From owner-freebsd-current@FreeBSD.ORG Mon Oct 9 00:22:15 2006 Return-Path: X-Original-To: freebsd-current@freebsd.org Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 610EF16A403; Mon, 9 Oct 2006 00:22:15 +0000 (UTC) (envelope-from jmg@hydrogen.funkthat.com) Received: from hydrogen.funkthat.com (gate.funkthat.com [69.17.45.168]) by mx1.FreeBSD.org (Postfix) with ESMTP id 0AABE43D45; Mon, 9 Oct 2006 00:22:13 +0000 (GMT) (envelope-from jmg@hydrogen.funkthat.com) Received: from hydrogen.funkthat.com (lxh0c4y7tvqj3v4s@localhost.funkthat.com [127.0.0.1]) by hydrogen.funkthat.com (8.13.6/8.13.3) with ESMTP id k990M47n076973; Sun, 8 Oct 2006 17:22:04 -0700 (PDT) (envelope-from jmg@hydrogen.funkthat.com) Received: (from jmg@localhost) by hydrogen.funkthat.com (8.13.6/8.13.3/Submit) id k990M1SE076972; Sun, 8 Oct 2006 17:22:01 -0700 (PDT) (envelope-from jmg) Date: Sun, 8 Oct 2006 17:22:00 -0700 From: John-Mark Gurney To: Kip Macy Message-ID: <20061009002200.GM793@funkthat.com> Mail-Followup-To: Kip Macy , Attilio Rao , David Xu , freebsd-current@freebsd.org, Ivan Voras References: <2fd864e0610080423q7ba6bdeal656a223e662a5d@mail.gmail.com> <20061008135031.G83537@demos.bsdclusters.com> <4529667D.8070108@fer.hr> <200610090634.31297.davidxu@freebsd.org> <20061008225150.GK793@funkthat.com> <3bbf2fe10610081555r67265368sf7f12edbf35bff0d@mail.gmail.com> <20061008155817.G29803@demos.bsdclusters.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20061008155817.G29803@demos.bsdclusters.com> User-Agent: Mutt/1.4.2.1i X-Operating-System: FreeBSD 5.4-RELEASE-p6 i386 X-PGP-Fingerprint: B7 EC EF F8 AE ED A7 31 96 7A 22 B3 D8 56 36 F4 X-Files: The truth is out there X-URL: http://resnet.uoregon.edu/~gurney_j/ X-Resume: http://resnet.uoregon.edu/~gurney_j/resume.html Cc: Attilio Rao , freebsd-current@freebsd.org, David Xu , Ivan Voras Subject: Re: [PATCH] MAXCPU alterable in kernel config - needs testers X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: John-Mark Gurney List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 09 Oct 2006 00:22:15 -0000 Kip Macy wrote this message on Sun, Oct 08, 2006 at 15:59 -0700: > > > > How would you see a sched_lock decomposition (and, if it is possible, > > how many locks it could be decomposed in?) > > Rather than having a per thread lock, Solaris uses the lock for the > current container that a thread is associated with (cpu, run queue, Wouldn't having a single run queue lock still serialize the cpu's when getting a thread to run? Don't we really need a per cpu run queue, and then have a scheduler that puts threads on the cpu's run queues? we probably should move some of the stats (LA) to pcpu data structure and desolving sched_lock from thread priority updates... This would mean sched_lock would need to be aquired less often, closer to quantum (which is ~100ms now) instead of each hz... There is probably work to be done to push the locks down around thread, proc and kse/ksg... It looks like a lot of the work done each HZ could be a lot more local than it currently is... It's probably not so much scheduling over head that is killing sun4v but the stats gathering.. Though I have very little knowlege about how scheduling works, so I am probably incorrect.. -- John-Mark Gurney Voice: +1 415 225 5579 "All that I will do, has been done, All that I have, has not."