Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932224AbVJ3TMq (ORCPT ); Sun, 30 Oct 2005 14:12:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932226AbVJ3TMq (ORCPT ); Sun, 30 Oct 2005 14:12:46 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:40935 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S932224AbVJ3TMp (ORCPT ); Sun, 30 Oct 2005 14:12:45 -0500 Subject: Re: select() for delay. From: Arjan van de Ven To: Arnd Bergmann Cc: madhu.subbaiah@wipro.com, linux-kernel@vger.kernel.org In-Reply-To: <200510302006.15892.arnd@arndb.de> References: <200510302006.15892.arnd@arndb.de> Content-Type: text/plain Date: Sun, 30 Oct 2005 20:12:29 +0100 Message-Id: <1130699550.2829.8.camel@laptopd505.fenrus.org> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 (2.2.3-2.fc4) Content-Transfer-Encoding: 7bit X-Spam-Score: 2.9 (++) X-Spam-Report: SpamAssassin version 3.0.4 on pentafluge.infradead.org summary: Content analysis details: (2.9 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 0.1 RCVD_IN_SORBS_DUL RBL: SORBS: sent directly from dynamic IP address [80.57.133.107 listed in dnsbl.sorbs.net] 2.8 RCVD_IN_DSBL RBL: Received via a relay in list.dsbl.org [] X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1224 Lines: 28 On Sun, 2005-10-30 at 20:06 +0100, Arnd Bergmann wrote: > On Maandag 24 Oktober 2005 12:55, madhu.subbaiah@wipro.com wrote: > > > This is regarding select() system call. > > > > Linux select() man page mentions " Some code calls select with all > > three sets empty, n zero, and a non-null timeout as a fairly portable > > way to sleep with subsecond precision". > > When you make a change to a system call, you should always check > if the change makes sense for the 32 bit emulation path as well. > > In this case, you should definitely do the same thing to both > sys_select and compat_sys_select if this is found worthwhile. > > > This patch improves the sys_select() execution when used for delay. > > Please describe what aspect of the syscall is improved. Is this only > speeding up the execution for the delay case while slowing down > the normal case, or do the actual semantics improve? there is something funky about increasing the speed of a delay ;) - 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/