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2024-03-05mm: huge_memory: enable debugfs to split huge pages to any orderZi Yan1-12/+22
It is used to test split_huge_page_to_list_to_order for pagecache THPs. Also add test cases for split_huge_page_to_list_to_order via both debugfs. [ziy@nvidia.com: fix issue discovered with NFS] Link: https://lkml.kernel.org/r/262E4DAA-4A78-4328-B745-1355AE356A07@nvidia.com Link: https://lkml.kernel.org/r/20240226205534.1603748-9-zi.yan@sent.com Signed-off-by: Zi Yan <ziy@nvidia.com> Tested-by: Aishwarya TCV <aishwarya.tcv@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Michal Koutny <mkoutny@suse.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zach O'Keefe <zokeefe@google.com> Cc: Aishwarya TCV <aishwarya.tcv@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-05mm: thp: split huge page to any lower order pagesZi Yan1-24/+83
To split a THP to any lower order pages, we need to reform THPs on subpages at given order and add page refcount based on the new page order. Also we need to reinitialize page_deferred_list after removing the page from the split_queue, otherwise a subsequent split will see list corruption when checking the page_deferred_list again. Note: Anonymous order-1 folio is not supported because _deferred_list, which is used by partially mapped folios, is stored in subpage 2 and an order-1 folio only has subpage 0 and 1. File-backed order-1 folios are fine, since they do not use _deferred_list. [ziy@nvidia.com: fixup per discussion with Ryan] Link: https://lkml.kernel.org/r/494F48CD-1F0F-4CAD-884E-6D48F40AF990@nvidia.com Link: https://lkml.kernel.org/r/20240226205534.1603748-8-zi.yan@sent.com Signed-off-by: Zi Yan <ziy@nvidia.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Michal Koutny <mkoutny@suse.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zach O'Keefe <zokeefe@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-05mm: page_owner: add support for splitting to any order in split page_ownerZi Yan3-7/+6
It adds a new_order parameter to set new page order in page owner. It prepares for upcoming changes to support split huge page to any lower order. Link: https://lkml.kernel.org/r/20240226205534.1603748-7-zi.yan@sent.com Signed-off-by: Zi Yan <ziy@nvidia.com> Cc: David Hildenbrand <david@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Michal Koutny <mkoutny@suse.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zach O'Keefe <zokeefe@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-05mm: memcg: make memcg huge page split support any order splitZi Yan3-8/+9
It sets memcg information for the pages after the split. A new parameter new_order is added to tell the order of subpages in the new page, always 0 for now. It prepares for upcoming changes to support split huge page to any lower order. Link: https://lkml.kernel.org/r/20240226205534.1603748-6-zi.yan@sent.com Signed-off-by: Zi Yan <ziy@nvidia.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Michal Koutny <mkoutny@suse.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zach O'Keefe <zokeefe@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-05mm/page_owner: use order instead of nr in split_page_owner()Zi Yan3-4/+5
We do not have non power of two pages, using nr is error prone if nr is not power-of-two. Use page order instead. Link: https://lkml.kernel.org/r/20240226205534.1603748-5-zi.yan@sent.com Signed-off-by: Zi Yan <ziy@nvidia.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Michal Koutny <mkoutny@suse.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zach O'Keefe <zokeefe@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-05mm/memcg: use order instead of nr in split_page_memcg()Zi Yan3-5/+7
We do not have non power of two pages, using nr is error prone if nr is not power-of-two. Use page order instead. Link: https://lkml.kernel.org/r/20240226205534.1603748-4-zi.yan@sent.com Signed-off-by: Zi Yan <ziy@nvidia.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Michal Koutny <mkoutny@suse.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zach O'Keefe <zokeefe@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-05mm: support order-1 folios in the page cacheMatthew Wilcox (Oracle)4-11/+16
Folios of order 1 have no space to store the deferred list. This is not a problem for the page cache as file-backed folios are never placed on the deferred list. All we need to do is prevent the core MM from touching the deferred list for order 1 folios and remove the code which prevented us from allocating order 1 folios. Link: https://lore.kernel.org/linux-mm/90344ea7-4eec-47ee-5996-0c22f42d6a6a@google.com/ Link: https://lkml.kernel.org/r/20240226205534.1603748-3-zi.yan@sent.com Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Zi Yan <ziy@nvidia.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Michal Koutny <mkoutny@suse.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zach O'Keefe <zokeefe@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-05mm/huge_memory: only split PMD mapping when necessary in unmap_folio()Zi Yan1-2/+5
Patch series "Split a folio to any lower order folios", v5. File folio supports any order and multi-size THP is upstreamed[1], so both file and anonymous folios can be >0 order. Currently, split_huge_page() only splits a huge page to order-0 pages, but splitting to orders higher than 0 might better utilize large folios, if done properly. In addition, Large Block Sizes in XFS support would benefit from it during truncate[2]. This patchset adds support for splitting a large folio to any lower order folios. In addition to this implementation of split_huge_page_to_list_to_order(), a possible optimization could be splitting a large folio to arbitrary smaller folios instead of a single order. As both Hugh and Ryan pointed out [3,5] that split to a single order might not be optimal, an order-9 folio might be better split into 1 order-8, 1 order-7, ..., 1 order-1, and 2 order-0 folios, depending on subsequent folio operations. Leave this as future work. [1] https://lore.kernel.org/all/20231207161211.2374093-1-ryan.roberts@arm.com/ [2] https://lore.kernel.org/linux-mm/20240226094936.2677493-1-kernel@pankajraghav.com/ [3] https://lore.kernel.org/linux-mm/9dd96da-efa2-5123-20d4-4992136ef3ad@google.com/ [4] https://lore.kernel.org/linux-mm/cbb1d6a0-66dd-47d0-8733-f836fe050374@arm.com/ [5] https://lore.kernel.org/linux-mm/20240213215520.1048625-1-zi.yan@sent.com/ This patch (of 8): As multi-size THP support is added, not all THPs are PMD-mapped, thus during a huge page split, there is no need to always split PMD mapping in unmap_folio(). Make it conditional. Link: https://lkml.kernel.org/r/20240226205534.1603748-1-zi.yan@sent.com Link: https://lkml.kernel.org/r/20240226205534.1603748-2-zi.yan@sent.com Signed-off-by: Zi Yan <ziy@nvidia.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Koutny <mkoutny@suse.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zach O'Keefe <zokeefe@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-05mm: madvise: pageout: ignore references rather than clearing youngBarry Song4-11/+13
While doing MADV_PAGEOUT, the current code will clear PTE young so that vmscan won't read young flags to allow the reclamation of madvised folios to go ahead. It seems we can do it by directly ignoring references, thus we can remove tlb flush in madvise and rmap overhead in vmscan. Regarding the side effect, in the original code, if a parallel thread runs side by side to access the madvised memory with the thread doing madvise, folios will get a chance to be re-activated by vmscan (though the time gap is actually quite small since checking PTEs is done immediately after clearing PTEs young). But with this patch, they will still be reclaimed. But this behaviour doing PAGEOUT and doing access at the same time is quite silly like DoS. So probably, we don't need to care. Or ignoring the new access during the quite small time gap is even better. For DAMON's DAMOS_PAGEOUT based on physical address region, we still keep its behaviour as is since a physical address might be mapped by multiple processes. MADV_PAGEOUT based on virtual address is actually much more aggressive on reclamation. To untouch paddr's DAMOS_PAGEOUT, we simply pass ignore_references as false in reclaim_pages(). A microbench as below has shown 6% decrement on the latency of MADV_PAGEOUT, #define PGSIZE 4096 main() { int i; #define SIZE 512*1024*1024 volatile long *p = mmap(NULL, SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); for (i = 0; i < SIZE/sizeof(long); i += PGSIZE / sizeof(long)) p[i] = 0x11; madvise(p, SIZE, MADV_PAGEOUT); } w/o patch w/ patch root@10:~# time ./a.out root@10:~# time ./a.out real 0m49.634s real 0m46.334s user 0m0.637s user 0m0.648s sys 0m47.434s sys 0m44.265s Link: https://lkml.kernel.org/r/20240226005739.24350-1-21cnbao@gmail.com Signed-off-by: Barry Song <v-songbaohua@oppo.com> Acked-by: Minchan Kim <minchan@kernel.org> Cc: SeongJae Park <sj@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-05kasan: fix a2 allocation and remove explicit cast in atomic testsPaul Heidekrüger1-3/+3
Address the additional feedback since 4e76c8cc3378 kasan: add atomic tests (""kasan: add atomic tests") by removing an explicit cast and fixing the size as well as the check of the allocation of `a2`. Link: https://lkml.kernel.org/r/20240224105414.211995-1-paul.heidekrueger@tum.de Link: https://lore.kernel.org/all/20240131210041.686657-1-paul.heidekrueger@tum.de/T/#u Fixes: 4e76c8cc3378 ("kasan: add atomic tests") Signed-off-by: Paul Heidekrüger <paul.heidekrueger@tum.de> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=214055 Reviewed-by: Marco Elver <elver@google.com> Tested-by: Marco Elver <elver@google.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-05mm: update mark_victim tracepoints fieldsCarlos Galo1-1/+5
The current implementation of the mark_victim tracepoint provides only the process ID (pid) of the victim process. This limitation poses challenges for userspace tools requiring real-time OOM analysis and intervention. Although this information is available from the kernel logs, it’s not the appropriate format to provide OOM notifications. In Android, BPF programs are used with the mark_victim trace events to notify userspace of an OOM kill. For consistency, update the trace event to include the same information about the OOMed victim as the kernel logs. - UID In Android each installed application has a unique UID. Including the `uid` assists in correlating OOM events with specific apps. - Process Name (comm) Enables identification of the affected process. - OOM Score Will allow userspace to get additional insight of the relative kill priority of the OOM victim. In Android, the oom_score_adj is used to categorize app state (foreground, background, etc.), which aids in analyzing user-perceptible impacts of OOM events [1]. - Total VM, RSS Stats, and pgtables Amount of memory used by the victim that will, potentially, be freed up by killing it. [1] https://cs.android.com/android/platform/superproject/main/+/246dc8fc95b6d93afcba5c6d6c133307abb3ac2e:frameworks/base/services/core/java/com/android/server/am/ProcessList.java;l=188-283 Signed-off-by: Carlos Galo <carlosgalo@google.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-05hugetlb: allow faults to be handled under the VMA lockVishal Moola (Oracle)1-6/+0
Hugetlb can now safely handle faults under the VMA lock, so allow it to do so. This patch may cause ltp hugemmap10 to "fail". Hugemmap10 tests hugetlb counters, and expects the counters to remain unchanged on failure to handle a fault. In hugetlb_no_page(), vmf_anon_prepare() may bailout with no anon_vma under the VMA lock after allocating a folio for the hugepage. In free_huge_folio(), this folio is completely freed on bailout iff there is a surplus of hugetlb pages. This will remove a folio off the freelist and decrement the number of hugepages while ltp expects these counters to remain unchanged on failure. Originally this could only happen due to OOM failures, but now it may also occur after we allocate a hugetlb folio without a suitable anon_vma under the VMA lock. This should only happen for the first freshly allocated hugepage in this vma. Link: https://lkml.kernel.org/r/20240221234732.187629-6-vishal.moola@gmail.com Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-05hugetlb: use vmf_anon_prepare() instead of anon_vma_prepare()Vishal Moola (Oracle)1-9/+9
hugetlb_no_page() and hugetlb_wp() call anon_vma_prepare(). In preparation for hugetlb to safely handle faults under the VMA lock, use vmf_anon_prepare() here instead. Additionally, passing hugetlb_wp() the vm_fault struct from hugetlb_fault() works toward cleaning up the hugetlb code and function stack. Link: https://lkml.kernel.org/r/20240221234732.187629-5-vishal.moola@gmail.com Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-05hugetlb: pass struct vm_fault through to hugetlb_handle_userfault()Vishal Moola (Oracle)1-29/+9
Now that hugetlb_fault() has a struct vm_fault, have hugetlb_handle_userfault() use it instead of creating one of its own. This lets us reduce the number of arguments passed to hugetlb_handle_userfault() from 7 to 3, cleaning up the code and stack. Link: https://lkml.kernel.org/r/20240221234732.187629-4-vishal.moola@gmail.com Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-05hugetlb: move vm_fault declaration to the top of hugetlb_fault()Vishal Moola (Oracle)1-13/+19
hugetlb_fault() currently defines a vm_fault to pass to the generic handle_userfault() function. We can move this definition to the top of hugetlb_fault() so that it can be used throughout the rest of the hugetlb fault path. This will help cleanup a number of excess variables and function arguments throughout the stack. Also, since vm_fault already has space to store the page offset, use that instead and get rid of idx. Link: https://lkml.kernel.org/r/20240221234732.187629-3-vishal.moola@gmail.com Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-05mm/memory: change vmf_anon_prepare() to be non-staticVishal Moola (Oracle)2-1/+2
Patch series "Handle hugetlb faults under the VMA lock", v2. It is generally safe to handle hugetlb faults under the VMA lock. The only time this is unsafe is when no anon_vma has been allocated to this vma yet, so we can use vmf_anon_prepare() instead of anon_vma_prepare() to bailout if necessary. This should only happen for the first hugetlb page in the vma. Additionally, this patchset begins to use struct vm_fault within hugetlb_fault(). This works towards cleaning up hugetlb code, and should significantly reduce the number of arguments passed to functions. The last patch in this series may cause ltp hugemmap10 to "fail". This is because vmf_anon_prepare() may bailout with no anon_vma under the VMA lock after allocating a folio for the hugepage. In free_huge_folio(), this folio is completely freed on bailout iff there is a surplus of hugetlb pages. This will remove a folio off the freelist and decrement the number of hugepages while ltp expects these counters to remain unchanged on failure. The rest of the ltp testcases pass. This patch (of 2): In order to handle hugetlb faults under the VMA lock, hugetlb can use vmf_anon_prepare() to ensure we can safely prepare an anon_vma. Change it to be a non-static function so it can be used within hugetlb as well. Link: https://lkml.kernel.org/r/20240221234732.187629-6-vishal.moola@gmail.com Link: https://lkml.kernel.org/r/20240221234732.187629-2-vishal.moola@gmail.com Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-05mm/page_alloc: make check_new_page() return boolHao Ge1-3/+3
Make check_new_page() return bool like check_new_pages() Link: https://lkml.kernel.org/r/20240222091932.54799-1-gehao@kylinos.cn Signed-off-by: Hao Ge <gehao@kylinos.cn> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-05mm/util.c: add byte count to __vm_enough_memory failure warningMatthew Cassell1-2/+4
Commit 44b414c8715c5dcf53288 ("mm/util.c: add warning if __vm_enough_memory fails") adds debug information which gives the process id and executable name should __vm_enough_memory() fail. Adding the number of pages to the failure message would benefit application developers and system administrators in debugging overambitious memory requests by providing a point of reference to the amount of memory causing __vm_enough_memory() to fail. 1. Set appropriate kernel tunable to reach code path for failure message: # echo 2 > /proc/sys/vm/overcommit_memory 2. Test program to generate failure - requests 1 gibibyte per iteration: #include <stdlib.h> #include <stdio.h> int main(int argc, char **argv) { for(;;) { if(malloc(1<<30) == NULL) break; printf("allocated 1 GiB\n"); } return 0; } 3. Output: Before: __vm_enough_memory: pid: 1218, comm: a.out, not enough memory for the allocation After: __vm_enough_memory: pid: 1137, comm: a.out, bytes: 1073741824, not enough memory for the allocation Link: https://lkml.kernel.org/r/20240222194617.1255-1-mcassell411@gmail.com Signed-off-by: Matthew Cassell <mcassell411@gmail.com> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-05mm/zswap: change zswap_pool kref to percpu_refChengming Zhou1-15/+33
All zswap entries will take a reference of zswap_pool when zswap_store(), and drop it when free. Change it to use the percpu_ref is better for scalability performance. Although percpu_ref use a bit more memory which should be ok for our use case, since we almost have only one zswap_pool to be using. The performance gain is for zswap_store/load hotpath. Testing kernel build (32 threads) in tmpfs with memory.max=2GB. (zswap shrinker and writeback enabled with one 50GB swapfile, on a 128 CPUs x86-64 machine, below is the average of 5 runs) mm-unstable zswap-global-lru real 63.20 63.12 user 1061.75 1062.95 sys 268.74 264.44 [chengming.zhou@linux.dev: fix zswap_pools_lock usages after changing to percpu_ref] Link: https://lkml.kernel.org/r/20240228154954.3028626-1-chengming.zhou@linux.dev Link: https://lkml.kernel.org/r/20240210-zswap-global-lru-v3-2-200495333595@bytedance.com Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Reviewed-by: Nhat Pham <nphamcs@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Yosry Ahmed <yosryahmed@google.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-05mm/zswap: global lru and shrinker shared by all zswap_poolsChengming Zhou1-105/+66
Patch series "mm/zswap: optimize for dynamic zswap_pools", v3. Dynamic pool creation has been supported for a long time, which maybe not used so much in practice. But with the per-memcg lru merged, the current structure of zswap_pool's lru and shrinker become less optimal. In the current structure, each zswap_pool has its own lru, shrinker and shrink_work, but only the latest zswap_pool will be the current used. 1. When memory has pressure, all shrinkers of zswap_pools will try to shrink its lru list, there is no order between them. 2. When zswap limit hit, only the last zswap_pool's shrink_work will try to shrink its own lru, which is inefficient. A more natural way is to have a global zswap lru shared between all zswap_pools, and so is the shrinker. The code becomes much simpler too. Another optimization is changing zswap_pool kref to percpu_ref, which will be taken reference by every zswap entry. So the scalability is better. Testing kernel build (32 threads) in tmpfs with memory.max=2GB. (zswap shrinker and writeback enabled with one 50GB swapfile, on a 128 CPUs x86-64 machine, below is the average of 5 runs) mm-unstable zswap-global-lru real 63.20 63.12 user 1061.75 1062.95 sys 268.74 264.44 This patch (of 3): Dynamic zswap_pool creation may create/reuse to have multiple zswap_pools in a list, only the first will be current used. Each zswap_pool has its own lru and shrinker, which is not necessary and has its problem: 1. When memory has pressure, all shrinker of zswap_pools will try to shrink its own lru, there is no order between them. 2. When zswap limit hit, only the last zswap_pool's shrink_work will try to shrink its lru list. The rationale here was to try and empty the old pool first so that we can completely drop it. However, since we only support exclusive loads now, the LRU ordering should be entirely decided by the order of stores, so the oldest entries on the LRU will naturally be from the oldest pool. Anyway, having a global lru and shrinker shared by all zswap_pools is better and efficient. Link: https://lkml.kernel.org/r/20240210-zswap-global-lru-v3-0-200495333595@bytedance.com Link: https://lkml.kernel.org/r/20240210-zswap-global-lru-v3-1-200495333595@bytedance.com Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Acked-by: Yosry Ahmed <yosryahmed@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Nhat Pham <nphamcs@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-05mm, mmap: fix vma_merge() case 7 with vma_ops->closeVlastimil Babka1-1/+9
When debugging issues with a workload using SysV shmem, Michal Hocko has come up with a reproducer that shows how a series of mprotect() operations can result in an elevated shm_nattch and thus leak of the resource. The problem is caused by wrong assumptions in vma_merge() commit 714965ca8252 ("mm/mmap: start distinguishing if vma can be removed in mergeability test"). The shmem vmas have a vma_ops->close callback that decrements shm_nattch, and we remove the vma without calling it. vma_merge() has thus historically avoided merging vma's with vma_ops->close and commit 714965ca8252 was supposed to keep it that way. It relaxed the checks for vma_ops->close in can_vma_merge_after() assuming that it is never called on a vma that would be a candidate for removal. However, the vma_merge() code does also use the result of this check in the decision to remove a different vma in the merge case 7. A robust solution would be to refactor vma_merge() code in a way that the vma_ops->close check is only done for vma's that are actually going to be removed, and not as part of the preliminary checks. That would both solve the existing bug, and also allow additional merges that the checks currently prevent unnecessarily in some cases. However to fix the existing bug first with a minimized risk, and for easier stable backports, this patch only adds a vma_ops->close check to the buggy case 7 specifically. All other cases of vma removal are covered by the can_vma_merge_before() check that includes the test for vma_ops->close. The reproducer code, adapted from Michal Hocko's code: int main(int argc, char *argv[]) { int segment_id; size_t segment_size = 20 * PAGE_SIZE; char * sh_mem; struct shmid_ds shmid_ds; key_t key = 0x1234; segment_id = shmget(key, segment_size, IPC_CREAT | IPC_EXCL | S_IRUSR | S_IWUSR); sh_mem = (char *)shmat(segment_id, NULL, 0); mprotect(sh_mem + 2*PAGE_SIZE, PAGE_SIZE, PROT_NONE); mprotect(sh_mem + PAGE_SIZE, PAGE_SIZE, PROT_WRITE); mprotect(sh_mem + 2*PAGE_SIZE, PAGE_SIZE, PROT_WRITE); shmdt(sh_mem); shmctl(segment_id, IPC_STAT, &shmid_ds); printf("nattch after shmdt(): %lu (expected: 0)\n", shmid_ds.shm_nattch); if (shmctl(segment_id, IPC_RMID, 0)) printf("IPCRM failed %d\n", errno); return (shmid_ds.shm_nattch) ? 1 : 0; } Link: https://lkml.kernel.org/r/20240222215930.14637-2-vbabka@suse.cz Fixes: 714965ca8252 ("mm/mmap: start distinguishing if vma can be removed in mergeability test") Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reported-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-05mm: userfaultfd: fix unexpected change to src_folio when UFFDIO_MOVE failsQi Zheng1-3/+3
After ptep_clear_flush(), if we find that src_folio is pinned we will fail UFFDIO_MOVE and put src_folio back to src_pte entry, but the change to src_folio->{mapping,index} is not restored in this process. This is not what we expected, so fix it. This can cause the rmap for that page to be invalid, possibly resulting in memory corruption. At least swapout+migration would no longer work, because we might fail to locate the mappings of that folio. Link: https://lkml.kernel.org/r/20240222080815.46291-1-zhengqi.arch@bytedance.com Fixes: adef440691ba ("userfaultfd: UFFDIO_MOVE uABI") Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-05mm, vmscan: prevent infinite loop for costly GFP_NOIO | __GFP_RETRY_MAYFAIL ↵Vlastimil Babka3-11/+11
allocations Sven reports an infinite loop in __alloc_pages_slowpath() for costly order __GFP_RETRY_MAYFAIL allocations that are also GFP_NOIO. Such combination can happen in a suspend/resume context where a GFP_KERNEL allocation can have __GFP_IO masked out via gfp_allowed_mask. Quoting Sven: 1. try to do a "costly" allocation (order > PAGE_ALLOC_COSTLY_ORDER) with __GFP_RETRY_MAYFAIL set. 2. page alloc's __alloc_pages_slowpath tries to get a page from the freelist. This fails because there is nothing free of that costly order. 3. page alloc tries to reclaim by calling __alloc_pages_direct_reclaim, which bails out because a zone is ready to be compacted; it pretends to have made a single page of progress. 4. page alloc tries to compact, but this always bails out early because __GFP_IO is not set (it's not passed by the snd allocator, and even if it were, we are suspending so the __GFP_IO flag would be cleared anyway). 5. page alloc believes reclaim progress was made (because of the pretense in item 3) and so it checks whether it should retry compaction. The compaction retry logic thinks it should try again, because: a) reclaim is needed because of the early bail-out in item 4 b) a zonelist is suitable for compaction 6. goto 2. indefinite stall. (end quote) The immediate root cause is confusing the COMPACT_SKIPPED returned from __alloc_pages_direct_compact() (step 4) due to lack of __GFP_IO to be indicating a lack of order-0 pages, and in step 5 evaluating that in should_compact_retry() as a reason to retry, before incrementing and limiting the number of retries. There are however other places that wrongly assume that compaction can happen while we lack __GFP_IO. To fix this, introduce gfp_compaction_allowed() to abstract the __GFP_IO evaluation and switch the open-coded test in try_to_compact_pages() to use it. Also use the new helper in: - compaction_ready(), which will make reclaim not bail out in step 3, so there's at least one attempt to actually reclaim, even if chances are small for a costly order - in_reclaim_compaction() which will make should_continue_reclaim() return false and we don't over-reclaim unnecessarily - in __alloc_pages_slowpath() to set a local variable can_compact, which is then used to avoid retrying reclaim/compaction for costly allocations (step 5) if we can't compact and also to skip the early compaction attempt that we do in some cases Link: https://lkml.kernel.org/r/20240221114357.13655-2-vbabka@suse.cz Fixes: 3250845d0526 ("Revert "mm, oom: prevent premature OOM killer invocation for high order request"") Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reported-by: Sven van Ashbrook <svenva@chromium.org> Closes: https://lore.kernel.org/all/CAG-rBihs_xMKb3wrMO1%2B-%2Bp4fowP9oy1pa_OTkfxBzPUVOZF%2Bg@mail.gmail.com/ Tested-by: Karthikeyan Ramasubramanian <kramasub@chromium.org> Cc: Brian Geffon <bgeffon@google.com> Cc: Curtis Malainey <cujomalainey@chromium.org> Cc: Jaroslav Kysela <perex@perex.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Takashi Iwai <tiwai@suse.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-04mm, slab: remove memcg_from_slab_obj()Vlastimil Babka1-5/+0
This empty wrapped exists only for !CONFIG_MEMCG_KMEM and seems it was never used. Probably a leftover from development of a series. Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev> Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-03-01mm, slab: remove the corner case of inc_slabs_node()Chengming Zhou1-11/+2
We already have the inc_slabs_node() after kmem_cache_node->node[node] initialized in early_kmem_cache_node_alloc(), this special case of inc_slabs_node() can be removed. Then we don't need to consider the existence of kmem_cache_node in inc_slabs_node() anymore. Signed-off-by: Chengming Zhou <chengming.zhou@linux.dev> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-03-01mm/slab: Fix a kmemleak in kmem_cache_destroy()Xiaolei Wang2-6/+8
For earlier kmem cache creation, slab_sysfs_init() has not been called. Consequently, kmem_cache_destroy() cannot utilize kobj_type::release to release the kmem_cache structure. Therefore, tweak kmem_cache_release() to use slab_kmem_cache_release() for releasing kmem_cache when slab_state isn't FULL. This will fixes the memory leaks like following: unreferenced object 0xffff0000c2d87080 (size 128): comm "swapper/0", pid 1, jiffies 4294893428 hex dump (first 32 bytes): 00 00 00 00 ad 4e ad de ff ff ff ff 6b 6b 6b 6b .....N......kkkk ff ff ff ff ff ff ff ff b8 ab 48 89 00 80 ff ff.....H..... backtrace (crc 8819d0f6): [<ffff80008317a298>] kmemleak_alloc+0xb0/0xc4 [<ffff8000807e553c>] kmem_cache_alloc_node+0x288/0x3a8 [<ffff8000807e95f0>] __kmem_cache_create+0x1e4/0x64c [<ffff8000807216bc>] kmem_cache_create_usercopy+0x1c4/0x2cc [<ffff8000807217e0>] kmem_cache_create+0x1c/0x28 [<ffff8000819f6278>] arm_v7s_alloc_pgtable+0x1c0/0x6d4 [<ffff8000819f53a0>] alloc_io_pgtable_ops+0xe8/0x2d0 [<ffff800084b2d2c4>] arm_v7s_do_selftests+0xe0/0x73c [<ffff800080016b68>] do_one_initcall+0x11c/0x7ac [<ffff800084a71ddc>] kernel_init_freeable+0x53c/0xbb8 [<ffff8000831728d8>] kernel_init+0x24/0x144 [<ffff800080018e98>] ret_from_fork+0x10/0x20 Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com> Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-02-29mm/shmem.c: Use new form of *@param in kernel-docAkira Yokosawa1-2/+2
Use the form of *@param which kernel-doc recognizes now. This resolves the warnings from "make htmldocs" as reported in [1]. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Link: [1] https://lore.kernel.org/r/20240223153636.41358be5@canb.auug.org.au/ Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Akira Yokosawa <akiyks@gmail.com> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-28Merge tag 'mm-hotfixes-stable-2024-02-27-14-52' of ↵Linus Torvalds7-102/+56
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull misc fixes from Andrew Morton: "Six hotfixes. Three are cc:stable and the remainder address post-6.7 issues or aren't considered appropriate for backporting" * tag 'mm-hotfixes-stable-2024-02-27-14-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: mm/debug_vm_pgtable: fix BUG_ON with pud advanced test mm: cachestat: fix folio read-after-free in cache walk MAINTAINERS: add memory mapping entry with reviewers mm/vmscan: fix a bug calling wakeup_kswapd() with a wrong zone index kasan: revert eviction of stack traces in generic mode stackdepot: use variable size records for non-evictable entries
2024-02-26mm, slab, kasan: replace kasan_never_merge() with SLAB_NO_MERGEVlastimil Babka2-17/+7
The SLAB_KASAN flag prevents merging of caches in some configurations, which is handled in a rather complicated way via kasan_never_merge(). Since we now have a generic SLAB_NO_MERGE flag, we can instead use it for KASAN caches in addition to SLAB_KASAN in those configurations, and simplify the SLAB_NEVER_MERGE handling. Tested-by: Xiongwei Song <xiongwei.song@windriver.com> Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Tested-by: David Rientjes <rientjes@google.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-02-26mm, slab: use an enum to define SLAB_ cache creation flagsVlastimil Babka1-3/+3
The values of SLAB_ cache creation flags are defined by hand, which is tedious and error-prone. Use an enum to assign the bit number and a __SLAB_FLAG_BIT() macro to #define the final flags. This renumbers the flag values, which is OK as they are only used internally. Also define a __SLAB_FLAG_UNUSED macro to assign value to flags disabled by their respective config options in a unified and sparse-friendly way. Reviewed-and-tested-by: Xiongwei Song <xiongwei.song@windriver.com> Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev> Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-02-26mm, slab: deprecate SLAB_MEM_SPREAD flagVlastimil Babka1-1/+0
The SLAB_MEM_SPREAD flag used to be implemented in SLAB, which was removed. SLUB instead relies on the page allocator's NUMA policies. Change the flag's value to 0 to free up the value it had, and mark it for full removal once all users are gone. Reported-by: Steven Rostedt <rostedt@goodmis.org> Closes: https://lore.kernel.org/all/20240131172027.10f64405@gandalf.local.home/ Reviewed-and-tested-by: Xiongwei Song <xiongwei.song@windriver.com> Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev> Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-02-25swap: port block device usage to fileChristian Brauner1-11/+11
Link: https://lore.kernel.org/r/20240123-vfs-bdev-file-v2-5-adbd023e19cc@kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-02-25Merge tag 'cxl-fixes-6.8-rc6' of ↵Linus Torvalds1-2/+3
git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl Pull cxl fixes from Dan Williams: "A collection of significant fixes for the CXL subsystem. The largest change in this set, that bordered on "new development", is the fix for the fact that the location of the new qos_class attribute did not match the Documentation. The fix ends up deleting more code than it added, and it has a new unit test to backstop basic errors in this interface going forward. So the "red-diff" and unit test saved the "rip it out and try again" response. In contrast, the new notification path for firmware reported CXL errors (CXL CPER notifications) has a locking context bug that can not be fixed with a red-diff. Given where the release cycle stands, it is not comfortable to squeeze in that fix in these waning days. So, that receives the "back it out and try again later" treatment. There is a regression fix in the code that establishes memory NUMA nodes for platform CXL regions. That has an ack from x86 folks. There are a couple more fixups for Linux to understand (reassemble) CXL regions instantiated by platform firmware. The policy around platforms that do not match host-physical-address with system-physical-address (i.e. systems that have an address translation mechanism between the address range reported in the ACPI CEDT.CFMWS and endpoint decoders) has been softened to abort driver load rather than teardown the memory range (can cause system hangs). Lastly, there is a robustness / regression fix for cases where the driver would previously continue in the face of error, and a fixup for PCI error notification handling. Summary: - Fix NUMA initialization from ACPI CEDT.CFMWS - Fix region assembly failures due to async init order - Fix / simplify export of qos_class information - Fix cxl_acpi initialization vs single-window-init failures - Fix handling of repeated 'pci_channel_io_frozen' notifications - Workaround platforms that violate host-physical-address == system-physical address assumptions - Defer CXL CPER notification handling to v6.9" * tag 'cxl-fixes-6.8-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: cxl/acpi: Fix load failures due to single window creation failure acpi/ghes: Remove CXL CPER notifications cxl/pci: Fix disabling memory if DVSEC CXL Range does not match a CFMWS window cxl/test: Add support for qos_class checking cxl: Fix sysfs export of qos_class for memdev cxl: Remove unnecessary type cast in cxl_qos_class_verify() cxl: Change 'struct cxl_memdev_state' *_perf_list to single 'struct cxl_dpa_perf' cxl/region: Allow out of order assembly of autodiscovered regions cxl/region: Handle endpoint decoders in cxl_region_find_decoder() x86/numa: Fix the sort compare func used in numa_fill_memblks() x86/numa: Fix the address overlap check in numa_fill_memblks() cxl/pci: Skip to handle RAS errors if CXL.mem device is detached
2024-02-24writeback: remove a use of write_cache_pages() from do_writepages()Matthew Wilcox (Oracle)1-13/+18
Use the new writeback_iter() directly instead of indirecting through a callback. [hch@lst.de: ported to the while based iter style] Link: https://lkml.kernel.org/r/20240215063649.2164017-15-hch@lst.de Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Christian Brauner <brauner@kernel.org> Cc: Dave Chinner <dchinner@redhat.com> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-24writeback: add a writeback iteratorChristoph Hellwig1-78/+114
Refactor the code left in write_cache_pages into an iterator that the file system can call to get the next folio for a writeback operation: struct folio *folio = NULL; while ((folio = writeback_iter(mapping, wbc, folio, &error))) { error = <do per-folio writeback>; } The twist here is that the error value is passed by reference, so that the iterator can restore it when breaking out of the loop. Handling of the magic AOP_WRITEPAGE_ACTIVATE value stays outside the iterator and needs is just kept in the write_cache_pages legacy wrapper. in preparation for eventually killing it off. Heavily based on a for_each* based iterator from Matthew Wilcox. Link: https://lkml.kernel.org/r/20240215063649.2164017-14-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Christian Brauner <brauner@kernel.org> Cc: Dave Chinner <dchinner@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-24writeback: move the folio_prepare_writeback loop out of write_cache_pages()Matthew Wilcox (Oracle)1-8/+10
Move the loop for should-we-write-this-folio to writeback_get_folio. [hch@lst.de: fold loop into existing helper instead of a separate one per Jan] Link: https://lkml.kernel.org/r/20240215063649.2164017-13-hch@lst.de Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Dave Chinner <dchinner@redhat.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-24writeback: use the folio_batch queue iteratorMatthew Wilcox (Oracle)1-13/+15
Instead of keeping our own local iterator variable, use the one just added to folio_batch. Link: https://lkml.kernel.org/r/20240215063649.2164017-12-hch@lst.de Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Dave Chinner <dchinner@redhat.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-24writeback: simplify the loops in write_cache_pages()Matthew Wilcox (Oracle)1-39/+36
Collapse the two nested loops into one. This is needed as a step towards turning this into an iterator. Note that this drops the "index <= end" check in the previous outer loop and just relies on filemap_get_folios_tag() to return 0 entries when index > end. This actually has a subtle implication when end == -1 because then the returned index will be -1 as well and thus if there is page present on index -1, we could be looping indefinitely. But as the comment in filemap_get_folios_tag documents this as already broken anyway we should not worry about it here either. The fix for that would probably a change to the filemap_get_folios_tag() calling convention. [hch@lst.de: update the commit log per Jan] Link: https://lkml.kernel.org/r/20240215063649.2164017-10-hch@lst.de Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Dave Chinner <dchinner@redhat.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-24writeback: factor writeback_get_batch() out of write_cache_pages()Matthew Wilcox (Oracle)1-22/+38
This simple helper will be the basis of the writeback iterator. To make this work, we need to remember the current index and end positions in writeback_control. [hch@lst.de: heavily rebased, add helpers to get the tag and end index, don't keep the end index in struct writeback_control] Link: https://lkml.kernel.org/r/20240215063649.2164017-9-hch@lst.de Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Dave Chinner <dchinner@redhat.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-24writeback: factor folio_prepare_writeback() out of write_cache_pages()Matthew Wilcox (Oracle)1-27/+34
Reduce write_cache_pages() by about 30 lines; much of it is commentary, but it all bundles nicely into an obvious function. [hch@lst.de: rename should_writeback_folio to folio_prepare_writeback per Jan] Link: https://lkml.kernel.org/r/20240215063649.2164017-8-hch@lst.de Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Dave Chinner <dchinner@redhat.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-24writeback: rework the loop termination condition in write_cache_pagesChristoph Hellwig1-51/+33
Rework the way we deal with the cleanup after the writepage call. First handle the magic AOP_WRITEPAGE_ACTIVATE separately from real error returns to get it out of the way of the actual error handling path. The split the handling on intgrity vs non-integrity branches first, and return early using a goto for the non-ingegrity early loop condition to remove the need for the done and done_index local variables, and for assigning the error to ret when we can just return error directly. Link: https://lkml.kernel.org/r/20240215063649.2164017-7-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Christian Brauner <brauner@kernel.org> Cc: Dave Chinner <dchinner@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-24writeback: only update ->writeback_index for range_cyclic writebackChristoph Hellwig1-10/+14
mapping->writeback_index is only [1] used as the starting point for range_cyclic writeback, so there is no point in updating it for other types of writeback. [1] except for btrfs_defrag_file which does really odd things with mapping->writeback_index. But btrfs doesn't use write_cache_pages at all, so this isn't relevant here. Link: https://lkml.kernel.org/r/20240215063649.2164017-6-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Dave Chinner <dchinner@redhat.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Howells <dhowells@redhat.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-24writeback: also update wbc->nr_to_write on writeback failureChristoph Hellwig1-1/+1
When exiting write_cache_pages early due to a non-integrity write failure, wbc->nr_to_write currently doesn't account for the folio we just failed to write. This doesn't matter because the callers always ingore the value on a failure, but moving the update to common code will allow to simplify the code, so do it. Link: https://lkml.kernel.org/r/20240215063649.2164017-5-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Dave Chinner <dchinner@redhat.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Howells <dhowells@redhat.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-24writeback: fix done_index when hitting the wbc->nr_to_writeChristoph Hellwig1-0/+1
When write_cache_pages finishes writing out a folio, it fails to update done_index to account for the number of pages in the folio just written. That means when range_cyclic writeback is restarted, it will be restarted at this folio instead of after it as it should. Fix that by updating done_index before breaking out of the loop. Link: https://lkml.kernel.org/r/20240215063649.2164017-4-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Dave Chinner <dchinner@redhat.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Howells <dhowells@redhat.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-24writeback: don't call mapping_set_error on AOP_WRITEPAGE_ACTIVATEChristoph Hellwig1-1/+3
Patch series "convert write_cache_pages() to an iterator", v8. This is an evolution of the series Matthew Wilcox originally sent in June 2023, which has changed quite a bit since and now has a while based iterator. This patch (of 14): mapping_set_error should only be called on 0 returns (which it ignores) or a negative error code. writepage_cb ends up being able to call writepage_cb on the magic AOP_WRITEPAGE_ACTIVATE return value from ->writepage which means success but the caller needs to unlock the page. Ignore that and just call mapping_set_error on negative errors. (no fixes tag as this goes back more than 20 years over various renames and refactors so I've given up chasing down the original introduction) Link: https://lkml.kernel.org/r/20240215063649.2164017-1-hch@lst.de Link: https://lkml.kernel.org/r/20240215063649.2164017-2-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Brian Foster <bfoster@redhat.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Howells <dhowells@redhat.com> Cc: Dave Chinner <dchinner@redhat.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-24mm/page_alloc: make bad_range() return boolHao Ge1-6/+6
bad_range() can return bool, so let us change it. Link: https://lkml.kernel.org/r/20240221073227.276234-1-gehao@kylinos.cn Signed-off-by: Hao Ge <gehao@kylinos.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-24madvise:madvise_cold_or_pageout_pte_range(): allow split while ↵Barry Song1-1/+1
folio_estimated_sharers = 0 The purpose is stopping splitting large folios whose mapcount are 2 or above. Folios whose estimated_shares = 0 should be still perfect and even better candidates than estimated_shares = 1. Consider a pte-mapped large folio with 16 subpages, if we unmap 1-15, the current code will split folios and reclaim them while madvise goes on this folio; but if we unmap subpage 0, we will keep this folio and break. This is weird. For pmd-mapped large folios, we can still use "= 1" as the condition as anyway we have the entire map for it. So this patch doesn't change the condition for pmd-mapped large folios. This also explains why we had been using "= 1" for both pmd-mapped and pte-mapped large folios before commit 07e8c82b5eff ("madvise: convert madvise_cold_or_pageout_pte_range() to use folios"), because in the past, we used the mapcount of the specific subpage, since the subpage had pte present, its mapcount wouldn't be 0. The problem can be quite easily reproduced by writing a small program, unmapping the first subpage of a pte-mapped large folio vs. unmapping anyone other than the first subpage. Link: https://lkml.kernel.org/r/20240221085036.105621-1-21cnbao@gmail.com Fixes: 2f406263e3e9 ("madvise:madvise_cold_or_pageout_pte_range(): don't use mapcount() against large folio for sharing check") Signed-off-by: Barry Song <v-songbaohua@oppo.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Yin Fengwei <fengwei.yin@intel.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-24mm/swapfile:__swap_duplicate: drop redundant WRITE_ONCE on swap_map for err ↵Barry Song1-1/+2
cases The code is quite hard to read, we are still writing swap_map after errors happen. Though the written value is as before, has_cache = count & SWAP_HAS_CACHE; count &= ~SWAP_HAS_CACHE; [snipped] WRITE_ONCE(p->swap_map[offset], count | has_cache); It would be better to entirely drop the WRITE_ONCE for both performance and readability. [akpm@linux-foundation.org: avoid using goto] Link: https://lkml.kernel.org/r/20240221091028.123122-1-21cnbao@gmail.com Signed-off-by: Barry Song <v-songbaohua@oppo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-24shmem: properly report quota mount optionsJan Kara1-0/+18
Report quota options among the set of mount options. This allows proper user visibility into whether quotas are enabled or not. Link: https://lkml.kernel.org/r/20240129120131.21145-1-jack@suse.cz Fixes: e09764cff44b ("shmem: quota support") Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com> Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-24mm/compaction: optimize >0 order folio compaction with free page split.Zi Yan1-5/+30
During migration in a memory compaction, free pages are placed in an array of page lists based on their order. But the desired free page order (i.e., the order of a source page) might not be always present, thus leading to migration failures and premature compaction termination. Split a high order free pages when source migration page has a lower order to increase migration successful rate. Note: merging free pages when a migration fails and a lower order free page is returned via compaction_free() is possible, but there is too much work. Since the free pages are not buddy pages, it is hard to identify these free pages using existing PFN-based page merging algorithm. Link: https://lkml.kernel.org/r/20240220183220.1451315-5-zi.yan@sent.com Signed-off-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com> Tested-by: Yu Zhao <yuzhao@google.com> Cc: Adam Manzanares <a.manzanares@samsung.com> Cc: David Hildenbrand <david@redhat.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yin Fengwei <fengwei.yin@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>