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2025-05-31Merge tag 'mm-stable-2025-05-31-14-50' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - "Add folio_mk_pte()" from Matthew Wilcox simplifies the act of creating a pte which addresses the first page in a folio and reduces the amount of plumbing which architecture must implement to provide this. - "Misc folio patches for 6.16" from Matthew Wilcox is a shower of largely unrelated folio infrastructure changes which clean things up and better prepare us for future work. - "memory,x86,acpi: hotplug memory alignment advisement" from Gregory Price adds early-init code to prevent x86 from leaving physical memory unused when physical address regions are not aligned to memory block size. - "mm/compaction: allow more aggressive proactive compaction" from Michal Clapinski provides some tuning of the (sadly, hard-coded (more sadly, not auto-tuned)) thresholds for our invokation of proactive compaction. In a simple test case, the reduction of a guest VM's memory consumption was dramatic. - "Minor cleanups and improvements to swap freeing code" from Kemeng Shi provides some code cleaups and a small efficiency improvement to this part of our swap handling code. - "ptrace: introduce PTRACE_SET_SYSCALL_INFO API" from Dmitry Levin adds the ability for a ptracer to modify syscalls arguments. At this time we can alter only "system call information that are used by strace system call tampering, namely, syscall number, syscall arguments, and syscall return value. This series should have been incorporated into mm.git's "non-MM" branch, but I goofed. - "fs/proc: extend the PAGEMAP_SCAN ioctl to report guard regions" from Andrei Vagin extends the info returned by the PAGEMAP_SCAN ioctl against /proc/pid/pagemap. This permits CRIU to more efficiently get at the info about guard regions. - "Fix parameter passed to page_mapcount_is_type()" from Gavin Shan implements that fix. No runtime effect is expected because validate_page_before_insert() happens to fix up this error. - "kernel/events/uprobes: uprobe_write_opcode() rewrite" from David Hildenbrand basically brings uprobe text poking into the current decade. Remove a bunch of hand-rolled implementation in favor of using more current facilities. - "mm/ptdump: Drop assumption that pxd_val() is u64" from Anshuman Khandual provides enhancements and generalizations to the pte dumping code. This might be needed when 128-bit Page Table Descriptors are enabled for ARM. - "Always call constructor for kernel page tables" from Kevin Brodsky ensures that the ctor/dtor is always called for kernel pgtables, as it already is for user pgtables. This permits the addition of more functionality such as "insert hooks to protect page tables". This change does result in various architectures performing unnecesary work, but this is fixed up where it is anticipated to occur. - "Rust support for mm_struct, vm_area_struct, and mmap" from Alice Ryhl adds plumbing to permit Rust access to core MM structures. - "fix incorrectly disallowed anonymous VMA merges" from Lorenzo Stoakes takes advantage of some VMA merging opportunities which we've been missing for 15 years. - "mm/madvise: batch tlb flushes for MADV_DONTNEED and MADV_FREE" from SeongJae Park optimizes process_madvise()'s TLB flushing. Instead of flushing each address range in the provided iovec, we batch the flushing across all the iovec entries. The syscall's cost was approximately halved with a microbenchmark which was designed to load this particular operation. - "Track node vacancy to reduce worst case allocation counts" from Sidhartha Kumar makes the maple tree smarter about its node preallocation. stress-ng mmap performance increased by single-digit percentages and the amount of unnecessarily preallocated memory was dramaticelly reduced. - "mm/gup: Minor fix, cleanup and improvements" from Baoquan He removes a few unnecessary things which Baoquan noted when reading the code. - ""Enhance sysfs handling for memory hotplug in weighted interleave" from Rakie Kim "enhances the weighted interleave policy in the memory management subsystem by improving sysfs handling, fixing memory leaks, and introducing dynamic sysfs updates for memory hotplug support". Fixes things on error paths which we are unlikely to hit. - "mm/damon: auto-tune DAMOS for NUMA setups including tiered memory" from SeongJae Park introduces new DAMOS quota goal metrics which eliminate the manual tuning which is required when utilizing DAMON for memory tiering. - "mm/vmalloc.c: code cleanup and improvements" from Baoquan He provides cleanups and small efficiency improvements which Baoquan found via code inspection. - "vmscan: enforce mems_effective during demotion" from Gregory Price changes reclaim to respect cpuset.mems_effective during demotion when possible. because presently, reclaim explicitly ignores cpuset.mems_effective when demoting, which may cause the cpuset settings to violated. This is useful for isolating workloads on a multi-tenant system from certain classes of memory more consistently. - "Clean up split_huge_pmd_locked() and remove unnecessary folio pointers" from Gavin Guo provides minor cleanups and efficiency gains in in the huge page splitting and migrating code. - "Use kmem_cache for memcg alloc" from Huan Yang creates a slab cache for `struct mem_cgroup', yielding improved memory utilization. - "add max arg to swappiness in memory.reclaim and lru_gen" from Zhongkun He adds a new "max" argument to the "swappiness=" argument for memory.reclaim MGLRU's lru_gen. This directs proactive reclaim to reclaim from only anon folios rather than file-backed folios. - "kexec: introduce Kexec HandOver (KHO)" from Mike Rapoport is the first step on the path to permitting the kernel to maintain existing VMs while replacing the host kernel via file-based kexec. At this time only memblock's reserve_mem is preserved. - "mm: Introduce for_each_valid_pfn()" from David Woodhouse provides and uses a smarter way of looping over a pfn range. By skipping ranges of invalid pfns. - "sched/numa: Skip VMA scanning on memory pinned to one NUMA node via cpuset.mems" from Libo Chen removes a lot of pointless VMA scanning when a task is pinned a single NUMA mode. Dramatic performance benefits were seen in some real world cases. - "JFS: Implement migrate_folio for jfs_metapage_aops" from Shivank Garg addresses a warning which occurs during memory compaction when using JFS. - "move all VMA allocation, freeing and duplication logic to mm" from Lorenzo Stoakes moves some VMA code from kernel/fork.c into the more appropriate mm/vma.c. - "mm, swap: clean up swap cache mapping helper" from Kairui Song provides code consolidation and cleanups related to the folio_index() function. - "mm/gup: Cleanup memfd_pin_folios()" from Vishal Moola does that. - "memcg: Fix test_memcg_min/low test failures" from Waiman Long addresses some bogus failures which are being reported by the test_memcontrol selftest. - "eliminate mmap() retry merge, add .mmap_prepare hook" from Lorenzo Stoakes commences the deprecation of file_operations.mmap() in favor of the new file_operations.mmap_prepare(). The latter is more restrictive and prevents drivers from messing with things in ways which, amongst other problems, may defeat VMA merging. - "memcg: decouple memcg and objcg stocks"" from Shakeel Butt decouples the per-cpu memcg charge cache from the objcg's one. This is a step along the way to making memcg and objcg charging NMI-safe, which is a BPF requirement. - "mm/damon: minor fixups and improvements for code, tests, and documents" from SeongJae Park is yet another batch of miscellaneous DAMON changes. Fix and improve minor problems in code, tests and documents. - "memcg: make memcg stats irq safe" from Shakeel Butt converts memcg stats to be irq safe. Another step along the way to making memcg charging and stats updates NMI-safe, a BPF requirement. - "Let unmap_hugepage_range() and several related functions take folio instead of page" from Fan Ni provides folio conversions in the hugetlb code. * tag 'mm-stable-2025-05-31-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (285 commits) mm: pcp: increase pcp->free_count threshold to trigger free_high mm/hugetlb: convert use of struct page to folio in __unmap_hugepage_range() mm/hugetlb: refactor __unmap_hugepage_range() to take folio instead of page mm/hugetlb: refactor unmap_hugepage_range() to take folio instead of page mm/hugetlb: pass folio instead of page to unmap_ref_private() memcg: objcg stock trylock without irq disabling memcg: no stock lock for cpu hot-unplug memcg: make __mod_memcg_lruvec_state re-entrant safe against irqs memcg: make count_memcg_events re-entrant safe against irqs memcg: make mod_memcg_state re-entrant safe against irqs memcg: move preempt disable to callers of memcg_rstat_updated memcg: memcg_rstat_updated re-entrant safe against irqs mm: khugepaged: decouple SHMEM and file folios' collapse selftests/eventfd: correct test name and improve messages alloc_tag: check mem_profiling_support in alloc_tag_init Docs/damon: update titles and brief introductions to explain DAMOS selftests/damon/_damon_sysfs: read tried regions directories in order mm/damon/tests/core-kunit: add a test for damos_set_filters_default_reject() mm/damon/paddr: remove unused variable, folio_list, in damon_pa_stat() mm/damon/sysfs-schemes: fix wrong comment on damons_sysfs_quota_goal_metric_strs ...
2025-05-11mm: convert free_page_and_swap_cache() to free_folio_and_swap_cache()Fan Ni
free_page_and_swap_cache() takes a struct page pointer as input parameter, but it will immediately convert it to folio and all operations following within use folio instead of page. It makes more sense to pass in folio directly. Convert free_page_and_swap_cache() to free_folio_and_swap_cache() to consume folio directly. Link: https://lkml.kernel.org/r/20250416201720.41678-1-nifan.cxl@gmail.com Signed-off-by: Fan Ni <fan.ni@samsung.com> Acked-by: Davidlohr Bueso <dave@stgolabs.net> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Adam Manzanares <a.manzanares@samsung.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Luis Chamberalin <mcgrof@kernel.org> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-07mm: Remove swap_writepage() and shmem_writepage()Matthew Wilcox (Oracle)
Call swap_writeout() and shmem_writeout() from pageout() instead. Signed-off-by: "Matthew Wilcox (Oracle)" <willy@infradead.org> Link: https://lore.kernel.org/r/20250402150005.2309458-9-willy@infradead.org Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-03-16mm, swap: simplify folio swap allocationKairui Song
With slot cache gone, clean up the allocation helpers even more. folio_alloc_swap will be the only entry for allocation and adding the folio to swap cache (except suspend), making it opposite of folio_free_swap. Link: https://lkml.kernel.org/r/20250313165935.63303-8-ryncsn@gmail.com Signed-off-by: Kairui Song <kasong@tencent.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Barry Song <v-songbaohua@oppo.com> Cc: Chris Li <chrisl@kernel.org> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Matthew Wilcow (Oracle) <willy@infradead.org> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16mm, swap: remove swap slot cacheKairui Song
Slot cache is no longer needed now, removing it and all related code. - vm-scalability with: `usemem --init-time -O -y -x -R -31 1G`, 12G memory cgroup using simulated pmem as SWAP (32G pmem, 32 CPUs), 16 test runs for each case, measuring the total throughput: Before (KB/s) (stdev) After (KB/s) (stdev) Random (4K): 424907.60 (24410.78) 414745.92 (34554.78) Random (64K): 163308.82 (11635.72) 167314.50 (18434.99) Sequential (4K, !-R): 6150056.79 (103205.90) 6321469.06 (115878.16) The performance changes are below noise level. - Build linux kernel with make -j96, using 4K folio with 1.5G memory cgroup limit and 64K folio with 2G memory cgroup limit, on top of tmpfs, 12 test runs, measuring the system time: Before (s) (stdev) After (s) (stdev) make -j96 (4K): 6445.69 (61.95) 6408.80 (69.46) make -j96 (64K): 6841.71 (409.04) 6437.99 (435.55) Similar to above, 64k mTHP case showed a slight improvement. Link: https://lkml.kernel.org/r/20250313165935.63303-7-ryncsn@gmail.com Signed-off-by: Kairui Song <kasong@tencent.com> Reviewed-by: Baoquan He <bhe@redhat.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <v-songbaohua@oppo.com> Cc: Chris Li <chrisl@kernel.org> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Matthew Wilcow (Oracle) <willy@infradead.org> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16mm, swap: avoid redundant swap device pinningKairui Song
Currently __read_swap_cache_async() has get/put_swap_device() calls to increase/decrease a swap device reference to prevent swapoff. While some of its callers have already held the swap device reference, e.g in do_swap_page() and shmem_swapin_folio() where __read_swap_cache_async() will finally called. Now there are only two callers not holding a swap device reference, so make them hold a reference instead. And drop the get/put_swap_device calls in __read_swap_cache_async. This should reduce the overhead for swap in during page fault slightly. Link: https://lkml.kernel.org/r/20250313165935.63303-4-ryncsn@gmail.com Signed-off-by: Kairui Song <kasong@tencent.com> Reviewed-by: Baoquan He <bhe@redhat.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <v-songbaohua@oppo.com> Cc: Chris Li <chrisl@kernel.org> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Matthew Wilcow (Oracle) <willy@infradead.org> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16mm/swap: rename swap_swapcount() to swap_entry_swapped()Baoquan He
The new function name can reflect the real behaviour of the function more clearly and more accurately. And the renaming avoids the confusion between swap_swapcount() and swp_swapcount(). Link: https://lkml.kernel.org/r/20250205092721.9395-11-bhe@redhat.com Signed-off-by: Baoquan He <bhe@redhat.com> Cc: Chris Li <chrisl@kernel.org> Cc: Kairui Song <ryncsn@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16mm/swap_state.c: remove the meaningless code commentBaoquan He
Since commit 8d93b41c09d1 ("mm: Convert add_to_swap_cache to XArray"), there's no returned _EEXIT, so the code comment doesn't make sense any more. Link: https://lkml.kernel.org/r/20250205092721.9395-9-bhe@redhat.com Signed-off-by: Baoquan He <bhe@redhat.com> Cc: Chris Li <chrisl@kernel.org> Cc: Kairui Song <ryncsn@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16mm/swap_state.c: optimize the code in clear_shadow_from_swap_cache()Baoquan He
Use ALIGN to achieve the same effect and simplify the code. Link: https://lkml.kernel.org/r/20250205092721.9395-3-bhe@redhat.com Signed-off-by: Baoquan He <bhe@redhat.com> Cc: Chris Li <chrisl@kernel.org> Cc: Kairui Song <ryncsn@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16mm/swap_state.c: fix the obsolete code commentBaoquan He
Patch series "Tiny cleanup and improvements about SWAP code". These are all made during review and from reading the patchset "[PATCH v3 00/13] mm, swap: rework of swap allocator locks" from Kairui. This patch (of 12): Since commit 85a1333417a7 ("mm/swap: use dedicated entry for swap in folio"), there's a dedicated field in folio for swap entry. Let's update the code comment above add_to_swap_cache() accordingly. Link: https://lkml.kernel.org/r/20250205092721.9395-1-bhe@redhat.com Link: https://lkml.kernel.org/r/20250205092721.9395-2-bhe@redhat.com Signed-off-by: Baoquan He <bhe@redhat.com> Reviewed-by: Kairui Song <kasong@tencent.com> Cc: Baoquan he <bhe@redhat.com> Cc: Chris Li <chrisl@kernel.org> (Google) Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16mm: memcontrol: move memsw charge callbacks to v1Johannes Weiner
The interweaving of two entirely different swap accounting strategies has been one of the more confusing parts of the memcg code. Split out the v1 code to clarify the implementation and a handful of callsites, and to avoid building the v1 bits when !CONFIG_MEMCG_V1. text data bss dec hex filename 39253 6446 4160 49859 c2c3 mm/memcontrol.o.old 38877 6382 4160 49419 c10b mm/memcontrol.o Link: https://lkml.kernel.org/r/20250124054132.45643-1-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Balbir Singh <balbirs@nvidia.com> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25mm: remove unnecessary calls to lru_add_drainRik van Riel
There seem to be several categories of calls to lru_add_drain and lru_add_drain_all. The first are code paths that recently allocated, swapped in, or otherwise processed a batch of pages, and want them all on the LRU. These drain pages that were recently allocated, probably on the local CPU. A second category are code paths that are actively trying to reclaim, migrate, or offline memory. These often use lru_add_drain_all, to drain the caches on all CPUs. However, there also seem to be some other callers where we aren't really doing either. They are calling lru_add_drain(), despite operating on pages that may have been allocated long ago, and quite possibly on different CPUs. Those calls are not likely to be effective at anything but creating lock contention on the LRU locks. Remove the lru_add_drain calls in the latter category. For detailed reasoning, see [1] and [2]. Link: https://lkml.kernel.org/r/dca2824e8e88e826c6b260a831d79089b5b9c79d.camel@surriel.com [1] Link: https://lkml.kernel.org/r/xxfhcjaq2xxcl5adastz5omkytenq7izo2e5f4q7e3ns4z6lko@odigjjc7hqrg [2] Link: https://lkml.kernel.org/r/20241219153253.3da9e8aa@fangorn Signed-off-by: Rik van Riel <riel@surriel.com> Suggested-by: David Hildenbrand <david@redhat.com> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Chris Li <chrisl@kernel.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-06mm: swap: use str_true_false() helper functionThorsten Blum
Remove hard-coded strings by using the helper function str_true_false(). Link: https://lkml.kernel.org/r/20241016141040.79168-2-thorsten.blum@linux.dev Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-17mm: add nr argument in mem_cgroup_swapin_uncharge_swap() helper to support ↵Barry Song
large folios With large folios swap-in, we might need to uncharge multiple entries all together, add nr argument in mem_cgroup_swapin_uncharge_swap(). For the existing two users, just pass nr=1. Link: https://lkml.kernel.org/r/20240908232119.2157-3-21cnbao@gmail.com Signed-off-by: Barry Song <v-songbaohua@oppo.com> Acked-by: Chris Li <chrisl@kernel.org> Reviewed-by: Yosry Ahmed <yosryahmed@google.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: David Hildenbrand <david@redhat.com> Cc: Gao Xiang <xiang@kernel.org> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kairui Song <kasong@tencent.com> Cc: Kairui Song <ryncsn@gmail.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Chuanhua Han <hanchuanhua@oppo.com> Cc: Kanchana P Sridhar <kanchana.p.sridhar@intel.com> Cc: Usama Arif <usamaarif642@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01mm: return the folio from swapin_readaheadMatthew Wilcox (Oracle)
The unuse_pte_range() caller only wants the folio while do_swap_page() wants both the page and the folio. Since do_swap_page() already has logic for handling both the folio and the page, move the folio-to-page logic there. This also lets us allocate larger folios in the SWP_SYNCHRONOUS_IO path in future. Link: https://lkml.kernel.org/r/20240807193734.1865400-1-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01zswap: track swapins from disk more accuratelyNhat Pham
Currently, there are a couple of issues with our disk swapin tracking for dynamic zswap shrinker heuristics: 1. We only increment the swapin counter on pivot pages. This means we are not taking into account pages that also need to be swapped in, but are already taken care of as part of the readahead window. 2. We are also incrementing when the pages are read from the zswap pool, which is inaccurate. This patch rectifies these issues by incrementing the counter whenever we need to perform a non-zswap read. Note that we are slightly overcounting, as a page might be read into memory by the readahead algorithm even though it will not be neeeded by users - however, this is an acceptable inaccuracy, as the readahead logic itself will adapt to these kind of scenarios. To test this change, I built the kernel under a cgroup with its memory.max set to 2 GB: real: 236.66s user: 4286.06s sys: 652.86s swapins: 81552 For comparison, with just the new second chance algorithm, the build time is as follows: real: 244.85s user: 4327.22s sys: 664.39s swapins: 94663 Without neither: real: 263.89s user: 4318.11s sys: 673.29s swapins: 227300.5 (average over 5 runs) With this change, the kernel CPU time reduces by a further 1.7%, and the real time is reduced by another 3.3%, compared to just the second chance algorithm by itself. The swapins count also reduces by another 13.85%. Combinng the two changes, we reduce the real time by 10.32%, kernel CPU time by 3%, and number of swapins by 64.12%. To gauge the new scheme's ability to offload cold data, I ran another benchmark, in which the kernel was built under a cgroup with memory.max set to 3 GB, but with 0.5 GB worth of cold data allocated before each build (in a shmem file). Under the old scheme: real: 197.18s user: 4365.08s sys: 289.02s zswpwb: 72115.2 Under the new scheme: real: 195.8s user: 4362.25s sys: 290.14s zswpwb: 87277.8 (average over 5 runs) Notice that we actually observe a 21% increase in the number of written back pages - so the new scheme is just as good, if not better at offloading pages from the zswap pool when they are cold. Build time reduces by around 0.7% as a result. [nphamcs@gmail.com: squeeze a comment into a single line] Link: https://lkml.kernel.org/r/20240806004518.3183562-1-nphamcs@gmail.com Link: https://lkml.kernel.org/r/20240805232243.2896283-3-nphamcs@gmail.com Fixes: b5ba474f3f51 ("zswap: shrink zswap pool based on memory pressure") Signed-off-by: Nhat Pham <nphamcs@gmail.com> Suggested-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Yosry Ahmed <yosryahmed@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Takero Funaki <flintglass@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01mm: swap: allocate folio only first time in __read_swap_cache_async()Zhaoyu Liu
It should be checked by filemap_get_folio() if SWAP_HAS_CACHE was marked while reading a share swap page. It would re-allocate a folio if the swap cache was not ready now. We save the new folio to avoid page allocating again. Link: https://lkml.kernel.org/r/20240731133101.GA2096752@bytedance Signed-off-by: Zhaoyu Liu <liuzhaoyu.zackary@bytedance.com> Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Cc: Kairui Song <kasong@tencent.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01mm: swap: add nr argument in swapcache_prepare and swapcache_clear to ↵Barry Song
support large folios Right now, swapcache_prepare() and swapcache_clear() supports one entry only, to support large folios, we need to handle multiple swap entries. To optimize stack usage, we iterate twice in __swap_duplicate(): the first time to verify that all entries are valid, and the second time to apply the modifications to the entries. Currently, we're using nr=1 for the existing users. [v-songbaohua@oppo.com: clarify swap_count_continued and improve readability for __swap_duplicate] Link: https://lkml.kernel.org/r/20240802071817.47081-1-21cnbao@gmail.com Link: https://lkml.kernel.org/r/20240730071339.107447-2-21cnbao@gmail.com Signed-off-by: Barry Song <v-songbaohua@oppo.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: David Hildenbrand <david@redhat.com> Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Chris Li <chrisl@kernel.org> Cc: Gao Xiang <xiang@kernel.org> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kairui Song <kasong@tencent.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12mm: swap_state: use folio_alloc_mpol() in __read_swap_cache_async()Kefeng Wang
Convert to use folio_alloc_mpol() helper() in __read_swap_cache_async(). Link: https://lkml.kernel.org/r/20240709105508.3933823-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm: swap: remove 'synchronous' argument to swap_read_folio()Yosry Ahmed
Commit [1] introduced IO polling support duding swapin to reduce swap read latency for block devices that can be polled. However later commit [2] removed polling support. Commit [3] removed the remnants of polling support from read_swap_cache_async() and __read_swap_cache_async(). However, it left behind some remnants in swap_read_folio(), the 'synchronous' argument. swap_read_folio() reads the folio synchronously if synchronous=true or if SWP_SYNCHRONOUS_IO is set in swap_info_struct. The only caller that passes synchronous=true is in do_swap_page() in the SWP_SYNCHRONOUS_IO case. Hence, the argument is redundant, it is only set to true when the swap read would have been synchronous anyway. Remove it. [1] Commit 23955622ff8d ("swap: add block io poll in swapin path") [2] Commit 9650b453a3d4 ("block: ignore RWF_HIPRI hint for sync dio") [3] Commit b243dcbf2f13 ("swap: remove remnants of polling from read_swap_cache_async") Link: https://lkml.kernel.org/r/20240607045515.1836558-1-yosryahmed@google.com Signed-off-by: Yosry Ahmed <yosryahmed@google.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm,swap: simplify VMA based swap readahead window calculationHuang Ying
Replace PFNs with addresses in readahead window calculation. This simplified the logic and reduce the code line number. No functionality change is expected. Link: https://lkml.kernel.org/r/20240531081230.310128-4-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Kairui Song <kasong@tencent.com> Cc: Barry Song <v-songbaohua@oppo.com> Cc: Chris Li <chrisl@kernel.org> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm,swap: remove struct vma_swap_readaheadHuang Ying
When VMA based swap readahead is introduced in commit ec560175c0b6 ("mm, swap: VMA based swap readahead"), "struct vma_swap_readahead" is defined to describe the readahead window. Because we wanted to save the PTE entries in the struct at that time. But after commit 4f8fcf4ced0b ("mm/swap: swap_vma_readahead() do the pte_offset_map()"), we no longer save PTE entries in the struct. The size of the struct becomes so small, that it's better to use the fields of the struct directly. This can simplify the code to improve the code readability. The line number of source code reduces too. No functionality change is expected in this patch. Link: https://lkml.kernel.org/r/20240531081230.310128-3-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Kairui Song <kasong@tencent.com> Cc: Barry Song <v-songbaohua@oppo.com> Cc: Chris Li <chrisl@kernel.org> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm,swap: fix a theoretical underflow in readahead window calculationHuang Ying
Patch series "mm,swap: cleanup VMA based swap readahead window calculation". When VMA based swap readahead is introduced in commit ec560175c0b6 ("mm, swap: VMA based swap readahead"), "struct vma_swap_readahead" is defined to describe the readahead window. Because we wanted to save the PTE entries in the struct at that time. But after commit 4f8fcf4ced0b ("mm/swap: swap_vma_readahead() do the pte_offset_map()"), we no longer save PTE entries in the struct. The size of the struct becomes so small, that it's better to use the fields of the struct directly. This can simplify the code to improve the code readability. The line number of source code reduces too. A theoretical underflow issue and some related code cleanup is done in the series too. This patch (of 3): In swap readahead window calculation, if the fault PFN is smaller than the readahead window size, underflow may occurs. This is only possible in theory, because the start of the virtual address space will not be used for anonymous pages in practice. Even if underflow occurs, there will be no functional bugs. In the worst cases, some swap entries may be swapped in incorrectly and some pages may be allocate on the wrong nodes. Anyway, we still needs to fix the issue via some underflow checking. Link: https://lkml.kernel.org/r/20240531081230.310128-1-ying.huang@intel.com Link: https://lkml.kernel.org/r/20240531081230.310128-2-ying.huang@intel.com Fixes: ec560175c0b6 ("mm, swap: VMA based swap readahead") Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Kairui Song <kasong@tencent.com> Cc: Barry Song <v-songbaohua@oppo.com> Cc: Chris Li <chrisl@kernel.org> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/swap: reduce swap cache search spaceKairui Song
Currently we use one swap_address_space for every 64M chunk to reduce lock contention, this is like having a set of smaller swap files inside one swap device. But when doing swap cache look up or insert, we are still using the offset of the whole large swap device. This is OK for correctness, as the offset (key) is unique. But Xarray is specially optimized for small indexes, it creates the radix tree levels lazily to be just enough to fit the largest key stored in one Xarray. So we are wasting tree nodes unnecessarily. For 64M chunk it should only take at most 3 levels to contain everything. But if we are using the offset from the whole swap device, the offset (key) value will be way beyond 64M, and so will the tree level. Optimize this by using a new helper swap_cache_index to get a swap entry's unique offset in its own 64M swap_address_space. I see a ~1% performance gain in benchmark and actual workload with high memory pressure. Test with `time memhog 128G` inside a 8G memcg using 128G swap (ramdisk with SWP_SYNCHRONOUS_IO dropped, tested 3 times, results are stable. The test result is similar but the improvement is smaller if SWP_SYNCHRONOUS_IO is enabled, as swap out path can never skip swap cache): Before: 6.07user 250.74system 4:17.26elapsed 99%CPU (0avgtext+0avgdata 8373376maxresident)k 0inputs+0outputs (55major+33555018minor)pagefaults 0swaps After (1.8% faster): 6.08user 246.09system 4:12.58elapsed 99%CPU (0avgtext+0avgdata 8373248maxresident)k 0inputs+0outputs (54major+33555027minor)pagefaults 0swaps Similar result with MySQL and sysbench using swap: Before: 94055.61 qps After (0.8% faster): 94834.91 qps Radix tree slab usage is also very slightly lower. Link: https://lkml.kernel.org/r/20240521175854.96038-12-ryncsn@gmail.com Signed-off-by: Kairui Song <kasong@tencent.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Cc: Anna Schumaker <anna@kernel.org> Cc: Barry Song <v-songbaohua@oppo.com> Cc: Chao Yu <chao@kernel.org> Cc: Chris Li <chrisl@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ilya Dryomov <idryomov@gmail.com> Cc: Jaegeuk Kim <jaegeuk@kernel.org> Cc: Jeff Layton <jlayton@kernel.org> Cc: Marc Dionne <marc.dionne@auristor.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Minchan Kim <minchan@kernel.org> Cc: NeilBrown <neilb@suse.de> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Xiubo Li <xiubli@redhat.com> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03mm/vmscan: update stale references to shrink_page_listIllia Ostapyshyn
Commit 49fd9b6df54e ("mm/vmscan: fix a lot of comments") renamed shrink_page_list() to shrink_folio_list(). Fix up the remaining references to the old name in comments and documentation. Link: https://lkml.kernel.org/r/20240517091348.1185566-1-illia@yshyn.com Signed-off-by: Illia Ostapyshyn <illia@yshyn.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25mm: remove struct page from get_shadow_from_swap_cacheMatthew Wilcox (Oracle)
We don't actually use any parts of struct page; all we do is check the value of the pointer. So give the pointer the appropriate name & type. Link: https://lkml.kernel.org/r/20240402201659.918308-1-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25mm: add is_huge_zero_folio()Matthew Wilcox (Oracle)
This is the folio equivalent of is_huge_zero_page(). It doesn't add any efficiency, but it does prevent the caller from passing a tail page and getting confused when the predicate returns false. Link: https://lkml.kernel.org/r/20240326202833.523759-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-04mm: convert free_swap_cache() to take a folioMatthew Wilcox (Oracle)
All but one caller already has a folio, so convert free_page_and_swap_cache() to have a folio and remove the call to page_folio(). Link: https://lkml.kernel.org/r/20240227174254.710559-19-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-04mm: convert free_pages_and_swap_cache() to use folios_put()Matthew Wilcox (Oracle)
Process the pages in batch-sized quantities instead of all-at-once. Link: https://lkml.kernel.org/r/20240227174254.710559-17-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: David Hildenbrand <david@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22mm/mmu_gather: add __tlb_remove_folio_pages()David Hildenbrand
Add __tlb_remove_folio_pages(), which will remove multiple consecutive pages that belong to the same large folio, instead of only a single page. We'll be using this function when optimizing unmapping/zapping of large folios that are mapped by PTEs. We're using the remaining spare bit in an encoded_page to indicate that the next enoced page in an array contains actually shifted "nr_pages". Teach swap/freeing code about putting multiple folio references, and delayed rmap handling to remove page ranges of a folio. This extension allows for still gathering almost as many small folios as we used to (-1, because we have to prepare for a possibly bigger next entry), but still allows for gathering consecutive pages that belong to the same large folio. Note that we don't pass the folio pointer, because it is not required for now. Further, we don't support page_size != PAGE_SIZE, it won't be required for simple PTE batching. We have to provide a separate s390 implementation, but it's fairly straight forward. Another, more invasive and likely more expensive, approach would be to use folio+range or a PFN range instead of page+nr_pages. But, we should do that consistently for the whole mmu_gather. For now, let's keep it simple and add "nr_pages" only. Note that it is now possible to gather significantly more pages: In the past, we were able to gather ~10000 pages, now we can also gather ~5000 folio fragments that span multiple pages. A folio fragment on x86-64 can span up to 512 pages (2 MiB THP) and on arm64 with 64k in theory 8192 pages (512 MiB THP). Gathering more memory is not considered something we should worry about, especially because these are already corner cases. While we can gather more total memory, we won't free more folio fragments. As long as page freeing time primarily only depends on the number of involved folios, there is no effective change for !preempt configurations. However, we'll adjust tlb_batch_pages_flush() separately to handle corner cases where page freeing time grows proportionally with the actual memory size. Link: https://lkml.kernel.org/r/20240214204435.167852-9-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Cc: Yin Fengwei <fengwei.yin@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-20mm/swap_state: update zswap LRU's protection range with the folio lockedNhat Pham
When a folio is swapped in, the protection size of the corresponding zswap LRU is incremented, so that the zswap shrinker is more conservative with its reclaiming action. This field is embedded within the struct lruvec, so updating it requires looking up the folio's memcg and lruvec. However, currently this lookup can happen after the folio is unlocked, for instance if a new folio is allocated, and swap_read_folio() unlocks the folio before returning. In this scenario, there is no stability guarantee for the binding between a folio and its memcg and lruvec: * A folio's memcg and lruvec can be freed between the lookup and the update, leading to a UAF. * Folio migration can clear the now-unlocked folio's memcg_data, which directs the zswap LRU protection size update towards the root memcg instead of the original memcg. This was recently picked up by the syzbot thanks to a warning in the inlined folio_lruvec() call. Move the zswap LRU protection range update above the swap_read_folio() call, and only when a new page is allocated, to prevent this. [nphamcs@gmail.com: add VM_WARN_ON_ONCE() to zswap_folio_swapin()] Link: https://lkml.kernel.org/r/20240206180855.3987204-1-nphamcs@gmail.com [nphamcs@gmail.com: remove unneeded if (folio) checks] Link: https://lkml.kernel.org/r/20240206191355.83755-1-nphamcs@gmail.com Link: https://lkml.kernel.org/r/20240205232442.3240571-1-nphamcs@gmail.com Fixes: b5ba474f3f51 ("zswap: shrink zswap pool based on memory pressure") Reported-by: syzbot+17a611d10af7d18a7092@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/000000000000ae47f90610803260@google.com/ Signed-off-by: Nhat Pham <nphamcs@gmail.com> Reviewed-by: Chengming Zhou <zhouchengming@bytedance.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29mm: convert swap_cluster_readahead and swap_vma_readahead to return a folioMatthew Wilcox (Oracle)
shmem_swapin_cluster() immediately converts the page back to a folio, and swapin_readahead() may as well call folio_file_page() once instead of having each function call it. [willy@infradead.org: avoid NULL pointer deref] Link: https://lkml.kernel.org/r/ZYI7OcVlM1voKfBl@casper.infradead.org Link: https://lkml.kernel.org/r/20231213215842.671461-14-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29mm: return a folio from read_swap_cache_async()Matthew Wilcox (Oracle)
The only two callers simply call put_page() on the page returned, so they're happier calling folio_put(). Saves two calls to compound_head(). Link: https://lkml.kernel.org/r/20231213215842.671461-13-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29mm: convert swap_readpage() to swap_read_folio()Matthew Wilcox (Oracle)
All callers have a folio, so pass it in, saving two calls to compound_head(). Link: https://lkml.kernel.org/r/20231213215842.671461-11-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-29mm: return the folio from __read_swap_cache_async()Matthew Wilcox (Oracle)
Patch series "More swap folio conversions". These all seem like fairly straightforward conversions to me. A lot of compound_head() calls get removed. And page_swap_info(), which is nice. This patch (of 13): Move the folio->page conversion into the callers that actually want that. Most of the callers are happier with the folio anyway. If the page_allocated boolean is set, the folio allocated is of order-0, so it is safe to pass the page directly to swap_readpage(). Link: https://lkml.kernel.org/r/20231213215842.671461-1-willy@infradead.org Link: https://lkml.kernel.org/r/20231213215842.671461-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-12zswap: shrink zswap pool based on memory pressureNhat Pham
Currently, we only shrink the zswap pool when the user-defined limit is hit. This means that if we set the limit too high, cold data that are unlikely to be used again will reside in the pool, wasting precious memory. It is hard to predict how much zswap space will be needed ahead of time, as this depends on the workload (specifically, on factors such as memory access patterns and compressibility of the memory pages). This patch implements a memcg- and NUMA-aware shrinker for zswap, that is initiated when there is memory pressure. The shrinker does not have any parameter that must be tuned by the user, and can be opted in or out on a per-memcg basis. Furthermore, to make it more robust for many workloads and prevent overshrinking (i.e evicting warm pages that might be refaulted into memory), we build in the following heuristics: * Estimate the number of warm pages residing in zswap, and attempt to protect this region of the zswap LRU. * Scale the number of freeable objects by an estimate of the memory saving factor. The better zswap compresses the data, the fewer pages we will evict to swap (as we will otherwise incur IO for relatively small memory saving). * During reclaim, if the shrinker encounters a page that is also being brought into memory, the shrinker will cautiously terminate its shrinking action, as this is a sign that it is touching the warmer region of the zswap LRU. As a proof of concept, we ran the following synthetic benchmark: build the linux kernel in a memory-limited cgroup, and allocate some cold data in tmpfs to see if the shrinker could write them out and improved the overall performance. Depending on the amount of cold data generated, we observe from 14% to 35% reduction in kernel CPU time used in the kernel builds. [nphamcs@gmail.com: check shrinker enablement early, use less costly stat flushing] Link: https://lkml.kernel.org/r/20231206194456.3234203-1-nphamcs@gmail.com Link: https://lkml.kernel.org/r/20231130194023.4102148-7-nphamcs@gmail.com Signed-off-by: Nhat Pham <nphamcs@gmail.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Tested-by: Bagas Sanjaya <bagasdotme@gmail.com> Cc: Chris Li <chrisl@kernel.org> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Seth Jennings <sjenning@redhat.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Vitaly Wool <vitaly.wool@konsulko.com> Cc: Yosry Ahmed <yosryahmed@google.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-12zswap: make shrinking memcg-awareDomenico Cerasuolo
Currently, we only have a single global LRU for zswap. This makes it impossible to perform worload-specific shrinking - an memcg cannot determine which pages in the pool it owns, and often ends up writing pages from other memcgs. This issue has been previously observed in practice and mitigated by simply disabling memcg-initiated shrinking: https://lore.kernel.org/all/20230530232435.3097106-1-nphamcs@gmail.com/T/#u This patch fully resolves the issue by replacing the global zswap LRU with memcg- and NUMA-specific LRUs, and modify the reclaim logic: a) When a store attempt hits an memcg limit, it now triggers a synchronous reclaim attempt that, if successful, allows the new hotter page to be accepted by zswap. b) If the store attempt instead hits the global zswap limit, it will trigger an asynchronous reclaim attempt, in which an memcg is selected for reclaim in a round-robin-like fashion. [nphamcs@gmail.com: use correct function for the onlineness check, use mem_cgroup_iter_break()] Link: https://lkml.kernel.org/r/20231205195419.2563217-1-nphamcs@gmail.com [nphamcs@gmail.com: drop the pool's reference at the end of the writeback step] Link: https://lkml.kernel.org/r/20231206030627.4155634-1-nphamcs@gmail.com Link: https://lkml.kernel.org/r/20231130194023.4102148-4-nphamcs@gmail.com Signed-off-by: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Co-developed-by: Nhat Pham <nphamcs@gmail.com> Signed-off-by: Nhat Pham <nphamcs@gmail.com> Tested-by: Bagas Sanjaya <bagasdotme@gmail.com> Cc: Chris Li <chrisl@kernel.org> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Seth Jennings <sjenning@redhat.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Vitaly Wool <vitaly.wool@konsulko.com> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-25mempolicy: alloc_pages_mpol() for NUMA policy without vmaHugh Dickins
Shrink shmem's stack usage by eliminating the pseudo-vma from its folio allocation. alloc_pages_mpol(gfp, order, pol, ilx, nid) becomes the principal actor for passing mempolicy choice down to __alloc_pages(), rather than vma_alloc_folio(gfp, order, vma, addr, hugepage). vma_alloc_folio() and alloc_pages() remain, but as wrappers around alloc_pages_mpol(). alloc_pages_bulk_*() untouched, except to provide the additional args to policy_nodemask(), which subsumes policy_node(). Cleanup throughout, cutting out some unhelpful "helpers". It would all be much simpler without MPOL_INTERLEAVE, but that adds a dynamic to the constant mpol: complicated by v3.6 commit 09c231cb8bfd ("tmpfs: distribute interleave better across nodes"), which added ino bias to the interleave, hidden from mm/mempolicy.c until this commit. Hence "ilx" throughout, the "interleave index". Originally I thought it could be done just with nid, but that's wrong: the nodemask may come from the shared policy layer below a shmem vma, or it may come from the task layer above a shmem vma; and without the final nodemask then nodeid cannot be decided. And how ilx is applied depends also on page order. The interleave index is almost always irrelevant unless MPOL_INTERLEAVE: with one exception in alloc_pages_mpol(), where the NO_INTERLEAVE_INDEX passed down from vma-less alloc_pages() is also used as hint not to use THP-style hugepage allocation - to avoid the overhead of a hugepage arg (though I don't understand why we never just added a GFP bit for THP - if it actually needs a different allocation strategy from other pages of the same order). vma_alloc_folio() still carries its hugepage arg here, but it is not used, and should be removed when agreed. get_vma_policy() no longer allows a NULL vma: over time I believe we've eradicated all the places which used to need it e.g. swapoff and madvise used to pass NULL vma to read_swap_cache_async(), but now know the vma. [hughd@google.com: handle NULL mpol being passed to __read_swap_cache_async()] Link: https://lkml.kernel.org/r/ea419956-4751-0102-21f7-9c93cb957892@google.com Link: https://lkml.kernel.org/r/74e34633-6060-f5e3-aee-7040d43f2e93@google.com Link: https://lkml.kernel.org/r/1738368e-bac0-fd11-ed7f-b87142a939fe@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Hildenbrand <david@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Huang Ying <ying.huang@intel.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Tejun heo <tj@kernel.org> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yosry Ahmed <yosryahmed@google.com> Cc: Domenico Cerasuolo <mimmocerasuolo@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-25mm/swap: avoid a xa load for swapout pathKairui Song
A variable is never used for swapout path (shadowp is NULL) and compiler is unable to optimize out the unneeded load since it's a function call. The was introduced by 3852f6768ede ("mm/swapcache: support to handle the shadow entries"). Link: https://lkml.kernel.org/r/20231017011728.37508-1-ryncsn@gmail.com Signed-off-by: Kairui Song <kasong@tencent.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Huang Ying <ying.huang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-24mm/swap: inline folio_set_swap_entry() and folio_swap_entry()David Hildenbrand
Let's simply work on the folio directly and remove the helpers. Link: https://lkml.kernel.org/r/20230821160849.531668-4-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Suggested-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Chris Li <chrisl@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Hugh Dickins <hughd@google.com> Cc: Peter Xu <peterx@redhat.com> Cc: Seth Jennings <sjenning@redhat.com> Cc: Vitaly Wool <vitaly.wool@konsulko.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-24mm/swap: stop using page->private on tail pages for THP_SWAPDavid Hildenbrand
Patch series "mm/swap: stop using page->private on tail pages for THP_SWAP + cleanups". This series stops using page->private on tail pages for THP_SWAP, replaces folio->private by folio->swap for swapcache folios, and starts using "new_folio" for tail pages that we are splitting to remove the usage of page->private for swapcache handling completely. This patch (of 4): Let's stop using page->private on tail pages, making it possible to just unconditionally reuse that field in the tail pages of large folios. The remaining usage of the private field for THP_SWAP is in the THP splitting code (mm/huge_memory.c), that we'll handle separately later. Update the THP_SWAP documentation and sanity checks in mm_types.h and __split_huge_page_tail(). [david@redhat.com: stop using page->private on tail pages for THP_SWAP] Link: https://lkml.kernel.org/r/6f0a82a3-6948-20d9-580b-be1dbf415701@redhat.com Link: https://lkml.kernel.org/r/20230821160849.531668-1-david@redhat.com Link: https://lkml.kernel.org/r/20230821160849.531668-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64] Reviewed-by: Yosry Ahmed <yosryahmed@google.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Peter Xu <peterx@redhat.com> Cc: Seth Jennings <sjenning@redhat.com> Cc: Vitaly Wool <vitaly.wool@konsulko.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-24swap: remove remnants of polling from read_swap_cache_asyncSuren Baghdasaryan
Patch series "Per-VMA lock support for swap and userfaults", v7. When per-VMA locks were introduced in [1] several types of page faults would still fall back to mmap_lock to keep the patchset simple. Among them are swap and userfault pages. The main reason for skipping those cases was the fact that mmap_lock could be dropped while handling these faults and that required additional logic to be implemented. Implement the mechanism to allow per-VMA locks to be dropped for these cases. First, change handle_mm_fault to drop per-VMA locks when returning VM_FAULT_RETRY or VM_FAULT_COMPLETED to be consistent with the way mmap_lock is handled. Then change folio_lock_or_retry to accept vm_fault and return vm_fault_t which simplifies later patches. Finally allow swap and uffd page faults to be handled under per-VMA locks by dropping per-VMA and retrying, the same way it's done under mmap_lock. Naturally, once VMA lock is dropped that VMA should be assumed unstable and can't be used. This patch (of 6): Commit [1] introduced IO polling support duding swapin to reduce swap read latency for block devices that can be polled. However later commit [2] removed polling support. Therefore it seems safe to remove do_poll parameter in read_swap_cache_async and always call swap_readpage with synchronous=false waiting for IO completion in folio_lock_or_retry. [1] commit 23955622ff8d ("swap: add block io poll in swapin path") [2] commit 9650b453a3d4 ("block: ignore RWF_HIPRI hint for sync dio") Link: https://lkml.kernel.org/r/20230630211957.1341547-1-surenb@google.com Link: https://lkml.kernel.org/r/20230630211957.1341547-2-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Suggested-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Hillf Danton <hdanton@sina.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Laurent Dufour <ldufour@linux.ibm.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Michel Lespinasse <michel@lespinasse.org> Cc: Minchan Kim <minchan@google.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Peter Xu <peterx@redhat.com> Cc: Punit Agrawal <punit.agrawal@bytedance.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21mm/swap_state.c: use helper macro K()ZhangPeng
Use helper macro K() to improve code readability. No functional modification involved. Link: https://lkml.kernel.org/r/20230804012559.2617515-4-zhangpeng362@huawei.com Signed-off-by: ZhangPeng <zhangpeng362@huawei.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-23mm: remove unnecessary pagevec includesMatthew Wilcox (Oracle)
These files no longer need pagevec.h, mostly due to function declarations being moved out of it. Link: https://lkml.kernel.org/r/20230621164557.3510324-14-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-19mm: ptep_get() conversionRyan Roberts
Convert all instances of direct pte_t* dereferencing to instead use ptep_get() helper. This means that by default, the accesses change from a C dereference to a READ_ONCE(). This is technically the correct thing to do since where pgtables are modified by HW (for access/dirty) they are volatile and therefore we should always ensure READ_ONCE() semantics. But more importantly, by always using the helper, it can be overridden by the architecture to fully encapsulate the contents of the pte. Arch code is deliberately not converted, as the arch code knows best. It is intended that arch code (arm64) will override the default with its own implementation that can (e.g.) hide certain bits from the core code, or determine young/dirty status by mixing in state from another source. Conversion was done using Coccinelle: ---- // $ make coccicheck \ // COCCI=ptepget.cocci \ // SPFLAGS="--include-headers" \ // MODE=patch virtual patch @ depends on patch @ pte_t *v; @@ - *v + ptep_get(v) ---- Then reviewed and hand-edited to avoid multiple unnecessary calls to ptep_get(), instead opting to store the result of a single call in a variable, where it is correct to do so. This aims to negate any cost of READ_ONCE() and will benefit arch-overrides that may be more complex. Included is a fix for an issue in an earlier version of this patch that was pointed out by kernel test robot. The issue arose because config MMU=n elides definition of the ptep helper functions, including ptep_get(). HUGETLB_PAGE=n configs still define a simple huge_ptep_clear_flush() for linking purposes, which dereferences the ptep. So when both configs are disabled, this caused a build error because ptep_get() is not defined. Fix by continuing to do a direct dereference when MMU=n. This is safe because for this config the arch code cannot be trying to virtualize the ptes because none of the ptep helpers are defined. Link: https://lkml.kernel.org/r/20230612151545.3317766-4-ryan.roberts@arm.com Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/oe-kbuild-all/202305120142.yXsNEo6H-lkp@intel.com/ Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Potapenko <glider@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Dave Airlie <airlied@gmail.com> Cc: Dimitri Sivanich <dimitri.sivanich@hpe.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ian Rogers <irogers@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: SeongJae Park <sj@kernel.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-19mm/swap: swap_vma_readahead() do the pte_offset_map()Hugh Dickins
swap_vma_readahead() has been proceeding in an unconventional way, its preliminary swap_ra_info() doing the pte_offset_map() and pte_unmap(), then relying on that pte pointer even after the pte_unmap() - in its CONFIG_64BIT case (I think !CONFIG_HIGHPTE was intended; whereas 32-bit copied ptes to stack while they were mapped, but had to limit how many). Though it would be difficult to construct a failing testcase, accessing page table after pte_unmap() will become bad practice, even on 64-bit: an rcu_read_unlock() in pte_unmap() will allow page table to be freed. Move relevant definitions from include/linux/swap.h to mm/swap_state.c, nothing else used them. Delete the CONFIG_64BIT distinction and buffer, delete all reference to ptes from swap_ra_info(), use pte_offset_map() repeatedly in swap_vma_readahead(), breaking from the loop if it fails. (Will the repeated "map" and "unmap" show up as a slowdown anywhere? If so, maybe modify __read_swap_cache_async() to do the pte_unmap() only when it does not find the page already in the swapcache.) Use ptep_get_lockless(), mainly for its READ_ONCE(). Correctly advance the address passed down to each call of __read__swap_cache_async(). Link: https://lkml.kernel.org/r/b7c64ab3-9e44-aac0-d2b-c57de578af1c@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Christoph Hellwig <hch@infradead.org> Cc: David Hildenbrand <david@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: SeongJae Park <sj@kernel.org> Cc: Song Liu <song@kernel.org> Cc: Steven Price <steven.price@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zack Rusin <zackr@vmware.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09swap: remove __swp_swapcount()Huang Ying
__swp_swapcount() just encloses the calling to swap_swapcount() with get/put_swap_device(). It is called in __read_swap_cache_async() only, which encloses the calling with get/put_swap_device() already. So, __read_swap_cache_async() can call swap_swapcount() directly. Link: https://lkml.kernel.org/r/20230529061355.125791-4-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Chris Li (Google) <chrisl@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09swap, __read_swap_cache_async(): enlarge get/put_swap_device protection rangeHuang Ying
This makes the function a little easier to be understood because we don't need to consider swapoff. And this makes it possible to remove get/put_swap_device() calling in some functions called by __read_swap_cache_async(). Link: https://lkml.kernel.org/r/20230529061355.125791-3-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Chris Li (Google) <chrisl@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05mm: return an ERR_PTR from __filemap_get_folioChristoph Hellwig
Instead of returning NULL for all errors, distinguish between: - no entry found and not asked to allocated (-ENOENT) - failed to allocate memory (-ENOMEM) - would block (-EAGAIN) so that callers don't have to guess the error based on the passed in flags. Also pass through the error through the direct callers: filemap_get_folio, filemap_lock_folio filemap_grab_folio and filemap_get_incore_folio. [hch@lst.de: fix null-pointer deref] Link: https://lkml.kernel.org/r/20230310070023.GA13563@lst.de Link: https://lkml.kernel.org/r/20230310043137.GA1624890@u2004 Link: https://lkml.kernel.org/r/20230307143410.28031-8-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> [nilfs2] Cc: Andreas Gruenbacher <agruenba@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05mm: use filemap_get_entry in filemap_get_incore_folioChristoph Hellwig
filemap_get_incore_folio wants to look at the details of xa_is_value entries, but doesn't need any of the other logic in filemap_get_folio. Switch it to use the lower-level filemap_get_entry interface. Link: https://lkml.kernel.org/r/20230307143410.28031-4-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Andreas Gruenbacher <agruenba@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>