- 18 Nov, 2021 5 commits
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Michal Hocko authored
commit 60e2793d upstream. Any allocation failure during the #PF path will return with VM_FAULT_OOM which in turn results in pagefault_out_of_memory. This can happen for 2 different reasons. a) Memcg is out of memory and we rely on mem_cgroup_oom_synchronize to perform the memcg OOM handling or b) normal allocation fails. The latter is quite problematic because allocation paths already trigger out_of_memory and the page allocator tries really hard to not fail allocations. Anyway, if the OOM killer has been already invoked there is no reason to invoke it again from the #PF path. Especially when the OOM condition might be gone by that time and we have no way to find out other than allocate. Moreover if the allocation failed and the OOM killer hasn't been invoked then we are unlikely to do the right thing from the #PF context because we have already lost the allocation context and restictions and therefore might oom kill a task from a different NUMA domain. This all suggests that there is no legitimate reason to trigger out_of_memory from pagefault_out_of_memory so drop it. Just to be sure that no #PF path returns with VM_FAULT_OOM without allocation print a warning that this is happening before we restart the #PF. [VvS: #PF allocation can hit into limit of cgroup v1 kmem controller. This is a local problem related to memcg, however, it causes unnecessary global OOM kills that are repeated over and over again and escalate into a real disaster. This has been broken since kmem accounting has been introduced for cgroup v1 (3.8). There was no kmem specific reclaim for the separate limit so the only way to handle kmem hard limit was to return with ENOMEM. In upstream the problem will be fixed by removing the outdated kmem limit, however stable and LTS kernels cannot do it and are still affected. This patch fixes the problem and should be backported into stable/LTS.] Link: https://lkml.kernel.org/r/f5fd8dd8-0ad4-c524-5f65-920b01972a42@virtuozzo.com Signed-off-by:
Michal Hocko <mhocko@suse.com> Signed-off-by:
Vasily Averin <vvs@virtuozzo.com> Acked-by:
Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Roman Gushchin <guro@fb.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Cc: Uladzislau Rezki <urezki@gmail.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Vasily Averin authored
commit 0b28179a upstream. Patch series "memcg: prohibit unconditional exceeding the limit of dying tasks", v3. Memory cgroup charging allows killed or exiting tasks to exceed the hard limit. It can be misused and allowed to trigger global OOM from inside a memcg-limited container. On the other hand if memcg fails allocation, called from inside #PF handler it triggers global OOM from inside pagefault_out_of_memory(). To prevent these problems this patchset: (a) removes execution of out_of_memory() from pagefault_out_of_memory(), becasue nobody can explain why it is necessary. (b) allow memcg to fail allocation of dying/killed tasks. This patch (of 3): Any allocation failure during the #PF path will return with VM_FAULT_OOM which in turn results in pagefault_out_of_memory which in turn executes out_out_memory() and can kill a random task. An allocation might fail when the current task is the oom victim and there are no memory reserves left. The OOM killer is already handled at the page allocator level for the global OOM and at the charging level for the memcg one. Both have much more information about the scope of allocation/charge request. This means that either the OOM killer has been invoked properly and didn't lead to the allocation success or it has been skipped because it couldn't have been invoked. In both cases triggering it from here is pointless and even harmful. It makes much more sense to let the killed task die rather than to wake up an eternally hungry oom-killer and send him to choose a fatter victim for breakfast. Link: https://lkml.kernel.org/r/0828a149-786e-7c06-b70a-52d086818ea3@virtuozzo.com Signed-off-by:
Vasily Averin <vvs@virtuozzo.com> Suggested-by:
Michal Hocko <mhocko@suse.com> Acked-by:
Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Roman Gushchin <guro@fb.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Cc: Uladzislau Rezki <urezki@gmail.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Vasily Averin authored
commit a4ebf1b6 upstream. Memory cgroup charging allows killed or exiting tasks to exceed the hard limit. It is assumed that the amount of the memory charged by those tasks is bound and most of the memory will get released while the task is exiting. This is resembling a heuristic for the global OOM situation when tasks get access to memory reserves. There is no global memory shortage at the memcg level so the memcg heuristic is more relieved. The above assumption is overly optimistic though. E.g. vmalloc can scale to really large requests and the heuristic would allow that. We used to have an early break in the vmalloc allocator for killed tasks but this has been reverted by commit b8c8a338 ("Revert "vmalloc: back off when the current task is killed""). There are likely other similar code paths which do not check for fatal signals in an allocation&charge loop. Also there are some kernel objects charged to a memcg which are not bound to a process life time. It has been observed that it is not really hard to trigger these bypasses and cause global OOM situation. One potential way to address these runaways would be to limit the amount of excess (similar to the global OOM with limited oom reserves). This is certainly possible but it is not really clear how much of an excess is desirable and still protects from global OOMs as that would have to consider the overall memcg configuration. This patch is addressing the problem by removing the heuristic altogether. Bypass is only allowed for requests which either cannot fail or where the failure is not desirable while excess should be still limited (e.g. atomic requests). Implementation wise a killed or dying task fails to charge if it has passed the OOM killer stage. That should give all forms of reclaim chance to restore the limit before the failure (ENOMEM) and tell the caller to back off. In addition, this patch renames should_force_charge() helper to task_is_dying() because now its use is not associated witch forced charging. This patch depends on pagefault_out_of_memory() to not trigger out_of_memory(), because then a memcg failure can unwind to VM_FAULT_OOM and cause a global OOM killer. Link: https://lkml.kernel.org/r/8f5cebbb-06da-4902-91f0-6566fc4b4203@virtuozzo.com Signed-off-by:
Vasily Averin <vvs@virtuozzo.com> Suggested-by:
Michal Hocko <mhocko@suse.com> Acked-by:
Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Roman Gushchin <guro@fb.com> Cc: Uladzislau Rezki <urezki@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Shakeel Butt <shakeelb@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Cc: <stable@vger.kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Matthew Wilcox (Oracle) authored
commit d417b49f upstream. It is not safe to check page->index without holding the page lock. It can be changed if the page is moved between the swap cache and the page cache for a shmem file, for example. There is a VM_BUG_ON below which checks page->index is correct after taking the page lock. Link: https://lkml.kernel.org/r/20210818144932.940640-1-willy@infradead.org Fixes: 5c211ba2 ("mm: add and use find_lock_entries") Signed-off-by:
Matthew Wilcox (Oracle) <willy@infradead.org> Reported-by: <syzbot+c87be4f669d920c76330@syzkaller.appspotmail.com> Cc: Hugh Dickins <hughd@google.com> Cc: <stable@vger.kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Miaohe Lin authored
[ Upstream commit afe8605c ] There is one possible race window between zs_pool_dec_isolated() and zs_unregister_migration() because wait_for_isolated_drain() checks the isolated count without holding class->lock and there is no order inside zs_pool_dec_isolated(). Thus the below race window could be possible: zs_pool_dec_isolated zs_unregister_migration check pool->destroying != 0 pool->destroying = true; smp_mb(); wait_for_isolated_drain() wait for pool->isolated_pages == 0 atomic_long_dec(&pool->isolated_pages); atomic_long_read(&pool->isolated_pages) == 0 Since we observe the pool->destroying (false) before atomic_long_dec() for pool->isolated_pages, waking pool->migration_wait up is missed. Fix this by ensure checking pool->destroying happens after the atomic_long_dec(&pool->isolated_pages). Link: https://lkml.kernel.org/r/20210708115027.7557-1-linmiaohe@huawei.com Fixes: 701d6785 ("mm/zsmalloc.c: fix race condition in zs_destroy_pool") Signed-off-by:
Miaohe Lin <linmiaohe@huawei.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Henry Burns <henryburns@google.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
Sasha Levin <sashal@kernel.org>
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- 12 Nov, 2021 1 commit
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Marco Elver authored
commit 07e8481d upstream. Regardless of KFENCE mode (CONFIG_KFENCE_STATIC_KEYS: either using static keys to gate allocations, or using a simple dynamic branch), always use a static branch to avoid the dynamic branch in kfence_alloc() if KFENCE was disabled at boot. For CONFIG_KFENCE_STATIC_KEYS=n, this now avoids the dynamic branch if KFENCE was disabled at boot. To simplify, also unifies the location where kfence_allocation_gate is read-checked to just be inline in kfence_alloc(). Link: https://lkml.kernel.org/r/20211019102524.2807208-1-elver@google.com Signed-off-by:
Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Jann Horn <jannh@google.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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- 29 Oct, 2021 9 commits
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SeongJae Park authored
Kunit test cases for 'damon_split_regions_of()' expects the number of regions after calling the function will be same to their request ('nr_sub'). However, the requested number is just an upper-limit, because the function randomly decides the size of each sub-region. This fixes the wrong expectation. Link: https://lkml.kernel.org/r/20211028090628.14948-1-sj@kernel.org Fixes: 17ccae8b ("mm/damon: add kunit tests") Signed-off-by:
SeongJae Park <sj@kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Yang Shi authored
The read-only THP for filesystems will collapse THP for files opened readonly and mapped with VM_EXEC. The intended usecase is to avoid TLB misses for large text segments. But it doesn't restrict the file types so a THP could be collapsed for a non-regular file, for example, block device, if it is opened readonly and mapped with EXEC permission. This may cause bugs, like [1] and [2]. This is definitely not the intended usecase, so just collapse THP for regular files in order to close the attack surface. [shy828301@gmail.com: fix vm_file check [3]] Link: https://lore.kernel.org/lkml/CACkBjsYwLYLRmX8GpsDpMthagWOjWWrNxqY6ZLNQVr6yx+f5vA@mail.gmail.com/ [1] Link: https://lore.kernel.org/linux-mm/000000000000c6a82505ce284e4c@google.com/ [2] Link: https://lkml.kernel.org/r/CAHbLzkqTW9U3VvTu1Ki5v_cLRC9gHW+znBukg_ycergE0JWj-A@mail.gmail.com [3] Link: https://lkml.kernel.org/r/20211027195221.3825-1-shy828301@gmail.com Fixes: 99cb0dbd ("mm,thp: add read-only THP support for (non-shmem) FS") Signed-off-by:
Hugh Dickins <hughd@google.com> Signed-off-by:
Yang Shi <shy828301@gmail.com> Reported-by:
Hao Sun <sunhao.th@gmail.com> Reported-by: syzbot+aae069be1de40fb11825@syzkaller.appspotmail.com Cc: Matthew Wilcox <willy@infradead.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Song Liu <songliubraving@fb.com> Cc: Andrea Righi <andrea.righi@canonical.com> Cc: <stable@vger.kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Rongwei Wang authored
Currently collapse_file does not explicitly check PG_writeback, instead, page_has_private and try_to_release_page are used to filter writeback pages. This does not work for xfs with blocksize equal to or larger than pagesize, because in such case xfs has no page->private. This makes collapse_file bail out early for writeback page. Otherwise, xfs end_page_writeback will panic as follows. page:fffffe00201bcc80 refcount:0 mapcount:0 mapping:ffff0003f88c86a8 index:0x0 pfn:0x84ef32 aops:xfs_address_space_operations [xfs] ino:30000b7 dentry name:"libtest.so" flags: 0x57fffe0000008027(locked|referenced|uptodate|active|writeback) raw: 57fffe0000008027 ffff80001b48bc28 ffff80001b48bc28 ffff0003f88c86a8 raw: 0000000000000000 0000000000000000 00000000ffffffff ffff0000c3e9a000 page dumped because: VM_BUG_ON_PAGE(((unsigned int) page_ref_count(page) + 127u <= 127u)) page->mem_cgroup:ffff0000c3e9a000 ------------[ cut here ]------------ kernel BUG at include/linux/mm.h:1212! Internal error: Oops - BUG: 0 [#1] SMP Modules linked in: BUG: Bad page state in process khugepaged pfn:84ef32 xfs(E) page:fffffe00201bcc80 refcount:0 mapcount:0 mapping:0 index:0x0 pfn:0x84ef32 libcrc32c(E) rfkill(E) aes_ce_blk(E) crypto_simd(E) ... CPU: 25 PID: 0 Comm: swapper/25 Kdump: loaded Tainted: ... pstate: 60400005 (nZCv daif +PAN -UAO -TCO BTYPE=--) Call trace: end_page_writeback+0x1c0/0x214 iomap_finish_page_writeback+0x13c/0x204 iomap_finish_ioend+0xe8/0x19c iomap_writepage_end_bio+0x38/0x50 bio_endio+0x168/0x1ec blk_update_request+0x278/0x3f0 blk_mq_end_request+0x34/0x15c virtblk_request_done+0x38/0x74 [virtio_blk] blk_done_softirq+0xc4/0x110 __do_softirq+0x128/0x38c __irq_exit_rcu+0x118/0x150 irq_exit+0x1c/0x30 __handle_domain_irq+0x8c/0xf0 gic_handle_irq+0x84/0x108 el1_irq+0xcc/0x180 arch_cpu_idle+0x18/0x40 default_idle_call+0x4c/0x1a0 cpuidle_idle_call+0x168/0x1e0 do_idle+0xb4/0x104 cpu_startup_entry+0x30/0x9c secondary_start_kernel+0x104/0x180 Code: d4210000 b0006161 910c8021 94013f4d (d4210000) ---[ end trace 4a88c6a074082f8c ]--- Kernel panic - not syncing: Oops - BUG: Fatal exception in interrupt Link: https://lkml.kernel.org/r/20211022023052.33114-1-rongwei.wang@linux.alibaba.com Fixes: 99cb0dbd ("mm,thp: add read-only THP support for (non-shmem) FS") Signed-off-by:
Rongwei Wang <rongwei.wang@linux.alibaba.com> Signed-off-by:
Xu Yu <xuyu@linux.alibaba.com> Suggested-by:
Yang Shi <shy828301@gmail.com> Reviewed-by:
Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by:
Yang Shi <shy828301@gmail.com> Acked-by:
Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Song Liu <song@kernel.org> Cc: William Kucharski <william.kucharski@oracle.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Chen Wandun authored
Eric Dumazet reported a strange numa spreading info in [1], and found commit 121e6f32 ("mm/vmalloc: hugepage vmalloc mappings") introduced this issue [2]. Dig into the difference before and after this patch, page allocation has some difference: before: alloc_large_system_hash __vmalloc __vmalloc_node(..., NUMA_NO_NODE, ...) __vmalloc_node_range __vmalloc_area_node alloc_page /* because NUMA_NO_NODE, so choose alloc_page branch */ alloc_pages_current alloc_page_interleave /* can be proved by print policy mode */ after: alloc_large_system_hash __vmalloc __vmalloc_node(..., NUMA_NO_NODE, ...) __vmalloc_node_range __vmalloc_area_node alloc_pages_node /* choose nid by nuam_mem_id() */ __alloc_pages_node(nid, ....) So after commit 121e6f32 ("mm/vmalloc: hugepage vmalloc mappings"), it will allocate memory in current node instead of interleaving allocate memory. Link: https://lore.kernel.org/linux-mm/CANn89iL6AAyWhfxdHO+jaT075iOa3XcYn9k6JJc7JR2XYn6k_Q@mail.gmail.com/ [1] Link: https://lore.kernel.org/linux-mm/CANn89iLofTR=AK-QOZY87RdUZENCZUT4O6a0hvhu3_EwRMerOg@mail.gmail.com/ [2] Link: https://lkml.kernel.org/r/20211021080744.874701-2-chenwandun@huawei.com Fixes: 121e6f32 ("mm/vmalloc: hugepage vmalloc mappings") Signed-off-by:
Chen Wandun <chenwandun@huawei.com> Reported-by:
Eric Dumazet <edumazet@google.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Hanjun Guo <guohanjun@huawei.com> Cc: Uladzislau Rezki <urezki@gmail.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Kees Cook authored
Quoting Dmitry: "refcount_inc() needs to be done before fd_install(). After fd_install() finishes, the fd can be used by userspace and we can have secret data in memory before the refcount_inc(). A straightforward misuse where a user will predict the returned fd in another thread before the syscall returns and will use it to store secret data is somewhat dubious because such a user just shoots themself in the foot. But a more interesting misuse would be to close the predicted fd and decrement the refcount before the corresponding refcount_inc, this way one can briefly drop the refcount to zero while there are other users of secretmem." Move fd_install() after refcount_inc(). Link: https://lkml.kernel.org/r/20211021154046.880251-1-keescook@chromium.org Link: https://lore.kernel.org/lkml/CACT4Y+b1sW6-Hkn8HQYw_SsT7X3tp-CJNh2ci0wG3ZnQz9jjig@mail.gmail.com Fixes: 9a436f8f ("PM: hibernate: disable when there are active secretmem users") Signed-off-by:
Kees Cook <keescook@chromium.org> Reported-by:
Dmitry Vyukov <dvyukov@google.com> Reviewed-by:
Dmitry Vyukov <dvyukov@google.com> Reviewed-by:
David Hildenbrand <david@redhat.com> Reviewed-by:
Jordy Zomer <jordy@pwning.systems> Cc: Mike Rapoport <rppt@kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Suren Baghdasaryan authored
Race between process_mrelease and exit_mmap, where free_pgtables is called while __oom_reap_task_mm is in progress, leads to kernel crash during pte_offset_map_lock call. oom-reaper avoids this race by setting MMF_OOM_VICTIM flag and causing exit_mmap to take and release mmap_write_lock, blocking it until oom-reaper releases mmap_read_lock. Reusing MMF_OOM_VICTIM for process_mrelease would be the simplest way to fix this race, however that would be considered a hack. Fix this race by elevating mm->mm_users and preventing exit_mmap from executing until process_mrelease is finished. Patch slightly refactors the code to adapt for a possible mmget_not_zero failure. This fix has considerable negative impact on process_mrelease performance and will likely need later optimization. Link: https://lkml.kernel.org/r/20211022014658.263508-1-surenb@google.com Fixes: 884a7e59 ("mm: introduce process_mrelease system call") Signed-off-by:
Suren Baghdasaryan <surenb@google.com> Acked-by:
Michal Hocko <mhocko@suse.com> Cc: David Rientjes <rientjes@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Roman Gushchin <guro@fb.com> Cc: Rik van Riel <riel@surriel.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Christian Brauner <christian@brauner.io> Cc: Christoph Hellwig <hch@infradead.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Christian Brauner <christian.brauner@ubuntu.com> Cc: Florian Weimer <fweimer@redhat.com> Cc: Jan Engelhardt <jengelh@inai.de> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Yang Shi authored
When handling shmem page fault the THP with corrupted subpage could be PMD mapped if certain conditions are satisfied. But kernel is supposed to send SIGBUS when trying to map hwpoisoned page. There are two paths which may do PMD map: fault around and regular fault. Before commit f9ce0be7 ("mm: Cleanup faultaround and finish_fault() codepaths") the thing was even worse in fault around path. The THP could be PMD mapped as long as the VMA fits regardless what subpage is accessed and corrupted. After this commit as long as head page is not corrupted the THP could be PMD mapped. In the regular fault path the THP could be PMD mapped as long as the corrupted page is not accessed and the VMA fits. This loophole could be fixed by iterating every subpage to check if any of them is hwpoisoned or not, but it is somewhat costly in page fault path. So introduce a new page flag called HasHWPoisoned on the first tail page. It indicates the THP has hwpoisoned subpage(s). It is set if any subpage of THP is found hwpoisoned by memory failure and after the refcount is bumped successfully, then cleared when the THP is freed or split. The soft offline path doesn't need this since soft offline handler just marks a subpage hwpoisoned when the subpage is migrated successfully. But shmem THP didn't get split then migrated at all. Link: https://lkml.kernel.org/r/20211020210755.23964-3-shy828301@gmail.com Fixes: 800d8c63 ("shmem: add huge pages support") Signed-off-by:
Yang Shi <shy828301@gmail.com> Reviewed-by:
Naoya Horiguchi <naoya.horiguchi@nec.com> Suggested-by:
Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Yang Shi authored
When handling THP hwpoison checked if the THP is in allocation or free stage since hwpoison may mistreat it as hugetlb page. After commit 415c64c1 ("mm/memory-failure: split thp earlier in memory error handling") the problem has been fixed, so this check is no longer needed. Remove it. The side effect of the removal is hwpoison may report unsplit THP instead of unknown error for shmem THP. It seems not like a big deal. The following patch "mm: filemap: check if THP has hwpoisoned subpage for PMD page fault" depends on this, which fixes shmem THP with hwpoisoned subpage(s) are mapped PMD wrongly. So this patch needs to be backported to -stable as well. Link: https://lkml.kernel.org/r/20211020210755.23964-2-shy828301@gmail.com Signed-off-by:
Yang Shi <shy828301@gmail.com> Suggested-by:
Naoya Horiguchi <naoya.horiguchi@nec.com> Acked-by:
Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Hugh Dickins <hughd@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Shakeel Butt authored
Commit 5c1f4e69 ("mm/vmalloc: switch to bulk allocator in __vmalloc_area_node()") switched to bulk page allocator for order 0 allocation backing vmalloc. However bulk page allocator does not support __GFP_ACCOUNT allocations and there are several users of kvmalloc(__GFP_ACCOUNT). For now make __GFP_ACCOUNT allocations bypass bulk page allocator. In future if there is workload that can be significantly improved with the bulk page allocator with __GFP_ACCCOUNT support, we can revisit the decision. Link: https://lkml.kernel.org/r/20211014151607.2171970-1-shakeelb@google.com Fixes: 5c1f4e69 ("mm/vmalloc: switch to bulk allocator in __vmalloc_area_node()") Signed-off-by:
Shakeel Butt <shakeelb@google.com> Reported-by:
Vasily Averin <vvs@virtuozzo.com> Tested-by:
Vasily Averin <vvs@virtuozzo.com> Acked-by:
David Hildenbrand <david@redhat.com> Acked-by:
Michal Hocko <mhocko@suse.com> Acked-by:
Roman Gushchin <guro@fb.com> Acked-by:
Johannes Weiner <hannes@cmpxchg.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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- 25 Oct, 2021 1 commit
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Matthew Wilcox (Oracle) authored
Commit 11086054 ("mm/secretmem: use refcount_t instead of atomic_t") attempted to fix the problem of secretmem_users wrapping to zero and allowing suspend once again. But it was reverted in commit 87066fdd ("Revert 'mm/secretmem: use refcount_t instead of atomic_t'") because of the problems it caused - a refcount_t was not semantically the right type to use. Instead prevent secretmem_users from wrapping to zero by forbidding new users if the number of users has wrapped from positive to negative. This stops a long way short of reaching the necessary 4 billion users where it wraps to zero again, so there's no need to be clever with special anti-wrap types or checking the return value from atomic_inc(). Signed-off-by:
Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Jordy Zomer <jordy@pwning.systems> Cc: Kees Cook <keescook@chromium.org>, Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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- 24 Oct, 2021 1 commit
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Linus Torvalds authored
This reverts commit 11086054 . Converting the "secretmem_users" counter to a refcount is incorrect, because a refcount is special in zero and can't just be incremented (but a count of users is not, and "no users" is actually perfectly valid and not a sign of a free'd resource). Reported-by: syzbot+75639e6a0331cd61d3e2@syzkaller.appspotmail.com Cc: Jordy Zomer <jordy@pwning.systems> Cc: Kees Cook <keescook@chromium.org>, Cc: Jordy Zomer <jordy@jordyzomer.github.io> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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- 22 Oct, 2021 2 commits
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Mike Rapoport authored
Vladimir Zapolskiy reports: Commit a7259df7 ("memblock: make memblock_find_in_range method private") invokes a kernel panic while running kmemleak on OF platforms with nomaped regions: Unable to handle kernel paging request at virtual address fff000021e00000 [...] scan_block+0x64/0x170 scan_gray_list+0xe8/0x17c kmemleak_scan+0x270/0x514 kmemleak_write+0x34c/0x4ac The memory allocated from memblock is registered with kmemleak, but if it is marked MEMBLOCK_NOMAP it won't have linear map entries so an attempt to scan such areas will fault. Ideally, memblock_mark_nomap() would inform kmemleak to ignore MEMBLOCK_NOMAP memory, but it can be called before kmemleak interfaces operating on physical addresses can use __va() conversion. Make sure that functions that mark allocated memory as MEMBLOCK_NOMAP take care of informing kmemleak to ignore such memory. Link: https://lore.kernel.org/all/8ade5174-b143-d621-8c8e-dc6a1898c6fb@linaro.org Link: https://lore.kernel.org/all/c30ff0a2-d196-c50d-22f0-bd50696b1205@quicinc.com Fixes: a7259df7 ("memblock: make memblock_find_in_range method private") Reported-by:
Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org> Signed-off-by:
Mike Rapoport <rppt@linux.ibm.com> Reviewed-by:
Catalin Marinas <catalin.marinas@arm.com> Tested-by:
Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org> Tested-by:
Qian Cai <quic_qiancai@quicinc.com> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Mike Rapoport authored
Commit 6e44bd6d ("memblock: exclude NOMAP regions from kmemleak") breaks boot on EFI systems with kmemleak and VM_DEBUG enabled: efi: Processing EFI memory map: efi: 0x000090000000-0x000091ffffff [Conventional| | | | | | | | | | |WB|WT|WC|UC] efi: 0x000092000000-0x0000928fffff [Runtime Data|RUN| | | | | | | | | |WB|WT|WC|UC] ------------[ cut here ]------------ kernel BUG at mm/kmemleak.c:1140! Internal error: Oops - BUG: 0 [#1] SMP Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 5.15.0-rc6-next-20211019+ #104 pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : kmemleak_free_part_phys+0x64/0x8c lr : kmemleak_free_part_phys+0x38/0x8c sp : ffff800011eafbc0 x29: ffff800011eafbc0 x28: 1fffff7fffb41c0d x27: fffffbfffda0e068 x26: 0000000092000000 x25: 1ffff000023d5f94 x24: ffff800011ed84d0 x23: ffff800011ed84c0 x22: ffff800011ed83d8 x21: 0000000000900000 x20: ffff800011782000 x19: 0000000092000000 x18: ffff800011ee0730 x17: 0000000000000000 x16: 0000000000000000 x15: 1ffff0000233252c x14: ffff800019a905a0 x13: 0000000000000001 x12: ffff7000023d5ed7 x11: 1ffff000023d5ed6 x10: ffff7000023d5ed6 x9 : dfff800000000000 x8 : ffff800011eaf6b7 x7 : 0000000000000001 x6 : ffff800011eaf6b0 x5 : 00008ffffdc2a12a x4 : ffff7000023d5ed7 x3 : 1ffff000023dbf99 x2 : 1ffff000022f0463 x1 : 0000000000000000 x0 : ffffffffffffffff Call trace: kmemleak_free_part_phys+0x64/0x8c memblock_mark_nomap+0x5c/0x78 reserve_regions+0x294/0x33c efi_init+0x2d0/0x490 setup_arch+0x80/0x138 start_kernel+0xa0/0x3ec __primary_switched+0xc0/0xc8 Code: 34000041 97d526e7 f9418e80 36000040 (d4210000) random: get_random_bytes called from print_oops_end_marker+0x34/0x80 with crng_init=0 ---[ end trace 0000000000000000 ]--- The crash happens because kmemleak_free_part_phys() tries to use __va() before memstart_addr is initialized and this triggers a VM_BUG_ON() in arch/arm64/include/asm/memory.h: Revert 6e44bd6d ("memblock: exclude NOMAP regions from kmemleak"), the issue it is fixing will be fixed differently. Reported-by:
Qian Cai <quic_qiancai@quicinc.com> Signed-off-by:
Mike Rapoport <rppt@linux.ibm.com> Acked-by:
Catalin Marinas <catalin.marinas@arm.com> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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- 19 Oct, 2021 11 commits
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Marek Szyprowski authored
Decrease nr_thps counter in file's mapping to ensure that the page cache won't be dropped excessively on file write access if page has been already split. I've tried a test scenario running a big binary, kernel remaps it with THPs, then force a THP split with /sys/kernel/debug/split_huge_pages. During any further open of that binary with O_RDWR or O_WRITEONLY kernel drops page cache for it, because of non-zero thps counter. Link: https://lkml.kernel.org/r/20211012120237.2600-1-m.szyprowski@samsung.com Signed-off-by:
Marek Szyprowski <m.szyprowski@samsung.com> Fixes: 09d91cda ("mm,thp: avoid writes to file with THP in pagecache") Fixes: 06d3eff6 ("mm/thp: fix node page state in split_huge_page_to_list()") Acked-by:
Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by:
Yang Shi <shy828301@gmail.com> Cc: <sfoon.kim@samsung.com> Cc: Song Liu <songliubraving@fb.com> Cc: Rik van Riel <riel@surriel.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Hillf Danton <hdanton@sina.com> Cc: Hugh Dickins <hughd@google.com> Cc: William Kucharski <william.kucharski@oracle.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Miaohe Lin authored
kmem_cache_free_bulk() will call memcg_slab_free_hook() for all objects when doing bulk free. So we shouldn't call memcg_slab_free_hook() again for bulk free to avoid incorrect memcg slab count. Link: https://lkml.kernel.org/r/20210916123920.48704-6-linmiaohe@huawei.com Fixes: d1b2cf6c ("mm: memcg/slab: uncharge during kmem_cache_free_bulk()") Signed-off-by:
Miaohe Lin <linmiaohe@huawei.com> Reviewed-by:
Vlastimil Babka <vbabka@suse.cz> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Bharata B Rao <bharata@linux.ibm.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Faiyaz Mohammed <faiyazm@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kees Cook <keescook@chromium.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Roman Gushchin <guro@fb.com> Cc: <stable@vger.kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Miaohe Lin authored
When sysfs_slab_add failed, we shouldn't call debugfs_slab_add() for s because s will be freed soon. And slab_debugfs_fops will use s later leading to a use-after-free. Link: https://lkml.kernel.org/r/20210916123920.48704-5-linmiaohe@huawei.com Fixes: 64dd6849 ("mm: slub: move sysfs slab alloc/free interfaces to debugfs") Signed-off-by:
Miaohe Lin <linmiaohe@huawei.com> Reviewed-by:
Vlastimil Babka <vbabka@suse.cz> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Bharata B Rao <bharata@linux.ibm.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Faiyaz Mohammed <faiyazm@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kees Cook <keescook@chromium.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Roman Gushchin <guro@fb.com> Cc: <stable@vger.kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Miaohe Lin authored
In error path, the random_seq of slub cache might be leaked. Fix this by using __kmem_cache_release() to release all the relevant resources. Link: https://lkml.kernel.org/r/20210916123920.48704-4-linmiaohe@huawei.com Fixes: 210e7a43 ("mm: SLUB freelist randomization") Signed-off-by:
Miaohe Lin <linmiaohe@huawei.com> Reviewed-by:
Vlastimil Babka <vbabka@suse.cz> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Bharata B Rao <bharata@linux.ibm.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Faiyaz Mohammed <faiyazm@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kees Cook <keescook@chromium.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Roman Gushchin <guro@fb.com> Cc: <stable@vger.kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Miaohe Lin authored
If object's reuse is delayed, it will be excluded from the reconstructed freelist. But we forgot to adjust the cnt accordingly. So there will be a mismatch between reconstructed freelist depth and cnt. This will lead to free_debug_processing() complaining about freelist count or a incorrect slub inuse count. Link: https://lkml.kernel.org/r/20210916123920.48704-3-linmiaohe@huawei.com Fixes: c3895391 ("kasan, slub: fix handling of kasan_slab_free hook") Signed-off-by:
Miaohe Lin <linmiaohe@huawei.com> Reviewed-by:
Vlastimil Babka <vbabka@suse.cz> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Bharata B Rao <bharata@linux.ibm.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Faiyaz Mohammed <faiyazm@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kees Cook <keescook@chromium.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Roman Gushchin <guro@fb.com> Cc: <stable@vger.kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Miaohe Lin authored
Patch series "Fixups for slub". This series contains various bug fixes for slub. We fix memoryleak, use-afer-free, NULL pointer dereferencing and so on in slub. More details can be found in the respective changelogs. This patch (of 5): It's possible that __seq_open_private() will return NULL. So we should check it before using lest dereferencing NULL pointer. And in error paths, we forgot to release private buffer via seq_release_private(). Memory will leak in these paths. Link: https://lkml.kernel.org/r/20210916123920.48704-1-linmiaohe@huawei.com Link: https://lkml.kernel.org/r/20210916123920.48704-2-linmiaohe@huawei.com Fixes: 64dd6849 ("mm: slub: move sysfs slab alloc/free interfaces to debugfs") Signed-off-by:
Miaohe Lin <linmiaohe@huawei.com> Reviewed-by:
Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Faiyaz Mohammed <faiyazm@codeaurora.org> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Kees Cook <keescook@chromium.org> Cc: Bharata B Rao <bharata@linux.ibm.com> Cc: Roman Gushchin <guro@fb.com> Cc: <stable@vger.kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Eric Dumazet authored
syzbot reported access to unitialized memory in mbind() [1] Issue came with commit bda420b9 ("numa balancing: migrate on fault among multiple bound nodes") This commit added a new bit in MPOL_MODE_FLAGS, but only checked valid combination (MPOL_F_NUMA_BALANCING can only be used with MPOL_BIND) in do_set_mempolicy() This patch moves the check in sanitize_mpol_flags() so that it is also used by mbind() [1] BUG: KMSAN: uninit-value in __mpol_equal+0x567/0x590 mm/mempolicy.c:2260 __mpol_equal+0x567/0x590 mm/mempolicy.c:2260 mpol_equal include/linux/mempolicy.h:105 [inline] vma_merge+0x4a1/0x1e60 mm/mmap.c:1190 mbind_range+0xcc8/0x1e80 mm/mempolicy.c:811 do_mbind+0xf42/0x15f0 mm/mempolicy.c:1333 kernel_mbind mm/mempolicy.c:1483 [inline] __do_sys_mbind mm/mempolicy.c:1490 [inline] __se_sys_mbind+0x437/0xb80 mm/mempolicy.c:1486 __x64_sys_mbind+0x19d/0x200 mm/mempolicy.c:1486 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae Uninit was created at: slab_alloc_node mm/slub.c:3221 [inline] slab_alloc mm/slub.c:3230 [inline] kmem_cache_alloc+0x751/0xff0 mm/slub.c:3235 mpol_new mm/mempolicy.c:293 [inline] do_mbind+0x912/0x15f0 mm/mempolicy.c:1289 kernel_mbind mm/mempolicy.c:1483 [inline] __do_sys_mbind mm/mempolicy.c:1490 [inline] __se_sys_mbind+0x437/0xb80 mm/mempolicy.c:1486 __x64_sys_mbind+0x19d/0x200 mm/mempolicy.c:1486 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae ===================================================== Kernel panic - not syncing: panic_on_kmsan set ... CPU: 0 PID: 15049 Comm: syz-executor.0 Tainted: G B 5.15.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1ff/0x28e lib/dump_stack.c:106 dump_stack+0x25/0x28 lib/dump_stack.c:113 panic+0x44f/0xdeb kernel/panic.c:232 kmsan_report+0x2ee/0x300 mm/kmsan/report.c:186 __msan_warning+0xd7/0x150 mm/kmsan/instrumentation.c:208 __mpol_equal+0x567/0x590 mm/mempolicy.c:2260 mpol_equal include/linux/mempolicy.h:105 [inline] vma_merge+0x4a1/0x1e60 mm/mmap.c:1190 mbind_range+0xcc8/0x1e80 mm/mempolicy.c:811 do_mbind+0xf42/0x15f0 mm/mempolicy.c:1333 kernel_mbind mm/mempolicy.c:1483 [inline] __do_sys_mbind mm/mempolicy.c:1490 [inline] __se_sys_mbind+0x437/0xb80 mm/mempolicy.c:1486 __x64_sys_mbind+0x19d/0x200 mm/mempolicy.c:1486 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae Link: https://lkml.kernel.org/r/20211001215630.810592-1-eric.dumazet@gmail.com Fixes: bda420b9 ("numa balancing: migrate on fault among multiple bound nodes") Signed-off-by:
Eric Dumazet <edumazet@google.com> Reported-by:
syzbot <syzkaller@googlegroups.com> Acked-by:
Mel Gorman <mgorman@suse.de> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Peng Fan authored
mem=[X][G|M] is broken on ARM64 platform, there are cases that even type.cnt is 1, but total_size is not 0 because regions are merged into 1. So only check 'cnt' is not enough, total_size should be used, othersize bootargs 'mem=[X][G|B]' not work anymore. Link: https://lkml.kernel.org/r/20210930024437.32598-1-peng.fan@oss.nxp.com Fixes: e888fa7b ("memblock: Check memory add/cap ordering") Signed-off-by:
Peng Fan <peng.fan@nxp.com> Reviewed-by:
Mike Rapoport <rppt@linux.ibm.com> Cc: Geert Uytterhoeven <geert+renesas@glider.be> Cc: David Hildenbrand <david@redhat.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Huang Ying authored
The node demotion order needs to be updated during CPU hotplug. Because whether a NUMA node has CPU may influence the demotion order. The update function should be called during CPU online/offline after the node_states[N_CPU] has been updated. That is done in CPUHP_AP_ONLINE_DYN during CPU online and in CPUHP_MM_VMSTAT_DEAD during CPU offline. But in commit 884a6e5d ("mm/migrate: update node demotion order on hotplug events"), the function to update node demotion order is called in CPUHP_AP_ONLINE_DYN during CPU online/offline. This doesn't satisfy the order requirement. For example, there are 4 CPUs (P0, P1, P2, P3) in 2 sockets (P0, P1 in S0 and P2, P3 in S1), the demotion order is - S0 -> NUMA_NO_NODE - S1 -> NUMA_NO_NODE After P2 and P3 is offlined, because S1 has no CPU now, the demotion order should have been changed to - S0 -> S1 - S1 -> NO_NODE but it isn't changed, because the order updating callback for CPU hotplug doesn't see the new nodemask. After that, if P1 is offlined, the demotion order is changed to the expected order as above. So in this patch, we added CPUHP_AP_MM_DEMOTION_ONLINE and CPUHP_MM_DEMOTION_DEAD to be called after CPUHP_AP_ONLINE_DYN and CPUHP_MM_VMSTAT_DEAD during CPU online and offline, and register the update function on them. Link: https://lkml.kernel.org/r/20210929060351.7293-1-ying.huang@intel.com Fixes: 884a6e5d ("mm/migrate: update node demotion order on hotplug events") Signed-off-by:
"Huang, Ying" <ying.huang@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Wei Xu <weixugc@google.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Greg Thelen <gthelen@google.com> Cc: Keith Busch <kbusch@kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Dave Hansen authored
Once upon a time, the node demotion updates were driven solely by memory hotplug events. But now, there are handlers for both CPU and memory hotplug. However, the #ifdef around the code checks only memory hotplug. A system that has HOTPLUG_CPU=y but MEMORY_HOTPLUG=n would miss CPU hotplug events. Update the #ifdef around the common code. Add memory and CPU-specific #ifdefs for their handlers. These memory/CPU #ifdefs avoid unused function warnings when their Kconfig option is off. [arnd@arndb.de: rework hotplug_memory_notifier() stub] Link: https://lkml.kernel.org/r/20211013144029.2154629-1-arnd@kernel.org Link: https://lkml.kernel.org/r/20210924161255.E5FE8F7E@davehans-spike.ostc.intel.com Fixes: 884a6e5d ("mm/migrate: update node demotion order on hotplug events") Signed-off-by:
Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by:
Arnd Bergmann <arnd@arndb.de> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Wei Xu <weixugc@google.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Greg Thelen <gthelen@google.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Dave Hansen authored
Patch series "mm/migrate: 5.15 fixes for automatic demotion", v2. This contains two fixes for the "automatic demotion" code which was merged into 5.15: * Fix memory hotplug performance regression by watching suppressing any real action on irrelevant hotplug events. * Ensure CPU hotplug handler is registered when memory hotplug is disabled. This patch (of 2): == tl;dr == Automatic demotion opted for a simple, lazy approach to handling hotplug events. This noticeably slows down memory hotplug[1]. Optimize away updates to the demotion order when memory hotplug events should have no effect. This has no effect on CPU hotplug. There is no known problem on the CPU side and any work there will be in a separate series. == Background == Automatic demotion is a memory migration strategy to ensure that new allocations have room in faster memory tiers on tiered memory systems. The kernel maintains an array (node_demotion[]) to drive these migrations. The node_demotion[] path is calculated by starting at nodes with CPUs and then "walking" to nodes with memory. Only hotplug events which online or offline a node with memory (N_ONLINE) or CPUs (N_CPU) will actually affect the migration order. == Problem == However, the current code is lazy. It completely regenerates the migration order on *any* CPU or memory hotplug event. The logic was that these events are extremely rare and that the overhead from indiscriminate order regeneration is minimal. Part of the update logic involves a synchronize_rcu(), which is a pretty big hammer. Its overhead was large enough to be detected by some 0day tests that watch memory hotplug performance[1]. == Solution == Add a new helper (node_demotion_topo_changed()) which can differentiate between superfluous and impactful hotplug events. Skip the expensive update operation for superfluous events. == Aside: Locking == It took me a few moments to declare the locking to be safe enough for node_demotion_topo_changed() to work. It all hinges on the memory hotplug lock: During memory hotplug events, 'mem_hotplug_lock' is held for write. This ensures that two memory hotplug events can not be called simultaneously. CPU hotplug has a similar lock (cpuhp_state_mutex) which also provides mutual exclusion between CPU hotplug events. In addition, the demotion code acquire and hold the mem_hotplug_lock for read during its CPU hotplug handlers. This provides mutual exclusion between the demotion memory hotplug callbacks and the CPU hotplug callbacks. This effectively allows treating the migration target generation code to act as if it is single-threaded. 1. https://lore.kernel.org/all/20210905135932.GE15026@xsang-OptiPlex-9020/ Link: https://lkml.kernel.org/r/20210924161251.093CCD06@davehans-spike.ostc.intel.com Link: https://lkml.kernel.org/r/20210924161253.D7673E31@davehans-spike.ostc.intel.com Fixes: 884a6e5d ("mm/migrate: update node demotion order on hotplug events") Signed-off-by:
Dave Hansen <dave.hansen@linux.intel.com> Reported-by:
kernel test robot <oliver.sang@intel.com> Reviewed-by:
David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Wei Xu <weixugc@google.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Greg Thelen <gthelen@google.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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- 13 Oct, 2021 1 commit
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Mike Rapoport authored
Vladimir Zapolskiy reports: commit a7259df7 ("memblock: make memblock_find_in_range method private") invokes a kernel panic while running kmemleak on OF platforms with nomaped regions: Unable to handle kernel paging request at virtual address fff000021e00000 [...] scan_block+0x64/0x170 scan_gray_list+0xe8/0x17c kmemleak_scan+0x270/0x514 kmemleak_write+0x34c/0x4ac Indeed, NOMAP regions don't have linear map entries so an attempt to scan these areas would fault. Prevent such faults by excluding NOMAP regions from kmemleak. Link: https://lore.kernel.org/all/8ade5174-b143-d621-8c8e-dc6a1898c6fb@linaro.org Fixes: a7259df7 ("memblock: make memblock_find_in_range method private") Signed-off-by:
Mike Rapoport <rppt@linux.ibm.com> Tested-by:
Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>
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- 24 Sep, 2021 8 commits
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Chen Jun authored
We get an unexpected value of /proc/sys/vm/overcommit_memory after running the following program: int main() { int fd = open("/proc/sys/vm/overcommit_memory", O_RDWR); write(fd, "1", 1); write(fd, "2", 1); close(fd); } write(fd, "2", 1) will pass *ppos = 1 to proc_dointvec_minmax. proc_dointvec_minmax will return 0 without setting new_policy. t.data = &new_policy; ret = proc_dointvec_minmax(&t, write, buffer, lenp, ppos) -->do_proc_dointvec -->__do_proc_dointvec if (write) { if (proc_first_pos_non_zero_ignore(ppos, table)) goto out; sysctl_overcommit_memory = new_policy; so sysctl_overcommit_memory will be set to an uninitialized value. Check whether new_policy has been changed by proc_dointvec_minmax. Link: https://lkml.kernel.org/r/20210923020524.13289-1-chenjun102@huawei.com Fixes: 56f3547b ("mm: adjust vm_committed_as_batch according to vm overcommit policy") Signed-off-by:
Chen Jun <chenjun102@huawei.com> Acked-by:
Michal Hocko <mhocko@suse.com> Reviewed-by:
Feng Tang <feng.tang@intel.com> Reviewed-by:
Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Rui Xiang <rui.xiang@huawei.com> Cc: <stable@vger.kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Qi Zheng authored
The paired pte_unmap() call is missing before the dev_pagemap_mapping_shift() returns. So fix it. David says: "I guess this code never runs on 32bit / highmem, that's why we didn't notice so far". [akpm@linux-foundation.org: cleanup] Link: https://lkml.kernel.org/r/20210923122642.4999-1-zhengqi.arch@bytedance.com Signed-off-by:
Qi Zheng <zhengqi.arch@bytedance.com> Reviewed-by:
David Hildenbrand <david@redhat.com> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Weizhao Ouyang authored
Sync up MR_DEMOTION to migrate_reason_names and add a synch prompt. Link: https://lkml.kernel.org/r/20210921064553.293905-3-o451686892@gmail.com Fixes: 26aa2d19 ("mm/migrate: demote pages during reclaim") Signed-off-by:
Weizhao Ouyang <o451686892@gmail.com> Reviewed-by:
"Huang, Ying" <ying.huang@intel.com> Reviewed-by:
John Hubbard <jhubbard@nvidia.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Mina Almasry <almasrymina@google.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Wei Xu <weixugc@google.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Weizhao Ouyang authored
Sync up MR_CONTIG_RANGE and MR_LONGTERM_PIN to migrate_reason_names. Link: https://lkml.kernel.org/r/20210921064553.293905-2-o451686892@gmail.com Fixes: 31025351 ("mm/migrate: rename migration reason MR_CMA to MR_CONTIG_RANGE") Fixes: d1e153fe ("mm/gup: migrate pinned pages out of movable zone") Signed-off-by:
Weizhao Ouyang <o451686892@gmail.com> Reviewed-by:
"Huang, Ying" <ying.huang@intel.com> Reviewed-by:
John Hubbard <jhubbard@nvidia.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Yang Shi <yang.shi@linux.alibaba.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Mina Almasry <almasrymina@google.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Wei Xu <weixugc@google.com> Cc: <stable@vger.kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Minchan Kim authored
The kernel test robot reported the regression of fio.write_iops[1] with commit 8cc621d2 ("mm: fs: invalidate BH LRU during page migration"). Since lru_add_drain is called frequently, invalidate bh_lrus there could increase bh_lrus cache miss ratio, which needs more IO in the end. This patch moves the bh_lrus invalidation from the hot path( e.g., zap_page_range, pagevec_release) to cold path(i.e., lru_add_drain_all, lru_cache_disable). Zhengjun Xing confirmed "I test the patch, the regression reduced to -2.9%" [1] https://lore.kernel.org/lkml/20210520083144.GD14190@xsang-OptiPlex-9020/ [2] 8cc621d2, mm: fs: invalidate BH LRU during page migration Link: https://lkml.kernel.org/r/20210907212347.1977686-1-minchan@kernel.org Signed-off-by:
Minchan Kim <minchan@kernel.org> Reported-by:
kernel test robot <oliver.sang@intel.com> Reviewed-by:
Chris Goldsworthy <cgoldswo@codeaurora.org> Tested-by:
"Xing, Zhengjun" <zhengjun.xing@intel.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Liu Yuntao authored
In the case of SHMEM_HUGE_WITHIN_SIZE, the page index is not rounded up correctly. When the page index points to the first page in a huge page, round_up() cannot bring it to the end of the huge page, but to the end of the previous one. An example: HPAGE_PMD_NR on my machine is 512(2 MB huge page size). After allcoating a 3000 KB buffer, I access it at location 2050 KB. In shmem_is_huge(), the corresponding index happens to be 512. After rounded up by HPAGE_PMD_NR, it will still be 512 which is smaller than i_size, and shmem_is_huge() will return true. As a result, my buffer takes an additional huge page, and that shouldn't happen when shmem_enabled is set to within_size. Link: https://lkml.kernel.org/r/20210909032007.18353-1-liuyuntao10@huawei.com Fixes: f3f0e1d2 ("khugepaged: add support of collapse for tmpfs/shmem pages") Signed-off-by:
Liu Yuntao <liuyuntao10@huawei.com> Acked-by:
Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by:
Hugh Dickins <hughd@google.com> Cc: wuxu.wu <wuxu.wu@huawei.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Adam Borowski authored
gcc knows the true length too, and rightfully complains. Link: https://lkml.kernel.org/r/20210912204447.10427-1-kilobyte@angband.pl Signed-off-by:
Adam Borowski <kilobyte@angband.pl> Cc: SeongJae Park <sj38.park@gmail.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Naoya Horiguchi authored
Commit fcc00621 ("mm/hwpoison: retry with shake_page() for unhandlable pages") changed the return value of __get_hwpoison_page() to retry for transiently unhandlable cases. However, __get_hwpoison_page() currently fails to properly judge buddy pages as handlable, so hard/soft offline for buddy pages always fail as "unhandlable page". This is totally regrettable. So let's add is_free_buddy_page() in HWPoisonHandlable(), so that __get_hwpoison_page() returns different return values between buddy pages and unhandlable pages as intended. Link: https://lkml.kernel.org/r/20210909004131.163221-1-naoya.horiguchi@linux.dev Fixes: fcc00621 ("mm/hwpoison: retry with shake_page() for unhandlable pages") Signed-off-by:
Naoya Horiguchi <naoya.horiguchi@nec.com> Acked-by:
David Hildenbrand <david@redhat.com> Reviewed-by:
Yang Shi <shy828301@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: <stable@vger.kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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- 23 Sep, 2021 1 commit
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Shakeel Butt authored
Prior to the commit 7e1c0d6f ("memcg: switch lruvec stats to rstat") and the commit aa48e47e ("memcg: infrastructure to flush memcg stats"), each lruvec memcg stats can be off by (nr_cgroups * nr_cpus * 32) at worst and for unbounded amount of time. The commit aa48e47e moved the lruvec stats to rstat infrastructure and the commit 7e1c0d6f bounded the error for all the lruvec stats to (nr_cpus * 32) at worst for at most 2 seconds. More specifically it decoupled the number of stats and the number of cgroups from the error rate. However this reduction in error comes with the cost of triggering the slowpath of stats update more frequently. Previously in the slowpath the kernel adds the stats up the memcg tree. After aa48e47e, the kernel triggers the asyn lruvec stats flush through queue_work(). This causes regression reports from 0day kernel bot [1] as well as from phoronix test suite [2]. We tried two options to fix the regression: 1) Increase the threshold to trigger the slowpath in lruvec stats update codepath from 32 to 512. 2) Remove the slowpath from lruvec stats update codepath and instead flush the stats in the page refault codepath. The assumption is that the kernel timely flush the stats, so, the update tree would be small in the refault codepath to not cause the preformance impact. Following are the results of will-it-scale/page_fault[1|2|3] benchmark on four settings i.e. (1) 5.15-rc1 as baseline (2) 5.15-rc1 with aa48e47e and 7e1c0d6f reverted (3) 5.15-rc1 with option-1 (4) 5.15-rc1 with option-2. test (1) (2) (3) (4) pg_f1 368563 406277 (10.23%) 399693 (8.44%) 416398 (12.97%) pg_f2 338399 372133 (9.96%) 369180 (9.09%) 381024 (12.59%) pg_f3 500853 575399 (14.88%) 570388 (13.88%) 576083 (15.02%) From the above result, it seems like the option-2 not only solves the regression but also improves the performance for at least these benchmarks. Feng Tang (intel) ran the aim7 benchmark with these two options and confirms that option-1 reduces the regression but option-2 removes the regression. Michael Larabel (phoronix) ran multiple benchmarks with these options and reported the results at [3] and it shows for most benchmarks option-2 removes the regression introduced by the commit aa48e47e ("memcg: infrastructure to flush memcg stats"). Based on the experiment results, this patch proposed the option-2 as the solution to resolve the regression. Link: https://lore.kernel.org/all/20210726022421.GB21872@xsang-OptiPlex-9020 [1] Link: https://www.phoronix.com/scan.php?page=article&item=linux515-compile-regress [2] Link: https://openbenchmarking.org/result/2109226-DEBU-LINUX5104 [3] Fixes: aa48e47e ("memcg: infrastructure to flush memcg stats") Signed-off-by:
Shakeel Butt <shakeelb@google.com> Tested-by:
Michael Larabel <Michael@phoronix.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Roman Gushchin <guro@fb.com> Cc: Feng Tang <feng.tang@intel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Hillf Danton <hdanton@sina.com>, Cc: Michal Koutný <mkoutny@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org>, Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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