Date: Wed, 6 Nov 2019 17:59:18 +0000 (UTC) From: Alexander Motin <mav@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-11@freebsd.org Subject: svn commit: r354404 - stable/11/sys/kern Message-ID: <201911061759.xA6HxISr085064@repo.freebsd.org>
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Author: mav Date: Wed Nov 6 17:59:18 2019 New Revision: 354404 URL: https://svnweb.freebsd.org/changeset/base/354404 Log: MFC r305368 (by markj): Micro-optimize sleepq_signal(). Lift a comparison out of the loop that finds the highest-priority thread on the queue. Modified: stable/11/sys/kern/subr_sleepqueue.c Directory Properties: stable/11/ (props changed) Modified: stable/11/sys/kern/subr_sleepqueue.c ============================================================================== --- stable/11/sys/kern/subr_sleepqueue.c Wed Nov 6 17:49:38 2019 (r354403) +++ stable/11/sys/kern/subr_sleepqueue.c Wed Nov 6 17:59:18 2019 (r354404) @@ -909,9 +909,9 @@ sleepq_signal(void *wchan, int flags, int pri, int que * been sleeping the longest since threads are always added to * the tail of sleep queues. */ - besttd = NULL; + besttd = TAILQ_FIRST(&sq->sq_blocked[queue]); TAILQ_FOREACH(td, &sq->sq_blocked[queue], td_slpq) { - if (besttd == NULL || td->td_priority < besttd->td_priority) + if (td->td_priority < besttd->td_priority) besttd = td; } MPASS(besttd != NULL);
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