diff options
authorLeonid Yegoshin <>2013-05-24 15:55:18 -0700
committerLinus Torvalds <>2013-05-24 16:22:51 -0700
commitc2cc499c5bcf9040a738f49e8051b42078205748 (patch)
parent1ccc819da6fda9bee10ab8b72e9adbb5ad3e4959 (diff)
mm compaction: fix of improper cache flush in migration code
Page 'new' during MIGRATION can't be flushed with flush_cache_page(). Using flush_cache_page(vma, addr, pfn) is justified only if the page is already placed in process page table, and that is done right after flush_cache_page(). But without it the arch function has no knowledge of process PTE and does nothing. Besides that, flush_cache_page() flushes an application cache page, but the kernel has a different page virtual address and dirtied it. Replace it with flush_dcache_page(new) which is the proper usage. The old page is flushed in try_to_unmap_one() before migration. This bug takes place in Sead3 board with M14Kc MIPS CPU without cache aliasing (but Harvard arch - separate I and D cache) in tight memory environment (128MB) each 1-3days on SOAK test. It fails in cc1 during kernel build (SIGILL, SIGBUS, SIGSEG) if CONFIG_COMPACTION is switched ON. Signed-off-by: Leonid Yegoshin <> Cc: Leonid Yegoshin <> Acked-by: Rik van Riel <> Cc: Michal Hocko <> Acked-by: Mel Gorman <> Cc: Ralf Baechle <> Cc: Russell King <> Cc: David Miller <> Cc: <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/migrate.c b/mm/migrate.c
index 27ed22579fd..b1f57501de9 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -165,7 +165,7 @@ static int remove_migration_pte(struct page *new, struct vm_area_struct *vma,
pte = arch_make_huge_pte(pte, vma, new, 0);
- flush_cache_page(vma, addr, pte_pfn(pte));
+ flush_dcache_page(new);
set_pte_at(mm, addr, ptep, pte);
if (PageHuge(new)) {