From owner-svn-src-all@freebsd.org Wed May 18 03:50:22 2016 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 4D794B3F753; Wed, 18 May 2016 03:50:22 +0000 (UTC) (envelope-from markj@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 mx1.freebsd.org (Postfix) with ESMTPS id 1B2171ECF; Wed, 18 May 2016 03:50:22 +0000 (UTC) (envelope-from markj@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id u4I3oLWI010005; Wed, 18 May 2016 03:50:21 GMT (envelope-from markj@FreeBSD.org) Received: (from markj@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id u4I3oLTI010004; Wed, 18 May 2016 03:50:21 GMT (envelope-from markj@FreeBSD.org) Message-Id: <201605180350.u4I3oLTI010004@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: markj set sender to markj@FreeBSD.org using -f From: Mark Johnston Date: Wed, 18 May 2016 03:50:21 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r300109 - head/sys/kern X-SVN-Group: head 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: 2.1.22 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: Wed, 18 May 2016 03:50:22 -0000 Author: markj Date: Wed May 18 03:50:21 2016 New Revision: 300109 URL: https://svnweb.freebsd.org/changeset/base/300109 Log: Micro-optimize sleepq_broadcast(). - Avoid a conditional branch on the return value of sleepq_resume_thread() by ORing its return value into the boolean wakeup_swapper. This is consistent with other sleepqueue functions which just pass this return value to their caller. - sleepq_resume_thread() unconditionally removes the thread from its queue, so there's no need to maintain a pointer to the next element in the queue. MFC after: 2 weeks Modified: head/sys/kern/subr_sleepqueue.c Modified: head/sys/kern/subr_sleepqueue.c ============================================================================== --- head/sys/kern/subr_sleepqueue.c Wed May 18 03:50:18 2016 (r300108) +++ head/sys/kern/subr_sleepqueue.c Wed May 18 03:50:21 2016 (r300109) @@ -865,7 +865,7 @@ int sleepq_broadcast(void *wchan, int flags, int pri, int queue) { struct sleepqueue *sq; - struct thread *td, *tdn; + struct thread *td; int wakeup_swapper; CTR2(KTR_PROC, "sleepq_broadcast(%p, %d)", wchan, flags); @@ -879,10 +879,9 @@ sleepq_broadcast(void *wchan, int flags, /* Resume all blocked threads on the sleep queue. */ wakeup_swapper = 0; - TAILQ_FOREACH_SAFE(td, &sq->sq_blocked[queue], td_slpq, tdn) { + while ((td = TAILQ_FIRST(&sq->sq_blocked[queue])) != NULL) { thread_lock(td); - if (sleepq_resume_thread(sq, td, pri)) - wakeup_swapper = 1; + wakeup_swapper |= sleepq_resume_thread(sq, td, pri); thread_unlock(td); } return (wakeup_swapper);