From owner-freebsd-stable@FreeBSD.ORG Sun Apr 29 12:04:52 2012 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id B0CD7106566B; Sun, 29 Apr 2012 12:04:52 +0000 (UTC) (envelope-from oliver.pntr@gmail.com) Received: from mail-gy0-f182.google.com (mail-gy0-f182.google.com [209.85.160.182]) by mx1.freebsd.org (Postfix) with ESMTP id 40C968FC17; Sun, 29 Apr 2012 12:04:52 +0000 (UTC) Received: by ghrr20 with SMTP id r20so1222781ghr.13 for ; Sun, 29 Apr 2012 05:04:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=Jb3q5vqoNMqeMlt48c8X2eEkMI9mws9lhRBMwLAtPu0=; b=FphnBktPeelb1j/bTUco6y2QL7Txx0vi0IDD7ONmHQ0plWHxno1lPVZKWllMxUDb5n Y16povFPuq7BPZoXaOwSVQvHEdDYwf8aM15oj/Lf+vPLJpc/E8pZvYP9DB+qtdpHZlJy nD3bgeN0Tr/qyIET/Ett8oSpYYWfiroO6B5+/X7sRwFPs3o1NrsyhsVN4LZoMp37lMQ4 +hYWmRnTW8O3cVi4NN+6c0FA/8XuW6d7mPNoT0ki0ffx/iBS93M21ZJ37o9XC7nZYiwe dZcNvo0ybTRxnjfUAtP2hq8ht2Ff5XbPU/rhZyQo5nUPh8nMr3U5iwSeplSAJvoez/J6 57rg== MIME-Version: 1.0 Received: by 10.236.145.34 with SMTP id o22mr19277521yhj.7.1335701091542; Sun, 29 Apr 2012 05:04:51 -0700 (PDT) Received: by 10.236.161.97 with HTTP; Sun, 29 Apr 2012 05:04:51 -0700 (PDT) In-Reply-To: <4F9CDE91.1060300@FreeBSD.org> References: <20120427203013.GB60961@pcjas.obspm.fr> <20120427213459.GA61125@pcjas.obspm.fr> <4F9B946D.3030607@FreeBSD.org> <4F9CCEF2.6050609@FreeBSD.org> <20120429155512.M91148@sola.nimnet.asn.au> <4F9CDE91.1060300@FreeBSD.org> Date: Sun, 29 Apr 2012 14:04:51 +0200 Message-ID: From: Oliver Pinter To: Alexander Motin Content-Type: text/plain; charset=ISO-8859-1 Cc: Davide Italiano , Albert Shih , Luigi Rizzo , freebsd-stable@freebsd.org, Ian Smith Subject: Re: High load event idl. X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 29 Apr 2012 12:04:52 -0000 Hi all! Removing dummynet from kernel don't chanage anything, that is releated to load average. The loadavg hold to 0.70 +/- 0.2. (single user : sh + top) On 4/29/12, Alexander Motin wrote: > On 04/29/12 09:09, Ian Smith wrote: >> On Sun, 29 Apr 2012 08:17:38 +0300, Alexander Motin wrote: >> > On 04/29/12 01:53, Oliver Pinter wrote: >> > > Attached the ktr file. This is on core2duo P9400 cpu ( >> > > smbios.system.product="HP ProBook 5310m (WD792EA#ABU)" ). The >> workload >> > > is only a single user boost: sh + top running, but the load >> average is >> > > near 0.5. >> > >> > ktr shows no real load there. But it shows that you are using >> dummynet, that >> > schedules its runs on every hardclock tick. I believe that load you >> see is >> > the result or synchronization between dummynet calls and loadvg >> sampling, >> > both of which called from hardclock. I think removing dummynet from >> equation, >> > should hide this problem and also reduce you laptops power >> consumption. >> > >> > What's about fixing this, it is loadavg sampling algorithm that >> should be >> > changed. Fixing dummynet to not run on every hardclock tick would >> also be >> > great. >> >> Wading in out of my depth, and copying Luigi in case he misses it .. but >> even back in the olden days when HZ defaulted to 100, one was advised to >> use HZ>= 1000 for smooth dummynet traffic shaping dispatch scheduling. >> >> I wonder, with the newer clocks and timers, whether there is another >> clock that could be used for dummynet scheduling, that would not have >> this effect (even if largely cosmetic?) on load average calculation? > > First of all, the easiest solution would be to make dummynet to schedule > callout not automatically, but on first queued packet. I believe that in > case of laptop the queue should be empty most of time and the callout > calls are completely useless there. Luigi promised to look on this once. > > What's about better precision/removing synchronization -- there is > starting GSoC project now (by davide@) to rewrite callout(9) subsystem > to use better precision allowed by new timer drivers. While now it is > possible to get raw access to additional timer hardware available on > some systems, I don't think it is a good idea. > > -- > Alexander Motin >