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2024-07-03mm: allow reuse of the lower 16 bit of the page type with an actual typeDavid Hildenbrand
As long as the owner sets a page type first, we can allow reuse of the lower 16 bit: sufficient to store an offset into a 64 KiB page, which is the maximum base page size in *common* configurations (ignoring the 256 KiB variant). Restrict it to the head page. We'll use that for zsmalloc next, to set a proper type while still reusing that field to store information (offset into a base page) that cannot go elsewhere for now. Let's reserve the lower 16 bit for that purpose and for catching mapcount underflows, and let's reduce PAGE_TYPE_BASE to a single bit. Note that we will still have to overflow the mapcount quite a lot until we would actually indicate a valid page type. Start handing out the type bits from highest to lowest, to make it clearer how many bits for types we have left. Out of 15 bit we can use for types, we currently use 6. If we run out of bits before we have better typing (e.g., memdesc), we can always investigate storing a value instead [1]. [1] https://lore.kernel.org/all/00ba1dff-7c05-46e8-b0d9-a78ac1cfc198@redhat.com/ [akpm@linux-foundation.org: fix PG_hugetlb typo, per David] Link: https://lkml.kernel.org/r/20240529111904.2069608-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org> [zram/zsmalloc workloads] Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm: update _mapcount and page_type documentationDavid Hildenbrand
Patch series "mm: page_type, zsmalloc and page_mapcount_reset()", v2. Wanting to remove the remaining abuser of _mapcount/page_type along with page_mapcount_reset(), I stumbled over zsmalloc, which is yet to be converted away from "struct page" [1]. Unfortunately, we cannot stop using the page_type field in zsmalloc code completely for its own purposes. All other fields in "struct page" are used one way or the other. Could we simply store a 2-byte offset value at the beginning of each page? Likely, but that will require a bit more work; and once we have memdesc we might want to move the offset in there (struct zsalloc?) again. ... but we can limit the abuse to 16 bit, glue it to a page type that must be set, and document it. page_has_type() will always successfully indicate such zsmalloc pages, and such zsmalloc pages only. We lose zsmalloc support for PAGE_SIZE > 64KB, which should be tolerable. We could use more bits from the page type, but 16 bit sounds like a good idea for now. So clarify the _mapcount/page_type documentation, use a proper page_type for zsmalloc, and remove page_mapcount_reset(). [1] https://lore.kernel.org/all/20231130101242.2590384-1-42.hyeyoo@gmail.com/ This patch (of 6): Let's make it clearer that _mapcount must no longer be used for own purposes, and how _mapcount and page_type behaves nowadays (also in the context of hugetlb folios, which are typed folios that will be mapped to user space). Move the documentation regarding "-1" over from page_mapcount_reset(), which we will remove next. Move "page_type" before "mapcount", to make it clearer what typed folios are. Link: https://lkml.kernel.org/r/20240529111904.2069608-1-david@redhat.com Link: https://lkml.kernel.org/r/20240529111904.2069608-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org> [zram/zsmalloc workloads] Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03selftests/mm: remove local __NR_* definitionsJohn Hubbard
This continues the work on getting the selftests to build without requiring people to first run "make headers" [1]. Now that the system call numbers are in the correct, checked-in locations in the kernel tree (./tools/include/uapi/asm/unistd*.h), make sure that the mm selftests include that file (indirectly). Doing so provides guaranteed definitions at build time, so remove all of the checks for "ifdef __NR_xxx" in the mm selftests, because they will always be true (defined). [1] commit e076eaca5906 ("selftests: break the dependency upon local header files") Link: https://lkml.kernel.org/r/20240618022422.804305-7-jhubbard@nvidia.com Signed-off-by: John Hubbard <jhubbard@nvidia.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Jeff Xu <jeffxu@chromium.org> Cc: Andrei Vagin <avagin@google.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Kees Cook <kees@kernel.org> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Muhammad Usama Anjum <usama.anjum@collabora.com> Cc: Peter Xu <peterx@redhat.com> Cc: Rich Felker <dalias@libc.org> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/huge_memory.c: fix used-uninitializedAndrew Morton
Fix used-uninitialized of `page'. Fixes: dce7d10be4bb ("mm/madvise: optimize lazyfreeing with mTHP in madvise_free") Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202406260514.SLhNM9kQ-lkp@intel.com Cc: Lance Yang <ioworker0@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03nilfs2: fix incorrect inode allocation from reserved inodesRyusuke Konishi
If the bitmap block that manages the inode allocation status is corrupted, nilfs_ifile_create_inode() may allocate a new inode from the reserved inode area where it should not be allocated. Previous fix commit d325dc6eb763 ("nilfs2: fix use-after-free bug of struct nilfs_root"), fixed the problem that reserved inodes with inode numbers less than NILFS_USER_INO (=11) were incorrectly reallocated due to bitmap corruption, but since the start number of non-reserved inodes is read from the super block and may change, in which case inode allocation may occur from the extended reserved inode area. If that happens, access to that inode will cause an IO error, causing the file system to degrade to an error state. Fix this potential issue by adding a wraparound option to the common metadata object allocation routine and by modifying nilfs_ifile_create_inode() to disable the option so that it only allocates inodes with inode numbers greater than or equal to the inode number read in "nilfs->ns_first_ino", regardless of the bitmap status of reserved inodes. Link: https://lkml.kernel.org/r/20240623051135.4180-4-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Jan Kara <jack@suse.cz> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03nilfs2: add missing check for inode numbers on directory entriesRyusuke Konishi
Syzbot reported that mounting and unmounting a specific pattern of corrupted nilfs2 filesystem images causes a use-after-free of metadata file inodes, which triggers a kernel bug in lru_add_fn(). As Jan Kara pointed out, this is because the link count of a metadata file gets corrupted to 0, and nilfs_evict_inode(), which is called from iput(), tries to delete that inode (ifile inode in this case). The inconsistency occurs because directories containing the inode numbers of these metadata files that should not be visible in the namespace are read without checking. Fix this issue by treating the inode numbers of these internal files as errors in the sanity check helper when reading directory folios/pages. Also thanks to Hillf Danton and Matthew Wilcox for their initial mm-layer analysis. Link: https://lkml.kernel.org/r/20240623051135.4180-3-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Reported-by: syzbot+d79afb004be235636ee8@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=d79afb004be235636ee8 Reported-by: Jan Kara <jack@suse.cz> Closes: https://lkml.kernel.org/r/20240617075758.wewhukbrjod5fp5o@quack3 Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03nilfs2: fix inode number range checksRyusuke Konishi
Patch series "nilfs2: fix potential issues related to reserved inodes". This series fixes one use-after-free issue reported by syzbot, caused by nilfs2's internal inode being exposed in the namespace on a corrupted filesystem, and a couple of flaws that cause problems if the starting number of non-reserved inodes written in the on-disk super block is intentionally (or corruptly) changed from its default value. This patch (of 3): In the current implementation of nilfs2, "nilfs->ns_first_ino", which gives the first non-reserved inode number, is read from the superblock, but its lower limit is not checked. As a result, if a number that overlaps with the inode number range of reserved inodes such as the root directory or metadata files is set in the super block parameter, the inode number test macros (NILFS_MDT_INODE and NILFS_VALID_INODE) will not function properly. In addition, these test macros use left bit-shift calculations using with the inode number as the shift count via the BIT macro, but the result of a shift calculation that exceeds the bit width of an integer is undefined in the C specification, so if "ns_first_ino" is set to a large value other than the default value NILFS_USER_INO (=11), the macros may potentially malfunction depending on the environment. Fix these issues by checking the lower bound of "nilfs->ns_first_ino" and by preventing bit shifts equal to or greater than the NILFS_USER_INO constant in the inode number test macros. Also, change the type of "ns_first_ino" from signed integer to unsigned integer to avoid the need for type casting in comparisons such as the lower bound check introduced this time. Link: https://lkml.kernel.org/r/20240623051135.4180-1-konishi.ryusuke@gmail.com Link: https://lkml.kernel.org/r/20240623051135.4180-2-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Jan Kara <jack@suse.cz> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm: avoid overflows in dirty throttling logicJan Kara
The dirty throttling logic is interspersed with assumptions that dirty limits in PAGE_SIZE units fit into 32-bit (so that various multiplications fit into 64-bits). If limits end up being larger, we will hit overflows, possible divisions by 0 etc. Fix these problems by never allowing so large dirty limits as they have dubious practical value anyway. For dirty_bytes / dirty_background_bytes interfaces we can just refuse to set so large limits. For dirty_ratio / dirty_background_ratio it isn't so simple as the dirty limit is computed from the amount of available memory which can change due to memory hotplug etc. So when converting dirty limits from ratios to numbers of pages, we just don't allow the result to exceed UINT_MAX. This is root-only triggerable problem which occurs when the operator sets dirty limits to >16 TB. Link: https://lkml.kernel.org/r/20240621144246.11148-2-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Reported-by: Zach O'Keefe <zokeefe@google.com> Reviewed-By: Zach O'Keefe <zokeefe@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03Revert "mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again"Jan Kara
Patch series "mm: Avoid possible overflows in dirty throttling". Dirty throttling logic assumes dirty limits in page units fit into 32-bits. This patch series makes sure this is true (see patch 2/2 for more details). This patch (of 2): This reverts commit 9319b647902cbd5cc884ac08a8a6d54ce111fc78. The commit is broken in several ways. Firstly, the removed (u64) cast from the multiplication will introduce a multiplication overflow on 32-bit archs if wb_thresh * bg_thresh >= 1<<32 (which is actually common - the default settings with 4GB of RAM will trigger this). Secondly, the div64_u64() is unnecessarily expensive on 32-bit archs. We have div64_ul() in case we want to be safe & cheap. Thirdly, if dirty thresholds are larger than 1<<32 pages, then dirty balancing is going to blow up in many other spectacular ways anyway so trying to fix one possible overflow is just moot. Link: https://lkml.kernel.org/r/20240621144017.30993-1-jack@suse.cz Link: https://lkml.kernel.org/r/20240621144246.11148-1-jack@suse.cz Fixes: 9319b647902c ("mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again") Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-By: Zach O'Keefe <zokeefe@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm: optimize the redundant loop of mm_update_owner_next()Jinliang Zheng
When mm_update_owner_next() is racing with swapoff (try_to_unuse()) or /proc or ptrace or page migration (get_task_mm()), it is impossible to find an appropriate task_struct in the loop whose mm_struct is the same as the target mm_struct. If the above race condition is combined with the stress-ng-zombie and stress-ng-dup tests, such a long loop can easily cause a Hard Lockup in write_lock_irq() for tasklist_lock. Recognize this situation in advance and exit early. Link: https://lkml.kernel.org/r/20240620122123.3877432-1-alexjlzheng@tencent.com Signed-off-by: Jinliang Zheng <alexjlzheng@tencent.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Mateusz Guzik <mjguzik@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Tycho Andersen <tandersen@netflix.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03khugepaged: simplify the allocation of slab cachesHongfu Li
Use the new KMEM_CACHE() macro instead of direct kmem_cache_create to simplify the creation of SLAB caches. Link: https://lkml.kernel.org/r/20240618014517.25954-1-lihongfu@kylinos.cn Signed-off-by: Hongfu Li <lihongfu@kylinos.cn> Acked-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm: ksm: drop KSM_KMEM_CACHE()Kefeng Wang
After commit 21fbd59136e0 ("ksm: add the ksm prefix to the names of the ksm private structures"), we could directly use KMEM_CACHE(). Link: https://lkml.kernel.org/r/20240618081201.134985-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/damon/lru_sort: remove unnecessary online tuning handling codeSeongJae Park
DAMON_LRU_SORT contains code for handling of online DAMON parameters update edge cases. It is no more necessary since damon_commit_ctx() takes care of the cases. Remove the unnecessary code. Link: https://lkml.kernel.org/r/20240618181809.82078-13-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/damon/lru_sort: use damon_commit_ctx()SeongJae Park
DAMON_LRU_SORT manually manipulates the DAMON context struct for online parameters update. Since the struct contains not only input parameters but also internal status and operation results, it is not that simple. Indeed, we found and fixed a few bugs in the code. Now DAMON core layer provides a function for the usage, namely damon_commit_ctx(). Replace the manual manipulation logic with the function. The core layer function could have its own bugs, but this change removes a source of bugs. Link: https://lkml.kernel.org/r/20240618181809.82078-12-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/damon/reclaim: remove unnecessary code for online tuningSeongJae Park
DAMON_RECLAIM contains code for handling of online DAMON parameters update edge cases. It is no more necessary since damon_commit_ctx() takes care of the cases. Remove the unnecessary code. Link: https://lkml.kernel.org/r/20240618181809.82078-11-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/damon/reclaim: use damon_commit_ctx()SeongJae Park
DAMON_RECLAIM manually manipulates the DAMON context struct for online parameters update. Since the struct contains not only input parameters but also internal status and operation results, it is not that simple. Indeed, we found and fixed a few bugs in the code. Now DAMON core layer provides a function for the usage, namely damon_commit_ctx(). Replace the manual manipulation logic with the function. The core layer function could have its own bugs, but this change removes a source of bugs. Link: https://lkml.kernel.org/r/20240618181809.82078-10-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/damon/sysfs-schemes: rename ↵SeongJae Park
*_set_{schemes,scheme_filters,quota_score,schemes}() The functions were for updating DAMON structs that may or may not be partially populated. Hence it was not for only adding items, but also removing unnecessary items and updating items in-place. A previous commit has changed the functions to assume the structs are not partially populated, and do only adding items. Make the names better explain the behavior. Link: https://lkml.kernel.org/r/20240618181809.82078-9-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/damon/sysfs-schemes: remove unnecessary online tuning handling codeSeongJae Park
damon/sysfs-schemes.c contains code for handling of online DAMON parameters update edge cases. The logics are no more necessary since damon_commit_ctx() and damon_commit_quota_goals() takes care of the cases. Remove the unnecessary code. Link: https://lkml.kernel.org/r/20240618181809.82078-8-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/damon/sysfs: rename damon_sysfs_set_targets() to ...add_targets()SeongJae Park
The function was for updating DAMON structs that may or may not be partially populated. Hence it was not for only adding items, but also removing unnecessary items and updating items in-place. A previous commit has changed the function to assume the structs are not partially populated, and do only adding items. Make the function name better explain the behavior. Link: https://lkml.kernel.org/r/20240618181809.82078-7-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/damon/sysfs: remove unnecessary online tuning handling codeSeongJae Park
damon/sysfs.c contains code for handling of online DAMON parameters update edge cases. It is no more necessary since damon_commit_ctx() takes care of the cases. Remove the unnecessary code. Link: https://lkml.kernel.org/r/20240618181809.82078-6-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/damon/sysfs-schemes: use damos_commit_quota_goals()SeongJae Park
DAMON_SYSFS manually manipulates the DAMOS quota structs for online quotal goals parameter update. Since the struct contains not only input parameters but also internal status and operation results, it is not that simple. Now DAMON core layer provides a function for the usage, namely damon_commit_quota_goals(). Replace the manual manipulation logic with the function. The core layer function could have its own bugs, but this change removes a source of bugs. Link: https://lkml.kernel.org/r/20240618181809.82078-5-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/damon/sysfs: use damon_commit_ctx()SeongJae Park
DAMON_SYSFS manually manipulates DAMON context structs for online parameters update. Since the struct contains not only input parameters but also internal status and operation results, it is not that simple. Indeed, we found and fixed a few bugs in the code. Now DAMON core layer provides a function for the usage, namely damon_commit_ctx(). Replace the manual manipulation logic with the function. The core layer function could have its own bugs, but this change removes a source of bugs. Link: https://lkml.kernel.org/r/20240618181809.82078-4-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/damon/core: implement DAMON context commit functionSeongJae Park
Implement functions for supporting online DAMON context level parameters update. The function receives two DAMON context structs. One is the struct that currently being used by a kdamond and therefore to be updated. The other one contains the parameters to be applied to the first one. The function applies the new parameters to the destination struct while keeping/updating the internal status and operation results. The function should be called from DAMON context-update-safe place, like DAMON callbacks. Link: https://lkml.kernel.org/r/20240618181809.82078-3-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/damon/core: implement DAMOS quota goals online commit functionSeongJae Park
Patch series "mm/damon: introduce DAMON parameters online commit function". DAMON context struct (damon_ctx) contains user requests (parameters), internal status, and operation results. For flexible usages, DAMON API users are encouraged to manually manipulate the struct. That works well for simple use cases. However, it has turned out that it is not that simple at least for online parameters udpate. It is easy to forget properly maintaining internal status and operation results. Also, such manual manipulation for online tuning is implemented multiple times on DAMON API users including DAMON sysfs interface, DAMON_RECLAIM and DAMON_LRU_SORT. As a result, we have multiple sources of bugs for same problem. Actually we found and fixed a few bugs from online parameter updating of DAMON API users. Implement a function for online DAMON parameters update in core layer, and replace DAMON API users' manual manipulation code for the use case. The core layer function could still have bugs, but this change reduces the source of bugs for the problem to one place. This patch (of 12): Implement functions for supporting online DAMOS quota goals parameters update. The function receives two DAMOS quota structs. One is the struct that currently being used by a kdamond and therefore to be updated. The other one contains the parameters to be applied to the first one. The function applies the new parameters to the destination struct while keeping/updating the internal status. The function should be called from parameters-update safe place, like DAMON callbacks. Link: https://lkml.kernel.org/r/20240618181809.82078-1-sj@kernel.org Link: https://lkml.kernel.org/r/20240618181809.82078-2-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm: memcontrol: add VM_BUG_ON_FOLIO() to catch lru folio in mem_cgroup_migrate()Baolin Wang
mem_cgroup_migrate() will clear the memcg data of the old folio, therefore, the callers must make sure the old folio is no longer on the LRU list, otherwise the old folio can not get the correct lruvec object without the memcg data, which could lead to potential problems [1]. Thus adding a VM_BUG_ON_FOLIO() to catch this issue. [1] https://lore.kernel.org/all/5ab860d8ee987955e917748f9d6da525d3b52690.1718326003.git.baolin.wang@linux.alibaba.com/ Link: https://lkml.kernel.org/r/66d181c41b7ced35dbd39ffd3f5774a11aef266a.1718327124.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Suggested-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03Docs/damon: document damos_migrate_{hot,cold}Honggyu Kim
This patch adds damon description for "migrate_hot" and "migrate_cold" actions for both usage and design documents as long as a new "target_nid" knob to set the migration target node. [sj@kernel.org: trivial fixups for DAMOS_MIGRATE_{HOT,COLD} documentation] Link: https://lkml.kernel.org/r/20240618213630.84846-2-sj@kernel.org Link: https://lkml.kernel.org/r/20240614030010.751-8-honggyu.kim@sk.com Signed-off-by: Honggyu Kim <honggyu.kim@sk.com> Signed-off-by: SeongJae Park <sj@kernel.org>Reviewed-by: SeongJae Park <sj@kernel.org> Cc: Gregory Price <gregory.price@memverge.com> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Hyeongtak Ji <hyeongtak.ji@sk.com> Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/damon/paddr: introduce DAMOS_MIGRATE_HOT action for promotionHyeongtak Ji
This patch introduces DAMOS_MIGRATE_HOT action, which is similar to DAMOS_MIGRATE_COLD, but proritizes hot pages. It migrates pages inside the given region to the 'target_nid' NUMA node in the sysfs. Here is one of the example usage of this 'migrate_hot' action. $ cd /sys/kernel/mm/damon/admin/kdamonds/<N> $ cat contexts/<N>/schemes/<N>/action migrate_hot $ echo 0 > contexts/<N>/schemes/<N>/target_nid $ echo commit > state $ numactl -p 2 ./hot_cold 500M 600M & $ numastat -c -p hot_cold Per-node process memory usage (in MBs) PID Node 0 Node 1 Node 2 Total -------------- ------ ------ ------ ----- 701 (hot_cold) 501 0 601 1101 Link: https://lkml.kernel.org/r/20240614030010.751-7-honggyu.kim@sk.com Signed-off-by: Hyeongtak Ji <hyeongtak.ji@sk.com> Signed-off-by: Honggyu Kim <honggyu.kim@sk.com> Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Gregory Price <gregory.price@memverge.com> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/damon/paddr: introduce DAMOS_MIGRATE_COLD action for demotionHonggyu Kim
This patch introduces DAMOS_MIGRATE_COLD action, which is similar to DAMOS_PAGEOUT, but migrate folios to the given 'target_nid' in the sysfs instead of swapping them out. The 'target_nid' sysfs knob informs the migration target node ID. Here is one of the example usage of this 'migrate_cold' action. $ cd /sys/kernel/mm/damon/admin/kdamonds/<N> $ cat contexts/<N>/schemes/<N>/action migrate_cold $ echo 2 > contexts/<N>/schemes/<N>/target_nid $ echo commit > state $ numactl -p 0 ./hot_cold 500M 600M & $ numastat -c -p hot_cold Per-node process memory usage (in MBs) PID Node 0 Node 1 Node 2 Total -------------- ------ ------ ------ ----- 701 (hot_cold) 501 0 601 1101 Since there are some common routines with pageout, many functions have similar logics between pageout and migrate cold. damon_pa_migrate_folio_list() is a minimized version of shrink_folio_list(). Link: https://lkml.kernel.org/r/20240614030010.751-6-honggyu.kim@sk.com Signed-off-by: Honggyu Kim <honggyu.kim@sk.com> Signed-off-by: Hyeongtak Ji <hyeongtak.ji@sk.com> Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Gregory Price <gregory.price@memverge.com> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/migrate: add MR_DAMON to migrate_reasonHonggyu Kim
The current patch series introduces DAMON based migration across NUMA nodes so it'd be better to have a new migrate_reason in trace events. Link: https://lkml.kernel.org/r/20240614030010.751-5-honggyu.kim@sk.com Signed-off-by: Honggyu Kim <honggyu.kim@sk.com> Reviewed-by: SeongJae Park <sj@kernel.org> Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Gregory Price <gregory.price@memverge.com> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Hyeongtak Ji <hyeongtak.ji@sk.com> Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/damon/sysfs-schemes: add target_nid on sysfs-schemesHyeongtak Ji
This patch adds target_nid under /sys/kernel/mm/damon/admin/kdamonds/<N>/contexts/<N>/schemes/<N>/ The 'target_nid' can be used as the destination node for DAMOS actions such as DAMOS_MIGRATE_{HOT,COLD} in the follow up patches. [sj@kernel.org: document target_nid file] Link: https://lkml.kernel.org/r/20240618213630.84846-3-sj@kernel.org Link: https://lkml.kernel.org/r/20240614030010.751-4-honggyu.kim@sk.com Signed-off-by: Hyeongtak Ji <hyeongtak.ji@sk.com> Signed-off-by: Honggyu Kim <honggyu.kim@sk.com> Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Gregory Price <gregory.price@memverge.com> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm: rename alloc_demote_folio to alloc_migrate_folioHonggyu Kim
The alloc_demote_folio can also be used for general migration including both demotion and promotion so it'd be better to rename it from alloc_demote_folio to alloc_migrate_folio. Link: https://lkml.kernel.org/r/20240614030010.751-3-honggyu.kim@sk.com Signed-off-by: Honggyu Kim <honggyu.kim@sk.com> Reviewed-by: SeongJae Park <sj@kernel.org> Cc: Gregory Price <gregory.price@memverge.com> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Hyeongtak Ji <hyeongtak.ji@sk.com> Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm: make alloc_demote_folio externally invokable for migrationHonggyu Kim
Patch series "DAMON based tiered memory management for CXL memory", v6. Introduction ============ With the advent of CXL/PCIe attached DRAM, which will be called simply as CXL memory in this cover letter, some systems are becoming more heterogeneous having memory systems with different latency and bandwidth characteristics. They are usually handled as different NUMA nodes in separate memory tiers and CXL memory is used as slow tiers because of its protocol overhead compared to local DRAM. In this kind of systems, we need to be careful placing memory pages on proper NUMA nodes based on the memory access frequency. Otherwise, some frequently accessed pages might reside on slow tiers and it makes performance degradation unexpectedly. Moreover, the memory access patterns can be changed at runtime. To handle this problem, we need a way to monitor the memory access patterns and migrate pages based on their access temperature. The DAMON(Data Access MONitor) framework and its DAMOS(DAMON-based Operation Schemes) can be useful features for monitoring and migrating pages. DAMOS provides multiple actions based on DAMON monitoring results and it can be used for proactive reclaim, which means swapping cold pages out with DAMOS_PAGEOUT action, but it doesn't support migration actions such as demotion and promotion between tiered memory nodes. This series supports two new DAMOS actions; DAMOS_MIGRATE_HOT for promotion from slow tiers and DAMOS_MIGRATE_COLD for demotion from fast tiers. This prevents hot pages from being stuck on slow tiers, which makes performance degradation and cold pages can be proactively demoted to slow tiers so that the system can increase the chance to allocate more hot pages to fast tiers. The DAMON provides various tuning knobs but we found that the proactive demotion for cold pages is especially useful when the system is running out of memory on its fast tier nodes. Our evaluation result shows that it reduces the performance slowdown compared to the default memory policy from 11% to 3~5% when the system runs under high memory pressure on its fast tier DRAM nodes. DAMON configuration =================== The specific DAMON configuration doesn't have to be in the scope of this patch series, but some rough idea is better to be shared to explain the evaluation result. The DAMON provides many knobs for fine tuning but its configuration file is generated by HMSDK[3]. It includes gen_config.py script that generates a json file with the full config of DAMON knobs and it creates multiple kdamonds for each NUMA node when the DAMON is enabled so that it can run hot/cold based migration for tiered memory. Evaluation Workload =================== The performance evaluation is done with redis[4], which is a widely used in-memory database and the memory access patterns are generated via YCSB[5]. We have measured two different workloads with zipfian and latest distributions but their configs are slightly modified to make memory usage higher and execution time longer for better evaluation. The idea of evaluation using these migrate_{hot,cold} actions covers system-wide memory management rather than partitioning hot/cold pages of a single workload. The default memory allocation policy creates pages to the fast tier DRAM node first, then allocates newly created pages to the slow tier CXL node when the DRAM node has insufficient free space. Once the page allocation is done then those pages never move between NUMA nodes. It's not true when using numa balancing, but it is not the scope of this DAMON based tiered memory management support. If the working set of redis can be fit fully into the DRAM node, then the redis will access the fast DRAM only. Since the performance of DRAM only is faster than partially accessing CXL memory in slow tiers, this environment is not useful to evaluate this patch series. To make pages of redis be distributed across fast DRAM node and slow CXL node to evaluate our migrate_{hot,cold} actions, we pre-allocate some cold memory externally using mmap and memset before launching redis-server. We assumed that there are enough amount of cold memory in datacenters as TMO[6] and TPP[7] papers mentioned. The evaluation sequence is as follows. 1. Turn on DAMON with DAMOS_MIGRATE_COLD action for DRAM node and DAMOS_MIGRATE_HOT action for CXL node. It demotes cold pages on DRAM node and promotes hot pages on CXL node in a regular interval. 2. Allocate a huge block of cold memory by calling mmap and memset at the fast tier DRAM node, then make the process sleep to make the fast tier has insufficient space for redis-server. 3. Launch redis-server and load prebaked snapshot image, dump.rdb. The redis-server consumes 52GB of anon pages and 33GB of file pages, but due to the cold memory allocated at 2, it fails allocating the entire memory of redis-server on the fast tier DRAM node so it partially allocates the remaining on the slow tier CXL node. The ratio of DRAM:CXL depends on the size of the pre-allocated cold memory. 4. Run YCSB to make zipfian or latest distribution of memory accesses to redis-server, then measure its execution time when it's completed. 5. Repeat 4 over 50 times to measure the average execution time for each run. 6. Increase the cold memory size then repeat goes to 2. For each test at 4 took about a minute so repeating it 50 times almost took about 1 hour for each test with a specific cold memory from 440GB to 500GB in 10GB increments for each evaluation. So it took about more than 10 hours for both zipfian and latest workloads to get the entire evaluation results. Repeating the same test set multiple times doesn't show much difference so I think it might be enough to make the result reliable. Evaluation Results ================== All the result values are normalized to DRAM-only execution time because the workload cannot be faster than DRAM-only unless the workload hits the peak bandwidth but our redis test doesn't go beyond the bandwidth limit. So the DRAM-only execution time is the ideal result without affected by the gap between DRAM and CXL performance difference. The NUMA node environment is as follows. node0 - local DRAM, 512GB with a CPU socket (fast tier) node1 - disabled node2 - CXL DRAM, 96GB, no CPU attached (slow tier) The following is the result of generating zipfian distribution to redis-server and the numbers are averaged by 50 times of execution. 1. YCSB zipfian distribution read only workload memory pressure with cold memory on node0 with 512GB of local DRAM. ====================+================================================+========= | cold memory occupied by mmap and memset | | 0G 440G 450G 460G 470G 480G 490G 500G | ====================+================================================+========= Execution time normalized to DRAM-only values | GEOMEAN --------------------+------------------------------------------------+--------- DRAM-only | 1.00 - - - - - - - | 1.00 CXL-only | 1.19 - - - - - - - | 1.19 default | - 1.00 1.05 1.08 1.12 1.14 1.18 1.18 | 1.11 DAMON tiered | - 1.03 1.03 1.03 1.03 1.03 1.07 *1.05 | 1.04 DAMON lazy | - 1.04 1.03 1.04 1.05 1.06 1.06 *1.06 | 1.05 ====================+================================================+========= CXL usage of redis-server in GB | AVERAGE --------------------+------------------------------------------------+--------- DRAM-only | 0.0 - - - - - - - | 0.0 CXL-only | 51.4 - - - - - - - | 51.4 default | - 0.6 10.6 20.5 30.5 40.5 47.6 50.4 | 28.7 DAMON tiered | - 0.6 0.5 0.4 0.7 0.8 7.1 5.6 | 2.2 DAMON lazy | - 0.5 3.0 4.5 5.4 6.4 9.4 9.1 | 5.5 ====================+================================================+========= Each test result is based on the execution environment as follows. DRAM-only: redis-server uses only local DRAM memory. CXL-only: redis-server uses only CXL memory. default: default memory policy(MPOL_DEFAULT). numa balancing disabled. DAMON tiered: DAMON enabled with DAMOS_MIGRATE_COLD for DRAM nodes and DAMOS_MIGRATE_HOT for CXL nodes. DAMON lazy: same as DAMON tiered, but turn on DAMON just before making memory access request via YCSB. The above result shows the "default" execution time goes up as the size of cold memory is increased from 440G to 500G because the more cold memory used, the more CXL memory is used for the target redis workload and this makes the execution time increase. However, "DAMON tiered" and other DAMON results show less slowdown because the DAMOS_MIGRATE_COLD action at DRAM node proactively demotes pre-allocated cold memory to CXL node and this free space at DRAM increases more chance to allocate hot or warm pages of redis-server to fast DRAM node. Moreover, DAMOS_MIGRATE_HOT action at CXL node also promotes hot pages of redis-server to DRAM node actively. As a result, it makes more memory of redis-server stay in DRAM node compared to "default" memory policy and this makes the performance improvement. Please note that the result numbers of "DAMON tiered" and "DAMON lazy" at 500G are marked with * stars, which means their test results are replaced with reproduced tests that didn't have OOM issue. That was needed because sometimes the test processes get OOM when DRAM has insufficient space. The DAMOS_MIGRATE_HOT doesn't kick reclaim but just gives up migration when there is not enough space at DRAM side. The problem happens when there is competition between normal allocation and migration and the migration is done before normal allocation, then the completely unrelated normal allocation can trigger reclaim, which incurs OOM. Because of this issue, I have also tested more cases with "demotion_enabled" flag enabled to make such reclaim doesn't trigger OOM, but just demote reclaimed pages. The following test results show more tests with "kswapd" marked. 2. YCSB zipfian distribution read only workload (with demotion_enabled true) memory pressure with cold memory on node0 with 512GB of local DRAM. ====================+================================================+========= | cold memory occupied by mmap and memset | | 0G 440G 450G 460G 470G 480G 490G 500G | ====================+================================================+========= Execution time normalized to DRAM-only values | GEOMEAN --------------------+------------------------------------------------+--------- DAMON tiered | - 1.03 1.03 1.03 1.03 1.03 1.07 1.05 | 1.04 DAMON lazy | - 1.04 1.03 1.04 1.05 1.06 1.06 1.06 | 1.05 DAMON tiered kswapd | - 1.03 1.03 1.03 1.03 1.02 1.02 1.03 | 1.03 DAMON lazy kswapd | - 1.04 1.04 1.04 1.03 1.05 1.04 1.05 | 1.04 ====================+================================================+========= CXL usage of redis-server in GB | AVERAGE --------------------+------------------------------------------------+--------- DAMON tiered | - 0.6 0.5 0.4 0.7 0.8 7.1 5.6 | 2.2 DAMON lazy | - 0.5 3.0 4.5 5.4 6.4 9.4 9.1 | 5.5 DAMON tiered kswapd | - 0.0 0.0 0.4 0.5 0.1 0.8 1.0 | 0.4 DAMON lazy kswapd | - 4.2 4.6 5.3 1.7 6.8 8.1 5.8 | 5.2 ====================+================================================+========= Each test result is based on the exeuction environment as follows. DAMON tiered: same as before DAMON lazy: same as before DAMON tiered kswapd: same as DAMON tiered, but turn on /sys/kernel/mm/numa/demotion_enabled to make kswapd or direct reclaim does demotion. DAMON lazy kswapd: same as DAMON lazy, but turn on /sys/kernel/mm/numa/demotion_enabled to make kswapd or direct reclaim does demotion. The "DAMON tiered kswapd" and "DAMON lazy kswapd" didn't trigger OOM at all unlike other tests because kswapd and direct reclaim from DRAM node can demote reclaimed pages to CXL node independently from DAMON actions and their results are slightly better than without having "demotion_enabled". In summary, the evaluation results show that DAMON memory management with DAMOS_MIGRATE_{HOT,COLD} actions reduces the performance slowdown compared to the "default" memory policy from 11% to 3~5% when the system runs with high memory pressure on its fast tier DRAM nodes. Having these DAMOS_MIGRATE_HOT and DAMOS_MIGRATE_COLD actions can make tiered memory systems run more efficiently under high memory pressures. This patch (of 7): The alloc_demote_folio can be used out of vmscan.c so it'd be better to remove static keyword from it. Link: https://lkml.kernel.org/r/20240614030010.751-1-honggyu.kim@sk.com Link: https://lkml.kernel.org/r/20240614030010.751-2-honggyu.kim@sk.com Signed-off-by: Honggyu Kim <honggyu.kim@sk.com> Reviewed-by: SeongJae Park <sj@kernel.org> Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Gregory Price <gregory.price@memverge.com> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Hyeongtak Ji <hyeongtak.ji@sk.com> Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/mm_init.c: simplify logic of deferred_[init|free]_pagesWei Yang
Function deferred_[init|free]_pages are only used in deferred_init_maxorder(), which makes sure the range to init/free is within MAX_ORDER_NR_PAGES size. With this knowledge, we can simplify these two functions. Since * only the first pfn could be IS_MAX_ORDER_ALIGNED() Also since the range passed to deferred_[init|free]_pages is always from memblock.memory for those we have already allocated memmap to cover, pfn_valid() always return true. Then we can remove related check. [richard.weiyang@gmail.com: adjust function declaration indention per David] Link: https://lkml.kernel.org/r/20240613114525.27528-1-richard.weiyang@gmail.com Link: https://lkml.kernel.org/r/20240612020421.31975-1-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/memory-failure: correct comment in me_swapcache_dirtyMiaohe Lin
Dirty swap cache page could live both in page table (not page cache) and swap cache when freshly swapped in. Correct comment. Link: https://lkml.kernel.org/r/20240612071835.157004-14-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: David Hildenbrand <david@redhat.com> Cc: kernel test robot <lkp@intel.com> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/memory-failure: remove obsolete comment in kill_proc()Miaohe Lin
When user sets SIGBUS to SIG_IGN, it won't cause loop now. For action required mce error, SIGBUS cannot be blocked. Also when a hwpoisoned page is re-accessed, kill_accessing_process() will be called to kill the process. Link: https://lkml.kernel.org/r/20240612071835.157004-13-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: David Hildenbrand <david@redhat.com> Cc: kernel test robot <lkp@intel.com> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/memory-failure: fix comment of get_hwpoison_page()Miaohe Lin
When return value is 0, it could also means the page is free hugetlb page or free buddy page. Fix the corresponding comment. Link: https://lkml.kernel.org/r/20240612071835.157004-12-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: David Hildenbrand <david@redhat.com> Cc: kernel test robot <lkp@intel.com> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/memory-failure: move some function declarations into internal.hMiaohe Lin
There are some functions only used inside mm. Move them into internal.h. No functional change intended. Link: https://lkml.kernel.org/r/20240612071835.157004-11-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202405251049.hxjwX7zO-lkp@intel.com/ Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: David Hildenbrand <david@redhat.com> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/memory-failure: remove obsolete comment in unpoison_memory()Miaohe Lin
Since commit 130d4df57390 ("mm/sl[au]b: rearrange struct slab fields to allow larger rcu_head"), folio->_mapcount is not overloaded with SLAB. Update corresponding comment. Link: https://lkml.kernel.org/r/20240612071835.157004-10-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: kernel test robot <lkp@intel.com> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/memory-failure: use helper macro task_pid_nr()Miaohe Lin
Use helper macro task_pid_nr() to get the pid of a task. No functional change intended. Link: https://lkml.kernel.org/r/20240612071835.157004-9-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: David Hildenbrand <david@redhat.com> Cc: kernel test robot <lkp@intel.com> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/memory-failure: don't export hwpoison_filter() when !CONFIG_HWPOISON_INJECTMiaohe Lin
When CONFIG_HWPOISON_INJECT is not enabled, there is no user of the hwpoison_filter() outside memory-failure. So there is no need to export it in that case. Link: https://lkml.kernel.org/r/20240612071835.157004-8-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202406070136.hGQwVbsv-lkp@intel.com/ Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: David Hildenbrand <david@redhat.com> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/memory-failure: remove confusing initialization to countMiaohe Lin
It's meaningless and confusing to init local variable count to 1. Remove it. No functional change intended. Link: https://lkml.kernel.org/r/20240612071835.157004-7-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: David Hildenbrand <david@redhat.com> Cc: kernel test robot <lkp@intel.com> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/memory-failure: remove unneeded empty stringMiaohe Lin
Remove unneeded empty string in definition of macro pr_fmt. No functional change intended. Link: https://lkml.kernel.org/r/20240612071835.157004-6-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: David Hildenbrand <david@redhat.com> Cc: kernel test robot <lkp@intel.com> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/memory-failure: save some page_folio() callsMiaohe Lin
Use local variable folio directly to save a page_folio() call. Also use folio_mapped() to save more page_folio() calls. No functional change intended. Link: https://lkml.kernel.org/r/20240612071835.157004-5-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: kernel test robot <lkp@intel.com> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/memory-failure: add macro GET_PAGE_MAX_RETRY_NUMMiaohe Lin
Add helper macro GET_PAGE_MAX_RETRY_NUM to replace magic number 3. No functional change intended. Link: https://lkml.kernel.org/r/20240612071835.157004-4-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: David Hildenbrand <david@redhat.com> Cc: kernel test robot <lkp@intel.com> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/memory-failure: remove MF_MSG_SLABMiaohe Lin
Since commit 46df8e73a4a3 ("mm: free up PG_slab"), MF_MSG_SLAB becomes unused. Remove it. No functional change intended. Link: https://lkml.kernel.org/r/20240612071835.157004-3-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: David Hildenbrand <david@redhat.com> Cc: kernel test robot <lkp@intel.com> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/memory-failure: simplify put_ref_page()Miaohe Lin
Patch series "Some cleanups for memory-failure", v3. This series contains a few cleanup patches to avoid exporting unused function, add helper macro, fix some obsolete comments and so on. More details can be found in the respective changelogs. This patch (of 13): Remove unneeded page != NULL check. pfn_to_page() won't return NULL. No functional change intended. Link: https://lkml.kernel.org/r/20240612071835.157004-1-linmiaohe@huawei.com Link: https://lkml.kernel.org/r/20240612071835.157004-2-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> Cc: David Hildenbrand <david@redhat.com> Cc: kernel test robot <lkp@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/hugetlb: guard dequeue_hugetlb_folio_nodemask against NUMA_NO_NODE usesOscar Salvador
dequeue_hugetlb_folio_nodemask() expects a preferred node where to get the hugetlb page from. It does not expect, though, users to pass NUMA_NO_NODE, otherwise we will get trash when trying to get the zonelist from that node. All current users are careful enough to not pass NUMA_NO_NODE, but it opens the door for new users to get this wrong since it is not documented [0]. Guard against this by getting the local nid if NUMA_NO_NODE was passed. [0] https://lore.kernel.org/linux-mm/0000000000004f12bb061a9acf07@google.com/ Closes: https://lore.kernel.org/linux-mm/0000000000004f12bb061a9acf07@google.com/ Link: https://lkml.kernel.org/r/20240612082936.10867-1-osalvador@suse.de Signed-off-by: Oscar Salvador <osalvador@suse.de> Reported-by: syzbot+569ed13f4054f271087b@syzkaller.appspotmail.com Tested-by: syzbot+569ed13f4054f271087b@syzkaller.appspotmail.com Reviewed-by: Muchun Song <muchun.song@linux.dev> Acked-by: Vivek Kasireddy <vivek.kasireddy@intel.com> Cc: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/hugetlb_cgroup: switch to the new cftypesXiu Jianfeng
The previous patch has already reconstructed the cftype attributes based on the templates and saved them in dfl_cftypes and legacy_cftypes. then remove the old procedure and switch to the new cftypes. Link: https://lkml.kernel.org/r/20240612092409.2027592-4-xiujianfeng@huawei.com Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/hugetlb_cgroup: prepare cftypes based on templateXiu Jianfeng
Unlike other cgroup subsystems, the hugetlb cgroup does not provide a static array of cftype that explicitly displays the properties, handling functions, etc., of each file. Instead, it dynamically creates the attribute of cftypes based on the hstate during the startup procedure. This reduces the readability of the code. To fix this issue, introduce two templates of cftypes, and rebuild the attributes according to the hstate to make it ready to be added to cgroup framework. Link: https://lkml.kernel.org/r/20240612092409.2027592-3-xiujianfeng@huawei.com Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Oscar Salvador <osalvador@suse.de> Cc: kernel test robot <oliver.sang@intel.com> From: Xiu Jianfeng <xiujianfeng@huawei.com> Subject: mm/hugetlb_cgroup: register lockdep key for cftype Date: Tue, 18 Jun 2024 07:19:22 +0000 When CONFIG_DEBUG_LOCK_ALLOC is enabled, the following commands can trigger a bug, mount -t cgroup2 none /sys/fs/cgroup cd /sys/fs/cgroup echo "+hugetlb" > cgroup.subtree_control The log is as below: BUG: key ffff8880046d88d8 has not been registered! ------------[ cut here ]------------ DEBUG_LOCKS_WARN_ON(1) WARNING: CPU: 3 PID: 226 at kernel/locking/lockdep.c:4945 lockdep_init_map_type+0x185/0x220 Modules linked in: CPU: 3 PID: 226 Comm: bash Not tainted 6.10.0-rc4-next-20240617-g76db4c64526c #544 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:lockdep_init_map_type+0x185/0x220 Code: 00 85 c0 0f 84 6c ff ff ff 8b 3d 6a d1 85 01 85 ff 0f 85 5e ff ff ff 48 c7 c6 21 99 4a 82 48 c7 c7 60 29 49 82 e8 3b 2e f5 RSP: 0018:ffffc9000083fc30 EFLAGS: 00000282 RAX: 0000000000000000 RBX: ffffffff828dd820 RCX: 0000000000000027 RDX: ffff88803cd9cac8 RSI: 0000000000000001 RDI: ffff88803cd9cac0 RBP: ffff88800674fbb0 R08: ffffffff828ce248 R09: 00000000ffffefff R10: ffffffff8285e260 R11: ffffffff828b8eb8 R12: ffff8880046d88d8 R13: 0000000000000000 R14: 0000000000000000 R15: ffff8880067281c0 FS: 00007f68601ea740(0000) GS:ffff88803cd80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005614f3ebc740 CR3: 000000000773a000 CR4: 00000000000006f0 Call Trace: <TASK> ? __warn+0x77/0xd0 ? lockdep_init_map_type+0x185/0x220 ? report_bug+0x189/0x1a0 ? handle_bug+0x3c/0x70 ? exc_invalid_op+0x18/0x70 ? asm_exc_invalid_op+0x1a/0x20 ? lockdep_init_map_type+0x185/0x220 __kernfs_create_file+0x79/0x100 cgroup_addrm_files+0x163/0x380 ? find_held_lock+0x2b/0x80 ? find_held_lock+0x2b/0x80 ? find_held_lock+0x2b/0x80 css_populate_dir+0x73/0x180 cgroup_apply_control_enable+0x12f/0x3a0 cgroup_subtree_control_write+0x30b/0x440 kernfs_fop_write_iter+0x13a/0x1f0 vfs_write+0x341/0x450 ksys_write+0x64/0xe0 do_syscall_64+0x4b/0x110 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f68602d9833 Code: 8b 15 61 26 0e 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 64 8b 04 25 18 00 00 00 85 c0 75 14 b8 01 00 00 00 08 RSP: 002b:00007fff9bbdf8e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 00007f68602d9833 RDX: 0000000000000009 RSI: 00005614f3ebc740 RDI: 0000000000000001 RBP: 00005614f3ebc740 R08: 000000000000000a R09: 0000000000000008 R10: 00005614f3db6ba0 R11: 0000000000000246 R12: 0000000000000009 R13: 00007f68603bd6a0 R14: 0000000000000009 R15: 00007f68603b8880 For lockdep, there is a sanity check in lockdep_init_map_type(), the lock-class key must either have been allocated statically or must have been registered as a dynamic key. However the commit e18df2889ff9 ("mm/hugetlb_cgroup: prepare cftypes based on template") has changed the cftypes from static allocated objects to dynamic allocated objects, so the cft->lockdep_key must be registered proactively. [xiujianfeng@huawei.com: fix BUG()] Link: https://lkml.kernel.org/r/20240619015527.2212698-1-xiujianfeng@huawei.com Link: https://lkml.kernel.org/r/20240618071922.2127289-1-xiujianfeng@huawei.com Link: https://lore.kernel.org/all/602186b3-5ce3-41b3-90a3-134792cc2a48@samsung.com/ Fixes: e18df2889ff9 ("mm/hugetlb_cgroup: prepare cftypes based on template") Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202406181046.8d8b2492-oliver.sang@intel.com Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Tested-by: SeongJae Park <sj@kernel.org> Closes: https://lore.kernel.org/20240618233608.400367-1-sj@kernel.org Cc: Muchun Song <muchun.song@linux.dev> Cc: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/hugetlb_cgroup: identify the legacy using cgroup_subsys_on_dfl()Xiu Jianfeng
Patch series "mm/hugetlb_cgroup: rework on cftypes", v3. This patchset provides an intuitive view of the control files through static templates of cftypes. This improves the readability of the code. This patch (of 3): Currently the numa_stat file encodes 1 into .private using the micro MEMFILE_PRIVATE() to identify the legacy. Actually, we can use cgroup_subsys_on_dfl() instead. This is helpful to handle .private in the static templates in the next patch. Link: https://lkml.kernel.org/r/20240612092409.2027592-1-xiujianfeng@huawei.com Link: https://lkml.kernel.org/r/20240612092409.2027592-2-xiujianfeng@huawei.com Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>