From owner-svn-src-all@freebsd.org Sun May 20 19:35:25 2018 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 33040EED82B; Sun, 20 May 2018 19:35:25 +0000 (UTC) (envelope-from mmacy@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id CB9CC6D469; Sun, 20 May 2018 19:35:24 +0000 (UTC) (envelope-from mmacy@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id A74301AA85; Sun, 20 May 2018 19:35:24 +0000 (UTC) (envelope-from mmacy@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id w4KJZOQF026413; Sun, 20 May 2018 19:35:24 GMT (envelope-from mmacy@FreeBSD.org) Received: (from mmacy@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id w4KJZONj026412; Sun, 20 May 2018 19:35:24 GMT (envelope-from mmacy@FreeBSD.org) Message-Id: <201805201935.w4KJZONj026412@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: mmacy set sender to mmacy@FreeBSD.org using -f From: Matt Macy Date: Sun, 20 May 2018 19:35:24 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r333935 - head/sys/dev/hwpmc X-SVN-Group: head X-SVN-Commit-Author: mmacy X-SVN-Commit-Paths: head/sys/dev/hwpmc X-SVN-Commit-Revision: 333935 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 20 May 2018 19:35:25 -0000 Author: mmacy Date: Sun May 20 19:35:24 2018 New Revision: 333935 URL: https://svnweb.freebsd.org/changeset/base/333935 Log: pmc: avoid potential race on shutdown Clear shutdown flag first, conservatively allow 5ms for all hardclock consumers to see flag before drainining Modified: head/sys/dev/hwpmc/hwpmc_logging.c Modified: head/sys/dev/hwpmc/hwpmc_logging.c ============================================================================== --- head/sys/dev/hwpmc/hwpmc_logging.c Sun May 20 18:26:09 2018 (r333934) +++ head/sys/dev/hwpmc/hwpmc_logging.c Sun May 20 19:35:24 2018 (r333935) @@ -872,18 +872,20 @@ pmclog_close(struct pmc_owner *po) pmclog_process_closelog(po); mtx_lock(&pmc_kthread_mtx); - /* + * Initiate shutdown: no new data queued, + * thread will close file on last block. + */ + po->po_flags |= PMC_PO_SHUTDOWN; + /* give time for all to see */ + DELAY(50); + + /* * Schedule the current buffer. */ pmclog_schedule_all(po); wakeup_one(po); - /* - * Initiate shutdown: no new data queued, - * thread will close file on last block. - */ - po->po_flags |= PMC_PO_SHUTDOWN; mtx_unlock(&pmc_kthread_mtx); return (0);