Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [ 047/127] mm compaction: fix of improper cache flush in migration code | Date | Wed, 5 Jun 2013 14:33:34 -0700 |
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3.9-stable review patch. If anyone has any objections, please let me know.
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From: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
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>
--- mm/migrate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/migrate.c +++ b/mm/migrate.c @@ -165,7 +165,7 @@ static int remove_migration_pte(struct p pte = arch_make_huge_pte(pte, vma, new, 0); } #endif - flush_cache_page(vma, addr, pte_pfn(pte)); + flush_dcache_page(new); set_pte_at(mm, addr, ptep, pte); if (PageHuge(new)) {
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