From owner-cvs-all Fri Jul 12 14:12:50 2002 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 81E1137B400; Fri, 12 Jul 2002 14:12:46 -0700 (PDT) Received: from cs.rice.edu (cs.rice.edu [128.42.1.30]) by mx1.FreeBSD.org (Postfix) with ESMTP id 0580D43E3B; Fri, 12 Jul 2002 13:55:32 -0700 (PDT) (envelope-from alc@cs.rice.edu) Received: from localhost (localhost [127.0.0.1]) by cs.rice.edu (Postfix) with ESMTP id 45ACE4AA13; Fri, 12 Jul 2002 15:55:17 -0500 (CDT) Received: by cs.rice.edu (Postfix, from userid 19572) id 1C5BD4AA4B; Fri, 12 Jul 2002 15:55:16 -0500 (CDT) Date: Fri, 12 Jul 2002 15:55:16 -0500 From: Alan Cox To: Matt Dillon Cc: cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/kern kern_synch.c src/sys/sys proc.h src/sys/vm vm_zeroidle.c src/sys/i386/i386 genassym.c pmap.c Message-ID: <20020712205516.GD5265@cs.rice.edu> References: <200207122017.g6CKH7fx096339@freefall.freebsd.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200207122017.g6CKH7fx096339@freefall.freebsd.org> User-Agent: Mutt/1.3.28i X-Virus-Scanned: by AMaViS snapshot-20010714 Sender: owner-cvs-all@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Fri, Jul 12, 2002 at 01:17:07PM -0700, Matt Dillon wrote: > dillon 2002/07/12 13:17:07 PDT > > Modified files: > sys/kern kern_synch.c > sys/sys proc.h > sys/vm vm_zeroidle.c > sys/i386/i386 genassym.c pmap.c > Log: > Re-enable the idle page-zeroing code. Remove all IPIs from the idle > page-zeroing code as well as from the general page-zeroing code and use a > lazy tlb page invalidation scheme based on a callback made at the end > of mi_switch. > I think we should try to take this a step further. Specifically, we should recognize when processors are running in user mode in order to avoid IPIs on kernel pmap changes. On reentry to the kernel, the processor would then do whatever is necessary to resync. If too many kernel pmap changes accumulate, then you force a single IPI that performs the changes in bulk. As a start, it would be interesting to know how many IPIs could be avoided by such a scheme. Alan To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message