium.org Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org> Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12mm: add per-order mTHP split countersLance Yang
Patch series "mm: introduce per-order mTHP split counters", v3. At present, the split counters in THP statistics no longer include PTE-mapped mTHP. Therefore, we want to introduce per-order mTHP split counters to monitor the frequency of mTHP splits. This will assist developers in better analyzing and optimizing system performance. /sys/kernel/mm/transparent_hugepage/hugepages-<size>/stats split split_failed split_deferred This patch (of 2): Currently, the split counters in THP statistics no longer include PTE-mapped mTHP. Therefore, we propose introducing per-order mTHP split counters to monitor the frequency of mTHP splits. This will help developers better analyze and optimize system performance. /sys/kernel/mm/transparent_hugepage/hugepages-<size>/stats split split_failed split_deferred [ioworker0@gmail.com: make things more readable, per Barry and Baolin] Link: https://lkml.kernel.org/r/20240704012905.42971-2-ioworker0@gmail.com [ioworker0@gmail.com: use == for `order' test, per David] Link: https://lkml.kernel.org/r/20240705113119.82210-1-ioworker0@gmail.com Link: https://lkml.kernel.org/r/20240704012905.42971-1-ioworker0@gmail.com Link: https://lkml.kernel.org/r/20240704012905.42971-2-ioworker0@gmail.com Link: https://lkml.kernel.org/r/20240628130750.73097-1-ioworker0@gmail.com Link: https://lkml.kernel.org/r/20240628130750.73097-2-ioworker0@gmail.com Signed-off-by: Mingzhe Yang <mingzhe.yang@ly.com> Signed-off-by: Lance Yang <ioworker0@gmail.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Acked-by: Barry Song <baohua@kernel.org> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Bang Li <libang.li@antgroup.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12mm/zsmalloc: move record_obj() into obj_malloc()Chengming Zhou
We always record_obj() to make handle points to object after obj_malloc(), so simplify the code by moving record_obj() into obj_malloc(). There should be no functional change. Link: https://lkml.kernel.org/r/20240627075959.611783-2-chengming.zhou@linux.dev Signed-off-by: Chengming Zhou <chengming.zhou@linux.dev> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12mm/zsmalloc: clarify class per-fullness zspage countsChengming Zhou
We always use insert_zspage() and remove_zspage() to update zspage's fullness location, which will account correctly. But this special async free path use "splice" instead of remove_zspage(), so the per-fullness zspage count for ZS_INUSE_RATIO_0 won't decrease. Clean things up by decreasing when iterate over the zspage free list. This doesn't actually fix anything. ZS_INUSE_RATIO_0 is just a "placeholder" which is never used anywhere. Link: https://lkml.kernel.org/r/20240627075959.611783-1-chengming.zhou@linux.dev Signed-off-by: Chengming Zhou <chengming.zhou@linux.dev> Cc: Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12mm/gup: introduce memfd_pin_folios() for pinning memfd foliosVivek Kasireddy
For drivers that would like to longterm-pin the folios associated with a memfd, the memfd_pin_folios() API provides an option to not only pin the folios via FOLL_PIN but also to check and migrate them if they reside in movable zone or CMA block. This API currently works with memfds but it should work with any files that belong to either shmemfs or hugetlbfs. Files belonging to other filesystems are rejected for now. The folios need to be located first before pinning them via FOLL_PIN. If they are found in the page cache, they can be immediately pinned. Otherwise, they need to be allocated using the filesystem specific APIs and then pinned. [akpm@linux-foundation.org: improve the CONFIG_MMU=n situation, per SeongJae] [vivek.kasireddy@intel.com: return -EINVAL if the end offset is greater than the size of memfd] Link: https://lkml.kernel.org/r/IA0PR11MB71850525CBC7D541CAB45DF1F8DB2@IA0PR11MB7185.namprd11.prod.outlook.com Link: https://lkml.kernel.org/r/20240624063952.1572359-4-vivek.kasireddy@intel.com Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com> Suggested-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> (v2) Reviewed-by: David Hildenbrand <david@redhat.com> (v3) Reviewed-by: Christoph Hellwig <hch@lst.de> (v6) Acked-by: Dave Airlie <airlied@redhat.com> Acked-by: Gerd Hoffmann <kraxel@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Hugh Dickins <hughd@google.com> Cc: Peter Xu <peterx@redhat.com> Cc: Dongwon Kim <dongwon.kim@intel.com> Cc: Junxiao Chang <junxiao.chang@intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christoph Hellwig <hch@infradead.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12mm/gup: introduce check_and_migrate_movable_folios()Vivek Kasireddy
This helper is the folio equivalent of check_and_migrate_movable_pages(). Therefore, all the rules that apply to check_and_migrate_movable_pages() also apply to this one as well. Currently, this helper is only used by memfd_pin_folios(). This patch also includes changes to rename and convert the internal functions collect_longterm_unpinnable_pages() and migrate_longterm_unpinnable_pages() to work on folios. As a result, check_and_migrate_movable_pages() is now a wrapper around check_and_migrate_movable_folios(). Link: https://lkml.kernel.org/r/20240624063952.1572359-3-vivek.kasireddy@intel.com Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com> Suggested-by: David Hildenbrand <david@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Dave Airlie <airlied@redhat.com> Acked-by: Gerd Hoffmann <kraxel@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Peter Xu <peterx@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dongwon Kim <dongwon.kim@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Junxiao Chang <junxiao.chang@intel.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12mm/gup: introduce unpin_folio/unpin_folios helpersVivek Kasireddy
Patch series "mm/gup: Introduce memfd_pin_folios() for pinning memfd folios", v16. Currently, some drivers (e.g, Udmabuf) that want to longterm-pin the pages/folios associated with a memfd, do so by simply taking a reference on them. This is not desirable because the pages/folios may reside in Movable zone or CMA block. Therefore, having drivers use memfd_pin_folios() API ensures that the folios are appropriately pinned via FOLL_PIN for longterm DMA. This patchset also introduces a few helpers and converts the Udmabuf driver to use folios and memfd_pin_folios() API to longterm-pin the folios for DMA. Two new Udmabuf selftests are also included to test the driver and the new API. This patch (of 9): These helpers are the folio versions of unpin_user_page/unpin_user_pages. They are currently only useful for unpinning folios pinned by memfd_pin_folios() or other associated routines. However, they could find new uses in the future, when more and more folio-only helpers are added to GUP. We should probably sanity check the folio as part of unpin similar to how it is done in unpin_user_page/unpin_user_pages but we cannot cleanly do that at the moment without also checking the subpage. Therefore, sanity checking needs to be added to these routines once we have a way to determine if any given folio is anon-exclusive (via a per folio AnonExclusive flag). Link: https://lkml.kernel.org/r/20240624063952.1572359-1-vivek.kasireddy@intel.com Link: https://lkml.kernel.org/r/20240624063952.1572359-2-vivek.kasireddy@intel.com Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com> Suggested-by: David Hildenbrand <david@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Dave Airlie <airlied@redhat.com> Acked-by: Gerd Hoffmann <kraxel@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Peter Xu <peterx@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dongwon Kim <dongwon.kim@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Junxiao Chang <junxiao.chang@intel.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12mm/zswap: use only one pool in zswapChengming Zhou
Zswap uses 32 pools to workaround the locking scalability problem in zswap backends (mainly zsmalloc nowadays), which brings its own problems like memory waste and more memory fragmentation. Testing results show that we can have near performance with only one pool in zswap after changing zsmalloc to use per-size_class lock instead of pool spinlock. Testing kernel build (make bzImage -j32) on tmpfs with memory.max=1GB, and zswap shrinker enabled with 10GB swapfile on ext4. real user sys 6.10.0-rc3 138.18 1241.38 1452.73 6.10.0-rc3-onepool 149.45 1240.45 1844.69 6.10.0-rc3-onepool-perclass 138.23 1242.37 1469.71 And do the same testing using zbud, which shows a little worse performance as expected since we don't do any locking optimization for zbud. I think it's acceptable since zsmalloc became a lot more popular than other backends, and we may want to support only zsmalloc in the future. real user sys 6.10.0-rc3-zbud 138.23 1239.58 1430.09 6.10.0-rc3-onepool-zbud 139.64 1241.37 1516.59 [chengming.zhou@linux.dev: fix error handling in zswap_pool_create(), per Dan Carpenter] Link: https://lkml.kernel.org/r/20240621-zsmalloc-lock-mm-everything-v2-2-d30e9cd2b793@linux.dev [chengming.zhou@linux.dev: fix error handling again in zswap_pool_create(), per Yosry] Link: https://lkml.kernel.org/r/20240625-zsmalloc-lock-mm-everything-v3-2-ad941699cb61@linux.dev Link: https://lkml.kernel.org/r/20240617-zsmalloc-lock-mm-everything-v1-2-5e5081ea11b3@linux.dev Signed-off-by: Chengming Zhou <chengming.zhou@linux.dev> Reviewed-by: Nhat Pham <nphamcs@gmail.com> Acked-by: Yosry Ahmed <yosryahmed@google.com> Cc: Chengming Zhou <zhouchengming@bytedance.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12mm/zsmalloc: change back to per-size_class lockChengming Zhou
Patch series "mm/zsmalloc: change back to per-size_class lock, v2". Commit c0547d0b6a4b ("zsmalloc: consolidate zs_pool's migrate_lock and size_class's locks") changed per-size_class lock to pool spinlock to prepare reclaim support in zsmalloc. Then reclaim support in zsmalloc had been dropped in favor of LRU reclaim in zswap, but this locking change had been left there. Obviously, the scalability of pool spinlock is worse than per-size_class. And we have a workaround that using 32 pools in zswap to avoid this scalability problem, which brings its own problems like memory waste and more memory fragmentation. So this series changes back to use per-size_class lock and using testing data in much stressed situation to verify that we can use only one pool in zswap. Note we only test and care about the zsmalloc backend, which makes sense now since zsmalloc became a lot more popular than other backends. Testing kernel build (make bzImage -j32) on tmpfs with memory.max=1GB, and zswap shrinker enabled with 10GB swapfile on ext4. real user sys 6.10.0-rc3 138.18 1241.38 1452.73 6.10.0-rc3-onepool 149.45 1240.45 1844.69 6.10.0-rc3-onepool-perclass 138.23 1242.37 1469.71 We can see from "sys" column that per-size_class locking with only one pool in zswap can have near performance with the current 32 pools. This patch (of 2): This patch is almost the revert of the commit c0547d0b6a4b ("zsmalloc: consolidate zs_pool's migrate_lock and size_class's locks"), which changed to use a global pool->lock instead of per-size_class lock and pool->migrate_lock, was preparation for suppporting reclaim in zsmalloc. Then reclaim in zsmalloc had been dropped in favor of LRU reclaim in zswap. In theory, per-size_class is more fine-grained than the pool->lock, since a pool can have many size_classes. As for the additional pool->migrate_lock, only free() and map() need to grab it to access stable handle to get zspage, and only in read lock mode. Link: https://lkml.kernel.org/r/20240625-zsmalloc-lock-mm-everything-v3-0-ad941699cb61@linux.dev Link: https://lkml.kernel.org/r/20240621-zsmalloc-lock-mm-everything-v2-0-d30e9cd2b793@linux.dev Link: https://lkml.kernel.org/r/20240617-zsmalloc-lock-mm-everything-v1-0-5e5081ea11b3@linux.dev Link: https://lkml.kernel.org/r/20240617-zsmalloc-lock-mm-everything-v1-1-5e5081ea11b3@linux.dev Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12mm/hugetlb.c: undo errant changeAndrew Morton
During conflict resolution a line was unintentionally removed by a ksm.c patch. Link: https://lkml.kernel.org/r/85b0d694-d1ac-8e7a-2e50-1edc03eee21a@google.com Fixes: ac90c56bbd73 ("mm/ksm: refactor out try_to_merge_with_zero_page()") Reported-by: Hugh Dickins <hughd@google.com> Cc: Aristeu Rozanski <aris@redhat.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12Merge tag 'loongarch-kvm-6.11' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson into HEAD LoongArch KVM changes for v6.11 1. Add ParaVirt steal time support. 2. Add some VM migration enhancement. 3. Add perf kvm-stat support for loongarch.
2024-07-12mm, virt: merge AS_UNMOVABLE and AS_INACCESSIBLEPaolo Bonzini
The flags AS_UNMOVABLE and AS_INACCESSIBLE were both added just for guest_memfd; AS_UNMOVABLE is already in existing versions of Linux, while AS_INACCESSIBLE was acked for inclusion in 6.11. But really, they are the same thing: only guest_memfd uses them, at least for now, and guest_memfd pages are unmovable because they should not be accessed by the CPU. So merge them into one; use the AS_INACCESSIBLE name which is more comprehensive. At the same time, this fixes an embarrassing bug where AS_INACCESSIBLE was used as a bit mask, despite it being just a bit index. The bug was mostly benign, because AS_INACCESSIBLE's bit representation (1010) corresponded to setting AS_UNEVICTABLE (which is already set) and AS_ENOSPC (except no async writes can happen on the guest_memfd). So the AS_INACCESSIBLE flag simply had no effect. Fixes: 1d23040caa8b ("KVM: guest_memfd: Use AS_INACCESSIBLE when creating guest_memfd inode") Fixes: c72ceafbd12c ("mm: Introduce AS_INACCESSIBLE for encrypted/confidential memory") Cc: linux-mm@kvack.org Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Hildenbrand <david@redhat.com> Tested-by: Michael Roth <michael.roth@amd.com> Reviewed-by: Michael Roth <michael.roth@amd.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-07-11mm, slab: move prepare_slab_obj_exts_hook under CONFIG_MEM_ALLOC_PROFILINGSuren Baghdasaryan
The only place prepare_slab_obj_exts_hook() is currently being used is from alloc_tagging_slab_alloc_hook() when CONFIG_MEM_ALLOC_PROFILING=y. Move its definition under CONFIG_MEM_ALLOC_PROFILING to prevent unused function warning for CONFIG_SLAB_OBJ_EXT=n case. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202407050845.zNONqauD-lkp@intel.com/ Signed-off-by: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Xiongwei Song <xiongwei.song@linux.dev> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-07-10mm/vmscan: drop checking if _deferred_list is empty before using TTU_SYNCBarry Song
The optimization of list_empty(&folio->_deferred_list) aimed to prevent increasing the PTL duration when a large folio is partially unmapped, for example, from subpage 0 to subpage (nr - 2). But Ryan's commit 5ed890ce5147 ("mm: vmscan: avoid split during shrink_folio_list()") actually splits this kind of large folios. This makes the "optimization" useless. Additionally, the list_empty() technically required a data_race() annotation. Link: https://lkml.kernel.org/r/20240629234155.53524-1-21cnbao@gmail.com Signed-off-by: Barry Song <v-songbaohua@oppo.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-10mm/page_alloc: remove prefetchw() on freeing page to buddy systemWei Yang
The prefetchw() is introduced from an ancient patch[1]. The change log says: The basic idea is to free higher order pages instead of going through every single one. Also, some unnecessary atomic operations are done away with and replaced with non-atomic equivalents, and prefetching is done where it helps the most. For a more in-depth discusion of this patch, please see the linux-ia64 archives (topic is "free bootmem feedback patch"). So there are several changes improve the bootmem freeing, in which the most basic idea is freeing higher order pages. And as Matthew says, "Itanium CPUs of this era had no prefetchers." I did 10 round bootup tests before and after this change, the data doesn't prove prefetchw() help speeding up bootmem freeing. The sum of the 10 round bootmem freeing time after prefetchw() removal even 5.2% faster than before. [1]: https://lore.kernel.org/linux-ia64/40F46962.4090604@sgi.com/ Link: https://lkml.kernel.org/r/20240702020931.7061-1-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Suggested-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-10mm: remove CONFIG_MEMCG_KMEMJohannes Weiner
CONFIG_MEMCG_KMEM used to be a user-visible option for whether slab tracking is enabled. It has been default-enabled and equivalent to CONFIG_MEMCG for almost a decade. We've only grown more kernel memory accounting sites since, and there is no imaginable cgroup usecase going forward that wants to track user pages but not the multitude of user-drivable kernel allocations. Link: https://lkml.kernel.org/r/20240701153148.452230-1-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: David Hildenbrand <david@redhat.com> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-10mm/shmem: fix input and output inconsistenciesBang Li
Commit 19eaf44954df ("mm: thp: support allocation of anonymous multi-size THP") added mTHP support for anonymous shmem. We can configure different policies through the multi-size THP sysfs interface for anonymous shmem. But when we configure the "advise" policy of /sys/kernel/mm/transparent_hugepage/hugepages-xxxkB/shmem_enabled, we cannot write the "advise", but write the "madvise", which is unreasonable. We should keep the output and input values consistent, which is more convenient for users. Link: https://lkml.kernel.org/r/20240628032327.16987-1-libang.li@antgroup.com Fixes: 61a57f1b1da9 ("mm: shmem: add multi-size THP sysfs interface for anonymous shmem") Signed-off-by: Bang Li <libang.li@antgroup.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Bang Li <libang.li@antgroup.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-09mm/hugetlb: fix kernel NULL pointer dereference when migrating hugetlb folioMiaohe Lin
A kernel crash was observed when migrating hugetlb folio: BUG: kernel NULL pointer dereference, address: 0000000000000008 PGD 0 P4D 0 Oops: Oops: 0002 [#1] PREEMPT SMP NOPTI CPU: 0 PID: 3435 Comm: bash Not tainted 6.10.0-rc6-00450-g8578ca01f21f #66 RIP: 0010:__folio_undo_large_rmappable+0x70/0xb0 RSP: 0018:ffffb165c98a7b38 EFLAGS: 00000097 RAX: fffffbbc44528090 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffffa30e000a2800 RSI: 0000000000000246 RDI: ffffa3153ffffcc0 RBP: fffffbbc44528000 R08: 0000000000002371 R09: ffffffffbe4e5868 R10: 0000000000000001 R11: 0000000000000001 R12: ffffa3153ffffcc0 R13: fffffbbc44468000 R14: 0000000000000001 R15: 0000000000000001 FS: 00007f5b3a716740(0000) GS:ffffa3151fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000008 CR3: 000000010959a000 CR4: 00000000000006f0 Call Trace: <TASK> __folio_migrate_mapping+0x59e/0x950 __migrate_folio.constprop.0+0x5f/0x120 move_to_new_folio+0xfd/0x250 migrate_pages+0x383/0xd70 soft_offline_page+0x2ab/0x7f0 soft_offline_page_store+0x52/0x90 kernfs_fop_write_iter+0x12c/0x1d0 vfs_write+0x380/0x540 ksys_write+0x64/0xe0 do_syscall_64+0xb9/0x1d0 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5b3a514887 RSP: 002b:00007ffe138fce68 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000000000c RCX: 00007f5b3a514887 RDX: 000000000000000c RSI: 0000556ab809ee10 RDI: 0000000000000001 RBP: 0000556ab809ee10 R08: 00007f5b3a5d1460 R09: 000000007fffffff R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000000c R13: 00007f5b3a61b780 R14: 00007f5b3a617600 R15: 00007f5b3a616a00 It's because hugetlb folio is passed to __folio_undo_large_rmappable() unexpectedly. large_rmappable flag is imperceptibly set to hugetlb folio since commit f6a8dd98a2ce ("hugetlb: convert alloc_buddy_hugetlb_folio to use a folio"). Then commit be9581ea8c05 ("mm: fix crashes from deferred split racing folio migration") makes folio_migrate_mapping() call folio_undo_large_rmappable() triggering the bug. Fix this issue by clearing large_rmappable flag for hugetlb folios. They don't need that flag set anyway. Link: https://lkml.kernel.org/r/20240709120433.4136700-1-linmiaohe@huawei.com Fixes: f6a8dd98a2ce ("hugetlb: convert alloc_buddy_hugetlb_folio to use a folio") Fixes: be9581ea8c05 ("mm: fix crashes from deferred split racing folio migration") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-09mm/hugetlb: fix potential race in __update_and_free_hugetlb_folio()Miaohe Lin
There is a potential race between __update_and_free_hugetlb_folio() and try_memory_failure_hugetlb(): CPU1 CPU2 __update_and_free_hugetlb_folio try_memory_failure_hugetlb folio_test_hugetlb -- It's still hugetlb folio. folio_clear_hugetlb_hwpoison spin_lock_irq(&hugetlb_lock); __get_huge_page_for_hwpoison folio_set_hugetlb_hwpoison spin_unlock_irq(&hugetlb_lock); spin_lock_irq(&hugetlb_lock); __folio_clear_hugetlb(folio); -- Hugetlb flag is cleared but too late. spin_unlock_irq(&hugetlb_lock); When the above race occurs, raw error page info will be leaked. Even worse, raw error pages won't have hwpoisoned flag set and hit pcplists/buddy. Fix this issue by deferring folio_clear_hugetlb_hwpoison() until __folio_clear_hugetlb() is done. So all raw error pages will have hwpoisoned flag set. Link: https://lkml.kernel.org/r/20240708025127.107713-1-linmiaohe@huawei.com Fixes: 32c877191e02 ("hugetlb: do not clear hugetlb dtor until allocating vmemmap") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Muchun Song <muchun.song@linux.dev> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-09filemap: replace pte_offset_map() with pte_offset_map_nolock()ZhangPeng
The vmf->ptl in filemap_fault_recheck_pte_none() is still set from handle_pte_fault(). But at the same time, we did a pte_unmap(vmf->pte). After a pte_unmap(vmf->pte) unmap and rcu_read_unlock(), the page table may be racily changed and vmf->ptl maybe fails to protect the actual page table. Fix this by replacing pte_offset_map() with pte_offset_map_nolock(). As David said, the PTL pointer might be stale so if we continue to use it infilemap_fault_recheck_pte_none(), it might trigger UAF. Also, if the PTL fails, the issue fixed by commit 58f327f2ce80 ("filemap: avoid unnecessary major faults in filemap_fault()") might reappear. Link: https://lkml.kernel.org/r/20240313012913.2395414-1-zhangpeng362@huawei.com Fixes: 58f327f2ce80 ("filemap: avoid unnecessary major faults in filemap_fault()") Signed-off-by: ZhangPeng <zhangpeng362@huawei.com> Suggested-by: David Hildenbrand <david@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yin Fengwei <fengwei.yin@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-08filemap: Convert generic_perform_write() to support large foliosMatthew Wilcox (Oracle)
Modelled after the loop in iomap_write_iter(), copy larger chunks from userspace if the filesystem has created large folios. [hch: use mapping_max_folio_size to keep supporting file systems that do not support large folios] Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Shaun Tancheff <shaun.tancheff@hpe.com> Tested-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2024-07-06mm: migrate: remove folio_migrate_copy()Kefeng Wang
The folio_migrate_copy() is just a wrapper of folio_copy() and folio_migrate_flags(), it is simple and only aio use it for now, unfold it and remove folio_migrate_copy(). Link: https://lkml.kernel.org/r/20240626085328.608006-7-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Jane Chu <jane.chu@oracle.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Jiaqi Yan <jiaqiyan@google.com> Cc: Lance Yang <ioworker0@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>