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| * mm, swap: fold swap_info_get_cont in the only callerKairui Song4 days1-24/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The name of the function is confusing, and the code is much easier to follow after folding, also rename the confusing naming "p" to more meaningful "si". Link: https://lkml.kernel.org/r/20250113175732.48099-3-ryncsn@gmail.com Signed-off-by: Kairui Song <kasong@tencent.com> Reviewed-by: Baoquan He <bhe@redhat.com> Cc: Barry Song <v-songbaohua@oppo.com> Cc: Chis Li <chrisl@kernel.org> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Hugh Dickens <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm, swap: minor clean up for swap entry allocationKairui Song4 days1-30/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "mm, swap: rework of swap allocator locks", v4. This series greatly improved swap performance by reworking the locking design and simplify a lot of code path. Test showed a up to 400% vm-scalability improvement with pmem as SWAP, and up to 37% reduce of kernel compile real time with ZRAM as SWAP (up to 60% improvement in system time). This is part of the new swap allocator discussed during the "Swap Abstraction" discussion at LSF/MM 2024, and "mTHP and swap allocator" discussion at LPC 2024. This is a follow up of previous swap cluster allocator series: https://lore.kernel.org/linux-mm/20240730-swap-allocator-v5-0-cb9c148b9297@kernel.org/ Also enables further optimizations which will come later. Previous series introduced a fully cluster based allocator, this series completely get rid of the old allocator and makes the new allocator avoid touching the si->lock unless needed. This bring huge performance gain and get rid of slot cache for freeing path. Currently, swap locking is mainly composed of two locks, cluster lock (ci->lock) and device lock (si->lock). The device lock is widely used to protect many things, causing it to be the main bottleneck for SWAP. Cluster lock is much more fine-grained, so it will be best to use ci->lock instead of si->lock as much as possible. `perf lock' indicates this issue clearly. Doing linux kernel build using tmpfs and ZRAM with limited memory (make -j64 with 1G memcg and 4k pages), result of "perf lock contention -ab sleep 3" shows: contended total wait max wait avg wait type caller 34948 53.63 s 7.11 ms 1.53 ms spinlock free_swap_and_cache_nr+0x350 16569 40.05 s 6.45 ms 2.42 ms spinlock get_swap_pages+0x231 11191 28.41 s 7.03 ms 2.54 ms spinlock swapcache_free_entries+0x59 4147 22.78 s 122.66 ms 5.49 ms spinlock page_vma_mapped_walk+0x6f3 4595 7.17 s 6.79 ms 1.56 ms spinlock swapcache_free_entries+0x59 406027 2.74 s 2.59 ms 6.74 us spinlock list_lru_add+0x39 ...snip... The top 5 caller are all users of si->lock, total wait time sums to several minutes in the 3 seconds time window. Following the new allocator design, many operation doesn't need to touch si->lock at all. We only need to take si->lock when doing operations across multiple clusters (changing the cluster list). So ideally allocator should always take ci->lock first, then take si->lock only if needed. But due to historical reasons, ci->lock is used inside si->lock critical section, causing lock inversion if we simply try to acquire si->lock after acquiring ci->lock. This series audited all si->lock usage, clean up legacy codes, eliminate usage of si->lock as much as possible by introducing new designs based on the new cluster allocator. Old HDD allocation codes are removed, cluster allocator is adapted with small changes for HDD usage, test is looking OK. And this also removed slot cache for freeing path. The performance is even better without it now, and this enables other clean up and optimizations as discussed before: https://lore.kernel.org/all/CAMgjq7ACohT_uerSz8E_994ZZCv709Zor+43hdmesW_59W1BWw@mail.gmail.com/ After this series, lock contention on si->lock is nearly unobservable with `perf lock` with the same test above: contended total wait max wait avg wait type caller ... snip ... 52 127.12 us 3.82 us 2.44 us spinlock move_cluster+0x2c 56 120.77 us 12.41 us 2.16 us spinlock move_cluster+0x2c ... snip ... 10 21.96 us 2.78 us 2.20 us spinlock isolate_lock_cluster+0x20 ... snip ... 9 19.27 us 2.70 us 2.14 us spinlock move_cluster+0x2c ... snip ... 5 11.07 us 2.70 us 2.21 us spinlock isolate_lock_cluster+0x20 `move_cluster' and `isolate_lock_cluster' (two new introduced helper) are basically the only users of si->lock now, performance gain is huge, and LOC is reduced. Tests Results: vm-scalability ============== Running `usemem --init-time -O -y -x -R -31 1G` from vm-scalability in a 12G memory cgroup using simulated pmem as SWAP backend (32G pmem, 32 CPUs). Using 4K folio by default, 64k mTHP and sequential access (!-R) results are also provided. 6 test runs for each case, Total Throughput: Test Before (KB/s) (stdev) After (KB/s) (stdev) Delta --------------------------------------------------------------------------- Random (4K): 69937.11 (16449.77) 369816.17 (24476.68) +428.78% Random (64k): 123442.83 (13207.51) 216379.00 (25024.83) +75.28% Sequential (4K): 6313909.83 (148856.12) 6419860.66 (183563.38) +1.7% Sequential access will cause lower stress for the allocator so the gain is limited, but with random access (which is much closer to real workloads) the performance gain is huge. Build kernel with defconfig on tmpfs with ZRAM ============================================== Below results shows a test matrix using different memory cgroup limit and job numbets, and scaled up progressive for a intuitive result. Done on a 48c96t system. 6 test run for each case, it can be seen clearly that as concurrent job number goes higher the performance gain is higher, but even -j6 is showing slight improvement. make -j<NR> | System Time (seconds) | Total Time (seconds) (NR / Mem / ZRAM) | (Before / After / Delta) | (Before / After / Delta) With 4k pages only: 6 / 192M / 3G | 1533 / 1522 / -0.7% | 1420 / 1414 / -0.3% 12 / 256M / 4G | 2275 / 2226 / -2.2% | 758 / 742 / -2.1% 24 / 384M / 5G | 3596 / 3154 / -12.3% | 476 / 422 / -11.3% 48 / 768M / 7G | 8159 / 3605 / -55.8% | 330 / 221 / -33.0% 96 / 1.5G / 10G | 18541 / 6462 / -65.1% | 283 / 180 / -36.4% With 64k mTHP: 24 / 512M / 5G | 3585 / 3469 / -3.2% | 293 / 290 / -0.1% 48 / 1G / 7G | 8173 / 3607 / -55.9% | 251 / 158 / -37.0% 96 / 2G / 10G | 16305 / 7791 / -52.2% | 226 / 144 / -36.3% The fragmentation are reduced too: With: make -j96 / 1152M memcg, 64K mTHP: (avg of 4 test run) Before: hugepages-64kB/stats/swpout: 1696184 hugepages-64kB/stats/swpout_fallback: 414318 After: (-63.2% mTHP swapout failure) hugepages-64kB/stats/swpout: 1866267 hugepages-64kB/stats/swpout_fallback: 158330 There is a up to 65.1% improvement in sys time for build kernel test, and lower fragmentation rate. Build kernel with tinyconfig on tmpfs with HDD as swap: ======================================================= This test is similar to above, but HDD test is very noisy and slow, the deviation is huge, so just use tinyconfig instead and take the median test result of 3 test run, which looks OK: Before this series: 114.44user 29.11system 39:42.90elapsed 6%CPU 2901232inputs+0outputs (238877major+4227640minor)pagefaults After this commit: 113.90user 23.81system 38:11.77elapsed 6%CPU 2548728inputs+0outputs (235471major+4238110minor)pagefaults Single thread SWAP: =================== Sequential SWAP should also be slightly faster as we removed a lot of unnecessary parts. Test using micro benchmark for swapout/in 4G zero memory using ZRAM, 10 test runs: Swapout Before (avg. 3359304): 3353796 3358551 3371305 3356043 3367524 3355303 3355924 3354513 3360776 Swapin Before (avg. 1928698): 1920283 1927183 1934105 1921373 1926562 1938261 1927726 1928636 1934155 Swapout After (avg. 3347511, -0.4%): 3337863 3347948 3355235 3339081 3333134 3353006 3354917 3346055 3360359 Swapin After (avg. 1922290, -0.3%): 1919101 1925743 1916810 1917007 1923930 1935152 1917403 1923549 1921913 The gain is limited at noise level but seems slightly better. This patch (of 13): Direct reclaim can skip the whole folio after reclaimed a set of folio based slots. Also simplify the code for allocation, reduce indention. Link: https://lkml.kernel.org/r/20250113175732.48099-1-ryncsn@gmail.com Link: https://lkml.kernel.org/r/20250113175732.48099-2-ryncsn@gmail.com Signed-off-by: Kairui Song <kasong@tencent.com> Reviewed-by: Baoquan He <bhe@redhat.com> Cc: Barry Song <v-songbaohua@oppo.com> Cc: Chis Li <chrisl@kernel.org> (Google) Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Hugh Dickens <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * memcg: fix soft lockup in the OOM processChen Ridong4 days2-2/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A soft lockup issue was found in the product with about 56,000 tasks were in the OOM cgroup, it was traversing them when the soft lockup was triggered. watchdog: BUG: soft lockup - CPU#2 stuck for 23s! [VM Thread:1503066] CPU: 2 PID: 1503066 Comm: VM Thread Kdump: loaded Tainted: G Hardware name: Huawei Cloud OpenStack Nova, BIOS RIP: 0010:console_unlock+0x343/0x540 RSP: 0000:ffffb751447db9a0 EFLAGS: 00000247 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 00000000ffffffff RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000247 RBP: ffffffffafc71f90 R08: 0000000000000000 R09: 0000000000000040 R10: 0000000000000080 R11: 0000000000000000 R12: ffffffffafc74bd0 R13: ffffffffaf60a220 R14: 0000000000000247 R15: 0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2fe6ad91f0 CR3: 00000004b2076003 CR4: 0000000000360ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: vprintk_emit+0x193/0x280 printk+0x52/0x6e dump_task+0x114/0x130 mem_cgroup_scan_tasks+0x76/0x100 dump_header+0x1fe/0x210 oom_kill_process+0xd1/0x100 out_of_memory+0x125/0x570 mem_cgroup_out_of_memory+0xb5/0xd0 try_charge+0x720/0x770 mem_cgroup_try_charge+0x86/0x180 mem_cgroup_try_charge_delay+0x1c/0x40 do_anonymous_page+0xb5/0x390 handle_mm_fault+0xc4/0x1f0 This is because thousands of processes are in the OOM cgroup, it takes a long time to traverse all of them. As a result, this lead to soft lockup in the OOM process. To fix this issue, call 'cond_resched' in the 'mem_cgroup_scan_tasks' function per 1000 iterations. For global OOM, call 'touch_softlockup_watchdog' per 1000 iterations to avoid this issue. Link: https://lkml.kernel.org/r/20241224025238.3768787-1-chenridong@huaweicloud.com Fixes: 9cbb78bb3143 ("mm, memcg: introduce own oom handler to iterate only over its own threads") Signed-off-by: Chen Ridong <chenridong@huawei.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Michal Koutný <mkoutny@suse.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/zsmalloc: introduce __zpdesc_clear/set_zsmalloc()Alex Shi4 days2-3/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add helper __zpdesc_clear_zsmalloc() for __ClearPageZsmalloc(), __zpdesc_set_zsmalloc() for __SetPageZsmalloc(), and use them in callers. [42.hyeyoo@gmail.com: keep reset_zpdesc() to use struct page] Link: https://lkml.kernel.org/r/20241216150450.1228021-19-42.hyeyoo@gmail.com Signed-off-by: Alex Shi <alexs@kernel.org> Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Acked-by: Sergey Senozhatsky <senozhatsky@chromium.org> Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/zsmalloc: convert get/set_first_obj_offset() to take zpdescAlex Shi4 days1-12/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that all users of get/set_first_obj_offset() are converted to use zpdesc, convert them to take zpdesc. Link: https://lkml.kernel.org/r/20241216150450.1228021-18-42.hyeyoo@gmail.com Signed-off-by: Alex Shi <alexs@kernel.org> Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Acked-by: Sergey Senozhatsky <senozhatsky@chromium.org> Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/zsmalloc: convert SetZsPageMovable and remove unused funcsAlex Shi4 days1-28/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Convert SetZsPageMovable() to use zpdesc, and then remove unused funcs: get_next_page()/get_first_page()/is_first_page(). Link: https://lkml.kernel.org/r/20241216150450.1228021-17-42.hyeyoo@gmail.com Originally-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Alex Shi <alexs@kernel.org> Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Acked-by: Sergey Senozhatsky <senozhatsky@chromium.org> Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/zsmalloc: convert get_zspage() to take zpdescHyeonggon Yoo4 days1-10/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that all users except get_next_page() (which will be removed in later patch) use zpdesc, convert get_zspage() to take zpdesc instead of page. Link: https://lkml.kernel.org/r/20241216150450.1228021-16-42.hyeyoo@gmail.com Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Alex Shi <alexs@kernel.org> Acked-by: Sergey Senozhatsky <senozhatsky@chromium.org> Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/zsmalloc: convert migrate_zspage() to use zpdescHyeonggon Yoo4 days1-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use get_first_zpdesc/get_next_zpdesc to replace get_first/next_page. No functional change. Link: https://lkml.kernel.org/r/20241216150450.1228021-15-42.hyeyoo@gmail.com Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Alex Shi <alexs@kernel.org> Acked-by: Sergey Senozhatsky <senozhatsky@chromium.org> Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/zsmalloc: convert location_to_obj() to take zpdescHyeonggon Yoo4 days1-7/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As all users of location_to_obj() now use zpdesc, convert location_to_obj() to take zpdesc. Link: https://lkml.kernel.org/r/20241216150450.1228021-14-42.hyeyoo@gmail.com Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Alex Shi <alexs@kernel.org> Acked-by: Sergey Senozhatsky <senozhatsky@chromium.org> Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/zsmalloc: convert __free_zspage() to use zpdescHyeonggon Yoo4 days2-10/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce zpdesc_is_locked() and convert __free_zspage() to use zpdesc. Link: https://lkml.kernel.org/r/20241216150450.1228021-13-42.hyeyoo@gmail.com Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Alex Shi <alexs@kernel.org> Acked-by: Sergey Senozhatsky <senozhatsky@chromium.org> Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/zsmalloc: convert reset_page to reset_zpdescAlex Shi4 days1-5/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | zpdesc.zspage matches with page.private, zpdesc.next matches with page.index. They will be reset in reset_page() which is called prior to free base pages of a zspage. Since the fields that need to be initialized are independent of the order in struct zpdesc, Keep it to use struct page to ensure robustness against potential rearrangements of struct zpdesc fields in the future. [42.hyeyoo@gmail.com: reset zpdesc fields in reset_zpdesc()] Link: https://lkml.kernel.org/r/Z4Uw136VdG7vlKCL@localhost.localdomain [42.hyeyoo@gmail.com: keep reset_zpdesc() to use struct page fields] Link: https://lkml.kernel.org/r/20241216150450.1228021-12-42.hyeyoo@gmail.com Signed-off-by: Alex Shi <alexs@kernel.org> Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Acked-by: Sergey Senozhatsky <senozhatsky@chromium.org> Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/zsmalloc: add two helpers for zs_page_migrate() and make it use zpdescHyeonggon Yoo4 days2-14/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | To convert page to zpdesc in zs_page_migrate(), we added zpdesc_is_isolated()/zpdesc_zone() helpers. No functional change. Link: https://lkml.kernel.org/r/20241216150450.1228021-11-42.hyeyoo@gmail.com Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Alex Shi <alexs@kernel.org> Acked-by: Sergey Senozhatsky <senozhatsky@chromium.org> Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/zsmalloc: convert obj_to_page() and zs_free() to use zpdescHyeonggon Yoo4 days1-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rename obj_to_page() to obj_to_zpdesc() and also convert it and its user zs_free() to use zpdesc. Link: https://lkml.kernel.org/r/20241216150450.1228021-10-42.hyeyoo@gmail.com Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Alex Shi <alexs@kernel.org> Acked-by: Sergey Senozhatsky <senozhatsky@chromium.org> Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/zsmalloc: convert init_zspage() to use zpdescHyeonggon Yoo4 days1-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Replace get_first/next_page func series and kmap_atomic to new helper, no functional change. Link: https://lkml.kernel.org/r/20241216150450.1228021-9-42.hyeyoo@gmail.com Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Alex Shi <alexs@kernel.org> Acked-by: Sergey Senozhatsky <senozhatsky@chromium.org> Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/zsmalloc: convert obj_allocated() and related helpers to use zpdescHyeonggon Yoo4 days1-10/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Convert obj_allocated(), and related helpers to take zpdesc. Also make its callers to cast (struct page *) to (struct zpdesc *) when calling them. The users will be converted gradually as there are many. Link: https://lkml.kernel.org/r/20241216150450.1228021-8-42.hyeyoo@gmail.com Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Alex Shi <alexs@kernel.org> Acked-by: Sergey Senozhatsky <senozhatsky@chromium.org> Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/zsmalloc: convert create_page_chain() and its users to use zpdescAlex Shi4 days2-39/+76
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce a few helper functions for conversion to convert create_page_chain() to use zpdesc, then use zpdesc in replace_sub_page(). Link: https://lkml.kernel.org/r/20241216150450.1228021-7-42.hyeyoo@gmail.com Originally-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Alex Shi <alexs@kernel.org> Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Acked-by: Sergey Senozhatsky <senozhatsky@chromium.org> Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/zsmalloc: convert obj_malloc() to use zpdescHyeonggon Yoo4 days1-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use get_first_zpdesc/get_next_zpdesc to replace get_first_page/get_next_page. no functional change. Link: https://lkml.kernel.org/r/20241216150450.1228021-6-42.hyeyoo@gmail.com Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Alex Shi <alexs@kernel.org> Acked-by: Sergey Senozhatsky <senozhatsky@chromium.org> Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/zsmalloc: add and use pfn/zpdesc seeking funcsHyeonggon Yoo4 days2-37/+52
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add pfn_zpdesc(), pfn_zpdesc() and kmap_local_zpdesc(). Convert obj_to_location() to take zpdesc and also convert its users to use zpdesc. Link: https://lkml.kernel.org/r/20241216150450.1228021-5-42.hyeyoo@gmail.com Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Alex Shi <alexs@kernel.org> Acked-by: Sergey Senozhatsky <senozhatsky@chromium.org> Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/zsmalloc: convert __zs_map_object/__zs_unmap_object to use zpdescHyeonggon Yoo4 days1-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These two functions take a pointer to an array of struct page. Make __zs_{map,unmap}_object() take pointer to an array of zpdesc instead of page. Add silly type casting when calling them. Casting will be removed later. Link: https://lkml.kernel.org/r/20241216150450.1228021-4-42.hyeyoo@gmail.com Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Alex Shi <alexs@kernel.org> Acked-by: Sergey Senozhatsky <senozhatsky@chromium.org> Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/zsmalloc: use zpdesc in trylock_zspage()/lock_zspage()Alex Shi4 days2-21/+73
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Convert trylock_zspage() and lock_zspage() to use zpdesc. To achieve that, introduce a couple of helper functions: - zpdesc_lock() - zpdesc_unlock() - zpdesc_trylock() - zpdesc_wait_locked() - zpdesc_get() - zpdesc_put() Here we use the folio version of functions for 2 reasons. First, zswap.zpool currently only uses order-0 pages and using folio could save some compound_head checks. Second, folio_put could bypass devmap checking that we don't need. BTW, thanks Intel LKP found a build warning on the patch. Originally-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Link: https://lkml.kernel.org/r/20241216150450.1228021-3-42.hyeyoo@gmail.com Signed-off-by: Alex Shi <alexs@kernel.org> Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Acked-by: Sergey Senozhatsky <senozhatsky@chromium.org> Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/zsmalloc: add zpdesc memory descriptor for zswap.zpoolAlex Shi4 days2-23/+112
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "Add zpdesc memory descriptor for zswap.zpool", v9. This patch series introduces a new memory descriptor for zswap.zpool that currently overlaps with struct page for now. This is part of the effort to reduce the size of struct page and to enable dynamic allocation of memory descriptors [1]. This series does not bloat anything for zsmalloc and no functional change is intended (except for using zpdesc and folios). In the near future, the removal of page->index from struct page [2] will be addressed and the project also depends on this patch series. Thanks to everyone got involved in this series, especially, Alex who's been pushing it forward this year. [1] https://lore.kernel.org/linux-mm/ZvRKzKizOfEWBtJp@casper.infradead.org [2] https://lore.kernel.org/linux-mm/Z09hOy-UY9KC8WMb@casper.infradead.org This patch (of 18): The 1st patch introduces new memory descriptor zpdesc and renames zspage.first_page to zspage.first_zpdesc, with no functional change. We removed the comment about PG_owner_priv_1 since it is no longer used after commit a41ec880aa7b ("zsmalloc: move huge compressed obj from page to zspage"). [rdunlap@infradead.org: fix function parameter kernel-doc notation] Link: https://lkml.kernel.org/r/20250111063305.911010-1-rdunlap@infradead.org [42.hyeyoo@gmail.com: rework comments a little bit] Link: https://lkml.kernel.org/r/20241216150450.1228021-1-42.hyeyoo@gmail.com Link: https://lkml.kernel.org/r/20241216150450.1228021-2-42.hyeyoo@gmail.com Originally-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Alex Shi <alexs@kernel.org> Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Sergey Senozhatsky <senozhatsky@chromium.org> Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Alex Shi <alexs@kernel.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/damon/sysfs-schemes: add a file for setting damos_filter->allowSeongJae Park4 days1-1/+31
| | | | | | | | | | | | | | | | | | | | | | Only kernel-space DAMON API users can use inclusive DAMOS filters. Add a sysfs file named 'allow' under DAMOS filter directory of DAMON sysfs interface, to let the user-space users use inclusive DAMOS filters. Link: https://lkml.kernel.org/r/20250109175126.57878-7-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/damon: add 'allow' argument to damos_new_filter()SeongJae Park4 days5-8/+10
| | | | | | | | | | | | | | | | | | | | | | | | DAMON API users should set damos_filter->allow manually to use a DAMOS allow-filter, since damos_new_filter() unsets the field always. It is cumbersome and easy to mistake. Add an arugment for setting the field to damos_new_filter(). Link: https://lkml.kernel.org/r/20250109175126.57878-6-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/damon/paddr: support damos_filter->allowSeongJae Park4 days1-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | Respect damos_filter->allow from 'paddr', which is a DAMON operations set implementation for the physical address space and supports a few types of region-internal DAMOS filters (anon, memcg and young). The change is similar to that of the previous commit for core layer update. Link: https://lkml.kernel.org/r/20250109175126.57878-5-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/damon/core: support damos_filter->allowSeongJae Park4 days2-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | DAMOS filters supports allowing behavior, but the core layer's DAMOS filters handling logic still assumes only rejecting (filtering-out) behavior. Update the logic to aware of and respect the behavioral decision by reading damos_filter->allow when making the decision to exclude a region or not. Link: https://lkml.kernel.org/r/20250109175126.57878-4-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/damon/core: add damos_filter->allow fieldSeongJae Park4 days1-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | DAMOS filters work as only exclusive (reject) filters. This makes it easy to be confused, and restrictive at combining multiple filters for covering various types of memory. Add a field named 'allow' to damos_filter. The field will be used to indicate whether the filter should work for inclusion or exclusion. To keep the old behavior, set it as 'false' (work as exclusive filter) by default, from damos_new_filter(). Following two commits will make the core and operations set layers, which handles damos_filter objects, respect the field, respectively. Link: https://lkml.kernel.org/r/20250109175126.57878-3-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm: alloc_pages_bulk: rename APILuiz Capitulino4 days2-9/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The previous commit removed the page_list argument from alloc_pages_bulk_noprof() along with the alloc_pages_bulk_list() function. Now that only the *_array() flavour of the API remains, we can do the following renaming (along with the _noprof() ones): alloc_pages_bulk_array -> alloc_pages_bulk alloc_pages_bulk_array_mempolicy -> alloc_pages_bulk_mempolicy alloc_pages_bulk_array_node -> alloc_pages_bulk_node Link: https://lkml.kernel.org/r/275a3bbc0be20fbe9002297d60045e67ab3d4ada.1734991165.git.luizcap@redhat.com Signed-off-by: Luiz Capitulino <luizcap@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Yunsheng Lin <linyunsheng@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm: alloc_pages_bulk_noprof: drop page_list argumentLuiz Capitulino4 days2-34/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "mm: alloc_pages_bulk: small API refactor", v2. Today, alloc_pages_bulk_noprof() supports two arguments to return allocated pages: a linked list and an array. There are also higher level APIs for both. However, the linked list API has apparently never been used. So, this series removes it along with the list API and also refactors the remaining API naming for consistency. This patch (of 2): commit 387ba26fb1cb ("mm/page_alloc: add a bulk page allocator") added __alloc_pages_bulk() along with the page_list argument. The next commit 0f87d9d30f21 ("mm/page_alloc: add an array-based interface to the bulk page allocator") added the array-based argument. As it turns out, the page_list argument has no users in the current tree (if it ever had any). Dropping it allows for a slight simplification and eliminates some unnecessary checks, now that page_array is required. Also, note that the removal of the page_list argument was proposed before in the thread below, where Matthew Wilcox mentions that: """ Iterating a linked list is _expensive_. It is about 10x quicker to iterate an array than a linked list. """ (https://lore.kernel.org/linux-mm/20231025093254.xvomlctwhcuerzky@techsingularity.net) Link: https://lkml.kernel.org/r/cover.1734991165.git.luizcap@redhat.com Link: https://lkml.kernel.org/r/f1c75db91d08cafd211eca6a3b199b629d4ffe16.1734991165.git.luizcap@redhat.com Signed-off-by: Luiz Capitulino <luizcap@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Yunsheng Lin <linyunsheng@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/hugetlb: unify restore reserve accounting for new allocationsPeter Xu4 days1-9/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Either hugetlb pages dequeued from hstate, or newly allocated from buddy, would require restore-reserve accounting to be managed properly. Merge the two paths on it. Add a small comment to make it slightly nicer. Link: https://lkml.kernel.org/r/20250107204002.2683356-8-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Cc: Ackerley Tng <ackerleytng@google.com> Cc: Breno Leitao <leitao@debian.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Rik van Riel <riel@surriel.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/hugetlb: drop vma_has_reserves()Peter Xu4 days1-17/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After the previous cleanup, vma_has_reserves() is mostly an empty helper except that it says "use reserve count" is inverted meaning from "needs a global reserve count", which is still true. To avoid confusions on having two inverted ways to ask the same question, always use the gbl_chg everywhere, and drop the function. When at it, rename "chg" to "gbl_chg" in dequeue_hugetlb_folio_vma(). It might be helpful for readers to see that the "chg" here is the global reserve count, not the vma resv count. Link: https://lkml.kernel.org/r/20250107204002.2683356-7-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Cc: Ackerley Tng <ackerleytng@google.com> Cc: Breno Leitao <leitao@debian.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Rik van Riel <riel@surriel.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/hugetlb: simplify vma_has_reserves()Peter Xu4 days1-60/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | vma_has_reserves() is a helper "trying" to know whether the vma should consume one reservation when allocating the hugetlb folio. However it's not clear on why we need such complexity, as such information is already represented in the "chg" variable. From alloc_hugetlb_folio() context, "chg" (or in the function's context, "gbl_chg") is defined as: - If gbl_chg=1, the allocation cannot reuse an existing reservation - If gbl_chg=0, the allocation should reuse an existing reservation Firstly, map_chg is defined as following, to cover all cases of hugetlb reservation scenarios (mostly, via vma_needs_reservation(), but cow_from_owner is an outlier): CONDITION HAS RESERVATION? ========= ================ - SHARED: always check against per-inode resv_map (ignore NONRESERVE) - If resv exists ==> YES [1] - If not ==> NO [2] - PRIVATE: complicated... - Request came from a CoW from owner resv map ==> NO [3] (when cow_from_owner==true) - If does not own a resv_map at all.. ==> NO [4] (examples: VM_NORESERVE, private fork()) - If owns a resv_map, but resv donsn't exists ==> NO [5] - If owns a resv_map, and resv exists ==> YES [6] Further on, gbl_chg considered spool setup, so that is a decision based on all the context. If we look at vma_has_reserves(), it almost does check that has already been processed by map_chg accounting (I marked each return value to the case above): static bool vma_has_reserves(struct vm_area_struct *vma, long chg) { if (vma->vm_flags & VM_NORESERVE) { if (vma->vm_flags & VM_MAYSHARE && chg == 0) return true; ==> [1] else return false; ==> [2] or [4] } if (vma->vm_flags & VM_MAYSHARE) { if (chg) return false; ==> [2] else return true; ==> [1] } if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { if (chg) return false; ==> [5] else return true; ==> [6] } return false; ==> [4] } It didn't check [3], but [3] case was actually already covered now by the "chg" / "gbl_chg" / "map_chg" calculations. In short, vma_has_reserves() doesn't provide anything more than return "!chg".. so just simplify all the things. There're a lot of comments describing truncation races, IIUC there should have no race as long as map_chg is properly done. Link: https://lkml.kernel.org/r/20250107204002.2683356-6-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Cc: Ackerley Tng <ackerleytng@google.com> Cc: Breno Leitao <leitao@debian.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Rik van Riel <riel@surriel.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/hugetlb: clean up map/global resv accounting when allocatePeter Xu4 days1-33/+77
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | alloc_hugetlb_folio() isn't a function easy to read, especially on reservation accountings for either VMA or globally (majorly, spool only). The 1st complexity lies in the special private CoW path, aka, cow_from_owner=true case. The 2nd complexity may be the confusing updates of gbl_chg after it's set once, which looks like they can change anytime on the fly. Logically, cow_from_user is only about vma reservation. We could already decouple the flag and consolidate it into map charge flag very early. Then we don't need to keep checking the CoW special flag every time. This patch does it by making map_chg a tri-state flag. Tri-state needed is unfortunate, and it's because currently vma_needs_reservation() has a side effect internally, that it must be followed by either a end() or commit(). We keep the same semantic as before on one thing: "if (map_chg)" means we need a separate per-vma resv count. It keeps most of the old code like before untouched with the new enum. After this patch, we take these steps to decide these variables, hopefully slightly easier to follow: - First, decide map_chg. This will take cow_from_owner into account, once and for all. It's about whether we could take a resv count from the vma, no matter it's shared, private, etc. - Then, decide gbl_chg. The only diff here is spool, comparing to map_chg. Now only update each flag once and for all, instead of keep any of them flipping which can be very hard to follow. With cow_from_owner merged into map_chg, we could remove quite a few such checks all over. Side benefit of such is that we can get rid of one more confusing flag, which is deferred_reserve. Cleanup the comments a bit too. E.g., MAP_NORESERVE may not need to check against spool limit, AFAIU, if it's on a shared mapping, and if the page cache folio has its inode's resv map available (in which case map_chg would have been set zero, hence the code should be correct, not the comment). There's one trivial detail that needs attention that this patch touched, which is this check right after vma_commit_reservation(): if (map_chg > map_commit) It changes to: if (unlikely(map_chg == MAP_CHG_NEEDED && retval == 0)) It should behave the same like before, because previously the only way to make "map_chg > map_commit" happen is map_chg=1 && map_commit=0. That's exactly the rewritten line. Meanwhile, either commit() or end() will need to be skipped if ENFORCE, to keep the old behavior. Even though it looks a lot changed, but no functional change expected. Link: https://lkml.kernel.org/r/20250107204002.2683356-5-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Cc: Ackerley Tng <ackerleytng@google.com> Cc: Breno Leitao <leitao@debian.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Rik van Riel <riel@surriel.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/hugetlb: rename avoid_reserve to cow_from_ownerPeter Xu4 days1-13/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The old name "avoid_reserve" can be too generic and can be used wrongly in the new call sites that want to allocate a hugetlb folio. It's confusing on two things: (1) whether one can opt-in to avoid global reservation, and (2) whether it should take more than one count. In reality, this flag is only used in an extremely hacky path, in an extremely hacky way in hugetlb CoW path only, and always use with 1 saying "skip global reservation". Rename the flag to avoid future abuse of this flag, making it a boolean so as to reflect its true representation that it's not a counter. To make it even harder to abuse, add a comment above the function to explain it. Link: https://lkml.kernel.org/r/20250107204002.2683356-4-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Ackerley Tng <ackerleytng@google.com> Cc: Breno Leitao <leitao@debian.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Rik van Riel <riel@surriel.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/hugetlb: stop using avoid_reserve flag in fork()Peter Xu4 days1-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When fork() and stumble on top of a dma-pinned hugetlb private page, CoW must happen during fork() to guarantee dma coherency. In this specific path, hugetlb pages need to be allocated for the child process. Stop using avoid_reserve=1 flag here: it's not required to be used here, as dest_vma (which is destined to be a MAP_PRIVATE hugetlb vma) will have no private vma resv map, and that will make sure it won't be able to use a vma reservation later. No functional change intended with this change. Said that, it's still wanted to do this, so as to reduce the usage of avoid_reserve to the only one user, which is also why this flag was introduced initially in commit 04f2cbe35699 ("hugetlb: guarantee that COW faults for a process that called mmap(MAP_PRIVATE) on hugetlbfs will succeed"). I don't see whoever else should set it at all. Further patch will clean up resv accounting based on this. Link: https://lkml.kernel.org/r/20250107204002.2683356-3-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Ackerley Tng <ackerleytng@google.com> Cc: Breno Leitao <leitao@debian.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Rik van Riel <riel@surriel.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/hugetlb: fix avoid_reserve to allow taking folio from subpoolPeter Xu4 days1-19/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "mm/hugetlb: Refactor hugetlb allocation resv accounting", v2. This is a follow up on Ackerley's series here as replacement: https://lore.kernel.org/r/cover.1728684491.git.ackerleytng@google.com The goal of this series is to cleanup hugetlb resv accounting, especially during folio allocation, to decouple a few things: - Hugetlb folios v.s. Hugetlbfs: IOW, the hope is in the future hugetlb folios can be allocated completely without hugetlbfs. - Decouple VMA v.s. hugetlb folio allocations: allocating a hugetlb folio should not always require a hugetlbfs VMA. For example, either it got allocated from the inode level (see hugetlbfs_fallocate() where it used a pesudo VMA for allocation), or it can be allocated by other kernel subsystems. It paves way for other users to allocate hugetlb folios out of either system reservations, or subpools (instead of hugetlbfs, as a file system). For longer term, this prepares hugetlb as a separate concept versus hugetlbfs, so that hugetlb folios can be allocated by not only hugetlbfs and other things. Tests I've done: - I had a reproducer in patch 1 for the bug I found, this will start to work after patch 1 or the whole set applied. - Hugetlb regression tests (on x86_64 2MBs), includes: - All vmtests on hugetlbfs - libhugetlbfs test suite (which may fail some tests, but no new failures will be introduced by this series, so all such failures happen before this series so shouldn't be relevant). This patch (of 7): Since commit 04f2cbe35699 ("hugetlb: guarantee that COW faults for a process that called mmap(MAP_PRIVATE) on hugetlbfs will succeed"), avoid_reserve was introduced for a special case of CoW on hugetlb private mappings, and only if the owner VMA is trying to allocate yet another hugetlb folio that is not reserved within the private vma reserved map. Later on, in commit d85f69b0b533 ("mm/hugetlb: alloc_huge_page handle areas hole punched by fallocate"), alloc_huge_page() enforced to not consume any global reservation as long as avoid_reserve=true. This operation doesn't look correct, because even if it will enforce the allocation to not use global reservation at all, it will still try to take one reservation from the spool (if the subpool existed). Then since the spool reserved pages take from global reservation, it'll also take one reservation globally. Logically it can cause global reservation to go wrong. I wrote a reproducer below, trigger this special path, and every run of such program will cause global reservation count to increment by one, until it hits the number of free pages: #define _GNU_SOURCE /* See feature_test_macros(7) */ #include <stdio.h> #include <fcntl.h> #include <errno.h> #include <unistd.h> #include <stdlib.h> #include <sys/mman.h> #define MSIZE (2UL << 20) int main(int argc, char *argv[]) { const char *path; int *buf; int fd, ret; pid_t child; if (argc < 2) { printf("usage: %s <hugetlb_file>\n", argv[0]); return -1; } path = argv[1]; fd = open(path, O_RDWR | O_CREAT, 0666); if (fd < 0) { perror("open failed"); return -1; } ret = fallocate(fd, 0, 0, MSIZE); if (ret != 0) { perror("fallocate"); return -1; } buf = mmap(NULL, MSIZE, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); if (buf == MAP_FAILED) { perror("mmap() failed"); return -1; } /* Allocate a page */ *buf = 1; child = fork(); if (child == 0) { /* child doesn't need to do anything */ exit(0); } /* Trigger CoW from owner */ *buf = 2; munmap(buf, MSIZE); close(fd); unlink(path); return 0; } It can only reproduce with a sub-mount when there're reserved pages on the spool, like: # sysctl vm.nr_hugepages=128 # mkdir ./hugetlb-pool # mount -t hugetlbfs -o min_size=8M,pagesize=2M none ./hugetlb-pool Then run the reproducer on the mountpoint: # ./reproducer ./hugetlb-pool/test Fix it by taking the reservation from spool if available. In general, avoid_reserve is IMHO more about "avoid vma resv map", not spool's. I copied stable, however I have no intention for backporting if it's not a clean cherry-pick, because private hugetlb mapping, and then fork() on top is too rare to hit. Link: https://lkml.kernel.org/r/20250107204002.2683356-1-peterx@redhat.com Link: https://lkml.kernel.org/r/20250107204002.2683356-2-peterx@redhat.com Fixes: d85f69b0b533 ("mm/hugetlb: alloc_huge_page handle areas hole punched by fallocate") Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: Ackerley Tng <ackerleytng@google.com> Tested-by: Ackerley Tng <ackerleytng@google.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Breno Leitao <leitao@debian.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Rik van Riel <riel@surriel.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm: shmem: skip swapcache for swapin of synchronous swap deviceBaolin Wang4 days1-5/+105
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With fast swap devices (such as zram), swapin latency is crucial to applications. For shmem swapin, similar to anonymous memory swapin, we can skip the swapcache operation to improve swapin latency. Testing 1G shmem sequential swapin without THP enabled, I observed approximately a 6% performance improvement: (Note: I repeated 5 times and took the mean data for each test) w/o patch w/ patch changes 534.8ms 501ms +6.3% In addition, currently, we always split the large swap entry stored in the shmem mapping during shmem large folio swapin, which is not perfect, especially with a fast swap device. We should swap in the whole large folio instead of splitting the precious large folios to take advantage of the large folios and improve the swapin latency if the swap device is synchronous device, which is similar to anonymous memory mTHP swapin. Testing 1G shmem sequential swapin with 64K mTHP and 2M mTHP, I observed obvious performance improvement: mTHP=64K w/o patch w/ patch changes 550.4ms 169.6ms +69% mTHP=2M w/o patch w/ patch changes 542.8ms 126.8ms +77% Note that skipping swapcache requires attention to concurrent swapin scenarios. Fortunately the swapcache_prepare() and shmem_add_to_page_cache() can help identify concurrent swapin and large swap entry split scenarios, and return -EEXIST for retry. [akpm@linux-foundation.org: use IS_ENABLED(), tweak comment grammar] Link: https://lkml.kernel.org/r/3d9f3bd3bc6ec953054baff5134f66feeaae7c1e.1736301701.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Kairui Song <kasong@tencent.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/memmap: prevent double scanning of memmap by kmemleakGuo Weikang4 days2-4/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | kmemleak explicitly scans the mem_map through the valid struct page objects. However, memmap_alloc() was also adding this memory to the gray object list, causing it to be scanned twice. Remove memmap_alloc() from the scan list and add a comment to clarify the behavior. Link: https://lore.kernel.org/lkml/CAOm6qn=FVeTpH54wGDFMHuCOeYtvoTx30ktnv9-w3Nh8RMofEA@mail.gmail.com/ Link: https://lkml.kernel.org/r/20250106021126.1678334-1-guoweikang.kernel@gmail.com Signed-off-by: Guo Weikang <guoweikang.kernel@gmail.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Mike Rapoport (Microsoft) <rppt@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/fake-numa: allow later numa node hotplugBruno Faccini4 days2-8/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Current fake-numa implementation prevents new Numa nodes to be later hot-plugged by drivers. A common symptom of this limitation is the "node <X> was absent from the node_possible_map" message by associated warning in mm/memory_hotplug.c: add_memory_resource(). This comes from the lack of remapping in both pxm_to_node_map[] and node_to_pxm_map[] tables to take fake-numa nodes into account and thus triggers collisions with original and physical nodes only-mapping that had been determined from BIOS tables. This patch fixes this by doing the necessary node-ids translation in both pxm_to_node_map[]/node_to_pxm_map[] tables. node_distance[] table has also been fixed accordingly. Details: When trying to use fake-numa feature on our system where new Numa nodes are being "hot-plugged" upon driver load, this fails with the following type of message and warning with stack : node 8 was absent from the node_possible_map WARNING: CPU: 61 PID: 4259 at mm/memory_hotplug.c:1506 add_memory_resource+0x3dc/0x418 This issue prevents the use of the fake-NUMA debug feature with the system's full configuration, when it has proven to be sometimes extremely useful for performance testing of multi-tasked, memory-bound applications, as it enables better isolation of processes/ranks compared to fat NUMA nodes. Usual numactl output after driver has “hot-plugged”/unveiled some new Numa nodes with and without memory : $ numactl --hardware available: 9 nodes (0-8) node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 node 0 size: 490037 MB node 0 free: 484432 MB node 1 cpus: node 1 size: 97280 MB node 1 free: 97279 MB node 2 cpus: node 2 size: 0 MB node 2 free: 0 MB node 3 cpus: node 3 size: 0 MB node 3 free: 0 MB node 4 cpus: node 4 size: 0 MB node 4 free: 0 MB node 5 cpus: node 5 size: 0 MB node 5 free: 0 MB node 6 cpus: node 6 size: 0 MB node 6 free: 0 MB node 7 cpus: node 7 size: 0 MB node 7 free: 0 MB node 8 cpus: node 8 size: 0 MB node 8 free: 0 MB node distances: node 0 1 2 3 4 5 6 7 8 0: 10 80 80 80 80 80 80 80 80 1: 80 10 255 255 255 255 255 255 255 2: 80 255 10 255 255 255 255 255 255 3: 80 255 255 10 255 255 255 255 255 4: 80 255 255 255 10 255 255 255 255 5: 80 255 255 255 255 10 255 255 255 6: 80 255 255 255 255 255 10 255 255 7: 80 255 255 255 255 255 255 10 255 8: 80 255 255 255 255 255 255 255 10 With recent M.Rapoport set of fake-numa patches in mm-everything and using numa=fake=4 boot parameter : $ numactl --hardware available: 4 nodes (0-3) node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 node 0 size: 122518 MB node 0 free: 117141 MB node 1 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 node 1 size: 219911 MB node 1 free: 219751 MB node 2 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 node 2 size: 122599 MB node 2 free: 122541 MB node 3 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 node 3 size: 122479 MB node 3 free: 122408 MB node distances: node 0 1 2 3 0: 10 10 10 10 1: 10 10 10 10 2: 10 10 10 10 3: 10 10 10 10 With recent M.Rapoport set of fake-numa patches in mm-everything, this patch on top, using numa=fake=4 boot parameter : # numactl —hardware available: 12 nodes (0-11) node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 node 0 size: 122518 MB node 0 free: 116429 MB node 1 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 node 1 size: 122631 MB node 1 free: 122576 MB node 2 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 node 2 size: 122599 MB node 2 free: 122544 MB node 3 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 node 3 size: 122479 MB node 3 free: 122419 MB node 4 cpus: node 4 size: 97280 MB node 4 free: 97279 MB node 5 cpus: node 5 size: 0 MB node 5 free: 0 MB node 6 cpus: node 6 size: 0 MB node 6 free: 0 MB node 7 cpus: node 7 size: 0 MB node 7 free: 0 MB node 8 cpus: node 8 size: 0 MB node 8 free: 0 MB node 9 cpus: node 9 size: 0 MB node 9 free: 0 MB node 10 cpus: node 10 size: 0 MB node 10 free: 0 MB node 11 cpus: node 11 size: 0 MB node 11 free: 0 MB node distances: node 0 1 2 3 4 5 6 7 8 9 10 11 0: 10 10 10 10 80 80 80 80 80 80 80 80 1: 10 10 10 10 80 80 80 80 80 80 80 80 2: 10 10 10 10 80 80 80 80 80 80 80 80 3: 10 10 10 10 80 80 80 80 80 80 80 80 4: 80 80 80 80 10 255 255 255 255 255 255 255 5: 80 80 80 80 255 10 255 255 255 255 255 255 6: 80 80 80 80 255 255 10 255 255 255 255 255 7: 80 80 80 80 255 255 255 10 255 255 255 255 8: 80 80 80 80 255 255 255 255 10 255 255 255 9: 80 80 80 80 255 255 255 255 255 10 255 255 10: 80 80 80 80 255 255 255 255 255 255 10 255 11: 80 80 80 80 255 255 255 255 255 255 255 10 Link: https://lkml.kernel.org/r/20250106120659.359610-2-bfaccini@nvidia.com Signed-off-by: Bruno Faccini <bfaccini@nvidia.com> Cc: David Hildenbrand <david@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/damon: remove DAMON debugfs interfaceSeongJae Park4 days3-1165/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's time to remove DAMON debugfs interface, which has deprecated long before in February 2023. Read the cover letter of this patch series for more details. All documents and related tests are also removed. Finally remove the interface. Link: https://lkml.kernel.org/r/20250106191941.107070-9-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Alex Shi <alexs@kernel.org> Cc: Brendan Higgins <brendan.higgins@linux.dev> Cc: David Gow <davidgow@google.com> Cc: Hu Haowen <2023002089@link.tyut.edu.cn> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Rae Moar <rmoar@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Yanteng Si <si.yanteng@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/damon: remove DAMON debugfs interface kunit testsSeongJae Park4 days4-194/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's time to remove DAMON debugfs interface, which has deprecated long before in February 2023. Read the cover letter of this patch series for more details. Remove kunit tests for the interface, to prevent unnecessary test failures. Link: https://lkml.kernel.org/r/20250106191941.107070-8-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Alex Shi <alexs@kernel.org> Cc: Brendan Higgins <brendan.higgins@linux.dev> Cc: David Gow <davidgow@google.com> Cc: Hu Haowen <2023002089@link.tyut.edu.cn> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Rae Moar <rmoar@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Yanteng Si <si.yanteng@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/damon/sysfs-schemes: expose per-region filter-passed bytesSeongJae Park4 days3-3/+21
| | | | | | | | | | | | | | | | | | | | | | | | Per-region operations set-handled DAMOS filters passed memory size information is provided to only DAMON core API users. Further expose it to the user space by adding a new DAMON sysfs interface file under each scheme tried region directory. Link: https://lkml.kernel.org/r/20250106193401.109161-14-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/damon/core: pass per-region filter-passed bytes to ↵SeongJae Park4 days2-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | damos_walk_control->walk_fn() Total size of memory that passed DAMON operations set layer-handled DAMOS filters per scheme is provided to DAMON core API and ABI (sysfs interface) users. Having it per-region in non-accumulated way can provide it in finer granularity. Provide it to damos_walk() core API users, by passing the data to damos_walk_control->walk_fn(). Link: https://lkml.kernel.org/r/20250106193401.109161-13-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/damon/syfs-schemes: implement per-scheme filter-passed bytes statSeongJae Park4 days1-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | Add a new DAMON sysfs interface file under scheme stat directory, namely 'sz_ops_filter_passed'. It represents total bytes that passed region-internal DAMOS filters of the scheme that handled by the DAMON operations set layer. Link: https://lkml.kernel.org/r/20250106193401.109161-9-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/damon/core: implement per-scheme ops-handled filter-passed bytes statSeongJae Park4 days1-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement a new per-DAMOS scheme statistic field, namely sz_ops_filter_passed, using the changed damon_operations->apply_scheme() interface. It counts total bytes of memory that given DAMOS action tried to be applied, and passed the operations layer handled region-internal filters of the scheme. DAMON API users can access it using DAMON-internal safe access features such as damon_call() and/or damos_walk(). Link: https://lkml.kernel.org/r/20250106193401.109161-8-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/damon/paddr: report filter-passed bytes back for DAMOS_STAT actionSeongJae Park4 days1-1/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | DAMOS_STAT action handling of paddr DAMON operations set implementation is simply ignoring the region-internal DAMOS filters, and therefore not reporting back the filter-passed bytes. Apply the filters and report back the information. Before this change, DAMOS_STAT was doing nothing for DAMOS filters. Hence users might see some performance regressions. Such regression for use cases where no region-internal DAMOS filter is added to the scheme will be negligible, since this change avoids unnecessary filtering works if no such filter is installed. For old users who are using DAMOS_STAT with the types of filters, the regression could be visible depending on the size of the region and the overhead of the installed DAMOS filters. But, because the filters were completely ignored before in the use case, no real users would really depend on such use case that makes no point. Link: https://lkml.kernel.org/r/20250106193401.109161-7-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/damon/paddr: report filter-passed bytes back for normal actionsSeongJae Park4 days1-11/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | damon_operations->apply_scheme() implementations are requested to report back how many bytes of the given region has passed DAMOS filter. 'paddr' operations set implementation supports some of region-internal DAMOS filter handling for normal DAMOS actions except DAMOS_STAT action. But, those are not respecting the request. Report the region-internal DAMOS filter-passed bytes back for the actions. Link: https://lkml.kernel.org/r/20250106193401.109161-6-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/damon: ask apply_scheme() to report filter-passed region-internal bytesSeongJae Park4 days3-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Some DAMOS filter types including those for young page, anon page, and belonging memcg are handled by underlying DAMON operations set implementation, via damon_operations->apply_scheme() interface. How many bytes of the region have passed the filter can be useful for DAMOS scheme tuning and access pattern monitoring. Modify the interface to let the callback implementation reports back the number if possible. Link: https://lkml.kernel.org/r/20250106193401.109161-5-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/damon/sysfs: remove unused code for schemes tried regions updateSeongJae Park4 days3-282/+2
| | | | | | | | | | | | | | | | | | | | | | | | DAMON sysfs interface was using damon_callback with its own complicated synchronization logics to update DAMOS scheme applied regions directories and files. But it is replaced to use damos_walk(), and the additional synchronization logics are no more being used. Remove those. Link: https://lkml.kernel.org/r/20250103174400.54890-11-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/damon/sysfs: use damos_walk() for update_schemes_tried_{bytes,regions}SeongJae Park4 days3-0/+96
| | | | | | | | | | | | | | | | | | | | | | | | | | DAMON sysfs interface uses damon_callback with its own complicated synchronization facility to handle update_schemes_tried_bytes and update_schemes_tried_regions commands. But damos_walk() can support the use case without the additional synchronizations. Convert the code to use damos_walk() instead. Link: https://lkml.kernel.org/r/20250103174400.54890-10-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/damon/core: implement damos_walk()SeongJae Park4 days1-0/+132
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce a new core layer interface, damos_walk(). It aims to replace some damon_callback usages that access DAMOS schemes applied regions of ongoing kdamond with additional synchronizations. It receives a function pointer and asks kdamond to invoke it for any region that it tried to apply any DAMOS action within one scheme apply interval for every scheme of it. The function further waits until the kdamond finishes the invocations for every scheme, or cancels the request, and returns. The kdamond invokes the function as requested within the main loop. If it is deactivated by DAMOS watermarks or going out of the main loop, it marks the request as canceled, so that damos_walk() can wakeup and return. Link: https://lkml.kernel.org/r/20250103174400.54890-8-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>