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2023-10-04mm/compaction: factor out code to test if we should run compaction for ↵Kemeng Shi
target order We always do zone_watermark_ok check and compaction_suitable check together to test if compaction for target order should be ran. Factor these code out to remove repeat code. Link: https://lkml.kernel.org/r/20230901155141.249860-7-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04mm/compaction: improve comment of is_via_compact_memoryKemeng Shi
We do proactive compaction with order == -1 via 1. /proc/sys/vm/compact_memory 2. /sys/devices/system/node/nodex/compact 3. /proc/sys/vm/compaction_proactiveness Add missed situation in which order == -1. Link: https://lkml.kernel.org/r/20230901155141.249860-6-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04mm/compaction: remove repeat compact_blockskip_flush check in ↵Kemeng Shi
reset_isolation_suitable We have compact_blockskip_flush check in __reset_isolation_suitable, just remove repeat check before __reset_isolation_suitable in compact_blockskip_flush. Link: https://lkml.kernel.org/r/20230901155141.249860-5-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04mm/compaction: correctly return failure with bogus compound_order in strict modeKemeng Shi
In strict mode, we should return 0 if there is any hole in pageblock. If we successfully isolated pages at beginning at pageblock and then have a bogus compound_order outside pageblock in next page. We will abort search loop with blockpfn > end_pfn. Although we will limit blockpfn to end_pfn, we will treat it as a successful isolation in strict mode as blockpfn is not < end_pfn and return partial isolated pages. Then isolate_freepages_range may success unexpectly with hole in isolated range. Link: https://lkml.kernel.org/r/20230901155141.249860-4-shikemeng@huaweicloud.com Fixes: 9fcd6d2e052e ("mm, compaction: skip compound pages by order in free scanner") Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04mm/compaction: call list_is_{first}/{last} more intuitively in ↵Kemeng Shi
move_freelist_{head}/{tail} We use move_freelist_head after list_for_each_entry_reverse to skip recent pages. And there is no need to do actual move if all freepages are searched in list_for_each_entry_reverse, e.g. freepage point to first page in freelist. It's more intuitively to call list_is_first with list entry as the first argument and list head as the second argument to check if list entry is the first list entry instead of call list_is_last with list entry and list head passed in reverse. Similarly, call list_is_last in move_freelist_tail is more intuitively. Link: https://lkml.kernel.org/r/20230901155141.249860-3-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04mm/compaction: use correct list in move_freelist_{head}/{tail}Kemeng Shi
Patch series "Fixes and cleanups to compaction", v3. This is a series to do fix and clean up to compaction. Patch 1-2 fix and clean up freepage list operation. Patch 3-4 fix and clean up isolation of freepages Patch 7 factor code to check if compaction is needed for allocation order. More details can be found in respective patches. This patch (of 6): The freepage is chained with buddy_list in freelist head. Use buddy_list instead of lru to correct the list operation. Link: https://lkml.kernel.org/r/20230901155141.249860-1-shikemeng@huaweicloud.com Link: https://lkml.kernel.org/r/20230901155141.249860-2-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21merge mm-hotfixes-stable into mm-stable to pick up depended-upon changesAndrew Morton
2023-08-21mm/compaction: remove unused parameter pgdata of fragmentation_score_wmarkKemeng Shi
Parameter pgdat is not used in fragmentation_score_wmark. Just remove it. Link: https://lkml.kernel.org/r/20230809094910.3092446-1-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21mm/compaction: only set skip flag if cc->no_set_skip_hint is falseKemeng Shi
Keep the same logic as update_pageblock_skip, only set skip if no_set_skip_hint is false which is more reasonable. Link: https://lkml.kernel.org/r/20230804110454.2935878-9-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21mm/compaction: remove unnecessary return for void functionKemeng Shi
Remove unnecessary return for void function Link: https://lkml.kernel.org/r/20230804110454.2935878-8-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21mm/compaction: correct comment to complete migration failureKemeng Shi
Commit cfccd2e63e7e0 ("mm, compaction: finish pageblocks on complete migration failure") convert cc->order aligned check to page block order aligned check. Correct comment relevant with it. Link: https://lkml.kernel.org/r/20230804110454.2935878-7-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: David Hildenbrand <david@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21mm/compaction: correct comment of cached migrate pfn updateKemeng Shi
Commit e380bebe47715 ("mm, compaction: keep migration source private to a single compaction instance") moved update of async and sync compact_cached_migrate_pfn from update_pageblock_skip to update_cached_migrate but left the comment behind. Move the relevant comment to correct this. Link: https://lkml.kernel.org/r/20230804110454.2935878-6-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21mm/compaction: correct comment of fast_find_migrateblock in isolate_migratepagesKemeng Shi
After 90ed667c03fe5 ("Revert "Revert "mm/compaction: fix set skip in fast_find_migrateblock"""), we remove skip set in fast_find_migrateblock. Correct comment that fast_find_block is used to avoid isolation_suitable check for pageblock returned from fast_find_migrateblock because fast_find_migrateblock will mark found pageblock skipped. Instead, comment that fast_find_block is used to avoid a redundant check of fast found pageblock which is already checked skip flag inside fast_find_migrateblock. Link: https://lkml.kernel.org/r/20230804110454.2935878-5-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: David Hildenbrand <david@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21mm/compaction: skip page block marked skip in isolate_migratepages_blockKemeng Shi
Move migrate_pfn to page block end when block is marked skip to avoid unnecessary scan retry of that block from upper caller. For example, compact_zone may wrongly rescan skip page block with finish_pageblock set as following: 1. cc->migrate point to the start of page block 2. compact_zone record last_migrated_pfn to cc->migrate 3. compact_zone->isolate_migratepages->isolate_migratepages_block tries to scan the block. The low_pfn maybe moved forward to middle of block because of free pages at beginning of block. 4. we find first lru page could be isolated but block was exclusive marked skip. 5. abort isolate_migratepages_block and make cc->migrate_pfn point to found lru page at middle of block. 6. compact_zone find cc->migrate_pfn and last_migrated_pfn are in the same block and wrongly rescan the block with finish_pageblock set. Link: https://lkml.kernel.org/r/20230804110454.2935878-4-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: David Hildenbrand <david@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21mm/compaction: correct last_migrated_pfn update in compact_zoneKemeng Shi
We record start pfn of last isolated page block with last_migrated_pfn. And then: 1. We check if we mark the page block skip for exclusive access in isolate_migratepages_block by test if next migrate pfn is still in last isolated page block. If so, we will set finish_pageblock to do the rescan. 2. We check if a full cc->order block is scanned by test if last scan range passes the cc->order block boundary. If so, we flush the pages were freed. We treat cc->migrate_pfn before isolate_migratepages as the start pfn of last isolated page range. However, we always align migrate_pfn to page block or move to another page block in fast_find_migrateblock or in linearly scan forward in isolate_migratepages before do page isolation in isolate_migratepages_block. Update last_migrated_pfn with pageblock_start_pfn(cc->migrate_pfn - 1) after scan to correctly set start pfn of last isolated page range. To avoid that: 1. Miss a rescan with finish_pageblock set as last_migrate_pfn does not point to right pageblock and the migrate will not be in pageblock of last_migrate_pfn as it should be. 2. Wrongly issue flush by test cc->order block boundary with wrong last_migrate_pfn. Link: https://lkml.kernel.org/r/20230804110454.2935878-3-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: David Hildenbrand <david@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21mm/compaction: remove unnecessary "else continue" at end of loop in ↵Kemeng Shi
isolate_freepages_block There is no behavior change to remove "else continue" code at end of scan loop. Just remove it to make code cleaner. Link: https://lkml.kernel.org/r/20230803094901.2915942-5-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: David Hildenbrand <david@redhat.com> Cc: Kemeng Shi <shikemeng@huawei.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21mm/compaction: remove unnecessary cursor page in isolate_freepages_blockKemeng Shi
The cursor is only used for page forward currently. We can simply move page forward directly to remove unnecessary cursor. Link: https://lkml.kernel.org/r/20230803094901.2915942-4-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: David Hildenbrand <david@redhat.com> Cc: Kemeng Shi <shikemeng@huawei.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21mm/compaction: merge end_pfn boundary check in isolate_freepages_rangeKemeng Shi
Merge the end_pfn boundary check for single page block forward and multiple page blocks forward to avoid do twice boundary check for multiple page blocks forward. Link: https://lkml.kernel.org/r/20230803094901.2915942-3-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: David Hildenbrand <david@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21mm/compaction: set compact_cached_free_pfn correctly in update_pageblock_skipKemeng Shi
Patch series "Fixes and cleanups to compaction", v2. This series contains random fixes and cleanups to free page isolation in compaction. This is based on another compact series[1]. More details can be found in respective patches. This patch (of 4): We will set skip to page block of block_start_pfn, it's more reasonable to set compact_cached_free_pfn to page block before the block_start_pfn. Link: https://lkml.kernel.org/r/20230803094901.2915942-1-shikemeng@huaweicloud.com Link: https://lkml.kernel.org/r/20230803094901.2915942-2-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: David Hildenbrand <david@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Kemeng Shi <shikemeng@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21mm: improve the comment in isolate_migratepages_block()Matthew Wilcox
A recent patch shows that not everybody understands that "stabilise the mapping" really means "prevent the mapping from being freed", so change the wording to hopefully make that more clear. Link: https://lkml.kernel.org/r/ZMLWEB4m3zvX6SBN@casper.infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-18mm/compaction: avoid unneeded pageblock_end_pfn when no_set_skip_hint is setKemeng Shi
Move pageblock_end_pfn after no_set_skip_hint check to avoid unneeded pageblock_end_pfn if no_set_skip_hint is set. Link: https://lkml.kernel.org/r/20230721150957.2058634-3-shikemeng@huawei.com Signed-off-by: Kemeng Shi <shikemeng@huawei.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-18mm/compaction: correct comment of candidate pfn in fast_isolate_freepagesKemeng Shi
Patch series "Two minor cleanups for compaction", v2. This series contains two random cleanups for compaction. This patch (of 2): If no preferred one was not found, we will use candidate page with maximum pfn > min_pfn which is saved in high_pfn. Correct "minimum" to "maximum candidate" in comment. Link: https://lkml.kernel.org/r/20230721150957.2058634-1-shikemeng@huawei.com Link: https://lkml.kernel.org/r/20230721150957.2058634-2-shikemeng@huawei.com Signed-off-by: Kemeng Shi <shikemeng@huawei.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-18mm: compaction: skip the memory hole rapidly when isolating free pagesBaolin Wang
Just like commit 9721fd82351d ("mm: compaction: skip memory hole rapidly when isolating migratable pages"), I can see it will also take more time to skip the larger memory hole (range: 0x1000000000 - 0x1800000000) when isolating free pages on my machine with below memory layout. So like commit 9721fd82351d, adding a new helper to skip the memory hole rapidly, which can reduce the time consumed from about 70us to less than 1us. [ 0.000000] Zone ranges: [ 0.000000] DMA [mem 0x0000000040000000-0x00000000ffffffff] [ 0.000000] DMA32 empty [ 0.000000] Normal [mem 0x0000000100000000-0x0000001fa7ffffff] [ 0.000000] Movable zone start for each node [ 0.000000] Early memory node ranges [ 0.000000] node 0: [mem 0x0000000040000000-0x0000000fffffffff] [ 0.000000] node 0: [mem 0x0000001800000000-0x0000001fa3c7ffff] [ 0.000000] node 0: [mem 0x0000001fa3c80000-0x0000001fa3ffffff] [ 0.000000] node 0: [mem 0x0000001fa4000000-0x0000001fa402ffff] [ 0.000000] node 0: [mem 0x0000001fa4030000-0x0000001fa40effff] [ 0.000000] node 0: [mem 0x0000001fa40f0000-0x0000001fa73cffff] [ 0.000000] node 0: [mem 0x0000001fa73d0000-0x0000001fa745ffff] [ 0.000000] node 0: [mem 0x0000001fa7460000-0x0000001fa746ffff] [ 0.000000] node 0: [mem 0x0000001fa7470000-0x0000001fa758ffff] [ 0.000000] node 0: [mem 0x0000001fa7590000-0x0000001fa7ffffff] [shikemeng@huaweicloud.com: avoid missing last page block in section after skip offline sections] Link: https://lkml.kernel.org/r/20230804110454.2935878-1-shikemeng@huaweicloud.com Link: https://lkml.kernel.org/r/20230804110454.2935878-2-shikemeng@huaweicloud.com Link: https://lkml.kernel.org/r/d2ba7e41ee566309b594311207ffca736375fc16.1688715750.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-18mm: compaction: use the correct type of list for free pagesBaolin Wang
Use the page->buddy_list instead of page->lru to clarify the correct type of list for free pages. Link: https://lkml.kernel.org/r/b21cd8e2e32b9a1d9bc9e43ebf8acaf35e87f8df.1688715750.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-04mm: compaction: fix endless looping over same migrate blockJohannes Weiner
During stress testing, the following situation was observed: 70 root 39 19 0 0 0 R 100.0 0.0 959:29.92 khugepaged 310936 root 20 0 84416 25620 512 R 99.7 1.5 642:37.22 hugealloc Tracing shows isolate_migratepages_block() endlessly looping over the first block in the DMA zone: hugealloc-310936 [001] ..... 237297.415718: mm_compaction_finished: node=0 zone=DMA order=9 ret=no_suitable_page hugealloc-310936 [001] ..... 237297.415718: mm_compaction_isolate_migratepages: range=(0x1 ~ 0x400) nr_scanned=513 nr_taken=0 hugealloc-310936 [001] ..... 237297.415718: mm_compaction_finished: node=0 zone=DMA order=9 ret=no_suitable_page hugealloc-310936 [001] ..... 237297.415718: mm_compaction_isolate_migratepages: range=(0x1 ~ 0x400) nr_scanned=513 nr_taken=0 hugealloc-310936 [001] ..... 237297.415718: mm_compaction_finished: node=0 zone=DMA order=9 ret=no_suitable_page hugealloc-310936 [001] ..... 237297.415718: mm_compaction_isolate_migratepages: range=(0x1 ~ 0x400) nr_scanned=513 nr_taken=0 hugealloc-310936 [001] ..... 237297.415718: mm_compaction_finished: node=0 zone=DMA order=9 ret=no_suitable_page hugealloc-310936 [001] ..... 237297.415718: mm_compaction_isolate_migratepages: range=(0x1 ~ 0x400) nr_scanned=513 nr_taken=0 The problem is that the functions tries to test and set the skip bit once on the block, to avoid skipping on its own skip-set, using pageblock_aligned() on the pfn as a test. But because this is the DMA zone which starts at pfn 1, this is never true for the first block, and the skip bit isn't set or tested at all. As a result, fast_find_migrateblock() returns the same pageblock over and over. If the pfn isn't pageblock-aligned, also check if it's the start of the zone to ensure test-and-set-exactly-once on unaligned ranges. Thanks to Vlastimil Babka for the help in debugging this. Link: https://lkml.kernel.org/r/20230731172450.1632195-1-hannes@cmpxchg.org Fixes: 90ed667c03fe ("Revert "Revert "mm/compaction: fix set skip in fast_find_migrateblock""") Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Mel Gorman <mgorman@techsingularity.net> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-23mm: compaction: convert to use a folio in isolate_migratepages_block()Kefeng Wang
Directly use a folio instead of page_folio() when page successfully isolated (hugepage and movable page) and after folio_get_nontail_page(), which removes several calls to compound_head(). Link: https://lkml.kernel.org/r/20230619110718.65679-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: James Gowans <jgowans@amazon.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-23mm: compaction: skip memory hole rapidly when isolating migratable pagesBaolin Wang
On some machines, the normal zone can have a large memory hole like below memory layout, and we can see the range from 0x100000000 to 0x1800000000 is a hole. So when isolating some migratable pages, the scanner can meet the hole and it will take more time to skip the large hole. From my measurement, I can see the isolation scanner will take 80us ~ 100us to skip the large hole [0x100000000 - 0x1800000000]. So adding a new helper to fast search next online memory section to skip the large hole can help to find next suitable pageblock efficiently. With this patch, I can see the large hole scanning only takes < 1us. [ 0.000000] Zone ranges: [ 0.000000] DMA [mem 0x0000000040000000-0x00000000ffffffff] [ 0.000000] DMA32 empty [ 0.000000] Normal [mem 0x0000000100000000-0x0000001fa7ffffff] [ 0.000000] Movable zone start for each node [ 0.000000] Early memory node ranges [ 0.000000] node 0: [mem 0x0000000040000000-0x0000000fffffffff] [ 0.000000] node 0: [mem 0x0000001800000000-0x0000001fa3c7ffff] [ 0.000000] node 0: [mem 0x0000001fa3c80000-0x0000001fa3ffffff] [ 0.000000] node 0: [mem 0x0000001fa4000000-0x0000001fa402ffff] [ 0.000000] node 0: [mem 0x0000001fa4030000-0x0000001fa40effff] [ 0.000000] node 0: [mem 0x0000001fa40f0000-0x0000001fa73cffff] [ 0.000000] node 0: [mem 0x0000001fa73d0000-0x0000001fa745ffff] [ 0.000000] node 0: [mem 0x0000001fa7460000-0x0000001fa746ffff] [ 0.000000] node 0: [mem 0x0000001fa7470000-0x0000001fa758ffff] [ 0.000000] node 0: [mem 0x0000001fa7590000-0x0000001fa7ffffff] [baolin.wang@linux.alibaba.com: limit next_ptn to not exceed cc->free_pfn] Link: https://lkml.kernel.org/r/a1d859c28af0c7e85e91795e7473f553eb180a9d.1686813379.git.baolin.wang@linux.alibaba.com Link: https://lkml.kernel.org/r/75b4c8ca36bf44ad8c42bf0685ac19d272e426ec.1686705221.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Suggested-by: David Hildenbrand <david@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: "Huang, Ying" <ying.huang@intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-19mm: compaction: mark kcompactd_run() and kcompactd_stop() __meminitMiaohe Lin
Add __meminit to kcompactd_run() and kcompactd_stop() to ensure they're default to __init when memory hotplug is not enabled. Link: https://lkml.kernel.org/r/20230610034615.997813-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09mm: compaction: skip fast freepages isolation if enough freepages are isolatedBaolin Wang
I've observed that fast isolation often isolates more pages than cc->migratepages, and the excess freepages will be released back to the buddy system. So skip fast freepages isolation if enough freepages are isolated to save some CPU cycles. Link: https://lkml.kernel.org/r/f39c2c07f2dba2732fd9c0843572e5bef96f7f67.1685018752.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09mm: compaction: add trace event for fast freepages isolationBaolin Wang
The fast_isolate_freepages() can also isolate freepages, but we can not know the fast isolation efficiency to understand the fast isolation pressure. So add a trace event to show some numbers to help to understand the efficiency for fast freepages isolation. Link: https://lkml.kernel.org/r/78d2932d0160d122c15372aceb3f2c45460a17fc.1685018752.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09mm: compaction: only set skip flag if cc->no_set_skip_hint is falseBaolin Wang
To keep the same logic as test_and_set_skip(), only set the skip flag if cc->no_set_skip_hint is false, which makes code more reasonable. Link: https://lkml.kernel.org/r/0eb2cd2407ffb259ae6e3071e10f70f2d41d0f3e.1685018752.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09mm: compaction: skip more fully scanned pageblockBaolin Wang
In fast_isolate_around(), it assumes the pageblock is fully scanned if cc->nr_freepages < cc->nr_migratepages after trying to isolate some free pages, and will set skip flag to avoid scanning in future. However this can miss setting the skip flag for a fully scanned pageblock (returned 'start_pfn' is equal to 'end_pfn') in the case where cc->nr_freepages is larger than cc->nr_migratepages. So using the returned 'start_pfn' from isolate_freepages_block() and 'end_pfn' to decide if a pageblock is fully scanned makes more sense. It can also cover the case where cc->nr_freepages < cc->nr_migratepages, which means the 'start_pfn' is usually equal to 'end_pfn' except some uncommon fatal error occurs after non-strict mode isolation. Link: https://lkml.kernel.org/r/f4efd2fa08735794a6d809da3249b6715ba6ad38.1685018752.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09mm: compaction: change fast_isolate_freepages() to void typeBaolin Wang
No caller cares about the return value of fast_isolate_freepages(), void it. Link: https://lkml.kernel.org/r/759fca20b22ebf4c81afa30496837b9e0fb2e53b.1685018752.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09mm: compaction: drop the redundant page validation in update_pageblock_skip()Baolin Wang
Patch series "Misc cleanups and improvements for compaction". This series cantains some cleanups and improvements for compaction. This patch (of 6): The caller has validated the page before calling update_pageblock_skip(), thus drop the redundant page validation in update_pageblock_skip(). Link: https://lkml.kernel.org/r/5142e15b9295fe8c447dbb39b7907a20177a1413.1685018752.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09mm: compaction: avoid GFP_NOFS ABBA deadlockJohannes Weiner
During stress testing with higher-order allocations, a deadlock scenario was observed in compaction: One GFP_NOFS allocation was sleeping on mm/compaction.c::too_many_isolated(), while all CPUs in the system were busy with compactors spinning on buffer locks held by the sleeping GFP_NOFS allocation. Reclaim is susceptible to this same deadlock; we fixed it by granting GFP_NOFS allocations additional LRU isolation headroom, to ensure it makes forward progress while holding fs locks that other reclaimers might acquire. Do the same here. This code has been like this since compaction was initially merged, and I only managed to trigger this with out-of-tree patches that dramatically increase the contexts that do GFP_NOFS compaction. While the issue is real, it seems theoretical in nature given existing allocation sites. Worth fixing now, but no Fixes tag or stable CC. Link: https://lkml.kernel.org/r/20230519111359.40475-1-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09mm: compaction: have compaction_suitable() return boolJohannes Weiner
Since it only returns COMPACT_CONTINUE or COMPACT_SKIPPED now, a bool return value simplifies the callsites. Link: https://lkml.kernel.org/r/20230602151204.GD161817@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Suggested-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09mm: compaction: drop redundant watermark check in compaction_zonelist_suitable()Johannes Weiner
The watermark check in compaction_zonelist_suitable(), called from should_compact_retry(), is sandwiched between two watermark checks already: before, there are freelist attempts as part of direct reclaim and direct compaction; after, there is a last-minute freelist attempt in __alloc_pages_may_oom(). The check in compaction_zonelist_suitable() isn't necessary. Kill it. Link: https://lkml.kernel.org/r/20230519123959.77335-6-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09mm: compaction: remove unnecessary is_via_compact_memory() checksJohannes Weiner
Remove from all paths not reachable via /proc/sys/vm/compact_memory. Link: https://lkml.kernel.org/r/20230519123959.77335-5-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09mm: compaction: refactor __compaction_suitable()Johannes Weiner
__compaction_suitable() is supposed to check for available migration targets. However, it also checks whether the operation was requested via /proc/sys/vm/compact_memory, and whether the original allocation request can already succeed. These don't apply to all callsites. Move the checks out to the callers, so that later patches can deal with them one by one. No functional change intended. [hannes@cmpxchg.org: fix comment, per Vlastimil] Link: https://lkml.kernel.org/r/20230602144942.GC161817@cmpxchg.org Link: https://lkml.kernel.org/r/20230519123959.77335-4-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09mm: convert migrate_pages() to work on foliosMatthew Wilcox (Oracle)
Almost all of the callers & implementors of migrate_pages() were already converted to use folios. compaction_alloc() & compaction_free() are trivial to convert a part of this patch and not worth splitting out. Link: https://lkml.kernel.org/r/20230513001101.276972-1-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09Revert "Revert "mm/compaction: fix set skip in fast_find_migrateblock""Mel Gorman
This reverts commit 95e7a450b819 ("Revert "mm/compaction: fix set skip in fast_find_migrateblock""). Commit 7efc3b726103 ("mm/compaction: fix set skip in fast_find_migrateblock") was reverted due to bug reports about khugepaged consuming large amounts of CPU without making progress. The underlying bug was partially fixed by commit cfccd2e63e7e ("mm, compaction: finish pageblocks on complete migration failure") but it only mitigated the problem and Vlastimil Babka pointing out the same issue could theoretically happen to kcompactd. As pageblocks containing pages that fail to migrate should now be forcibly rescanned to set the skip hint if skip hints are used, fast_find_migrateblock() should no longer loop on a small subset of pageblocks for prolonged periods of time. Revert the revert so fast_find_migrateblock() is effective again. Using the mmtests config workload-usemem-stress-numa-compact, the number of unique ranges scanned was analysed for both kcompactd and !kcompactd activity. 6.4.0-rc1-vanilla kcompactd 7 range=(0x10d600~0x10d800) 7 range=(0x110c00~0x110e00) 7 range=(0x110e00~0x111000) 7 range=(0x111800~0x111a00) 7 range=(0x111a00~0x111c00) !kcompactd 1 range=(0x113e00~0x114000) 1 range=(0x114000~0x114020) 1 range=(0x114400~0x114489) 1 range=(0x114489~0x1144aa) 1 range=(0x1144aa~0x114600) 6.4.0-rc1-mm-revertfastmigrate kcompactd 17 range=(0x104200~0x104400) 17 range=(0x104400~0x104600) 17 range=(0x104600~0x104800) 17 range=(0x104800~0x104a00) 17 range=(0x104a00~0x104c00) !kcompactd 1793 range=(0x15c200~0x15c400) 5436 range=(0x105800~0x105a00) 19826 range=(0x150a00~0x150c00) 19833 range=(0x150800~0x150a00) 19834 range=(0x11ce00~0x11d000) 6.4.0-rc1-mm-follupfastfind kcompactd 22 range=(0x107200~0x107400) 23 range=(0x107400~0x107600) 23 range=(0x107600~0x107800) 23 range=(0x107c00~0x107e00) 23 range=(0x107e00~0x108000) !kcompactd 3 range=(0x890240~0x890400) 5 range=(0x886e00~0x887000) 5 range=(0x88a400~0x88a600) 6 range=(0x88f800~0x88fa00) 9 range=(0x88a400~0x88a420) Note that the vanilla kernel and the full series had some duplication of ranges scanned but it was not severe and would be in line with compaction resets when the skip hints are cleared. Just a revert of commit 7efc3b726103 ("mm/compaction: fix set skip in fast_find_migrateblock") showed excessive rescans of the same ranges so the series should not reintroduce bug 1206848. Link: https://bugzilla.suse.com/show_bug.cgi?id=1206848 Link: https://lkml.kernel.org/r/20230515113344.6869-5-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Tested-by: Raghavendra K T <raghavendra.kt@amd.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Chuyi Zhou <zhouchuyi@bytedance.com> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Maxim Levitsky <mlevitsk@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Pedro Falcato <pedro.falcato@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09mm: compaction: update pageblock skip when first migration candidate is not ↵Mel Gorman
at the start isolate_migratepages_block should mark a pageblock as skip if scanning started on an aligned pageblock boundary but it only updates the skip flag if the first migration candidate is also aligned. Tracing during a compaction stress load (mmtests: workload-usemem-stress-numa-compact) that many pageblocks are not marked skip causing excessive scanning of blocks that had been recently checked. Update pageblock skip based on "valid_page" which is set if scanning started on a pageblock boundary. [mgorman@techsingularity.net: fix handling of skip bit] Link: https://lkml.kernel.org/r/20230602111622.swtxhn6lu2qwgrwq@techsingularity.net Link: https://lkml.kernel.org/r/20230515113344.6869-4-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Tested-by: Raghavendra K T <raghavendra.kt@amd.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Chuyi Zhou <zhouchuyi@bytedance.com> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Maxim Levitsky <mlevitsk@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Pedro Falcato <pedro.falcato@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09mm: compaction: only force pageblock scan completion when skip hints are obeyedMel Gorman
fast_find_migrateblock relies on skip hints to avoid rescanning a recently selected pageblock but compact_zone() only forces the pageblock scan completion to set the skip hint if in direct compaction. While this prevents direct compaction repeatedly scanning a subset of blocks due to fast_find_migrateblock(), it does not prevent proactive compaction, node compaction and kcompactd encountering the same problem described in commit cfccd2e63e7e ("mm, compaction: finish pageblocks on complete migration failure"). Force the scan completion of a pageblock to set the skip hint if skip hints are obeyed to prevent fast_find_migrateblock() repeatedly selecting a subset of pageblocks. Link: https://lkml.kernel.org/r/20230515113344.6869-3-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Suggested-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Raghavendra K T <raghavendra.kt@amd.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Chuyi Zhou <zhouchuyi@bytedance.com> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Maxim Levitsky <mlevitsk@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Pedro Falcato <pedro.falcato@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09mm: compaction: ensure rescanning only happens on partially scanned pageblocksMel Gorman
Patch series "Follow-up "Fix excessive CPU usage during compaction"". The series "Fix excessive CPU usage during compaction" [1] attempted to fix a bug [2] but Vlastimil noted that the fix was incomplete [3]. While the series was merged, fast_find_migrateblock was still disabled. This series should fix the corner cases and allow 95e7a450b819 ("Revert "mm/compaction: fix set skip in fast_find_migrateblock"") to be safely reverted. Details on how many pageblocks are rescanned are in the changelog of the last patch. "Raghavendra K T" tested this and reported "decent improvement from perf perspective as well as compaction related data [4] [1] https://lore.kernel.org/r/20230125134434.18017-1-mgorman@techsingularity.net [2] https://bugzilla.suse.com/show_bug.cgi?id=1206848 [3] https://lore.kernel.org/r/a55cf026-a2f9-ef01-9a4c-398693e048ea@suse.cz [4] https://lkml.kernel.org/r/6d62686f-964d-342c-e085-0eae2555cc54@amd.com This patch (of 4): compact_zone() intends to rescan pageblocks if there is a failure to migrate "within the current order-aligned block". However, the pageblock scan may already be complete and moved to the next block causing the next pageblock to be "rescanned". Ensure only the most recent pageblock is rescanned. Link: https://lkml.kernel.org/r/20230515113344.6869-1-mgorman@techsingularity.net Link: https://lkml.kernel.org/r/20230515113344.6869-2-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Reported-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Raghavendra K T <raghavendra.kt@amd.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Chuyi Zhou <zhouchuyi@bytedance.com> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Maxim Levitsky <mlevitsk@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Pedro Falcato <pedro.falcato@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09mm: compaction: optimize compact_memory to comply with the admin-guideWen Yang
For the /proc/sys/vm/compact_memory file, the admin-guide states: When 1 is written to the file, all zones are compacted such that free memory is available in contiguous blocks where possible. This can be important for example in the allocation of huge pages although processes will also directly compact memory as required But it was not strictly followed, writing any value would cause all zones to be compacted. It has been slightly optimized to comply with the admin-guide. Enforce the 1 on the unlikely chance that the sysctl handler is ever extended to do something different. Commit ef4984384172 ("mm/compaction: remove unused variable sysctl_compact_memory") has also been optimized a bit here, as the declaration in the external header file has been eliminated, and sysctl_compact_memory also needs to be verified. [akpm@linux-foundation.org: add __read_mostly, per Mel] Link: https://lkml.kernel.org/r/tencent_DFF54DB2A60F3333F97D3F6B5441519B050A@qq.com Signed-off-by: Wen Yang <wenyang.linux@foxmail.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: William Lam <william.lam@bytedance.com> Cc: Pintu Kumar <pintu@codeaurora.org> Cc: Fu Wei <wefu@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-27Merge tag 'mm-stable-2023-04-27-15-30' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of switching from a user process to a kernel thread. - More folio conversions from Kefeng Wang, Zhang Peng and Pankaj Raghav. - zsmalloc performance improvements from Sergey Senozhatsky. - Yue Zhao has found and fixed some data race issues around the alteration of memcg userspace tunables. - VFS rationalizations from Christoph Hellwig: - removal of most of the callers of write_one_page() - make __filemap_get_folio()'s return value more useful - Luis Chamberlain has changed tmpfs so it no longer requires swap backing. Use `mount -o noswap'. - Qi Zheng has made the slab shrinkers operate locklessly, providing some scalability benefits. - Keith Busch has improved dmapool's performance, making part of its operations O(1) rather than O(n). - Peter Xu adds the UFFD_FEATURE_WP_UNPOPULATED feature to userfaultd, permitting userspace to wr-protect anon memory unpopulated ptes. - Kirill Shutemov has changed MAX_ORDER's meaning to be inclusive rather than exclusive, and has fixed a bunch of errors which were caused by its unintuitive meaning. - Axel Rasmussen give userfaultfd the UFFDIO_CONTINUE_MODE_WP feature, which causes minor faults to install a write-protected pte. - Vlastimil Babka has done some maintenance work on vma_merge(): cleanups to the kernel code and improvements to our userspace test harness. - Cleanups to do_fault_around() by Lorenzo Stoakes. - Mike Rapoport has moved a lot of initialization code out of various mm/ files and into mm/mm_init.c. - Lorenzo Stoakes removd vmf_insert_mixed_prot(), which was added for DRM, but DRM doesn't use it any more. - Lorenzo has also coverted read_kcore() and vread() to use iterators and has thereby removed the use of bounce buffers in some cases. - Lorenzo has also contributed further cleanups of vma_merge(). - Chaitanya Prakash provides some fixes to the mmap selftesting code. - Matthew Wilcox changes xfs and afs so they no longer take sleeping locks in ->map_page(), a step towards RCUification of pagefaults. - Suren Baghdasaryan has improved mmap_lock scalability by switching to per-VMA locking. - Frederic Weisbecker has reworked the percpu cache draining so that it no longer causes latency glitches on cpu isolated workloads. - Mike Rapoport cleans up and corrects the ARCH_FORCE_MAX_ORDER Kconfig logic. - Liu Shixin has changed zswap's initialization so we no longer waste a chunk of memory if zswap is not being used. - Yosry Ahmed has improved the performance of memcg statistics flushing. - David Stevens has fixed several issues involving khugepaged, userfaultfd and shmem. - Christoph Hellwig has provided some cleanup work to zram's IO-related code paths. - David Hildenbrand has fixed up some issues in the selftest code's testing of our pte state changing. - Pankaj Raghav has made page_endio() unneeded and has removed it. - Peter Xu contributed some rationalizations of the userfaultfd selftests. - Yosry Ahmed has fixed an issue around memcg's page recalim accounting. - Chaitanya Prakash has fixed some arm-related issues in the selftests/mm code. - Longlong Xia has improved the way in which KSM handles hwpoisoned pages. - Peter Xu fixes a few issues with uffd-wp at fork() time. - Stefan Roesch has changed KSM so that it may now be used on a per-process and per-cgroup basis. * tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits) mm,unmap: avoid flushing TLB in batch if PTE is inaccessible shmem: restrict noswap option to initial user namespace mm/khugepaged: fix conflicting mods to collapse_file() sparse: remove unnecessary 0 values from rc mm: move 'mmap_min_addr' logic from callers into vm_unmapped_area() hugetlb: pte_alloc_huge() to replace huge pte_alloc_map() maple_tree: fix allocation in mas_sparse_area() mm: do not increment pgfault stats when page fault handler retries zsmalloc: allow only one active pool compaction context selftests/mm: add new selftests for KSM mm: add new KSM process and sysfs knobs mm: add new api to enable ksm per process mm: shrinkers: fix debugfs file permissions mm: don't check VMA write permissions if the PTE/PMD indicates write permissions migrate_pages_batch: fix statistics for longterm pin retry userfaultfd: use helper function range_in_vma() lib/show_mem.c: use for_each_populated_zone() simplify code mm: correct arg in reclaim_pages()/reclaim_clean_pages_from_list() fs/buffer: convert create_page_buffers to folio_create_buffers fs/buffer: add folio_create_empty_buffers helper ...
2023-04-13mm: compaction: remove incorrect #ifdef checksArnd Bergmann
Without CONFIG_SYSCTL, the compiler warns about a few unused functions: mm/compaction.c:3076:12: error: 'proc_dointvec_minmax_warn_RT_change' defined but not used [-Werror=unused-function] mm/compaction.c:2780:12: error: 'sysctl_compaction_handler' defined but not used [-Werror=unused-function] mm/compaction.c:2750:12: error: 'compaction_proactiveness_sysctl_handler' defined but not used [-Werror=unused-function] The #ifdef is actually not necessary here, as the alternative register_sysctl_init() stub function does not use its argument, which lets the compiler drop the rest implicitly, while avoiding the warning. Fixes: c521126610c3 ("mm: compaction: move compaction sysctl to its own file") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-04-13mm: compaction: move compaction sysctl to its own fileMinghao Chi
This moves all compaction sysctls to its own file. Move sysctl to where the functionality truly belongs to improve readability, reduce merge conflicts, and facilitate maintenance. I use x86_defconfig and linux-next-20230327 branch $ make defconfig;make all -jn CONFIG_COMPACTION=y add/remove: 1/0 grow/shrink: 1/1 up/down: 350/-256 (94) Function old new delta vm_compaction - 320 +320 kcompactd_init 180 210 +30 vm_table 2112 1856 -256 Total: Before=21119987, After=21120081, chg +0.00% Despite the addition of 94 bytes the patch still seems a worthwile cleanup. Link: https://lore.kernel.org/lkml/067f7347-ba10-5405-920c-0f5f985c84f4@suse.cz/ Signed-off-by: Minghao Chi <chi.minghao@zte.com.cn> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-04-05mm: compaction: fix the possible deadlock when isolating hugetlb pagesBaolin Wang
When trying to isolate a migratable pageblock, it can contain several normal pages or several hugetlb pages (e.g. CONT-PTE 64K hugetlb on arm64) in a pageblock. That means we may hold the lru lock of a normal page to continue to isolate the next hugetlb page by isolate_or_dissolve_huge_page() in the same migratable pageblock. However in the isolate_or_dissolve_huge_page(), it may allocate a new hugetlb page and dissolve the old one by alloc_and_dissolve_hugetlb_folio() if the hugetlb's refcount is zero. That means we can still enter the direct compaction path to allocate a new hugetlb page under the current lru lock, which may cause possible deadlock. To avoid this possible deadlock, we should release the lru lock when trying to isolate a hugetbl page. Moreover it does not make sense to take the lru lock to isolate a hugetlb, which is not in the lru list. Link: https://lkml.kernel.org/r/7ab3bffebe59fb419234a68dec1e4572a2518563.1678962352.git.baolin.wang@linux.alibaba.com Fixes: 369fa227c219 ("mm: make alloc_contig_range handle free hugetlb pages") Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: William Lam <william.lam@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05mm: compaction: consider the number of scanning compound pages in isolate ↵Baolin Wang
fail path commit b717d6b93b54 ("mm: compaction: include compound page count for scanning in pageblock isolation") added compound page statistics for scanning in pageblock isolation, to make sure the number of scanned pages is always larger than the number of isolated pages when isolating mirgratable or free pageblock. However, when failing to isolate the pages when scanning the migratable or free pageblocks, the isolation failure path did not consider the scanning statistics of the compound pages, which result in showing the incorrect number of scanned pages in tracepoints or in vmstats which will confuse people about the page scanning pressure in memory compaction. Thus we should take into account the number of scanning pages when failing to isolate the compound pages to make the statistics accurate. Link: https://lkml.kernel.org/r/73d6250a90707649cc010731aedc27f946d722ed.1678962352.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: William Lam <william.lam@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>