Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752651Ab3EJJwS (ORCPT ); Fri, 10 May 2013 05:52:18 -0400 Received: from cantor2.suse.de ([195.135.220.15]:47660 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751764Ab3EJJwQ (ORCPT ); Fri, 10 May 2013 05:52:16 -0400 Date: Fri, 10 May 2013 10:52:12 +0100 From: Mel Gorman To: Leonid Yegoshin Cc: riel@redhat.com, mhocko@suse.cz, akpm@linux-foundation.org, kamezawa.hiroyu@jp.fujitsu.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] COMPACTION: bugfix of improper cache flush in MIGRATION code. Message-ID: <20130510095212.GM11497@suse.de> References: <20130509001821.15951.98705.stgit@linux-yegoshin> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20130509001821.15951.98705.stgit@linux-yegoshin> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1364 Lines: 33 On Wed, May 08, 2013 at 05:18:21PM -0700, Leonid Yegoshin wrote: > Page 'new' during MIGRATION can't be flushed by flush_cache_page(). > Using flush_cache_page(vma, addr, pfn) is justified only if > 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, > kernel has a different page virtual address and dirtied it. > > Replace it with flush_dcache_page(new) which is a proper usage. > > 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. > > Author: Leonid Yegoshin > Signed-off-by: Leonid Yegoshin Acked-by: Mel Gorman -- Mel Gorman SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/