- 04 Oct, 2023 40 commits
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Alexander Potapenko authored
Clang 18 learned to optimize away memcpy() calls of small uninitialized scalar values. To ensure that memcpy tests in kmsan_test.c still perform calls to memcpy() (which KMSAN replaces with __msan_memcpy()), declare a separate memcpy_noinline() function with volatile parameters, which won't be optimized. Also retire DO_NOT_OPTIMIZE(), as memcpy_noinline() is apparently enough. Link: https://lkml.kernel.org/r/20230911145702.2663753-2-glider@google.comSigned-off-by: Alexander Potapenko <glider@google.com> Acked-by: Marco Elver <elver@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Alexander Potapenko authored
kmsan_internal_memmove_metadata() is the function that implements copying metadata every time memcpy()/memmove() is called. Because shadow memory stores 1 byte per each byte of kernel memory, copying the shadow is trivial and can be done by a single memmove() call. Origins, on the other hand, are stored as 4-byte values corresponding to every aligned 4 bytes of kernel memory. Therefore, if either the source or the destination of kmsan_internal_memmove_metadata() is unaligned, the number of origin slots corresponding to the source or destination may differ: 1) memcpy(0xffff888080a00000, 0xffff888080900000, 4) copies 1 origin slot into 1 origin slot: src (0xffff888080900000): xxxx src origins: o111 dst (0xffff888080a00000): xxxx dst origins: o111 2) memcpy(0xffff888080a00001, 0xffff888080900000, 4) copies 1 origin slot into 2 origin slots: src (0xffff888080900000): xxxx src origins: o111 dst (0xffff888080a00000): .xxx x... dst origins: o111 o111 3) memcpy(0xffff888080a00000, 0xffff888080900001, 4) copies 2 origin slots into 1 origin slot: src (0xffff888080900000): .xxx x... src origins: o111 o222 dst (0xffff888080a00000): xxxx dst origins: o111 (or o222) Previously, kmsan_internal_memmove_metadata() tried to solve this problem by copying min(src_slots, dst_slots) as is and cloning the missing slot on one of the ends, if needed. This was error-prone even in the simple cases where 4 bytes were copied, and did not account for situations where the total number of nonzero origin slots could have increased by more than one after copying: memcpy(0xffff888080a00000, 0xffff888080900002, 8) src (0xffff888080900002): ..xx .... xx.. src origins: o111 0000 o222 dst (0xffff888080a00000): xx.. ..xx o111 0000 (or 0000 o222) The new implementation simply copies the shadow byte by byte, and updates the corresponding origin slot, if the shadow byte is nonzero. This approach can handle complex cases with mixed initialized and uninitialized bytes. Similarly to KMSAN inline instrumentation, latter writes to bytes sharing the same origin slots take precedence. Link: https://lkml.kernel.org/r/20230911145702.2663753-1-glider@google.com Fixes: f80be457 ("kmsan: add KMSAN runtime core") Signed-off-by: Alexander Potapenko <glider@google.com> Acked-by: Marco Elver <elver@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Aleksa Sarai authored
Commit 434ed335 ("memfd: improve userspace warnings for missing exec-related flags") attempted to make these warnings more useful (so they would work as an incentive to get users to switch to specifying these flags -- as intended by the original MFD_NOEXEC_SEAL patchset). Unfortunately, it turns out that even INFO-level logging is too extreme to enable by default and alternative solutions to the spam issue (such as doing more extreme rate-limiting per-task) are either too ugly or overkill for something as simple as emitting a log as a developer aid. Given that the flags are new and there is no harm to not specifying them (after all, we maintain backwards compatibility) we can just drop the warnings for now until some time in the future when most programs have migrated and distributions start using vm.memfd_noexec=1 (where failing to pass the flag would result in unexpected errors for programs that use executable memfds). Link: https://lkml.kernel.org/r/20230912-memfd-reduce-spam-v2-1-7d92a4964b6a@cyphar.com Fixes: 434ed335 ("memfd: improve userspace warnings for missing exec-related flags") Fixes: 2562d67b ("revert "memfd: improve userspace warnings for missing exec-related flags".") Signed-off-by: Aleksa Sarai <cyphar@cyphar.com> Reported-by: Damian Tometzki <dtometzki@fedoraproject.org> Reviewed-by: Christian Brauner <brauner@kernel.org> Cc: Daniel Verkamp <dverkamp@chromium.org> Cc: Jeff Xu <jeffxu@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Ying Sun authored
The value of “.fs_flags” in line 4608 is a dead code which will never be implemented,because its conditions of line 47 "#ifdef CONFIG_SHMEM" and line 4607 are mutually exclusive. It is recommended to delete redundant code. Link: https://lkml.kernel.org/r/20230906045012.14999-1-sunying@nj.iscas.ac.cnSigned-off-by: Ying Sun <sunying@nj.iscas.ac.cn> Suggested-by: Yanjie Ren <renyanjie01@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Angus Chen authored
If panic is enable,the err information will not be printed before bugon, So swap it. Print the return value of PTR_ERR(pgdat->kswapd) also. Link: https://lkml.kernel.org/r/20230906083700.181-1-angus.chen@jaguarmicro.comSigned-off-by: Angus Chen <angus.chen@jaguarmicro.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Yajun Deng authored
There is a similar pr_info in free_area_init_node(), so remove the redundant pr_info. before: [ 0.006314] Initializing node 0 as memoryless [ 0.006445] Initmem setup node 0 as memoryless [ 0.006450] Initmem setup node 1 [mem 0x0000000000001000-0x000000003fffffff] [ 0.006453] Initmem setup node 2 [mem 0x0000000040000000-0x000000007ffd7fff] [ 0.006454] Initializing node 3 as memoryless [ 0.006584] Initmem setup node 3 as memoryless [ 0.006585] Initmem setup node 4 [mem 0x0000000100000000-0x00000001bfffffff] [ 0.006586] Initmem setup node 5 [mem 0x00000001c0000000-0x00000001ffffffff] [ 0.006587] Initmem setup node 6 [mem 0x0000000200000000-0x000000023fffffff] after: [ 0.004147] Initmem setup node 0 as memoryless [ 0.004148] Initmem setup node 1 [mem 0x0000000000001000-0x000000003fffffff] [ 0.004150] Initmem setup node 2 [mem 0x0000000040000000-0x000000007ffd7fff] [ 0.004154] Initmem setup node 3 as memoryless [ 0.004155] Initmem setup node 4 [mem 0x0000000100000000-0x00000001bfffffff] [ 0.004156] Initmem setup node 5 [mem 0x00000001c0000000-0x00000001ffffffff] [ 0.004157] Initmem setup node 6 [mem 0x0000000200000000-0x000000023fffffff] Link: https://lkml.kernel.org/r/20230906091113.4029983-1-yajun.deng@linux.devSigned-off-by: Yajun Deng <yajun.deng@linux.dev> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Yuan Can authored
In vmemmap_remap_free(), a new head vmemmap page is allocated to avoid breaking a contiguous block of struct page memory, however, the allocation can always fail when the given node is movable node. Remove the __GFP_THISNODE to help avoid fragmentation. Link: https://lkml.kernel.org/r/20230906093157.9737-1-yuancan@huawei.comSigned-off-by: Yuan Can <yuancan@huawei.com> Suggested-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Suggested-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Xiu Jianfeng authored
expand_upwards() and expand_downwards() will return -EFAULT if VM_GROWSUP or VM_GROWSDOWN is not correctly set in vma->vm_flags, however in !CONFIG_STACK_GROWSUP case, expand_stack_locked() returns -EINVAL first if !(vma->vm_flags & VM_GROWSDOWN) before calling expand_downwards(), to keep the consistency with CONFIG_STACK_GROWSUP case, remove this check. The usages of this function are as below: A:fs/exec.c ret = expand_stack_locked(vma, stack_base); if (ret) ret = -EFAULT; or B:mm/memory.c mm/mmap.c if (expand_stack_locked(vma, addr)) return NULL; which means the return value will not propagate to other places, so I believe there is no user-visible effects of this change, and it's unnecessary to backport to earlier versions. Link: https://lkml.kernel.org/r/20230906103312.645712-1-xiujianfeng@huaweicloud.com Fixes: f440fa1a ("mm: make find_extend_vma() fail if write lock not held") Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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SeongJae Park authored
damon_aggregateed tracepoint is receiving 'struct target *', but doesn't use it. Remove it from the prototype. Link: https://lkml.kernel.org/r/20230907022929.91361-12-sj@kernel.orgSigned-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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SeongJae Park authored
The comment for explaining about watermarks-based monitoring part deactivation is duplicated in two paragraphs. Remove one. Link: https://lkml.kernel.org/r/20230907022929.91361-11-sj@kernel.orgSigned-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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SeongJae Park authored
The comment on struct damon_region about nr_accesses field looks not sufficient. Many people actually used to ask what nr_accesses mean. There is more detailed explanation of the mechanism on the comment for struct damon_attrs, but it is also ambiguous, as it doesn't specify the name of the counter for aggregating the access check results. Make those more detailed. Link: https://lkml.kernel.org/r/20230907022929.91361-10-sj@kernel.orgSigned-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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SeongJae Park authored
The comment on damon_set_attrs() says it should not be called while the kdamond is running, but now some DAMON modules like sysfs interface and DAMON_RECLAIM call it from after_aggregation() and/or after_wmarks_check() callbacks for online tuning. Update the comment. Link: https://lkml.kernel.org/r/20230907022929.91361-9-sj@kernel.orgSigned-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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SeongJae Park authored
The explanation of kdamond and context is duplicated in the design and the usage documents. Replace that in the usage with links to those in the design document. Link: https://lkml.kernel.org/r/20230907022929.91361-8-sj@kernel.orgSigned-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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SeongJae Park authored
The design document is not explaining about the concept of kdamond and the DAMON context, while usage document does. Those concept explanation should be in the design document, and usage document should link those. Add a section for those. Link: https://lkml.kernel.org/r/20230907022929.91361-7-sj@kernel.orgSigned-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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SeongJae Park authored
The example of the section for damon_aggregated tracepoint is not explaining how the output looks like, and how it can be interpreted. Add it. Link: https://lkml.kernel.org/r/20230907022929.91361-6-sj@kernel.orgSigned-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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SeongJae Park authored
The design document is explaining about the access tracking mechanism and the access rate counter (nr_accesses), but not directly mentions the name. Add a sentence for making it clear. Link: https://lkml.kernel.org/r/20230907022929.91361-5-sj@kernel.orgSigned-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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SeongJae Park authored
On the DAMON usage introduction section, the introduction of DAMON debugfs interface, which is deprecated, is above kernel API, which is actively supported. Move the DAMON debugfs intro to bottom, so that readers have less chances to read it. Link: https://lkml.kernel.org/r/20230907022929.91361-4-sj@kernel.orgSigned-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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SeongJae Park authored
debugfs interface is deprecated. Put it at the bottom of the document so that readers have less chances to read it. Link: https://lkml.kernel.org/r/20230907022929.91361-3-sj@kernel.orgSigned-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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SeongJae Park authored
Patch series "mm/damon: misc fixups for documents, comments and its tracepoint". This patchset contains miscellaneous simple fixups for documents, comments and tracepoint of DAMON. This patch (of 11): A cross-link reference in DAMON usage document is missing ':ref:' Sphynx keyword. Fix it. Link: https://lkml.kernel.org/r/20230907022929.91361-1-sj@kernel.org Link: https://lkml.kernel.org/r/20230907022929.91361-2-sj@kernel.orgSigned-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Nhat Pham authored
Out of zswap's 3 allocators, zsmalloc is the clear superior in terms of memory utilization, both in theory and as observed in practice, with its high storage density and low internal fragmentation. zsmalloc is also more actively developed and maintained, since it is the allocator of choice for zswap for many users, as well as the only allocator for zram. A historical objection to the selection of zsmalloc as the default allocator for zswap is its lack of writeback capability. However, this has changed, with the zsmalloc writeback patchset, and the subsequent zswap LRU refactor. With this, there is not a lot of good reasons to keep zbud, an otherwise inferior allocator, as the default instead of zswap. This patch changes the default allocator to zsmalloc. The only exception is on settings without MMU, in which case zbud will remain as the default. Link: https://lkml.kernel.org/r/20230908235115.2943486-1-nphamcs@gmail.comSigned-off-by: Nhat Pham <nphamcs@gmail.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Yosry Ahmed <yosryahmed@google.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Cc: Seth Jennings <sjenning@redhat.com> Cc: Vitaly Wool <vitaly.wool@konsulko.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Joel Fernandes authored
It is possible that the aligned address falls on no existing mapping, however that does not mean that we can just align it down to that. This test verifies that the "vma->vm_start != addr_to_align" check in can_align_down() prevents disastrous results if aligning down when source and dest are mutually aligned within a PMD but the source/dest addresses requested are not at the beginning of the respective mapping containing these addresses. Link: https://lkml.kernel.org/r/20230903151328.2981432-8-joel@joelfernandes.orgSigned-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lokesh Gidra <lokeshgidra@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Joel Fernandes (Google) authored
Move a block of memory within a memory range. Any alignment optimization on the source address may cause corruption. Verify using kselftest that it works. I have also verified with tracing that such optimization does not happen due to this check in can_align_down(): if (!for_stack && vma->vm_start != addr_to_align) return false; Link: https://lkml.kernel.org/r/20230903151328.2981432-7-joel@joelfernandes.orgSigned-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lokesh Gidra <lokeshgidra@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Joel Fernandes (Google) authored
This patch adds support for verifying that we correctly handle the situation where something is already mapped before the destination of the remap. Any realignment of destination address and PMD-copy will destroy that existing mapping. In such cases, we need to avoid doing the optimization. To test this, we map an area called the preamble before the remap region. Then we verify after the mremap operation that this region did not get corrupted. Putting some prints in the kernel, I verified that we optimize correctly in different situations: Optimize when there is alignment and no previous mapping (this is tested by previous patch). <prints> can_align_down(old_vma->vm_start=2900000, old_addr=2900000, mask=-2097152): 0 can_align_down(new_vma->vm_start=2f00000, new_addr=2f00000, mask=-2097152): 0 === Starting move_page_tables === Doing PUD move for 2800000 -> 2e00000 of extent=200000 <-- Optimization Doing PUD move for 2a00000 -> 3000000 of extent=200000 Doing PUD move for 2c00000 -> 3200000 of extent=200000 </prints> Don't optimize when there is alignment but there is previous mapping (this is tested by this patch). Notice that can_align_down() returns 1 for the destination mapping as we detected there is something there. <prints> can_align_down(old_vma->vm_start=2900000, old_addr=2900000, mask=-2097152): 0 can_align_down(new_vma->vm_start=5700000, new_addr=5700000, mask=-2097152): 1 === Starting move_page_tables === Doing move_ptes for 2900000 -> 5700000 of extent=100000 <-- Unoptimized Doing PUD move for 2a00000 -> 5800000 of extent=200000 Doing PUD move for 2c00000 -> 5a00000 of extent=200000 </prints> Link: https://lkml.kernel.org/r/20230903151328.2981432-6-joel@joelfernandes.orgSigned-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lokesh Gidra <lokeshgidra@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Joel Fernandes (Google) authored
This patch adds a test case to check if a PMD-alignment optimization successfully happens. I add support to make sure there is some room before the source mapping, otherwise the optimization to trigger PMD-aligned move will be disabled as the kernel will detect that a mapping before the source exists and such optimization becomes impossible. Link: https://lkml.kernel.org/r/20230903151328.2981432-5-joel@joelfernandes.orgSigned-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lokesh Gidra <lokeshgidra@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Joel Fernandes (Google) authored
When a valid remap region could not be found, the source mapping is not cleaned up. Fix the goto statement such that the clean up happens. Link: https://lkml.kernel.org/r/20230903151328.2981432-4-joel@joelfernandes.orgSigned-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lokesh Gidra <lokeshgidra@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Joel Fernandes (Google) authored
For the stack move happening in shift_arg_pages(), the move is happening within the same VMA which spans the old and new ranges. In case the aligned address happens to fall within that VMA, allow such moves and don't abort the mremap alignment optimization. In the regular non-stack mremap case, we cannot allow any such moves as will end up destroying some part of the mapping (either the source of the move, or part of the existing mapping). So just avoid it for stack moves. Link: https://lkml.kernel.org/r/20230903151328.2981432-3-joel@joelfernandes.orgSigned-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lokesh Gidra <lokeshgidra@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Joel Fernandes (Google) authored
Patch series "Optimize mremap during mutual alignment within PMD", v6. This patchset optimizes the start addresses in move_page_tables() and tests the changes. It addresses a warning [1] that occurs due to a downward, overlapping move on a mutually-aligned offset within a PMD during exec. By initiating the copy process at the PMD level when such alignment is present, we can prevent this warning and speed up the copying process at the same time. Linus Torvalds suggested this idea. Check the individual patches for more details. [1] https://lore.kernel.org/all/ZB2GTBD%2FLWTrkOiO@dhcp22.suse.cz/ This patch (of 7): Recently, we see reports [1] of a warning that triggers due to move_page_tables() doing a downward and overlapping move on a mutually-aligned offset within a PMD. By mutual alignment, I mean the source and destination addresses of the mremap are at the same offset within a PMD. This mutual alignment along with the fact that the move is downward is sufficient to cause a warning related to having an allocated PMD that does not have PTEs in it. This warning will only trigger when there is mutual alignment in the move operation. A solution, as suggested by Linus Torvalds [2], is to initiate the copy process at the PMD level whenever such alignment is present. Implementing this approach will not only prevent the warning from being triggered, but it will also optimize the operation as this method should enhance the speed of the copy process whenever there's a possibility to start copying at the PMD level. Some more points: a. The optimization can be done only when both the source and destination of the mremap do not have anything mapped below it up to a PMD boundary. I add support to detect that. b. #1 is not a problem for the call to move_page_tables() from exec.c as nothing is expected to be mapped below the source. However, for non-overlapping mutually aligned moves as triggered by mremap(2), I added support for checking such cases. c. I currently only optimize for PMD moves, in the future I/we can build on this work and do PUD moves as well if there is a need for this. But I want to take it one step at a time. d. We need to be careful about mremap of ranges within the VMA itself. For this purpose, I added checks to determine if the address after alignment falls within its VMA itself. [1] https://lore.kernel.org/all/ZB2GTBD%2FLWTrkOiO@dhcp22.suse.cz/ [2] https://lore.kernel.org/all/CAHk-=whd7msp8reJPfeGNyt0LiySMT0egExx3TVZSX3Ok6X=9g@mail.gmail.com/ Link: https://lkml.kernel.org/r/20230903151328.2981432-1-joel@joelfernandes.org Link: https://lkml.kernel.org/r/20230903151328.2981432-2-joel@joelfernandes.orgSigned-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Lokesh Gidra <lokeshgidra@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Yuan Can authored
The decreasing of hugetlb pages number failed with the following message given: sh: page allocation failure: order:0, mode:0x204cc0(GFP_KERNEL|__GFP_RETRY_MAYFAIL|__GFP_THISNODE) CPU: 1 PID: 112 Comm: sh Not tainted 6.5.0-rc7-... #45 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace.part.6+0x84/0xe4 show_stack+0x18/0x24 dump_stack_lvl+0x48/0x60 dump_stack+0x18/0x24 warn_alloc+0x100/0x1bc __alloc_pages_slowpath.constprop.107+0xa40/0xad8 __alloc_pages+0x244/0x2d0 hugetlb_vmemmap_restore+0x104/0x1e4 __update_and_free_hugetlb_folio+0x44/0x1f4 update_and_free_hugetlb_folio+0x20/0x68 update_and_free_pages_bulk+0x4c/0xac set_max_huge_pages+0x198/0x334 nr_hugepages_store_common+0x118/0x178 nr_hugepages_store+0x18/0x24 kobj_attr_store+0x18/0x2c sysfs_kf_write+0x40/0x54 kernfs_fop_write_iter+0x164/0x1dc vfs_write+0x3a8/0x460 ksys_write+0x6c/0x100 __arm64_sys_write+0x1c/0x28 invoke_syscall+0x44/0x100 el0_svc_common.constprop.1+0x6c/0xe4 do_el0_svc+0x38/0x94 el0_svc+0x28/0x74 el0t_64_sync_handler+0xa0/0xc4 el0t_64_sync+0x174/0x178 Mem-Info: ... The reason is that the hugetlb pages being released are allocated from movable nodes, and with hugetlb_optimize_vmemmap enabled, vmemmap pages need to be allocated from the same node during the hugetlb pages releasing. With GFP_KERNEL and __GFP_THISNODE set, allocating from movable node is always failed. Fix this problem by removing __GFP_THISNODE. Link: https://lkml.kernel.org/r/20230905124503.24899-1-yuancan@huawei.com Fixes: ad2fa371 ("mm: hugetlb: alloc the vmemmap pages associated with each HugeTLB page") Signed-off-by: Yuan Can <yuancan@huawei.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Uros Bizjak authored
Use this_cpu_try_cmpxchg instead of this_cpu_cmpxchg (*ptr, old, new) == old in mod_zone_state and mod_node_state. x86 CMPXCHG instruction returns success in ZF flag, so this change saves a compare after cmpxchg (and related move instruction in front of cmpxchg). Also, try_cmpxchg implicitly assigns old *ptr value to "old" when cmpxchg fails. There is no need to re-read the value in the loop. No functional change intended. Link: https://lkml.kernel.org/r/20230904150917.8318-1-ubizjak@gmail.comSigned-off-by: Uros Bizjak <ubizjak@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Matthew Wilcox (Oracle) authored
The one caller of DAX lock/unlock page already calls compound_head(), so use page_folio() instead, then use a folio throughout the DAX code to remove uses of page->mapping and page->index. [jane.chu@oracle.com: add comment to mf_generic_kill_procss(), simplify mf_generic_kill_procs:folio initialization] Link: https://lkml.kernel.org/r/20230908222336.186313-1-jane.chu@oracle.com Link: https://lkml.kernel.org/r/20230822231314.349200-1-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Jane Chu <jane.chu@oracle.com> Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jane Chu <jane.chu@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Mateusz Guzik authored
The feature got retired in f1a79412 ("mm: convert mm's rss stats into percpu_counter"), but the patch failed to fully clean it up. Link: https://lkml.kernel.org/r/20230823170556.2281747-1-mjguzik@gmail.comSigned-off-by: Mateusz Guzik <mjguzik@gmail.com> Acked-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Vern Hao authored
In skip_cma(), we can use folio_migratetype() to replace get_pageblock_migratetype(). Link: https://lkml.kernel.org/r/20230825075735.52436-1-user@VERNHAO-MC1Signed-off-by: Vern Hao <vernhao@tencent.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Zhaoyang Huang <zhaoyang.huang@unisoc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Lorenzo Stoakes authored
si_mem_available() needlessly places LRU statistics into an array before retrieving only two of them, simply access those directly. In addition, refactor the code so that the blocks of code which calculate the page cache and reclaimable components each resemble one another to clearly indicate we cap both against wmark_low in the same fashion. Link: https://lkml.kernel.org/r/20230827110848.43510-1-lstoakes@gmail.comSigned-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Xueshi Hu authored
In set_nr_huge_pages(), local variable "count" is used to record persistent_huge_pages(), but when it cames to nodes huge page allocation, the semantics changes to nr_huge_pages. When there exists surplus huge pages and using the interface under /sys/devices/system/node/node*/hugepages to change huge page pool size, this difference can result in the allocation of an unexpected number of huge pages. Steps to reproduce the bug: Starting with: Node 0 Node 1 Total HugePages_Total 0.00 0.00 0.00 HugePages_Free 0.00 0.00 0.00 HugePages_Surp 0.00 0.00 0.00 create 100 huge pages in Node 0 and consume it, then set Node 0 's nr_hugepages to 0. yields: Node 0 Node 1 Total HugePages_Total 200.00 0.00 200.00 HugePages_Free 0.00 0.00 0.00 HugePages_Surp 200.00 0.00 200.00 write 100 to Node 1's nr_hugepages echo 100 > /sys/devices/system/node/node1/\ hugepages/hugepages-2048kB/nr_hugepages gets: Node 0 Node 1 Total HugePages_Total 200.00 400.00 600.00 HugePages_Free 0.00 400.00 400.00 HugePages_Surp 200.00 0.00 200.00 Kernel is expected to create only 100 huge pages and it gives 200. Link: https://lkml.kernel.org/r/20230829033343.467779-1-xueshi.hu@smartx.com Fixes: 9a305230 ("hugetlb: add per node hstate attributes") Signed-off-by: Xueshi Hu <xueshi.hu@smartx.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Mike Kravetz authored
Currently, vmemmap optimization of hugetlb pages is performed before the hugetlb flag (previously hugetlb destructor) is set identifying it as a hugetlb folio. This means there is a window of time where an ordinary folio does not have all associated vmemmap present. The core mm only expects vmemmap to be potentially optimized for hugetlb and device dax. This can cause problems in code such as memory error handling that may want to write to tail struct pages. There is only one call to perform hugetlb vmemmap optimization today. To fix this issue, simply set the hugetlb flag before that call. There was a similar issue in the free hugetlb path that was previously addressed. The two routines that optimize or restore hugetlb vmemmap should only be passed hugetlb folios/pages. To catch any callers not following this rule, add VM_WARN_ON calls to the routines. In the hugetlb free code paths, some calls could be made to restore vmemmap after clearing the hugetlb flag. This was 'safe' as in these cases vmemmap was already present and the call was a NOOP. However, for consistency these calls where eliminated so that we can add the VM_WARN_ON checks. Link: https://lkml.kernel.org/r/20230829213734.69673-1-mike.kravetz@oracle.com Fixes: f41f2ed4 ("mm: hugetlb: free the vmemmap pages associated with each HugeTLB page") Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Cc: James Houghton <jthoughton@google.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev> Cc: Usama Arif <usama.arif@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Anthony Yznaga authored
Fix insert_vm_struct() so that only accounted memory is unaccounted if vma_link() fails. Link: https://lkml.kernel.org/r/20230830004324.16101-1-anthony.yznaga@oracle.com Fixes: d4af56c5 ("mm: start tracking VMAs with maple tree") Signed-off-by: Anthony Yznaga <anthony.yznaga@oracle.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Anthony Yznaga authored
Fix mremap so that only accounted memory is unaccounted if the mapping is expandable but vma_merge() fails. Link: https://lkml.kernel.org/r/20230830004549.16131-1-anthony.yznaga@oracle.com Fixes: fdbef614 ("mm/mremap: don't account pages in vma_to_resize()") Signed-off-by: Anthony Yznaga <anthony.yznaga@oracle.com> Acked-by: Brian Geffon <bgeffon@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Ding Xiang authored
The opened file should be closed in run_with_tmpfile(), otherwise resource leak will occur Link: https://lkml.kernel.org/r/20230831093144.7520-1-dingxiang@cmss.chinamobile.comSigned-off-by: Ding Xiang <dingxiang@cmss.chinamobile.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Kemeng Shi authored
We always do zone_watermark_ok check and compaction_suitable check together to test if compaction for target order should be ran. Factor these code out to remove repeat code. Link: https://lkml.kernel.org/r/20230901155141.249860-7-shikemeng@huaweicloud.comSigned-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Kemeng Shi authored
We do proactive compaction with order == -1 via 1. /proc/sys/vm/compact_memory 2. /sys/devices/system/node/nodex/compact 3. /proc/sys/vm/compaction_proactiveness Add missed situation in which order == -1. Link: https://lkml.kernel.org/r/20230901155141.249860-6-shikemeng@huaweicloud.comSigned-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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