Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753773AbYKBCn4 (ORCPT ); Sat, 1 Nov 2008 22:43:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752644AbYKBCns (ORCPT ); Sat, 1 Nov 2008 22:43:48 -0400 Received: from casper.infradead.org ([85.118.1.10]:46174 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752626AbYKBCns (ORCPT ); Sat, 1 Nov 2008 22:43:48 -0400 Date: Sat, 1 Nov 2008 19:43:57 -0700 From: Arjan van de Ven To: Alan Stern Cc: Andrew Morton , Ingo Molnar , Linus Torvalds , Kernel development list Subject: Re: (BUG?) round_jiffies() is non-monotonic on SMP Message-ID: <20081101194357.1810f57a@infradead.org> In-Reply-To: References: <20081101131648.398fe54a@infradead.org> Organization: Intel X-Mailer: Claws Mail 3.5.0 (GTK+ 2.12.12; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1124 Lines: 31 On Sat, 1 Nov 2008 22:36:30 -0400 (EDT) Alan Stern wrote: > On Sat, 1 Nov 2008, Arjan van de Ven wrote: > > > > Come to think of it, is there any good reason why > > > round_jiffies() doesn't always round up? It seems a lot safer. > > > > at the time folks had concerns about making a big error in that > > direction... > > All right then. Would it be preferable to add a new > round_jiffies_up() routine, or to change round_jiffies() so that it > never rounds down? I'd prefer the former. But to be honest.. I would even more prefer the use of range timers ;) They're in 2.6.28-rc now ... and more power friendly than rounded timers (although I will readily admit that rounding is just easier) -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org -- 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/