Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030493AbWEYWd0 (ORCPT ); Thu, 25 May 2006 18:33:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030492AbWEYWd0 (ORCPT ); Thu, 25 May 2006 18:33:26 -0400 Received: from ozlabs.org ([203.10.76.45]:43149 "EHLO ozlabs.org") by vger.kernel.org with ESMTP id S1030490AbWEYWdZ (ORCPT ); Thu, 25 May 2006 18:33:25 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <17526.12463.412158.700850@cargo.ozlabs.ibm.com> Date: Fri, 26 May 2006 08:33:19 +1000 From: Paul Mackerras To: Andrew Morton Cc: Wu Fengguang , linux-kernel@vger.kernel.org Subject: Re: [PATCH 06/33] readahead: refactor __do_page_cache_readahead() In-Reply-To: <20060525093039.21b4246b.akpm@osdl.org> References: <20060524111246.420010595@localhost.localdomain> <348469538.91213@ustc.edu.cn> <20060525093039.21b4246b.akpm@osdl.org> X-Mailer: VM 7.19 under Emacs 21.4.1 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 914 Lines: 25 Andrew Morton writes: > Wu Fengguang wrote: > > @@ -302,6 +303,8 @@ __do_page_cache_readahead(struct address > > break; > > page->index = page_offset; > > list_add(&page->lru, &page_pool); > > + if (page_idx == nr_to_read - lookahead_size) > > + __SetPageReadahead(page); > > ret++; > > } > > OK. But the __SetPageFoo() things still give me the creeps. I just hope that Wu Fengguang, or whoever is making these patches, realizes that on some architectures, doing __set_bit on one CPU concurrently with another CPU doing set_bit on a different bit in the same word can result in the second CPU's update getting lost... Paul. - 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/