From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757152AbYH2QYW (ORCPT ); Fri, 29 Aug 2008 12:24:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751732AbYH2QYO (ORCPT ); Fri, 29 Aug 2008 12:24:14 -0400 Received: from gateway-1237.mvista.com ([63.81.120.158]:17290 "EHLO gateway-1237.mvista.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751184AbYH2QYN (ORCPT ); Fri, 29 Aug 2008 12:24:13 -0400 Subject: Re: [PATCH 4/5] select: make select() use schedule_hrtimeout() From: Daniel Walker To: Arjan van de Ven Cc: linux-kernel@vger.kernel.org, mingo@elte.hu, tglx@tglx.de, torvalds@linux-foundation.org In-Reply-To: <20080829080809.0e42a323@infradead.org> References: <20080829080549.6906b744@infradead.org> <20080829080809.0e42a323@infradead.org> Content-Type: text/plain Date: Fri, 29 Aug 2008 08:59:58 -0700 Message-Id: <1220025598.4417.63.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.22.3.1 (2.22.3.1-1.fc9) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2008-08-29 at 08:08 -0700, Arjan van de Ven wrote: > rom: Arjan van de Ven > Date: Thu, 28 Aug 2008 13:45:38 -0700 > Subject: [PATCH] select: make select() use schedule_hrtimeout() > > now that we have schedule_hrtimeout(), make select() use it. > But only for short delays; really long delays are assumed to not > need the highres level of accuracy but rather want the regular > timer behavior for now. > > This is only done for delays shorter than 1 second; currently > the assumption is that longer delays have no desire to get the > higher accuracy. Do you have any basis to make this "short delays" assumption? I would think if regular timers can be used for longer than a second, people will naturally assume anything else that's high res will also .. The futex_wait() has code which looks a lot like your schedule_hrtimeout() , (you might want to replace your code there instead) , and it doesn't seem to have the short delays restriction .. Daniel