From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarek Poplawski Subject: Re: loaded router, excessive getnstimeofday in oprofile Date: Tue, 26 Aug 2008 10:47:17 +0000 Message-ID: <20080826104717.GB2609@ff.dom.local> References: <20080826095126.GA2609@ff.dom.local> <200808261329.53741.denys@visp.net.lb> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: Denys Fedoryshchenko Return-path: Received: from ik-out-1112.google.com ([66.249.90.181]:38710 "EHLO ik-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752937AbYHZKrX (ORCPT ); Tue, 26 Aug 2008 06:47:23 -0400 Received: by ik-out-1112.google.com with SMTP id c28so1699015ika.5 for ; Tue, 26 Aug 2008 03:47:22 -0700 (PDT) Content-Disposition: inline In-Reply-To: <200808261329.53741.denys@visp.net.lb> Sender: netdev-owner@vger.kernel.org List-ID: On Tue, Aug 26, 2008 at 01:29:53PM +0300, Denys Fedoryshchenko wrote: > On Tuesday 26 August 2008, Jarek Poplawski wrote: > > > > This function is really used in many places, and these profiles are > > not enough at least to me, but it seems you could have a lot of > > softirqs (and probably hrtimers) scheduling, so maybe you should try > > if e.g. disabling hrtimers or changing kernel HZ makes any difference. > > > > Jarek P. > One user is shapers, it is ok for me. The question is if you really need so exact shaping at a cost of higher system load. > I am not sure, but maybe another user is softlockup debug option... and if > there is a lot of task switches maybe it will cause excessive load of timers > slow? Maybe. Anyway, you could try if lower HZ (with longer jiffies) can help with processing more skbs without rescheduling. Jarek P.