From owner-freebsd-current@FreeBSD.ORG Mon Dec 19 21:22:47 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 720BB1065672 for ; Mon, 19 Dec 2011 21:22:47 +0000 (UTC) (envelope-from avg@FreeBSD.org) Received: from citadel.icyb.net.ua (citadel.icyb.net.ua [212.40.38.140]) by mx1.freebsd.org (Postfix) with ESMTP id 836868FC08 for ; Mon, 19 Dec 2011 21:22:44 +0000 (UTC) Received: from porto.starpoint.kiev.ua (porto-e.starpoint.kiev.ua [212.40.38.100]) by citadel.icyb.net.ua (8.8.8p3/ICyb-2.3exp) with ESMTP id XAA13903; Mon, 19 Dec 2011 23:22:42 +0200 (EET) (envelope-from avg@FreeBSD.org) Received: from localhost ([127.0.0.1]) by porto.starpoint.kiev.ua with esmtp (Exim 4.34 (FreeBSD)) id 1RckfS-000GLT-HD; Mon, 19 Dec 2011 23:22:42 +0200 Message-ID: <4EEFAB20.4070300@FreeBSD.org> Date: Mon, 19 Dec 2011 23:22:40 +0200 From: Andriy Gapon User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:8.0) Gecko/20111206 Thunderbird/8.0 MIME-Version: 1.0 To: Nathan Whitehorn 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> In-Reply-To: <4EEF5D5A.5050700@freebsd.org> X-Enigmail-Version: undefined Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: freebsd-performance@FreeBSD.org, freebsd-current@FreeBSD.org Subject: Re: SCHED_ULE should not be the default X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 19 Dec 2011 21:22:47 -0000 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. -- Andriy Gapon