From owner-freebsd-current@FreeBSD.ORG Tue Dec 20 09:30:00 2011 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id CEE73106564A; Tue, 20 Dec 2011 09:30:00 +0000 (UTC) (envelope-from gljennjohn@googlemail.com) Received: from mail-ee0-f54.google.com (mail-ee0-f54.google.com [74.125.83.54]) by mx1.freebsd.org (Postfix) with ESMTP id D4B4F8FC12; Tue, 20 Dec 2011 09:29:59 +0000 (UTC) Received: by eekc50 with SMTP id c50so7341739eek.13 for ; Tue, 20 Dec 2011 01:29:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=gamma; h=date:from:to:cc:subject:message-id:in-reply-to:references:reply-to :x-mailer:mime-version:content-type:content-transfer-encoding; bh=3t0Usdm1HKG61fuGPfVDA7MaB10LmXBKnzyAXpm8tLM=; b=aX8WXLG6TU6LcTtrr/I7te38dqJ/+x13hm9cw0NAYC/Tz+Mo0DdPw38cQIqRZ7iRmW 1UwDfYKEmGLMhppPLoKTTSsff98w8nPjpLJAluO65sAaFrH3OYS3Bdx0CPqKHxvdceZd /YY0LHJvGVFue/+vkENeK7rCla9R52h1z+f7o= Received: by 10.213.110.6 with SMTP id l6mr344419ebp.71.1324373398491; Tue, 20 Dec 2011 01:29:58 -0800 (PST) Received: from ernst.jennejohn.org (p578E26BF.dip.t-dialin.net. [87.142.38.191]) by mx.google.com with ESMTPS id s16sm4547200eef.2.2011.12.20.01.29.56 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 20 Dec 2011 01:29:57 -0800 (PST) Date: Tue, 20 Dec 2011 10:29:55 +0100 From: Gary Jennejohn To: Andriy Gapon Message-ID: <20111220102955.068bb756@ernst.jennejohn.org> In-Reply-To: <4EEFAB20.4070300@FreeBSD.org> References: <4EE1EAFE.3070408@m5p.com> <4EE22421.9060707@gmail.com> <4EE6060D.5060201@mail.zedat.fu-berlin.de> <4EE69C5A.3090005@FreeBSD.org> <20111213104048.40f3e3de@nonamehost> <20111213090051.GA3339@vniz.net> <4EED5200.20302@cran.org.uk> <20111218164924.L64681@sola.nimnet.asn.au> <20111218075241.GA45367@vniz.net> <20111218102401.GA42627@freebsd.org> <20111218102600.GA44118@freebsd.org> <4EEF5D5A.5050700@freebsd.org> <4EEFAB20.4070300@FreeBSD.org> X-Mailer: Claws Mail 3.8.0 (GTK+ 2.24.6; amd64-portbld-freebsd10.0) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: freebsd-performance@FreeBSD.org, freebsd-current@FreeBSD.org, Nathan Whitehorn Subject: Re: SCHED_ULE should not be the default X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: gljennjohn@googlemail.com List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 20 Dec 2011 09:30:00 -0000 On Mon, 19 Dec 2011 23:22:40 +0200 Andriy Gapon wrote: > on 19/12/2011 17:50 Nathan Whitehorn said the following: > > The thing I've seen is that ULE is substantially more enthusiastic about > > migrating processes between cores than 4BSD. > > Hmm, this seems to be contrary to my theoretical expectations. I thought that > with 4BSD all threads that were not in one of the following categories: > - temporary pinned > - bound to cpu in kernel via sched_bind > - belong to a cpu set which a strict subset of a total set > were placed onto a common queue that was shared by all cpus. And as such I > expected them to get picked up by the cpus semi-randomly. > > In other words, I thought that it was ULE that took into account cpu/cache > affinities while 4BSD was deliberately entirely ignorant of those details. > I have a 6-core AMD CPU running FreeeBSD 10.0 and SCHED_4BSD. I've noticed with large ports builds which are not MAKE_JOBS_SAFE that the compile load migrates between the cores pretty quickly, but I haven't compared it to ULE. -- Gary Jennejohn