Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752282AbYKXE5y (ORCPT ); Sun, 23 Nov 2008 23:57:54 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751178AbYKXE5o (ORCPT ); Sun, 23 Nov 2008 23:57:44 -0500 Received: from x35.xmailserver.org ([64.71.152.41]:36060 "EHLO x35.xmailserver.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750876AbYKXE5n (ORCPT ); Sun, 23 Nov 2008 23:57:43 -0500 X-AuthUser: davidel@xmailserver.org Date: Sun, 23 Nov 2008 20:57:39 -0800 (PST) From: Davide Libenzi X-X-Sender: davide@alien.or.mcafeemobile.com To: Tejun Heo cc: Ingo Molnar , Andrew Morton , Matthew Wilcox , Miklos Szeredi , arjan@linux.intel.com, Linus Torvalds , hch@infradead.org, rminnich@sandia.gov, ericvh@gmail.com, Linux Kernel Mailing List , linux-fsdevel@vger.kernel.org, Peter Zijlstra Subject: Re: poll: allow f_op->poll to sleep, take #3 In-Reply-To: <492A2DBF.3030208@gmail.com> Message-ID: References: <20081122123942.GF5707@parisc-linux.org> <4927FE87.6050005@gmail.com> <20081122105356.87856d04.akpm@linux-foundation.org> <4928B162.9030404@gmail.com> <20081123085902.GI30453@elte.hu> <49291F06.5040907@gmail.com> <20081123093420.GN30453@elte.hu> <492925B0.9030404@gmail.com> <20081123094551.GQ30453@elte.hu> <492A2DBF.3030208@gmail.com> User-Agent: Alpine 1.10 (DEB 962 2008-03-14) X-GPG-FINGRPRINT: CFAE 5BEE FD36 F65E E640 56FE 0974 BF23 270F 474E X-GPG-PUBLIC_KEY: http://www.xmailserver.org/davidel.asc 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: 1412 Lines: 34 On Mon, 24 Nov 2008, Tejun Heo wrote: > Ingo Molnar wrote: > >> And @sync might be useful depending on who's waking it up, so we > >> either need to change the wake interface or give it an easier way to > >> pass those parameters as received. The callback function isn't the > >> right place to ignore those parameters. It simply doesn't know why > >> the caller is passing them in or what they mean under the > >> circumstances. > > > > We'll likely eliminate the 'sync' parameter from the scheduler. It's > > not a flag that should be proliferated. > > But it's still being used in quite hot paths (pipe, splice, socket) > and I don't really wanna mix up a change which can cause subtle > scheduling related performance regression into this patch. How about > using the dummy waitqueue hack for now and when removing the @sync > param, switch it to one of wakeup APIs? I'll be happy to add big /* > TODO */ comment in the function. I was noticing that wake ups on the poll queues do not use sync=1, AFAICS. So using wake_up_state() and ignoring 'sync' should be fine. And 'key' is already ignored by default by default_wake_function(). - Davide -- 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/