The quilt patch titled Subject: mm/page_isolation: fix isolate_single_pageblock() isolation behavior has been removed from the -mm tree. Its filename was mm-page_isolation-fix-isolate_single_pageblock-isolation-behavior.patch

This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------ From: Zi Yan ziy@nvidia.com Subject: mm/page_isolation: fix isolate_single_pageblock() isolation behavior Date: Tue, 13 Sep 2022 22:39:13 -0400

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...., 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 ziy@nvidia.com Reported-by: Doug Berger opendmb@gmail.com Cc: David Hildenbrand david@redhat.com Cc: Doug Berger opendmb@gmail.com Cc: Mike Kravetz mike.kravetz@oracle.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

mm/page_isolation.c | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-)

--- a/mm/page_isolation.c~mm-page_isolation-fix-isolate_single_pageblock-isolation-behavior +++ a/mm/page_isolation.c @@ -288,6 +288,7 @@ __first_valid_page(unsigned long pfn, un * @isolate_before: isolate the pageblock before the boundary_pfn * @skip_isolation: the flag to skip the pageblock isolation in second * isolate_single_pageblock() + * @migratetype: migrate type to set in error recovery. * * Free and in-use pages can be as big as MAX_ORDER-1 and contain more than one * pageblock. When not all pageblocks within a page are isolated at the same @@ -302,9 +303,9 @@ __first_valid_page(unsigned long pfn, un * the in-use page then splitting the free page. */ static int isolate_single_pageblock(unsigned long boundary_pfn, int flags, - gfp_t gfp_flags, bool isolate_before, bool skip_isolation) + gfp_t gfp_flags, bool isolate_before, bool skip_isolation, + int migratetype) { - unsigned char saved_mt; unsigned long start_pfn; unsigned long isolate_pageblock; unsigned long pfn; @@ -328,13 +329,13 @@ static int isolate_single_pageblock(unsi start_pfn = max(ALIGN_DOWN(isolate_pageblock, MAX_ORDER_NR_PAGES), zone->zone_start_pfn);

- saved_mt = get_pageblock_migratetype(pfn_to_page(isolate_pageblock)); + if (skip_isolation) { + int mt = get_pageblock_migratetype(pfn_to_page(isolate_pageblock));

- if (skip_isolation) - VM_BUG_ON(!is_migrate_isolate(saved_mt)); - else { - ret = set_migratetype_isolate(pfn_to_page(isolate_pageblock), saved_mt, flags, - isolate_pageblock, isolate_pageblock + pageblock_nr_pages); + VM_BUG_ON(!is_migrate_isolate(mt)); + } else { + ret = set_migratetype_isolate(pfn_to_page(isolate_pageblock), migratetype, + flags, isolate_pageblock, isolate_pageblock + pageblock_nr_pages);

if (ret) return ret; @@ -475,7 +476,7 @@ static int isolate_single_pageblock(unsi failed: /* restore the original migratetype */ if (!skip_isolation) - unset_migratetype_isolate(pfn_to_page(isolate_pageblock), saved_mt); + unset_migratetype_isolate(pfn_to_page(isolate_pageblock), migratetype); return -EBUSY; }

@@ -537,7 +538,8 @@ int start_isolate_page_range(unsigned lo bool skip_isolation = false;

/* isolate [isolate_start, isolate_start + pageblock_nr_pages) pageblock */ - ret = isolate_single_pageblock(isolate_start, flags, gfp_flags, false, skip_isolation); + ret = isolate_single_pageblock(isolate_start, flags, gfp_flags, false, + skip_isolation, migratetype); if (ret) return ret;

@@ -545,7 +547,8 @@ int start_isolate_page_range(unsigned lo skip_isolation = true;

/* isolate [isolate_end - pageblock_nr_pages, isolate_end) pageblock */ - ret = isolate_single_pageblock(isolate_end, flags, gfp_flags, true, skip_isolation); + ret = isolate_single_pageblock(isolate_end, flags, gfp_flags, true, + skip_isolation, migratetype); if (ret) { unset_migratetype_isolate(pfn_to_page(isolate_start), migratetype); return ret; _

Patches currently in -mm which might be from ziy@nvidia.com are