kernel/linux.git/mm/page_isolation.c, branch v6.4

mm, treewide: redefine MAX_ORDER sanely

2023-04-06T02:42:46+00:00

MAX_ORDER currently defined as number of orders page allocator supports: user can ask buddy allocator for page order between 0 and MAX_ORDER-1. This definition is counter-intuitive and lead to number of bugs all over the kernel. Change the definition of MAX_ORDER to be inclusive: the range of orders user can ask from buddy allocator is 0..MAX_ORDER now. [kirill@shutemov.name: fix min() warning] Link: https://lkml.kernel.org/r/20230315153800.32wib3n5rickolvh@box [akpm@linux-foundation.org: fix another min_t warning] [kirill@shutemov.name: fixups per Zi Yan] Link: https://lkml.kernel.org/r/20230316232144.b7ic4cif4kjiabws@box.shutemov.name [akpm@linux-foundation.org: fix underlining in docs] Link: https://lore.kernel.org/oe-kbuild-all/202303191025.VRCTk6mP-lkp@intel.com/ Link: https://lkml.kernel.org/r/20230315113133.11326-11-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov Reviewed-by: Michael Ellerman [powerpc] Cc: "Kirill A. Shutemov" Cc: Zi Yan Signed-off-by: Andrew Morton

mm/page_isolation: fix clang deadcode warning

2022-10-28T20:37:22+00:00

When !CONFIG_VM_BUG_ON, there is warning of clang-analyzer-deadcode.DeadStores: Value stored to 'mt' during its initialization is never read. Link: https://lkml.kernel.org/r/20221021101555.7992-2-quic_aiquny@quicinc.com Signed-off-by: Maria Yu Cc: David Hildenbrand Cc: Doug Berger Cc: Mike Kravetz Cc: Zi Yan Cc: Matthew Wilcox Signed-off-by: Andrew Morton

mm: add pageblock_aligned() macro

2022-10-03T21:03:04+00:00

Add pageblock_aligned() and use it to simplify code. Link: https://lkml.kernel.org/r/20220907060844.126891-3-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang Acked-by: Mike Rapoport Cc: David Hildenbrand Cc: Oscar Salvador Cc: Vlastimil Babka Signed-off-by: Andrew Morton

mm: add pageblock_align() macro

2022-10-03T21:03:04+00:00

Add pageblock_align() macro and use it to simplify code. Link: https://lkml.kernel.org/r/20220907060844.126891-2-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang Acked-by: Mike Rapoport Reviewed-by: David Hildenbrand Cc: Oscar Salvador Cc: Vlastimil Babka Signed-off-by: Andrew Morton

mm: reuse pageblock_start/end_pfn() macro

2022-10-03T21:03:03+00:00

Move pageblock_start_pfn/pageblock_end_pfn() into pageblock-flags.h, then they could be used somewhere else, not only in compaction, also use ALIGN_DOWN() instead of round_down() to be pair with ALIGN(), which should be same for pageblock usage. Link: https://lkml.kernel.org/r/20220907060844.126891-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang Acked-by: Mike Rapoport Reviewed-by: David Hildenbrand Cc: Oscar Salvador Cc: Vlastimil Babka Signed-off-by: Andrew Morton

mm/page_isolation: fix isolate_single_pageblock() isolation behavior

2022-09-26T19:14:34+00:00

set_migratetype_isolate() does not allow isolating MIGRATE_CMA pageblocks unless it is used for CMA allocation. isolate_single_pageblock() did not have the same behavior when it is used together with set_migratetype_isolate() in start_isolate_page_range(). This allows alloc_contig_range() with migratetype other than MIGRATE_CMA, like MIGRATE_MOVABLE (used by alloc_contig_pages()), to isolate first and last pageblock but fail the rest. The failure leads to changing migratetype of the first and last pageblock to MIGRATE_MOVABLE from MIGRATE_CMA, corrupting the CMA region. This can happen during gigantic page allocations. Like Doug said here: https://lore.kernel.org/linux-mm/a3363a52-883b-dcd1-b77f-f2bb378d6f2d@gmail.com/T/#u, for gigantic page allocations, the user would notice no difference, since the allocation on CMA region will fail as well as it did before. But it might hurt the performance of device drivers that use CMA, since CMA region size decreases. Fix it by passing migratetype into isolate_single_pageblock(), so that set_migratetype_isolate() used by isolate_single_pageblock() will prevent the isolation happening. Link: https://lkml.kernel.org/r/20220914023913.1855924-1-zi.yan@sent.com Fixes: b2c9e2fbba32 ("mm: make alloc_contig_range work at pageblock granularity") Signed-off-by: Zi Yan Reported-by: Doug Berger Cc: David Hildenbrand Cc: Doug Berger Cc: Mike Kravetz Cc: Signed-off-by: Andrew Morton

mm/page_isolation.c: fix one kernel-doc comment

2022-06-17T02:11:30+00:00

Remove one warning found by running scripts/kernel-doc, which is caused by using 'make W=1': mm/page_isolation.c:304: warning: Function parameter or member 'skip_isolation' not described in 'isolate_single_pageblock' Link: https://lkml.kernel.org/r/20220602062116.61199-1-yang.lee@linux.alibaba.com Signed-off-by: Yang Li Reported-by: Abaci Robot Signed-off-by: Andrew Morton

mm: page_isolation: use compound_nr() correctly in isolate_single_pageblock()

2022-06-01T22:57:16+00:00

When compound_nr(page) was used, page was not guaranteed to be the head of the compound page and it could cause an infinite loop. Fix it by calling it on the head page. Link: https://lkml.kernel.org/r/20220531024450.2498431-1-zi.yan@sent.com Fixes: b2c9e2fbba32 ("mm: make alloc_contig_range work at pageblock granularity") Signed-off-by: Zi Yan Reported-by: Anshuman Khandual Link: https://lore.kernel.org/linux-mm/20220530115027.123341-1-anshuman.khandual@arm.com/ Reviewed-by: Anshuman Khandual Reviewed-by: Miaohe Lin Reviewed-by: Oscar Salvador Acked-by: Muchun Song Cc: David Hildenbrand Cc: Qian Cai Cc: Vlastimil Babka Cc: Mel Gorman Cc: Eric Ren Cc: Mike Rapoport Cc: Christophe Leroy Signed-off-by: Andrew Morton

mm: split free page with properly free memory accounting and without race

2022-05-27T16:33:43+00:00

In isolate_single_pageblock(), free pages are checked without holding zone lock, but they can go away in split_free_page() when zone lock is held. Check the free page and its order again in split_free_page() when zone lock is held. Recheck the page if the free page is gone under zone lock. In addition, in split_free_page(), the free page was deleted from the page list without changing free page accounting. Add the missing free page accounting code. Fix the type of order parameter in split_free_page(). Link: https://lore.kernel.org/lkml/20220525103621.987185e2ca0079f7b97b856d@linux-foundation.org/ Link: https://lkml.kernel.org/r/20220526231531.2404977-2-zi.yan@sent.com Fixes: b2c9e2fbba32 ("mm: make alloc_contig_range work at pageblock granularity") Signed-off-by: Zi Yan Reported-by: Doug Berger Link: https://lore.kernel.org/linux-mm/c3932a6f-77fe-29f7-0c29-fe6b1c67ab7b@gmail.com/ Cc: David Hildenbrand Cc: Qian Cai Cc: Vlastimil Babka Cc: Mel Gorman Cc: Eric Ren Cc: Mike Rapoport Cc: Oscar Salvador Cc: Christophe Leroy Cc: Marek Szyprowski Cc: Michael Walle Signed-off-by: Andrew Morton

mm: page-isolation: skip isolated pageblock in start_isolate_page_range()

2022-05-27T16:33:42+00:00

start_isolate_page_range() first isolates the first and the last pageblocks in the range and ensure pages across range boundaries are split during isolation. But it missed the case when the range is <= a pageblock and the first and the last pageblocks are the same one, so the second isolate_single_pageblock() will always fail. To fix it, skip the pageblock isolation in second isolate_single_pageblock(). Link: https://lkml.kernel.org/r/20220526231531.2404977-1-zi.yan@sent.com Fixes: 88ee134320b8 ("mm: fix a potential infinite loop in start_isolate_page_range()") Signed-off-by: Zi Yan Reported-by: Marek Szyprowski Tested-by: Marek Szyprowski Link: https://lore.kernel.org/linux-mm/ac65adc0-a7e4-cdfe-a0d8-757195b86293@samsung.com/ Reported-by: Michael Walle Tested-by: Michael Walle Link: https://lore.kernel.org/linux-mm/8ca048ca8b547e0dd1c95387ee05c23d@walle.cc/ Cc: Christophe Leroy Cc: David Hildenbrand Cc: Doug Berger Cc: Eric Ren Cc: Mel Gorman Cc: Mike Rapoport Cc: Oscar Salvador Cc: Qian Cai Cc: Vlastimil Babka Signed-off-by: Andrew Morton