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authorZi Yan <ziy@nvidia.com>2022-05-27 02:15:30 +0300
committerakpm <akpm@linux-foundation.org>2022-05-27 19:33:42 +0300
commit9b209e557d698f24317d2619d8628b98b6728e4f (patch)
tree22147bc373ba47fda550097bbc3e4b0cdfe31f84 /mm/page_isolation.c
parentf403f22f8ccb12860b2b62fec3173c6ccd45938b (diff)
downloadlinux-9b209e557d698f24317d2619d8628b98b6728e4f.tar.xz
mm: page-isolation: skip isolated pageblock in start_isolate_page_range()
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 <ziy@nvidia.com> Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Link: https://lore.kernel.org/linux-mm/ac65adc0-a7e4-cdfe-a0d8-757195b86293@samsung.com/ Reported-by: Michael Walle <michael@walle.cc> Tested-by: Michael Walle <michael@walle.cc> Link: https://lore.kernel.org/linux-mm/8ca048ca8b547e0dd1c95387ee05c23d@walle.cc/ Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: David Hildenbrand <david@redhat.com> Cc: Doug Berger <opendmb@gmail.com> Cc: Eric Ren <renzhengeek@gmail.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Mike Rapoport <rppt@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Qian Cai <quic_qiancai@quicinc.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/page_isolation.c')
-rw-r--r--mm/page_isolation.c26
1 files changed, 18 insertions, 8 deletions
diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index c643c8420809..fbd820b21292 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -300,7 +300,7 @@ __first_valid_page(unsigned long pfn, unsigned long nr_pages)
* 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)
+ gfp_t gfp_flags, bool isolate_before, bool skip_isolation)
{
unsigned char saved_mt;
unsigned long start_pfn;
@@ -327,11 +327,16 @@ static int isolate_single_pageblock(unsigned long boundary_pfn, int flags,
zone->zone_start_pfn);
saved_mt = get_pageblock_migratetype(pfn_to_page(isolate_pageblock));
- ret = set_migratetype_isolate(pfn_to_page(isolate_pageblock), saved_mt, flags,
- isolate_pageblock, isolate_pageblock + pageblock_nr_pages);
- if (ret)
- return ret;
+ 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);
+
+ if (ret)
+ return ret;
+ }
/*
* Bail out early when the to-be-isolated pageblock does not form
@@ -463,7 +468,8 @@ static int isolate_single_pageblock(unsigned long boundary_pfn, int flags,
return 0;
failed:
/* restore the original migratetype */
- unset_migratetype_isolate(pfn_to_page(isolate_pageblock), saved_mt);
+ if (!skip_isolation)
+ unset_migratetype_isolate(pfn_to_page(isolate_pageblock), saved_mt);
return -EBUSY;
}
@@ -522,14 +528,18 @@ int start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
unsigned long isolate_start = ALIGN_DOWN(start_pfn, pageblock_nr_pages);
unsigned long isolate_end = ALIGN(end_pfn, pageblock_nr_pages);
int ret;
+ bool skip_isolation = false;
/* isolate [isolate_start, isolate_start + pageblock_nr_pages) pageblock */
- ret = isolate_single_pageblock(isolate_start, flags, gfp_flags, false);
+ ret = isolate_single_pageblock(isolate_start, flags, gfp_flags, false, skip_isolation);
if (ret)
return ret;
+ if (isolate_start == isolate_end - pageblock_nr_pages)
+ skip_isolation = true;
+
/* isolate [isolate_end - pageblock_nr_pages, isolate_end) pageblock */
- ret = isolate_single_pageblock(isolate_end, flags, gfp_flags, true);
+ ret = isolate_single_pageblock(isolate_end, flags, gfp_flags, true, skip_isolation);
if (ret) {
unset_migratetype_isolate(pfn_to_page(isolate_start), migratetype);
return ret;