From owner-cvs-all@FreeBSD.ORG Wed Apr 2 17:16:26 2003 Return-Path: Delivered-To: cvs-all@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 098BD37B407 for ; Wed, 2 Apr 2003 17:16:26 -0800 (PST) Received: from rootlabs.com (root.org [67.118.192.226]) by mx1.FreeBSD.org (Postfix) with SMTP id D1A8443FA3 for ; Wed, 2 Apr 2003 17:16:23 -0800 (PST) (envelope-from nate@rootlabs.com) Received: (qmail 12803 invoked by uid 1000); 3 Apr 2003 01:16:25 -0000 Date: Wed, 2 Apr 2003 17:16:25 -0800 (PST) From: Nate Lawson To: Peter Wemm In-Reply-To: <20030402235345.90F4737B418@hub.freebsd.org> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII cc: cvs-src@FreeBSD.org cc: src-committers@FreeBSD.org cc: cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/conf options.i386 src/sys/i386/i386machdep.c mp_machdep.c pmap.c swtch.s src/sys/i386/include md_var.h pmap.h smp.h src/sys/i386/isa apic_vector.s intr_machdep.h src/sys/kern kern_switch.c kern_synch.c kern_thr.c kern_thread.c subr_witness.c ... X-BeenThere: cvs-all@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: CVS commit messages for the entire tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 03 Apr 2003 01:16:26 -0000 On Wed, 2 Apr 2003, Peter Wemm wrote: > Commit a partial lazy thread switch mechanism for i386. it isn't as lazy > as it could be and can do with some more cleanup. Currently its under > options LAZY_SWITCH. What this does is avoid %cr3 reloads for short > context switches that do not involve another user process. This is awesome! > One non-trivial change was to select a new thread before calling > cpu_switch() in the first place. This allows us to catch the silly > case of doing a cpu_switch() to the current process. This happens > uncomfortably often. This simplifies a bit of the asm code in cpu_switch > (no longer have to call choosethread() in the middle). This has been > implemented on i386 and (thanks to jake) sparc64. The others will come > soon. This is actually seperate to the lazy switch stuff. Shouldn't there be a "if (thread == curthread) return;" in the scheduling code somewhere? -Nate