From owner-cvs-all@FreeBSD.ORG Thu Jun 9 16:39:32 2005 Return-Path: X-Original-To: cvs-all@FreeBSD.org 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 450B316A41C; Thu, 9 Jun 2005 16:39:32 +0000 (GMT) (envelope-from jroberson@chesapeake.net) Received: from mail.chesapeake.net (chesapeake.net [208.142.252.6]) by mx1.FreeBSD.org (Postfix) with ESMTP id 8E7F843D49; Thu, 9 Jun 2005 16:39:29 +0000 (GMT) (envelope-from jroberson@chesapeake.net) Received: from mail.chesapeake.net (localhost [127.0.0.1]) by mail.chesapeake.net (8.12.10/8.12.10) with ESMTP id j59GdSk9026348; Thu, 9 Jun 2005 12:39:28 -0400 (EDT) (envelope-from jroberson@chesapeake.net) Received: from localhost (jroberson@localhost) by mail.chesapeake.net (8.12.10/8.12.10/Submit) with ESMTP id j59GdS8U026343; Thu, 9 Jun 2005 12:39:28 -0400 (EDT) (envelope-from jroberson@chesapeake.net) X-Authentication-Warning: mail.chesapeake.net: jroberson owned process doing -bs Date: Thu, 9 Jun 2005 12:39:27 -0400 (EDT) From: Jeff Roberson To: Alfred Perlstein In-Reply-To: <20050609135438.GS17867@elvis.mu.org> Message-ID: <20050609123920.T16943@mail.chesapeake.net> References: <200506082026.j58KQ6cT052316@repoman.freebsd.org> <20050609135438.GS17867@elvis.mu.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: cvs-src@FreeBSD.org, Jeff Roberson , src-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/kern vfs_bio.c X-BeenThere: cvs-all@freebsd.org X-Mailman-Version: 2.1.5 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, 09 Jun 2005 16:39:32 -0000 On Thu, 9 Jun 2005, Alfred Perlstein wrote: > MFC? :D Yes, after a few weeks. > > * Jeff Roberson [050608 13:26] wrote: > > jeff 2005-06-08 20:26:06 UTC > > > > FreeBSD src repository > > > > Modified files: > > sys/kern vfs_bio.c > > Log: > > - Under heavy IO load the buf daemon can run for many hundereds of > > milliseconds due to what is essentially n^2 algorithmic complexity. This > > change makes the algorithm N*2 instead. This heavy processing manifested > > itself as skipping in audio and video playback due to the long scheduling > > latencies and contention on giant by pcm. > > - flushbufqueues() is now responsible for flushing multiple buffers > > rather than one at a time. This allows us to save our progress in the > > list by using a sentinal. We must do the numdirtywakeup() and > > waitrunningbufspace() here now rather than in buf_daemon(). > > - Also add a uio_yield() after we have processed the list once for bufs > > without deps and again for bufs with deps. This is to release Giant > > and allow any other giant locked code to proceed. > > > > Tested by: Many users on current@ > > Revealed by: schedgraph traces sent by Emil Mikulic & Anthony Ginepro > > > > Revision Changes Path > > 1.487 +28 -6 src/sys/kern/vfs_bio.c > > -- > - Alfred Perlstein > - email: bright@mu.org cell: 408-480-4684 >