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authorLeonid Yegoshin <Leonid.Yegoshin@imgtec.com>2013-05-24 15:55:18 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-06-07 12:46:36 -0700
commitc0872911a5926b9c0a3e570cf8bf2a027275a664 (patch)
tree2f55f747f526359c4d11cfd333140d0e188e6766
parent891694374dbdf88b12f41fa412ead40a4d255071 (diff)
mm compaction: fix of improper cache flush in migration code
commit c2cc499c5bcf9040a738f49e8051b42078205748 upstream. 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 <Leonid.Yegoshin@imgtec.com> Cc: Leonid Yegoshin <yegoshin@mips.com> Acked-by: Rik van Riel <riel@redhat.com> Cc: Michal Hocko <mhocko@suse.cz> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Russell King <rmk@arm.linux.org.uk> Cc: David Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--mm/migrate.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/migrate.c b/mm/migrate.c
index 480714b6f3f..d41b945d53f 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -147,7 +147,7 @@ static int remove_migration_pte(struct page *new, struct vm_area_struct *vma,
if (PageHuge(new))
pte = pte_mkhuge(pte);
#endif
- flush_cache_page(vma, addr, pte_pfn(pte));
+ flush_dcache_page(new);
set_pte_at(mm, addr, ptep, pte);
if (PageHuge(new)) {