Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757952Ab3DAXfm (ORCPT ); Mon, 1 Apr 2013 19:35:42 -0400 Received: from mail-pb0-f44.google.com ([209.85.160.44]:55491 "EHLO mail-pb0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756625Ab3DAXfl (ORCPT ); Mon, 1 Apr 2013 19:35:41 -0400 Date: Mon, 1 Apr 2013 16:35:38 -0700 (PDT) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Minchan Kim cc: Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Mel Gorman , Andrea Arcangeli , Hugh Dickins Subject: Re: [PATCH] THP: Use explicit memory barrier In-Reply-To: <1364773535-26264-1-git-send-email-minchan@kernel.org> Message-ID: References: <1364773535-26264-1-git-send-email-minchan@kernel.org> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 826 Lines: 20 On Mon, 1 Apr 2013, Minchan Kim wrote: > __do_huge_pmd_anonymous_page depends on page_add_new_anon_rmap's > spinlock for making sure that clear_huge_page write become visible > after set set_pmd_at() write. > > But lru_cache_add_lru uses pagevec so it could miss spinlock > easily so above rule was broken so user may see inconsistent data. > > This patch fixes it with using explict barrier rather than depending > on lru spinlock. > Is this the same issue that Andrea responded to in the "thp and memory barrier assumptions" thread at http://marc.info/?t=134333512700004 ? -- 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/