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2025-11-16mm/page_owner: simplify zone iteration logic in init_early_allocated_pages()Song Hu
The current implementation uses nested loops: first iterating over all online nodes, then over zones within each node. This can be simplified by using the for_each_populated_zone() macro which directly iterates through all populated zones. This change: 1. Removes the intermediate init_zones_in_node() function 2. Simplifies init_early_allocated_pages() to use direct zone iteration 3. Updates init_pages_in_zone() to take only zone parameter and access node_id via zone->zone_pgdat The functionality remains identical, but the code is cleaner and more maintainable. Link: https://lkml.kernel.org/r/20250930092153.843109-2-husong@kylinos.cn Signed-off-by: Song Hu <husong@kylinos.cn> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Ye Liu <liuye@kylinos.cn> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Brendan Jackman <jackmanb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/page_owner: rename proc-prefixed variables for claritySong Hu
`proc_page_owner_operations` and related variables were renamed to `page_owner_fops` to better reflect their association with `debugfs` rather than `/proc`. This improves code clarity and aligns with kernel naming conventions. Link: https://lkml.kernel.org/r/20250930092153.843109-1-husong@kylinos.cn Signed-off-by: Song Hu <husong@kylinos.cn> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Ye Liu <liuye@kylinos.cn> Cc: Brendan Jackman <jackmanb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/page_owner: add debugfs file 'show_stacks_handles'Mauricio Faria de Oliveira
Add the file 'show_stacks_handles' to show just stack traces and their handles, in order to resolve stack traces and handles (i.e., to identify the stack traces for handles in previous reads from 'show_handles'). All stacks/handles must show up, regardless of their number of pages, that might have become zero or no longer make 'count_threshold', but made it in previous reads from 'show_handles' -- and need to be resolved later. P.S.: now, print the extra newline independently of the number of pages. Link: https://lkml.kernel.org/r/20251001175611.575861-5-mfo@igalia.com Signed-off-by: Mauricio Faria de Oliveira <mfo@igalia.com> Cc: Brendan Jackman <jackmanb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/page_owner: add debugfs file 'show_handles'Mauricio Faria de Oliveira
Add the flag STACK_PRINT_FLAG_HANDLE to print a stack's handle number from stackdepot, and add the file 'show_handles' to show just handles and their number of pages. This is similar to 'show_stacks', with handles instead of stack traces. Link: https://lkml.kernel.org/r/20251001175611.575861-4-mfo@igalia.com Signed-off-by: Mauricio Faria de Oliveira <mfo@igalia.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Brendan Jackman <jackmanb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/page_owner: add struct stack_print_ctx.flagsMauricio Faria de Oliveira
Add the flags field to stack_print_ctx, and define two flags for current behavior (printing stack traces and their number of base pages). The plumbing of flags is debugfs_create_file(data) -> inode.i_private -> page_owner_stack_open() -> stack_print_ctx.flags -> stack_print(). No behavior change intended. Link: https://lkml.kernel.org/r/20251001175611.575861-3-mfo@igalia.com Signed-off-by: Mauricio Faria de Oliveira <mfo@igalia.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Brendan Jackman <jackmanb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/page_owner: introduce struct stack_print_ctxMauricio Faria de Oliveira
Patch series "mm/page_owner: add debugfs files 'show_handles' and 'show_stacks_handles'", v2. Context: The page_owner debug feature can help understand a particular situation in in a point in time (e.g., identify biggest memory consumers; verify memory counters that do not add up). Another useful usecase is to collect data repeatedly over time, and use it for profiling, monitoring, and even comparing different kernel versions, at the stack trace level (e.g., watch for trends, leaks, correlations, and regressions). For this usecase, userspace periorically collects the data from page_owner and organizes it in data structures appropriate for access per-stack trace. Problem: The usecase of tracking memory usage per stack trace (or tracking it for a particular stack trace) requires uniquely identifying each stack trace (i.e., keys to store their memory usage over periodic data collections). This has to be done for every stack trace in every sample/data collection, even if tracking only one stack trace (to identify it among all others). Therefore, an approach like hashing the stack traces in userspace to create unique keys/identifiers for them during post-processing can quickly become expensive, considering the repetition and a growing number of stack traces. Solution: Fortunately, the kernel can provide a unique identifier for stack traces in page_owner, which is the handle number in stackdepot. This eliminates the need for creating keys (hashing) in userspace during post-processing. Additionally, with that information, the stack traces themselves are not needed until the memory usage should be resolved from a handle to a stack trace (say, to look at the stack traces of a few top consumers). This can reduce the amount of text emitted/copied by the kernel to userspace, and save userspace from matching and discarding stack traces when not needed. Changes: This patchset adds 2 files to provide information, like 'show_stacks': - show_handles: print handle number and number of pages (no stack traces) - show_stacks_handles: print handle numbers and stack traces (no pages) Now, it's possible to periodically collect data with handle numbers (keys) and without stack traces (lower overhead) from 'show_handles', and later do a final collection with handles and stack traces from 'show_stacks_handles' to resolve the handles to their stack traces. The output format follows the existing 'show_stacks' file, for simplicity, but it can certainly be changed if a different format is more convenient. Example: The number of base pages collected can be stored per-handle number over the periodic data collections, and finally resolved to stack traces per-handle number as well with a final collection. Later, one can, for example, identify the biggest consumers and watch their trends or correlate increases/decreases with other events in the system, or watch a particular stack trace(s) of interest during development. Testing: Tested on next-20250929. - show_stacks: register_dummy_stack+0x32/0x70 init_page_owner+0x29/0x2f0 page_ext_init+0x27c/0x2b0 mm_core_init+0xdc/0x110 nr_base_pages: 47 - show_handles: handle: 1 nr_base_pages: 47 - show_stacks_handles: register_dummy_stack+0x32/0x70 init_page_owner+0x29/0x2f0 page_ext_init+0x27c/0x2b0 mm_core_init+0xdc/0x110 handle: 1 - count_threshold: # echo 100 >/sys/kernel/debug/page_owner_stacks/count_threshold # grep register_dummy_stack show_stacks # not present # grep -B4 '^handle: 1$' show_handles # not present # grep -B4 '^handle: 1$' show_stacks_handles # present register_dummy_stack+0x32/0x70 init_page_owner+0x29/0x2f0 page_ext_init+0x27c/0x2b0 mm_core_init+0xdc/0x110 handle: 1 This patch (of 5): Currently, struct seq_file.private is used as an iterator in stack_list by stack_start|next(), for stack_print(). Create a context struct for this, in order to add another field next. No behavior change intended. P.S.: page_owner_stack_open() is expanded with separate statements for variable definition and return just in preparation for the next patch. Link: https://lkml.kernel.org/r/20251001175611.575861-1-mfo@igalia.com Link: https://lkml.kernel.org/r/20251001175611.575861-2-mfo@igalia.com Signed-off-by: Mauricio Faria de Oliveira <mfo@igalia.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Brendan Jackman <jackmanb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-10-15mm: don't spin in add_stack_record when gfp flags don't allowAlexei Starovoitov
syzbot was able to find the following path: add_stack_record_to_list mm/page_owner.c:182 [inline] inc_stack_record_count mm/page_owner.c:214 [inline] __set_page_owner+0x2c3/0x4a0 mm/page_owner.c:333 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3858 alloc_pages_nolock_noprof+0x94/0x120 mm/page_alloc.c:7554 Don't spin in add_stack_record_to_list() when it is called from *_nolock() context. Link: https://lkml.kernel.org/r/CAADnVQK_8bNYEA7TJYgwTYR57=TTFagsvRxp62pFzS_z129eTg@mail.gmail.com Fixes: 97769a53f117 ("mm, bpf: Introduce try_alloc_pages() for opportunistic page allocation") Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reported-by: syzbot+8259e1d0e3ae8ed0c490@syzkaller.appspotmail.com Reported-by: syzbot+665739f456b28f32b23d@syzkaller.appspotmail.com Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Brendan Jackman <jackmanb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Zi Yan <ziy@nvidia.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-19mm/page_owner: convert set_page_owner_migrate_reason() to foliosSidhartha Kumar
Both callers of set_page_owner_migrate_reason() use folios. Convert the function to take a folio directly and move the &folio->page conversion inside __set_page_owner_migrate_reason(). Link: https://lkml.kernel.org/r/20250711145910.90135-1-sidhartha.kumar@oracle.com Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Muchun Song <muchun.song@linux.dev> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-22mm: rename try_alloc_pages() to alloc_pages_nolock()Alexei Starovoitov
The "try_" prefix is confusing, since it made people believe that try_alloc_pages() is analogous to spin_trylock() and NULL return means EAGAIN. This is not the case. If it returns NULL there is no reason to call it again. It will most likely return NULL again. Hence rename it to alloc_pages_nolock() to make it symmetrical to free_pages_nolock() and document that NULL means ENOMEM. Link: https://lkml.kernel.org/r/20250517003446.60260-1-alexei.starovoitov@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: Harry Yoo <harry.yoo@oracle.com> Cc: Andrii Nakryiko <andrii@kernel.org> Cc: Kumar Kartikeya Dwivedi <memxor@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-01Merge tag 'mm-stable-2025-03-30-16-52' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - The series "Enable strict percpu address space checks" from Uros Bizjak uses x86 named address space qualifiers to provide compile-time checking of percpu area accesses. This has caused a small amount of fallout - two or three issues were reported. In all cases the calling code was found to be incorrect. - The series "Some cleanup for memcg" from Chen Ridong implements some relatively monir cleanups for the memcontrol code. - The series "mm: fixes for device-exclusive entries (hmm)" from David Hildenbrand fixes a boatload of issues which David found then using device-exclusive PTE entries when THP is enabled. More work is needed, but this makes thins better - our own HMM selftests now succeed. - The series "mm: zswap: remove z3fold and zbud" from Yosry Ahmed remove the z3fold and zbud implementations. They have been deprecated for half a year and nobody has complained. - The series "mm: further simplify VMA merge operation" from Lorenzo Stoakes implements numerous simplifications in this area. No runtime effects are anticipated. - The series "mm/madvise: remove redundant mmap_lock operations from process_madvise()" from SeongJae Park rationalizes the locking in the madvise() implementation. Performance gains of 20-25% were observed in one MADV_DONTNEED microbenchmark. - The series "Tiny cleanup and improvements about SWAP code" from Baoquan He contains a number of touchups to issues which Baoquan noticed when working on the swap code. - The series "mm: kmemleak: Usability improvements" from Catalin Marinas implements a couple of improvements to the kmemleak user-visible output. - The series "mm/damon/paddr: fix large folios access and schemes handling" from Usama Arif provides a couple of fixes for DAMON's handling of large folios. - The series "mm/damon/core: fix wrong and/or useless damos_walk() behaviors" from SeongJae Park fixes a few issues with the accuracy of kdamond's walking of DAMON regions. - The series "expose mapping wrprotect, fix fb_defio use" from Lorenzo Stoakes changes the interaction between framebuffer deferred-io and core MM. No functional changes are anticipated - this is preparatory work for the future removal of page structure fields. - The series "mm/damon: add support for hugepage_size DAMOS filter" from Usama Arif adds a DAMOS filter which permits the filtering by huge page sizes. - The series "mm: permit guard regions for file-backed/shmem mappings" from Lorenzo Stoakes extends the guard region feature from its present "anon mappings only" state. The feature now covers shmem and file-backed mappings. - The series "mm: batched unmap lazyfree large folios during reclamation" from Barry Song cleans up and speeds up the unmapping for pte-mapped large folios. - The series "reimplement per-vma lock as a refcount" from Suren Baghdasaryan puts the vm_lock back into the vma. Our reasons for pulling it out were largely bogus and that change made the code more messy. This patchset provides small (0-10%) improvements on one microbenchmark. - The series "Docs/mm/damon: misc DAMOS filters documentation fixes and improves" from SeongJae Park does some maintenance work on the DAMON docs. - The series "hugetlb/CMA improvements for large systems" from Frank van der Linden addresses a pile of issues which have been observed when using CMA on large machines. - The series "mm/damon: introduce DAMOS filter type for unmapped pages" from SeongJae Park enables users of DMAON/DAMOS to filter my the page's mapped/unmapped status. - The series "zsmalloc/zram: there be preemption" from Sergey Senozhatsky teaches zram to run its compression and decompression operations preemptibly. - The series "selftests/mm: Some cleanups from trying to run them" from Brendan Jackman fixes a pile of unrelated issues which Brendan encountered while runnimg our selftests. - The series "fs/proc/task_mmu: add guard region bit to pagemap" from Lorenzo Stoakes permits userspace to use /proc/pid/pagemap to determine whether a particular page is a guard page. - The series "mm, swap: remove swap slot cache" from Kairui Song removes the swap slot cache from the allocation path - it simply wasn't being effective. - The series "mm: cleanups for device-exclusive entries (hmm)" from David Hildenbrand implements a number of unrelated cleanups in this code. - The series "mm: Rework generic PTDUMP configs" from Anshuman Khandual implements a number of preparatoty cleanups to the GENERIC_PTDUMP Kconfig logic. - The series "mm/damon: auto-tune aggregation interval" from SeongJae Park implements a feedback-driven automatic tuning feature for DAMON's aggregation interval tuning. - The series "Fix lazy mmu mode" from Ryan Roberts fixes some issues in powerpc, sparc and x86 lazy MMU implementations. Ryan did this in preparation for implementing lazy mmu mode for arm64 to optimize vmalloc. - The series "mm/page_alloc: Some clarifications for migratetype fallback" from Brendan Jackman reworks some commentary to make the code easier to follow. - The series "page_counter cleanup and size reduction" from Shakeel Butt cleans up the page_counter code and fixes a size increase which we accidentally added late last year. - The series "Add a command line option that enables control of how many threads should be used to allocate huge pages" from Thomas Prescher does that. It allows the careful operator to significantly reduce boot time by tuning the parallalization of huge page initialization. - The series "Fix calculations in trace_balance_dirty_pages() for cgwb" from Tang Yizhou fixes the tracing output from the dirty page balancing code. - The series "mm/damon: make allow filters after reject filters useful and intuitive" from SeongJae Park improves the handling of allow and reject filters. Behaviour is made more consistent and the documention is updated accordingly. - The series "Switch zswap to object read/write APIs" from Yosry Ahmed updates zswap to the new object read/write APIs and thus permits the removal of some legacy code from zpool and zsmalloc. - The series "Some trivial cleanups for shmem" from Baolin Wang does as it claims. - The series "fs/dax: Fix ZONE_DEVICE page reference counts" from Alistair Popple regularizes the weird ZONE_DEVICE page refcount handling in DAX, permittig the removal of a number of special-case checks. - The series "refactor mremap and fix bug" from Lorenzo Stoakes is a preparatoty refactoring and cleanup of the mremap() code. - The series "mm: MM owner tracking for large folios (!hugetlb) + CONFIG_NO_PAGE_MAPCOUNT" from David Hildenbrand reworks the manner in which we determine whether a large folio is known to be mapped exclusively into a single MM. - The series "mm/damon: add sysfs dirs for managing DAMOS filters based on handling layers" from SeongJae Park adds a couple of new sysfs directories to ease the management of DAMON/DAMOS filters. - The series "arch, mm: reduce code duplication in mem_init()" from Mike Rapoport consolidates many per-arch implementations of mem_init() into code generic code, where that is practical. - The series "mm/damon/sysfs: commit parameters online via damon_call()" from SeongJae Park continues the cleaning up of sysfs access to DAMON internal data. - The series "mm: page_ext: Introduce new iteration API" from Luiz Capitulino reworks the page_ext initialization to fix a boot-time crash which was observed with an unusual combination of compile and cmdline options. - The series "Buddy allocator like (or non-uniform) folio split" from Zi Yan reworks the code to split a folio into smaller folios. The main benefit is lessened memory consumption: fewer post-split folios are generated. - The series "Minimize xa_node allocation during xarry split" from Zi Yan reduces the number of xarray xa_nodes which are generated during an xarray split. - The series "drivers/base/memory: Two cleanups" from Gavin Shan performs some maintenance work on the drivers/base/memory code. - The series "Add tracepoints for lowmem reserves, watermarks and totalreserve_pages" from Martin Liu adds some more tracepoints to the page allocator code. - The series "mm/madvise: cleanup requests validations and classifications" from SeongJae Park cleans up some warts which SeongJae observed during his earlier madvise work. - The series "mm/hwpoison: Fix regressions in memory failure handling" from Shuai Xue addresses two quite serious regressions which Shuai has observed in the memory-failure implementation. - The series "mm: reliable huge page allocator" from Johannes Weiner makes huge page allocations cheaper and more reliable by reducing fragmentation. - The series "Minor memcg cleanups & prep for memdescs" from Matthew Wilcox is preparatory work for the future implementation of memdescs. - The series "track memory used by balloon drivers" from Nico Pache introduces a way to track memory used by our various balloon drivers. - The series "mm/damon: introduce DAMOS filter type for active pages" from Nhat Pham permits users to filter for active/inactive pages, separately for file and anon pages. - The series "Adding Proactive Memory Reclaim Statistics" from Hao Jia separates the proactive reclaim statistics from the direct reclaim statistics. - The series "mm/vmscan: don't try to reclaim hwpoison folio" from Jinjiang Tu fixes our handling of hwpoisoned pages within the reclaim code. * tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (431 commits) mm/page_alloc: remove unnecessary __maybe_unused in order_to_pindex() x86/mm: restore early initialization of high_memory for 32-bits mm/vmscan: don't try to reclaim hwpoison folio mm/hwpoison: introduce folio_contain_hwpoisoned_page() helper cgroup: docs: add pswpin and pswpout items in cgroup v2 doc mm: vmscan: split proactive reclaim statistics from direct reclaim statistics selftests/mm: speed up split_huge_page_test selftests/mm: uffd-unit-tests support for hugepages > 2M docs/mm/damon/design: document active DAMOS filter type mm/damon: implement a new DAMOS filter type for active pages fs/dax: don't disassociate zero page entries MM documentation: add "Unaccepted" meminfo entry selftests/mm: add commentary about 9pfs bugs fork: use __vmalloc_node() for stack allocation docs/mm: Physical Memory: Populate the "Zones" section xen: balloon: update the NR_BALLOON_PAGES state hv_balloon: update the NR_BALLOON_PAGES state balloon_compaction: update the NR_BALLOON_PAGES state meminfo: add a per node counter for balloon drivers mm: remove references to folio in __memcg_kmem_uncharge_page() ...
2025-03-17mm: page_owner: use new iteration APILuiz Capitulino
The page_ext_next() function assumes that page extension objects for a page order allocation always reside in the same memory section, which may not be true and could lead to crashes. Use the new page_ext iteration API instead. Link: https://lkml.kernel.org/r/93c80b040960fa2ebab4a9729073f77a30649862.1741301089.git.luizcap@redhat.com Fixes: cf54f310d0d3 ("mm/hugetlb: use __GFP_COMP for gigantic folios") Signed-off-by: Luiz Capitulino <luizcap@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-17mm: let _folio_nr_pages overlay memcg_data in first tail pageDavid Hildenbrand
Let's free up some more of the "unconditionally available on 64BIT" space in order-1 folios by letting _folio_nr_pages overlay memcg_data in the first tail page (second folio page). Consequently, we have the optimization now whenever we have CONFIG_MEMCG, independent of 64BIT. We have to make sure that page->memcg on tail pages does not return "surprises". page_memcg_check() already properly refuses PageTail(). Let's do that earlier in print_page_owner_memcg() to avoid printing wrong "Slab cache page" information. No other code should touch that field on tail pages of compound pages. Reset the "_nr_pages" to 0 when splitting folios, or when freeing them back to the buddy (to avoid false page->memcg_data "bad page" reports). Note that in __split_huge_page(), folio_nr_pages() would stop working already as soon as we start messing with the subpages. Most kernel configs should have at least CONFIG_MEMCG enabled, even if disabled at runtime. 64byte "struct memmap" is what we usually have on 64BIT. While at it, rename "_folio_nr_pages" to "_nr_pages". Hopefully memdescs / dynamically allocating "strut folio" in the future will further clean this up, e.g., making _nr_pages available in all configs and maybe even in small folios. Doing that should be fairly easy on top of this change. [david@redhat.com: make "make htmldoc" happy] Link: https://lkml.kernel.org/r/a97f8a91-ec41-4796-81e3-7c9e0e491ba4@redhat.com Link: https://lkml.kernel.org/r/20250303163014.1128035-4-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andy Lutomirks^H^Hski <luto@kernel.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Lance Yang <ioworker0@gmail.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcow (Oracle) <willy@infradead.org> Cc: Michal Koutn <mkoutny@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: tejun heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zefan Li <lizefan.x@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-02-27mm, bpf: Introduce free_pages_nolock()Alexei Starovoitov
Introduce free_pages_nolock() that can free pages without taking locks. It relies on trylock and can be called from any context. Since spin_trylock() cannot be used in PREEMPT_RT from hard IRQ or NMI it uses lockless link list to stash the pages which will be freed by subsequent free_pages() from good context. Do not use llist unconditionally. BPF maps continuously allocate/free, so we cannot unconditionally delay the freeing to llist. When the memory becomes free make it available to the kernel and BPF users right away if possible, and fallback to llist as the last resort. Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/r/20250222024427.30294-4-alexei.starovoitov@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-05-19mm/page-owner: use gfp_nested_mask() instead of open coded maskingDave Chinner
The page-owner tracking code records stack traces during page allocation. To do this, it must do a memory allocation for the stack information from inside an existing memory allocation context. This internal allocation must obey the high level caller allocation constraints to avoid generating false positive warnings that have nothing to do with the code they are instrumenting/tracking (e.g. through lockdep reclaim state tracking) We also don't want recording stack traces to deplete emergency memory reserves - debug code is useless if it creates new issues that can't be replicated when the debug code is disabled. Switch the stack tracking allocation masking to use gfp_nested_mask() to address these issues. gfp_nested_mask() naturally strips GFP_ZONEMASK, too, which greatly simplifies this code. Link: https://lkml.kernel.org/r/20240430054604.4169568-4-david@fromorbit.com Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Marco Elver <elver@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-19Merge tag 'mm-stable-2024-05-17-19-19' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull mm updates from Andrew Morton: "The usual shower of singleton fixes and minor series all over MM, documented (hopefully adequately) in the respective changelogs. Notable series include: - Lucas Stach has provided some page-mapping cleanup/consolidation/ maintainability work in the series "mm/treewide: Remove pXd_huge() API". - In the series "Allow migrate on protnone reference with MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's MPOL_PREFERRED_MANY mode, yielding almost doubled performance in one test. - In their series "Memory allocation profiling" Kent Overstreet and Suren Baghdasaryan have contributed a means of determining (via /proc/allocinfo) whereabouts in the kernel memory is being allocated: number of calls and amount of memory. - Matthew Wilcox has provided the series "Various significant MM patches" which does a number of rather unrelated things, but in largely similar code sites. - In his series "mm: page_alloc: freelist migratetype hygiene" Johannes Weiner has fixed the page allocator's handling of migratetype requests, with resulting improvements in compaction efficiency. - In the series "make the hugetlb migration strategy consistent" Baolin Wang has fixed a hugetlb migration issue, which should improve hugetlb allocation reliability. - Liu Shixin has hit an I/O meltdown caused by readahead in a memory-tight memcg. Addressed in the series "Fix I/O high when memory almost met memcg limit". - In the series "mm/filemap: optimize folio adding and splitting" Kairui Song has optimized pagecache insertion, yielding ~10% performance improvement in one test. - Baoquan He has cleaned up and consolidated the early zone initialization code in the series "mm/mm_init.c: refactor free_area_init_core()". - Baoquan has also redone some MM initializatio code in the series "mm/init: minor clean up and improvement". - MM helper cleanups from Christoph Hellwig in his series "remove follow_pfn". - More cleanups from Matthew Wilcox in the series "Various page->flags cleanups". - Vlastimil Babka has contributed maintainability improvements in the series "memcg_kmem hooks refactoring". - More folio conversions and cleanups in Matthew Wilcox's series: "Convert huge_zero_page to huge_zero_folio" "khugepaged folio conversions" "Remove page_idle and page_young wrappers" "Use folio APIs in procfs" "Clean up __folio_put()" "Some cleanups for memory-failure" "Remove page_mapping()" "More folio compat code removal" - David Hildenbrand chipped in with "fs/proc/task_mmu: convert hugetlb functions to work on folis". - Code consolidation and cleanup work related to GUP's handling of hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2". - Rick Edgecombe has developed some fixes to stack guard gaps in the series "Cover a guard gap corner case". - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the series "mm/ksm: fix ksm exec support for prctl". - Baolin Wang has implemented NUMA balancing for multi-size THPs. This is a simple first-cut implementation for now. The series is "support multi-size THP numa balancing". - Cleanups to vma handling helper functions from Matthew Wilcox in the series "Unify vma_address and vma_pgoff_address". - Some selftests maintenance work from Dev Jain in the series "selftests/mm: mremap_test: Optimizations and style fixes". - Improvements to the swapping of multi-size THPs from Ryan Roberts in the series "Swap-out mTHP without splitting". - Kefeng Wang has significantly optimized the handling of arm64's permission page faults in the series "arch/mm/fault: accelerate pagefault when badaccess" "mm: remove arch's private VM_FAULT_BADMAP/BADACCESS" - GUP cleanups from David Hildenbrand in "mm/gup: consistently call it GUP-fast". - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault path to use struct vm_fault". - selftests build fixes from John Hubbard in the series "Fix selftests/mm build without requiring "make headers"". - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the series "Improved Memory Tier Creation for CPUless NUMA Nodes". Fixes the initialization code so that migration between different memory types works as intended. - David Hildenbrand has improved follow_pte() and fixed an errant driver in the series "mm: follow_pte() improvements and acrn follow_pte() fixes". - David also did some cleanup work on large folio mapcounts in his series "mm: mapcount for large folios + page_mapcount() cleanups". - Folio conversions in KSM in Alex Shi's series "transfer page to folio in KSM". - Barry Song has added some sysfs stats for monitoring multi-size THP's in the series "mm: add per-order mTHP alloc and swpout counters". - Some zswap cleanups from Yosry Ahmed in the series "zswap same-filled and limit checking cleanups". - Matthew Wilcox has been looking at buffer_head code and found the documentation to be lacking. The series is "Improve buffer head documentation". - Multi-size THPs get more work, this time from Lance Yang. His series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free" optimizes the freeing of these things. - Kemeng Shi has added more userspace-visible writeback instrumentation in the series "Improve visibility of writeback". - Kemeng Shi then sent some maintenance work on top in the series "Fix and cleanups to page-writeback". - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in the series "Improve anon_vma scalability for anon VMAs". Intel's test bot reported an improbable 3x improvement in one test. - SeongJae Park adds some DAMON feature work in the series "mm/damon: add a DAMOS filter type for page granularity access recheck" "selftests/damon: add DAMOS quota goal test" - Also some maintenance work in the series "mm/damon/paddr: simplify page level access re-check for pageout" "mm/damon: misc fixes and improvements" - David Hildenbrand has disabled some known-to-fail selftests ni the series "selftests: mm: cow: flag vmsplice() hugetlb tests as XFAIL". - memcg metadata storage optimizations from Shakeel Butt in "memcg: reduce memory consumption by memcg stats". - DAX fixes and maintenance work from Vishal Verma in the series "dax/bus.c: Fixups for dax-bus locking"" * tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (426 commits) memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_order selftests/mm: hugetlb_madv_vs_map: avoid test skipping by querying hugepage size at runtime mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_wp mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_fault selftests: cgroup: add tests to verify the zswap writeback path mm: memcg: make alloc_mem_cgroup_per_node_info() return bool mm/damon/core: fix return value from damos_wmark_metric_value mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED selftests: cgroup: remove redundant enabling of memory controller Docs/mm/damon/maintainer-profile: allow posting patches based on damon/next tree Docs/mm/damon/maintainer-profile: change the maintainer's timezone from PST to PT Docs/mm/damon/design: use a list for supported filters Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file selftests/damon: classify tests for functionalities and regressions selftests/damon/_damon_sysfs: use 'is' instead of '==' for 'None' selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts selftests/damon/_damon_sysfs: check errors from nr_schemes file reads mm/damon/core: initialize ->esz_bp from damos_quota_init_priv() selftests/damon: add a test for DAMOS quota goal ...
2024-05-05mm,page_owner: don't remove __GFP_NOLOCKDEP in add_stack_record_to_listChristoph Hellwig
Otherwise we'll generate false lockdep positives. Link: https://lkml.kernel.org/r/20240429082828.1615986-1-hch@lst.de Fixes: 217b2119b9e2 ("mm,page_owner: implement the tracking of the stacks count") Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Oscar Salvador <osalvador@suse.de> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Darrick J. Wong <djwong@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Marco Elver <elver@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05mm: page_owner: fix wrong information in dump_page_ownerManinder Singh
With commit ea4b5b33bf8a ("mm,page_owner: update metadata for tail pages"), new API __update_page_owner_handle was introduced and arguemnt was passed in wrong order from __set_page_owner and thus page_owner is giving wrong data. [ 15.982420] page last allocated via order 0, migratetype Unmovable, gfp_mask 0xcc0(GFP_KERNEL), pid 80, tgid -1210279584 (insmod), ts 80, free_ts 0 Fixing the same. Correct output: [ 14.556482] page last allocated via order 0, migratetype Unmovable, gfp_mask 0xcc0(GFP_KERNEL), pid 80, tgid 80 (insmod), ts 14552004992, free_ts 0 Link: https://lkml.kernel.org/r/20240424111838.3782931-1-hariom1.p@samsung.com Fixes: ea4b5b33bf8a ("mm,page_owner: update metadata for tail pages") Signed-off-by: Maninder Singh <maninder1.s@samsung.com> Signed-off-by: Hariom Panthi <hariom1.p@samsung.com> Acked-by: Oscar Salvador <osalvador@suse.de> Cc: Christoph Hellwig <hch@infradead.org> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Rohit Thapliyal <r.thapliyal@samsung.com> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25mm: introduce slabobj_ext to support slab object extensionsSuren Baghdasaryan
Currently slab pages can store only vectors of obj_cgroup pointers in page->memcg_data. Introduce slabobj_ext structure to allow more data to be stored for each slab object. Wrap obj_cgroup into slabobj_ext to support current functionality while allowing to extend slabobj_ext in the future. Link: https://lkml.kernel.org/r/20240321163705.3067592-7-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Kees Cook <keescook@chromium.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alex Gaynor <alex.gaynor@gmail.com> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Andreas Hindborg <a.hindborg@samsung.com> Cc: Benno Lossin <benno.lossin@proton.me> Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Gary Guo <gary@garyguo.net> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Wedson Almeida Filho <wedsonaf@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-16mm,page_owner: defer enablement of static branchOscar Salvador
Kefeng Wang reported that he was seeing some memory leaks with kmemleak with page_owner enabled. The reason is that we enable the page_owner_inited static branch and then proceed with the linking of stack_list struct to dummy_stack, which means that exists a race window between these two steps where we can have pages already being allocated calling add_stack_record_to_list(), allocating objects and linking them to stack_list, but then we set stack_list pointing to dummy_stack in init_page_owner. Which means that the objects that have been allocated during that time window are unreferenced and lost. Fix this by deferring the enablement of the branch until we have properly set up the list. Link: https://lkml.kernel.org/r/20240409131715.13632-1-osalvador@suse.de Fixes: 4bedfb314bdd ("mm,page_owner: maintain own list of stack_records structs") Signed-off-by: Oscar Salvador <osalvador@suse.de> Reported-by: Kefeng Wang <wangkefeng.wang@huawei.com> Closes: https://lore.kernel.org/linux-mm/74b147b0-718d-4d50-be75-d6afc801cd24@huawei.com/ Tested-by: Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-16mm,page_owner: fix printing of stack recordsOscar Salvador
When seq_* code sees that its buffer overflowed, it re-allocates a bigger onecand calls seq_operations->start() callback again. stack_start() naively though that if it got called again, it meant that the old record got already printed so it returned the next object, but that is not true. The consequence of that is that every time stack_stop() -> stack_start() get called because we needed a bigger buffer, stack_start() will skip entries, and those will not be printed. Fix it by not advancing to the next object in stack_start(). Link: https://lkml.kernel.org/r/20240404070702.2744-5-osalvador@suse.de Fixes: 765973a09803 ("mm,page_owner: display all stacks and their count") Signed-off-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Alexander Potapenko <glider@google.com> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Marco Elver <elver@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-16mm,page_owner: fix accounting of pages when migratingOscar Salvador
Upon migration, new allocated pages are being given the handle of the old pages. This is problematic because it means that for the stack which allocated the old page, we will be substracting the old page + the new one when that page is freed, creating an accounting imbalance. There is an interest in keeping it that way, as otherwise the output will biased towards migration stacks should those operations occur often, but that is not really helpful. The link from the new page to the old stack is being performed by calling __update_page_owner_handle() in __folio_copy_owner(). The only thing that is left is to link the migrate stack to the old page, so the old page will be subtracted from the migrate stack, avoiding by doing so any possible imbalance. Link: https://lkml.kernel.org/r/20240404070702.2744-4-osalvador@suse.de Fixes: 217b2119b9e2 ("mm,page_owner: implement the tracking of the stacks count") Signed-off-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Alexander Potapenko <glider@google.com> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Marco Elver <elver@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-16mm,page_owner: fix refcount imbalanceOscar Salvador
Current code does not contemplate scenarios were an allocation and free operation on the same pages do not handle it in the same amount at once. To give an example, page_alloc_exact(), where we will allocate a page of enough order to stafisfy the size request, but we will free the remainings right away. In the above example, we will increment the stack_record refcount only once, but we will decrease it the same number of times as number of unused pages we have to free. This will lead to a warning because of refcount imbalance. Fix this by recording the number of base pages in the refcount field. Link: https://lkml.kernel.org/r/20240404070702.2744-3-osalvador@suse.de Reported-by: syzbot+41bbfdb8d41003d12c0f@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-mm/00000000000090e8ff0613eda0e5@google.com Fixes: 217b2119b9e2 ("mm,page_owner: implement the tracking of the stacks count") Signed-off-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Marco Elver <elver@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-16mm,page_owner: update metadata for tail pagesOscar Salvador
Patch series "page_owner: Fix refcount imbalance and print fixup", v4. This series consists of a refactoring/correctness of updating the metadata of tail pages, a couple of fixups for the refcounting part and a fixup for the stack_start() function. From this series on, instead of counting the stacks, we count the outstanding nr_base_pages each stack has, which gives us a much better memory overview. The other fixup is for the migration part. A more detailed explanation can be found in the changelog of the respective patches. This patch (of 4): __set_page_owner_handle() and __reset_page_owner() update the metadata of all pages when the page is of a higher-order, but we miss to do the same when the pages are migrated. __folio_copy_owner() only updates the metadata of the head page, meaning that the information stored in the first page and the tail pages will not match. Strictly speaking that is not a big problem because 1) we do not print tail pages and 2) upon splitting all tail pages will inherit the metadata of the head page, but it is better to have all metadata in check should there be any problem, so it can ease debugging. For that purpose, a couple of helpers are created __update_page_owner_handle() which updates the metadata on allocation, and __update_page_owner_free_handle() which does the same when the page is freed. __folio_copy_owner() will make use of both as it needs to entirely replace the page_owner metadata for the new page. Link: https://lkml.kernel.org/r/20240404070702.2744-1-osalvador@suse.de Link: https://lkml.kernel.org/r/20240404070702.2744-2-osalvador@suse.de Signed-off-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Alexander Potapenko <glider@google.com> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Marco Elver <elver@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-26mm,page_owner: fix recursionOscar Salvador
Prior to 217b2119b9e2 ("mm,page_owner: implement the tracking of the stacks count") the only place where page_owner could potentially go into recursion due to its need of allocating more memory was in save_stack(), which ends up calling into stackdepot code with the possibility of allocating memory. We made sure to guard against that by signaling that the current task was already in page_owner code, so in case a recursion attempt was made, we could catch that and return dummy_handle. After above commit, a new place in page_owner code was introduced where we could allocate memory, meaning we could go into recursion would we take that path. Make sure to signal that we are in page_owner in that codepath as well. Move the guard code into two helpers {un}set_current_in_page_owner() and use them prior to calling in the two functions that might allocate memory. Link: https://lkml.kernel.org/r/20240315222610.6870-1-osalvador@suse.de Signed-off-by: Oscar Salvador <osalvador@suse.de> Fixes: 217b2119b9e2 ("mm,page_owner: implement the tracking of the stacks count") Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Marco Elver <elver@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-06mm,page_owner: drop unnecessary checkOscar Salvador
stackdepot only saves stack_records which size is greather than 0, so we cannot possibly have empty stack_records. Drop the check. Link: https://lkml.kernel.org/r/20240306123217.29774-3-osalvador@suse.de Signed-off-by: Oscar Salvador <osalvador@suse.de> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: kernel test robot <oliver.sang@intel.com> Cc: Marco Elver <elver@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-06mm,page_owner: check for null stack_record before bumping its refcountOscar Salvador
Patch series "page_owner: Fixup and cleanup". This patchset consists of a fixup by an error that was reported by intel robot, where it seems to be that by the time page_owner gets initialized, stackdepot has already depleted its allocation space and returns 0-handles, turning that into null stack_records when trying to retrieve the stack_record. I was not able to reproduce that from the config because it booted fine for me, but when setting e.g: dummy_handle to 0 artificially, I could see the same error that was reported. The second patch is a cleanup that can also lead to a compilation warning. This patch (of 2): Although the retrieval of the stack_records for {dummy,failure}_handle happen when page_owner gets initialized, there seems to be some situations where stackdepot space has been already depleted by then, so we get 0-handles which make stack_records being NULL for those cases. Be careful to 1) only bump stack_records refcount and 2) only access stack_record fields if we actually have a non-null stack_record between hands. Link: https://lkml.kernel.org/r/20240306123217.29774-1-osalvador@suse.de Link: https://lkml.kernel.org/r/20240306123217.29774-2-osalvador@suse.de Fixes: 4bedfb314bdd ("mm,page_owner: implement the tracking of the stacks count") Signed-off-by: Oscar Salvador <osalvador@suse.de> Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202403051032.e2f865a-lkp@intel.com Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Marco Elver <elver@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-04mm: page_owner: add support for splitting to any order in split page_ownerZi Yan
It adds a new_order parameter to set new page order in page owner. It prepares for upcoming changes to support split huge page to any lower order. Link: https://lkml.kernel.org/r/20240226205534.1603748-7-zi.yan@sent.com Signed-off-by: Zi Yan <ziy@nvidia.com> Cc: David Hildenbrand <david@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Michal Koutny <mkoutny@suse.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zach O'Keefe <zokeefe@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-04mm/page_owner: use order instead of nr in split_page_owner()Zi Yan
We do not have non power of two pages, using nr is error prone if nr is not power-of-two. Use page order instead. Link: https://lkml.kernel.org/r/20240226205534.1603748-5-zi.yan@sent.com Signed-off-by: Zi Yan <ziy@nvidia.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Michal Koutny <mkoutny@suse.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zach O'Keefe <zokeefe@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-23mm,page_owner: filter out stacks by a thresholdOscar Salvador
We want to be able to filter out the stacks based on a threshold we can can tune. By writing to 'count_threshold' file, we can adjust the threshold value. Link: https://lkml.kernel.org/r/20240215215907.20121-7-osalvador@suse.de Signed-off-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Andrey Konovalov <andreyknvl@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Marco Elver <elver@google.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-23mm,page_owner: display all stacks and their countOscar Salvador
This patch adds a new directory called 'page_owner_stacks' under /sys/kernel/debug/, with a file called 'show_stacks' in it. Reading from that file will show all stacks that were added by page_owner followed by their counting, giving us a clear overview of stack <-> count relationship. E.g: prep_new_page+0xa9/0x120 get_page_from_freelist+0x801/0x2210 __alloc_pages+0x18b/0x350 alloc_pages_mpol+0x91/0x1f0 folio_alloc+0x14/0x50 filemap_alloc_folio+0xb2/0x100 __filemap_get_folio+0x14a/0x490 ext4_write_begin+0xbd/0x4b0 [ext4] generic_perform_write+0xc1/0x1e0 ext4_buffered_write_iter+0x68/0xe0 [ext4] ext4_file_write_iter+0x70/0x740 [ext4] vfs_write+0x33d/0x420 ksys_write+0xa5/0xe0 do_syscall_64+0x80/0x160 entry_SYSCALL_64_after_hwframe+0x6e/0x76 stack_count: 4578 The seq stack_{start,next} functions will iterate through the list stack_list in order to print all stacks. Link: https://lkml.kernel.org/r/20240215215907.20121-6-osalvador@suse.de Signed-off-by: Oscar Salvador <osalvador@suse.de> Acked-by: Marco Elver <elver@google.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Andrey Konovalov <andreyknvl@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-23mm,page_owner: implement the tracking of the stacks countOscar Salvador
Implement {inc,dec}_stack_record_count() which increments or decrements on respective allocation and free operations, via __reset_page_owner() (free operation) and __set_page_owner() (alloc operation). Newly allocated stack_record structs will be added to the list stack_list via add_stack_record_to_list(). Modifications on the list are protected via a spinlock with irqs disabled, since this code can also be reached from IRQ context. Link: https://lkml.kernel.org/r/20240215215907.20121-5-osalvador@suse.de Signed-off-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Marco Elver <elver@google.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Andrey Konovalov <andreyknvl@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-23mm,page_owner: maintain own list of stack_records structsOscar Salvador
page_owner needs to increment a stack_record refcount when a new allocation occurs, and decrement it on a free operation. In order to do that, we need to have a way to get a stack_record from a handle. Implement __stack_depot_get_stack_record() which just does that, and make it public so page_owner can use it. Also, traversing all stackdepot buckets comes with its own complexity, plus we would have to implement a way to mark only those stack_records that were originated from page_owner, as those are the ones we are interested in. For that reason, page_owner maintains its own list of stack_records, because traversing that list is faster than traversing all buckets while keeping at the same time a low complexity. For now, add to stack_list only the stack_records of dummy_handle and failure_handle, and set their refcount of 1. Further patches will add code to increment or decrement stack_records count on allocation and free operation. Link: https://lkml.kernel.org/r/20240215215907.20121-4-osalvador@suse.de Signed-off-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Marco Elver <elver@google.com> Acked-by: Andrey Konovalov <andreyknvl@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-01-08mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDERKirill A. Shutemov
commit 23baf831a32c ("mm, treewide: redefine MAX_ORDER sanely") has changed the definition of MAX_ORDER to be inclusive. This has caused issues with code that was not yet upstream and depended on the previous definition. To draw attention to the altered meaning of the define, rename MAX_ORDER to MAX_PAGE_ORDER. Link: https://lkml.kernel.org/r/20231228144704.14033-2-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29mm: remove unnecessary ia64 code and commentKefeng Wang
IA64 has gone with commit cf8e8658100d ("arch: Remove Itanium (IA-64) architecture"), remove unnecessary ia64 special mm code and comment too. Link: https://lkml.kernel.org/r/20231222070203.2966980-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-10mm/page_owner: record and dump free_pid and free_tgidBarry Song
While investigating some complex memory allocation and free bugs especially in multi-processes and multi-threads cases, from time to time, I feel the free stack isn't sufficient as a page can be freed by processes or threads other than the one allocating it. And other processes and threads which free the page often have the exactly same free stack with the one allocating the page. We can't know who free the page only through the free stack though the current page_owner does tell us the pid and tgid of the one allocating the page. This makes the bug investigation often hard. So this patch adds free pid and tgid in page_owner, so that we can easily figure out if the freeing is crossing processes or threads. Link: https://lkml.kernel.org/r/20231114034202.73098-1-v-songbaohua@oppo.com Signed-off-by: Barry Song <v-songbaohua@oppo.com> Cc: Audra Mitchell <audra@redhat.com> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kassey Li <quic_yingangl@quicinc.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18mm/page_owner: remove free_ts from page_owner outputAudra Mitchell
Patch series "Fix page_owner's use of free timestamps". While page ower output is used to investigate memory utilization, typically the allocation pathway, the introduction of timestamps to the page owner records caused each record to become unique due to the granularity of the nanosecond timestamp (for example): Page allocated via order 0 ... ts 5206196026 ns, free_ts 5187156703 ns Page allocated via order 0 ... ts 5206198540 ns, free_ts 5187162702 ns Furthermore, the page_owner output only dumps the currently allocated records, so having the free timestamps is nonsensical for the typical use case. In addition, the introduction of timestamps was not properly handled in the page_owner_sort tool causing most use cases to be broken. This series is meant to remove the free timestamps from the page_owner output and fix the page_owner_sort tool so proper collation can occur. This patch (of 5): When printing page_owner data via the sysfs interface, no free pages will ever be dumped due to the series of checks in read_page_owner(): /* * Although we do have the info about past allocation of free * pages, it's not relevant for current memory usage. */ if (!test_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags)) The free_ts values are still used when dump_page_owner() is called, so keeping the field for other use cases but removing them for the typical page_owner case. Link: https://lkml.kernel.org/r/20231013190350.579407-1-audra@redhat.com Link: https://lkml.kernel.org/r/20231013190350.579407-2-audra@redhat.com Fixes: 866b48526217 ("mm/page_owner: record the timestamp of all pages during free") Signed-off-by: Audra Mitchell <audra@redhat.com> Acked-by: Rafael Aquini <aquini@redhat.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Georgi Djakov <djakov@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21mm/page_ext: use page_ext_data helper in page_ownerKemeng Shi
Use page_ext_data helper in page_owner to avoid access offset directly. Link: https://lkml.kernel.org/r/20230718145812.1991717-4-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Andrew Morton <akpm@linux-foudation.org> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-19mm/page_owner/cma: show pfn in cma/page_owner with hex formatKassey Li
cma: display pfn as well as pfn_to_page(pfn) page_owner: display pfn in hex rather than decimal Link: https://lkml.kernel.org/r/20230613092533.15449-1-quic_yingangl@quicinc.com Signed-off-by: Kassey Li <quic_yingangl@quicinc.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05mm, treewide: redefine MAX_ORDER sanelyKirill A. Shutemov
MAX_ORDER currently defined as number of orders page allocator supports: user can ask buddy allocator for page order between 0 and MAX_ORDER-1. This definition is counter-intuitive and lead to number of bugs all over the kernel. Change the definition of MAX_ORDER to be inclusive: the range of orders user can ask from buddy allocator is 0..MAX_ORDER now. [kirill@shutemov.name: fix min() warning] Link: https://lkml.kernel.org/r/20230315153800.32wib3n5rickolvh@box [akpm@linux-foundation.org: fix another min_t warning] [kirill@shutemov.name: fixups per Zi Yan] Link: https://lkml.kernel.org/r/20230316232144.b7ic4cif4kjiabws@box.shutemov.name [akpm@linux-foundation.org: fix underlining in docs] Link: https://lore.kernel.org/oe-kbuild-all/202303191025.VRCTk6mP-lkp@intel.com/ Link: https://lkml.kernel.org/r/20230315113133.11326-11-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc] Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-16lib/stackdepot, mm: rename stack_depot_want_early_initAndrey Konovalov
Rename stack_depot_want_early_init to stack_depot_request_early_init. The old name is confusing, as it hints at returning some kind of intention of stack depot. The new name reflects that this function requests an action from stack depot instead. No functional changes. [akpm@linux-foundation.org: update mm/kmemleak.c] Link: https://lkml.kernel.org/r/359f31bf67429a06e630b4395816a967214ef753.1676063693.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Alexander Potapenko <glider@google.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02mm/page_owner: record single timestamp value for high order allocationsHyeonggon Yoo
When allocating a high-order page, separate allocation timestamp is recorded for each sub-page resulting in different timestamp values between them. This behavior is not consistent with the behavior when recording free timestamp and caused confusion when analyzing memory dumps. Record single timestamp for the entire allocation, aligning with the behavior for free timestamps. Link: https://lkml.kernel.org/r/20230121165054.520507-1-42.hyeyoo@gmail.com Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02mm/page_ext: do not allocate space for page_ext->flags if not neededPasha Tatashin
There is 8 byte page_ext->flags field allocated per page whenever CONFIG_PAGE_EXTENSION is enabled. However, not every user of page_ext uses flags. Therefore, check whether flags is needed at least by one user and if so allocate space for it. For example when page_table_check is enabled, on a machine with 128G of memory before the fix: [ 2.244288] allocated 536870912 bytes of page_ext after the fix: [ 2.160154] allocated 268435456 bytes of page_ext Also, add a kernel-doc comment before page_ext_operations that describes the fields, and remove check if need() is set, as that is now a required field. [pasha.tatashin@soleen.com: address comments from Mike Rapoport] Link: https://lkml.kernel.org/r/20230117202103.1412449-1-pasha.tatashin@soleen.com Link: https://lkml.kernel.org/r/20230113154253.92480-1-pasha.tatashin@soleen.com Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Rientjes <rientjes@google.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Charan Teja Kalla <quic_charante@quicinc.com> Cc: Li Zhe <lizhe.67@bytedance.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03mm: reuse pageblock_start/end_pfn() macroKefeng Wang
Move pageblock_start_pfn/pageblock_end_pfn() into pageblock-flags.h, then they could be used somewhere else, not only in compaction, also use ALIGN_DOWN() instead of round_down() to be pair with ALIGN(), which should be same for pageblock usage. Link: https://lkml.kernel.org/r/20220907060844.126891-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03mm/page_owner.c: remove redundant drain_all_pagesZhenhua Huang
Remove an expensive and unnecessary operation as PCP pages are safely skipped when reading page owner.PCP pages can be skipped because PAGE_EXT_OWNER_ALLOCATED is cleared. With draining PCP pages, these pages are moved to buddy list so they can be identified as buddy pages and skipped quickly. Although it improved efficiency of PFN walker, the drain is guaranteed expensive that is unlikely to be offset by a slight increase in efficiency when skipping free pages. PAGE_EXT_OWNER_ALLOCATED is cleared in the page owner reset path below: free_unref_page -> free_unref_page_prepare -> free_pcp_prepare -> free_pages_prepare which do page owner reset -> free_unref_page_commit which add pages into pcp list Link: https://lkml.kernel.org/r/1662704326-15899-1-git-send-email-quic_zhenhuah@quicinc.com Link: https://lkml.kernel.org/r/1662633204-10044-1-git-send-email-quic_zhenhuah@quicinc.com Link: https://lkml.kernel.org/r/1662537673-9392-1-git-send-email-quic_zhenhuah@quicinc.com Signed-off-by: Zhenhua Huang <quic_zhenhuah@quicinc.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11mm/page_owner.c: add llseek for page_ownerKassey Li
It is too slow to dump all the pages, in some usage we just want to dump a given start pfn, for example: a CMA range or a single page. To speed up and save time, this change allows specifying of a start pfn by adding llseek for page_owner. Link: https://lkml.kernel.org/r/20220818022425.31056-1-quic_yingangl@quicinc.com Signed-off-by: Kassey Li <quic_yingangl@quicinc.com> Suggested-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11mm: fix use-after free of page_ext after race with memory-offlineCharan Teja Kalla
The below is one path where race between page_ext and offline of the respective memory blocks will cause use-after-free on the access of page_ext structure. process1 process2 --------- --------- a)doing /proc/page_owner doing memory offline through offline_pages. b) PageBuddy check is failed thus proceed to get the page_owner information through page_ext access. page_ext = lookup_page_ext(page); migrate_pages(); ................. Since all pages are successfully migrated as part of the offline operation,send MEM_OFFLINE notification where for page_ext it calls: offline_page_ext()--> __free_page_ext()--> free_page_ext()--> vfree(ms->page_ext) mem_section->page_ext = NULL c) Check for the PAGE_EXT flags in the page_ext->flags access results into the use-after-free (leading to the translation faults). As mentioned above, there is really no synchronization between page_ext access and its freeing in the memory_offline. The memory offline steps(roughly) on a memory block is as below: 1) Isolate all the pages 2) while(1) try free the pages to buddy.(->free_list[MIGRATE_ISOLATE]) 3) delete the pages from this buddy list. 4) Then free page_ext.(Note: The struct page is still alive as it is freed only during hot remove of the memory which frees the memmap, which steps the user might not perform). This design leads to the state where struct page is alive but the struct page_ext is freed, where the later is ideally part of the former which just representing the page_flags (check [3] for why this design is chosen). The abovementioned race is just one example __but the problem persists in the other paths too involving page_ext->flags access(eg: page_is_idle())__. Fix all the paths where offline races with page_ext access by maintaining synchronization with rcu lock and is achieved in 3 steps: 1) Invalidate all the page_ext's of the sections of a memory block by storing a flag in the LSB of mem_section->page_ext. 2) Wait until all the existing readers to finish working with the ->page_ext's with synchronize_rcu(). Any parallel process that starts after this call will not get page_ext, through lookup_page_ext(), for the block parallel offline operation is being performed. 3) Now safely free all sections ->page_ext's of the block on which offline operation is being performed. Note: If synchronize_rcu() takes time then optimizations can be done in this path through call_rcu()[2]. Thanks to David Hildenbrand for his views/suggestions on the initial discussion[1] and Pavan kondeti for various inputs on this patch. [1] https://lore.kernel.org/linux-mm/59edde13-4167-8550-86f0-11fc67882107@quicinc.com/ [2] https://lore.kernel.org/all/a26ce299-aed1-b8ad-711e-a49e82bdd180@quicinc.com/T/#u [3] https://lore.kernel.org/all/6fa6b7aa-731e-891c-3efb-a03d6a700efa@redhat.com/ [quic_charante@quicinc.com: rename label `loop' to `ext_put_continue' per David] Link: https://lkml.kernel.org/r/1661496993-11473-1-git-send-email-quic_charante@quicinc.com Link: https://lkml.kernel.org/r/1660830600-9068-1-git-send-email-quic_charante@quicinc.com Signed-off-by: Charan Teja Kalla <quic_charante@quicinc.com> Suggested-by: David Hildenbrand <david@redhat.com> Suggested-by: Michal Hocko <mhocko@suse.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Fernand Sieber <sieberf@amazon.com> Cc: Minchan Kim <minchan@google.com> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Pavan Kondeti <quic_pkondeti@quicinc.com> Cc: SeongJae Park <sjpark@amazon.de> Cc: Shakeel Butt <shakeelb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: William Kucharski <william.kucharski@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-26Merge tag 'mm-stable-2022-05-25' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: "Almost all of MM here. A few things are still getting finished off, reviewed, etc. - Yang Shi has improved the behaviour of khugepaged collapsing of readonly file-backed transparent hugepages. - Johannes Weiner has arranged for zswap memory use to be tracked and managed on a per-cgroup basis. - Munchun Song adds a /proc knob ("hugetlb_optimize_vmemmap") for runtime enablement of the recent huge page vmemmap optimization feature. - Baolin Wang contributes a series to fix some issues around hugetlb pagetable invalidation. - Zhenwei Pi has fixed some interactions between hwpoisoned pages and virtualization. - Tong Tiangen has enabled the use of the presently x86-only page_table_check debugging feature on arm64 and riscv. - David Vernet has done some fixup work on the memcg selftests. - Peter Xu has taught userfaultfd to handle write protection faults against shmem- and hugetlbfs-backed files. - More DAMON development from SeongJae Park - adding online tuning of the feature and support for monitoring of fixed virtual address ranges. Also easier discovery of which monitoring operations are available. - Nadav Amit has done some optimization of TLB flushing during mprotect(). - Neil Brown continues to labor away at improving our swap-over-NFS support. - David Hildenbrand has some fixes to anon page COWing versus get_user_pages(). - Peng Liu fixed some errors in the core hugetlb code. - Joao Martins has reduced the amount of memory consumed by device-dax's compound devmaps. - Some cleanups of the arch-specific pagemap code from Anshuman Khandual. - Muchun Song has found and fixed some errors in the TLB flushing of transparent hugepages. - Roman Gushchin has done more work on the memcg selftests. ... and, of course, many smaller fixes and cleanups. Notably, the customary million cleanup serieses from Miaohe Lin" * tag 'mm-stable-2022-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (381 commits) mm: kfence: use PAGE_ALIGNED helper selftests: vm: add the "settings" file with timeout variable selftests: vm: add "test_hmm.sh" to TEST_FILES selftests: vm: check numa_available() before operating "merge_across_nodes" in ksm_tests selftests: vm: add migration to the .gitignore selftests/vm/pkeys: fix typo in comment ksm: fix typo in comment selftests: vm: add process_mrelease tests Revert "mm/vmscan: never demote for memcg reclaim" mm/kfence: print disabling or re-enabling message include/trace/events/percpu.h: cleanup for "percpu: improve percpu_alloc_percpu event trace" include/trace/events/mmflags.h: cleanup for "tracing: incorrect gfp_t conversion" mm: fix a potential infinite loop in start_isolate_page_range() MAINTAINERS: add Muchun as co-maintainer for HugeTLB zram: fix Kconfig dependency warning mm/shmem: fix shmem folio swapoff hang cgroup: fix an error handling path in alloc_pagecache_max_30M() mm: damon: use HPAGE_PMD_SIZE tracing: incorrect isolate_mote_t cast in mm_vmscan_lru_isolate nodemask.h: fix compilation error with GCC12 ...
2022-05-19mm/page_owner.c: add missing __initdata attributeFanjun Kong
This patch fixes two issues: 1. Add __initdata attribute according to include/linux/init.h: For initialized data: You should insert __initdata between the variable name and equal sign followed by value 2. Fix below error reported by checkpatch.pl: ERROR: do not initialise statics to false Special thanks to Muchun Song :) Link: https://lkml.kernel.org/r/20220516030039.1487005-1-bh1scw@gmail.com Signed-off-by: Fanjun Kong <bh1scw@gmail.com> Suggested-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13mm/page_owner: use strscpy() instead of strlcpy()Eric Dumazet
current->comm[] is not a string (no guarantee for a zero byte in it). strlcpy(s1, s2, l) is calling strlen(s2), potentially causing out-of-bound access, as reported by syzbot: detected buffer overflow in __fortify_strlen ------------[ cut here ]------------ kernel BUG at lib/string_helpers.c:980! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 4087 Comm: dhcpcd-run-hooks Not tainted 5.18.0-rc3-syzkaller-01537-g20b87e7c29df #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:fortify_panic+0x18/0x1a lib/string_helpers.c:980 Code: 8c e8 c5 ba e1 fa e9 23 0f bf fa e8 0b 5d 8c f8 eb db 55 48 89 fd e8 e0 49 40 f8 48 89 ee 48 c7 c7 80 f5 26 8a e8 99 09 f1 ff <0f> 0b e8 ca 49 40 f8 48 8b 54 24 18 4c 89 f1 48 c7 c7 00 00 27 8a RSP: 0018:ffffc900000074a8 EFLAGS: 00010286 RAX: 000000000000002c RBX: ffff88801226b728 RCX: 0000000000000000 RDX: ffff8880198e0000 RSI: ffffffff81600458 RDI: fffff52000000e87 RBP: ffffffff89da2aa0 R08: 000000000000002c R09: 0000000000000000 R10: ffffffff815fae2e R11: 0000000000000000 R12: ffff88801226b700 R13: ffff8880198e0830 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5876ad6ff8 CR3: 000000001a48c000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: <IRQ> __fortify_strlen include/linux/fortify-string.h:128 [inline] strlcpy include/linux/fortify-string.h:143 [inline] __set_page_owner_handle+0x2b1/0x3e0 mm/page_owner.c:171 __set_page_owner+0x3e/0x50 mm/page_owner.c:190 prep_new_page mm/page_alloc.c:2441 [inline] get_page_from_freelist+0xba2/0x3e00 mm/page_alloc.c:4182 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5408 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2272 alloc_slab_page mm/slub.c:1799 [inline] allocate_slab+0x26c/0x3c0 mm/slub.c:1944 new_slab mm/slub.c:2004 [inline] ___slab_alloc+0x8df/0xf20 mm/slub.c:3005 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3092 slab_alloc_node mm/slub.c:3183 [inline] slab_alloc mm/slub.c:3225 [inline] __kmem_cache_alloc_lru mm/slub.c:3232 [inline] kmem_cache_alloc+0x360/0x3b0 mm/slub.c:3242 dst_alloc+0x146/0x1f0 net/core/dst.c:92 Link: https://lkml.kernel.org/r/20220509145949.265184-1-eric.dumazet@gmail.com Fixes: 865ed6a32786 ("mm/page_owner: record task command name") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Acked-by: Waiman Long <longman@redhat.com> Acked-by: Shakeel Butt <shakeelb@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-04-06lib/stackdepot: allow requesting early initialization dynamicallyVlastimil Babka
In a later patch we want to add stackdepot support for object owner tracking in slub caches, which is enabled by slub_debug boot parameter. This creates a bootstrap problem as some caches are created early in boot when slab_is_available() is false and thus stack_depot_init() tries to use memblock. But, as reported by Hyeonggon Yoo [1] we are already beyond memblock_free_all(). Ideally memblock allocation should fail, yet it succeeds, but later the system crashes, which is a separately handled issue. To resolve this boostrap issue in a robust way, this patch adds another way to request stack_depot_early_init(), which happens at a well-defined point of time. In addition to build-time CONFIG_STACKDEPOT_ALWAYS_INIT, code that's e.g. processing boot parameters (which happens early enough) can call a new function stack_depot_want_early_init(), which sets a flag that stack_depot_early_init() will check. In this patch we also convert page_owner to this approach. While it doesn't have the bootstrap issue as slub, it's also a functionality enabled by a boot param and can thus request stack_depot_early_init() with memblock allocation instead of later initialization with kvmalloc(). As suggested by Mike, make stack_depot_early_init() only attempt memblock allocation and stack_depot_init() only attempt kvmalloc(). Also change the latter to kvcalloc(). In both cases we can lose the explicit array zeroing, which the allocations do already. As suggested by Marco, provide empty implementations of the init functions for !CONFIG_STACKDEPOT builds to simplify the callers. [1] https://lore.kernel.org/all/YhnUcqyeMgCrWZbd@ip-172-31-19-208.ap-northeast-1.compute.internal/ Reported-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Suggested-by: Mike Rapoport <rppt@linux.ibm.com> Suggested-by: Marco Elver <elver@google.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Marco Elver <elver@google.com> Reviewed-and-tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: David Rientjes <rientjes@google.com>