Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S269152AbUIYApQ (ORCPT ); Fri, 24 Sep 2004 20:45:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S269153AbUIYApQ (ORCPT ); Fri, 24 Sep 2004 20:45:16 -0400 Received: from smtp207.mail.sc5.yahoo.com ([216.136.129.97]:41614 "HELO smtp207.mail.sc5.yahoo.com") by vger.kernel.org with SMTP id S269152AbUIYApM (ORCPT ); Fri, 24 Sep 2004 20:45:12 -0400 Message-ID: <4154BF8F.9070904@yahoo.com.au> Date: Sat, 25 Sep 2004 10:45:03 +1000 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.2) Gecko/20040820 Debian/1.7.2-4 X-Accept-Language: en MIME-Version: 1.0 To: Andrew Morton CC: Steven Pratt , linux-kernel@vger.kernel.org Subject: Re: [PATCH/RFC] Simplified Readahead References: <4152F46D.1060200@austin.ibm.com> <20040923194216.1f2b7b05.akpm@osdl.org> <41543FE2.5040807@austin.ibm.com> <20040924150523.4853465b.akpm@osdl.org> In-Reply-To: <20040924150523.4853465b.akpm@osdl.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 859 Lines: 21 Andrew Morton wrote: > Steven Pratt wrote: >>Can you expand on the POSIX_FADV_WILLNEED. > > > It's an application-specified readahead hint. It should ideally be > asynchronous so the application can get some I/O underway while it's > crunching on something else. If the queue is contested then the > application will accidentally block when launching the readahead, which > kinda defeats the purpose. > > Yes, the application will block when it does the subsequent read() anyway, > but applications expect to block in read(). Seems saner this way. Good point. I guess you're right. - 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/