From owner-freebsd-stable@FreeBSD.ORG Sun Nov 28 08:24:23 2010 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 2EDC8106566C for ; Sun, 28 Nov 2010 08:24:23 +0000 (UTC) (envelope-from amvandemore@gmail.com) Received: from mail-fx0-f54.google.com (mail-fx0-f54.google.com [209.85.161.54]) by mx1.freebsd.org (Postfix) with ESMTP id B39078FC1D for ; Sun, 28 Nov 2010 08:24:22 +0000 (UTC) Received: by fxm16 with SMTP id 16so1792532fxm.13 for ; Sun, 28 Nov 2010 00:24:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:received:in-reply-to :references:date:message-id:subject:from:to:cc:content-type; bh=wEqRoSgK+TDhY4O2P4M9FEB0pe2Cd65VvaQDBQbcKTc=; b=enbQyday1DJW5zKtM3tSEN1IuM3Dqb3cwNx707rUl6kbuINBSegoWKXxgXTP/nTD3S 3AL9FgqSCX9pG6MoGcPxdDJKYOCj6Vp1UNdw8E8N/9ueIV9kMFPAjbLVyWI4g9VXrLfO 2/20hxh3G9kepqU6KbIb7irZzSXjzqGNXa1hU= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; b=wdrqVmCdYRZA2bt2cXUFe6omSXcGc2sPOUK4oJlazoHuvlV7nQ2DHDQlC/uIuOGZpa ix02aZFSbbtu9vMhYYkP4S5oG+OJDaYShISJ1SpOnm2v3i3g+I85eUnxGlH50nS/Ldb+ WPjuJL2AnIYo75+xm0g3gwEzxF8uc2udZZFmY= MIME-Version: 1.0 Received: by 10.223.117.2 with SMTP id o2mr3940382faq.6.1290932661587; Sun, 28 Nov 2010 00:24:21 -0800 (PST) Received: by 10.223.121.138 with HTTP; Sun, 28 Nov 2010 00:24:21 -0800 (PST) In-Reply-To: <20101128072624.GA76358@server.vk2pj.dyndns.org> References: <20101128072624.GA76358@server.vk2pj.dyndns.org> Date: Sun, 28 Nov 2010 02:24:21 -0600 Message-ID: From: Adam Vande More To: Peter Jeremy Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: freebsd-stable@freebsd.org Subject: Re: idprio processes slowing down system 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, 28 Nov 2010 08:24:23 -0000 On Sun, Nov 28, 2010 at 1:26 AM, Peter Jeremy wrote: > Since all the boinc processes are running at i31, why are they impacting > a buildkernel that runs with 0 nicety? > Someone please enlighten me if I'm wrong, but I'll take a stab at it. With the setup you presented you're going to have a lot of context switches as the buildworld is going to give plenty of oppurtunities for boinc processes to get some time. When it does switch out, the CPU cache is invalidated, then invalidated again when the buildworld preempts back. This is what makes it slow. If gcc was building one massive binary at that priority, you wouldn't have boinc getting much/any time. Since the buildworld is much more modular and consists of a large amount of small operations some CPU intentisive, some IO intensive, boinc can interrupt and impact overall performance even if the inital process was started at a much higher priority. I'm not sure how well ULE handles CPU affinity. Some other stuff I ran into earlier suggested there's room for improvement, but in your particular use case I'm not sure even ideal CPU affinity would improve things much. -- Adam Vande More