Return-Path: Message-Id: <20130703184048.863130458@goodmis.org> Date: Wed, 03 Jul 2013 14:39:23 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Leonid Yegoshin , Leonid Yegoshin , Rik van Riel , Michal Hocko , Mel Gorman , Ralf Baechle , Russell King , David Miller , Andrew Morton Subject: [026/141] mm compaction: fix of improper cache flush in migration code References: <20130703183857.307196999@goodmis.org> Content-Disposition: inline; filename=0026-mm-compaction-fix-of-improper-cache-flush-in-migrati.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.6.11.6 stable review patch. If anyone has any objections, please let me know. ------------------ From: Leonid Yegoshin [ Upstream commit c2cc499c5bcf9040a738f49e8051b42078205748 ] 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 Signed-off-by: Steven Rostedt --- mm/migrate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/migrate.c b/mm/migrate.c index 77ed2d7..a303524 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -146,7 +146,7 @@ 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)) { -- 1.7.10.4