From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751505AbVH0M6Q (ORCPT ); Sat, 27 Aug 2005 08:58:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751600AbVH0M6Q (ORCPT ); Sat, 27 Aug 2005 08:58:16 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:64948 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S1751505AbVH0M6Q (ORCPT ); Sat, 27 Aug 2005 08:58:16 -0400 Subject: Re: Linux 2.6 context switching and posix threads performance question From: Arjan van de Ven To: Mateusz Berezecki Cc: linux-kernel@vger.kernel.org In-Reply-To: <20050827121158.GA18406@oepkgtn.mshome.net> References: <20050827121158.GA18406@oepkgtn.mshome.net> Content-Type: text/plain Date: Sat, 27 Aug 2005 14:58:09 +0200 Message-Id: <1125147489.7756.10.camel@laptopd505.fenrus.org> Mime-Version: 1.0 X-Mailer: Evolution 2.2.2 (2.2.2-5) 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 > I'm asking for some kind of an authoritative answer > quite urgently. What is the optimum thread amount on 2 CPU SMP system > running Linux ? context switching in linux isn't THAT expensive compared to some other operating systems, but it's not free either. The optimum is obviously 2 threads, one for each cpu that processes your network service in a state machine like way. This is why thttpd beats apache by 10x if not more.