From owner-svn-src-user@FreeBSD.ORG Tue May 26 14:59:07 2009 Return-Path: Delivered-To: svn-src-user@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 58305106566C; Tue, 26 May 2009 14:59:07 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from cyrus.watson.org (cyrus.watson.org [65.122.17.42]) by mx1.freebsd.org (Postfix) with ESMTP id 27E388FC0C; Tue, 26 May 2009 14:59:07 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from bigwig.baldwin.cx (66.111.2.69.static.nyinternet.net [66.111.2.69]) by cyrus.watson.org (Postfix) with ESMTPSA id CD16B46B91; Tue, 26 May 2009 10:59:06 -0400 (EDT) Received: from jhbbsd.hudson-trading.com (unknown [209.249.190.8]) by bigwig.baldwin.cx (Postfix) with ESMTPA id AAA968A029; Tue, 26 May 2009 10:59:05 -0400 (EDT) From: John Baldwin To: Kip Macy Date: Tue, 26 May 2009 08:30:36 -0400 User-Agent: KMail/1.9.7 References: <200905222145.n4MLjhm3019802@svn.freebsd.org> In-Reply-To: <200905222145.n4MLjhm3019802@svn.freebsd.org> MIME-Version: 1.0 Content-Disposition: inline Message-Id: <200905260830.36831.jhb@freebsd.org> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.0.1 (bigwig.baldwin.cx); Tue, 26 May 2009 10:59:05 -0400 (EDT) X-Virus-Scanned: clamav-milter 0.95 at bigwig.baldwin.cx X-Virus-Status: Clean X-Spam-Status: No, score=-2.5 required=4.2 tests=AWL,BAYES_00,RDNS_NONE autolearn=no version=3.2.5 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on bigwig.baldwin.cx Cc: src-committers@freebsd.org, svn-src-user@freebsd.org Subject: Re: svn commit: r192604 - in user/kmacy/releng_7_2_fcs/sys: dev/hwpmc sys X-BeenThere: svn-src-user@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "SVN commit messages for the experimental " user" src tree" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 26 May 2009 14:59:07 -0000 On Friday 22 May 2009 5:45:43 pm Kip Macy wrote: > Author: kmacy > Date: Fri May 22 21:45:43 2009 > New Revision: 192604 > URL: http://svn.freebsd.org/changeset/base/192604 > > Log: > - remove pmc_kthread_mtx > - replace sleep/wakeup on kthread with a condvar If you do not sleep on the kthread/kproc when waiting for a kthread to exit, then you open up a race window. Usually this matters more for any kthreads that live in a module since the race allows the module to be unmapped before the thread is finished executing code from the module resulting in a fatal page fault in the kernel. -- John Baldwin