From owner-freebsd-hackers@FreeBSD.ORG Thu Sep 1 14:11:57 2011 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id BF0781065740 for ; Thu, 1 Sep 2011 14:11:57 +0000 (UTC) (envelope-from asmrookie@gmail.com) Received: from mail-ww0-f42.google.com (mail-ww0-f42.google.com [74.125.82.42]) by mx1.freebsd.org (Postfix) with ESMTP id 2D7E38FC25 for ; Thu, 1 Sep 2011 14:11:56 +0000 (UTC) Received: by wwe5 with SMTP id 5so1234971wwe.1 for ; Thu, 01 Sep 2011 07:11:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type :content-transfer-encoding; bh=9avCe1ovYV8z3XzSDWXE098ME9LFiGyjdes3Zw3DYSk=; b=BTR6LfHSKoDwy8S5YI/wurvZQSZyH9eoOybo8Jt9xNjZqDLsE9E5TwZyHJcpu019R5 69aCpn2vzQp6ELdP3GQAqVHgoROpEluH2Je6cMv8zRMarxlHcoVK1rtiLHFmcSDVd8g+ mOB6qtVKM0+fnapP7TZHfCr32twzsZ0jVpoBs= MIME-Version: 1.0 Received: by 10.227.3.2 with SMTP id 2mr1733744wbl.4.1314886315818; Thu, 01 Sep 2011 07:11:55 -0700 (PDT) Sender: asmrookie@gmail.com Received: by 10.227.206.139 with HTTP; Thu, 1 Sep 2011 07:11:55 -0700 (PDT) In-Reply-To: <1314818323.2610.6.camel@hitfishpass-lx.corp.yahoo.com> References: <201108291415.32605.jhb@freebsd.org> <1314818323.2610.6.camel@hitfishpass-lx.corp.yahoo.com> Date: Thu, 1 Sep 2011 16:11:55 +0200 X-Google-Sender-Auth: 2l1GKAvuU0kOMOgeOARF3QhuIf4 Message-ID: From: Attilio Rao To: Sean Bruno Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: "freebsd-hackers@freebsd.org" , Ivan Voras Subject: Re: Large machine test ideas X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 01 Sep 2011 14:11:57 -0000 2011/8/31 Sean Bruno : > On Tue, 2011-08-30 at 17:11 -0700, Ivan Voras wrote: >> On 29.8.2011. 20:15, John Baldwin wrote: >> >> > However, the SRAT code just ignores the table when it encounters an is= sue like >> > this, it doesn't hang. =C2=A0Something else later in the boot must hav= e hung. >> >> Anyway... that machine can in its maximal configuration be populated >> with eight 10-core CPUs, i.e. 80 physical / 160 logical, so here's a >> vote from me to bump the shiny new cpuset infrastructure maximum CPU >> count to 256 before 9.0. >> >> http://www.supermicro.com/products/system/5U/5086/SYS-5086B-TRF.cfm > > Doesn't that (MAXCPU) seriously impact VM usage, lock contention > etc ... ? > > I mean, if we have 2 cpus in a machine, but MAXCPU is set to 256, there > is a bunch of "lost" memory and higher levels of lock contention? > > I thought that attilio was taking a stab at enhancing this, but at the > current time anything more than a value of 64 for MAXCPU is kind of a > "caveat emptor" area of FreeBSD. With newest current you can redefine MAXCPU in your kernel config, so you don't need to bump the default value. I think 64 as default value is good enough. Removing MAXCPU dependency from the KBI is an important project someone should adopt and bring to conclusion. Thanks, Attilio --=20 Peace can only be achieved by understanding - A. Einstein