Date: Fri, 9 Mar 2012 19:09:09 +0000 (UTC) From: Alexander Motin <mav@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r232740 - head/sys/kern Message-ID: <201203091909.q29J99jZ020917@svn.freebsd.org>
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Author: mav Date: Fri Mar 9 19:09:08 2012 New Revision: 232740 URL: http://svn.freebsd.org/changeset/base/232740 Log: Make kern.sched.idlespinthresh default value adaptive depending of HZ. Otherwise with HZ above 8000 CPU may never skip timer ticks on idle. Modified: head/sys/kern/sched_ule.c Modified: head/sys/kern/sched_ule.c ============================================================================== --- head/sys/kern/sched_ule.c Fri Mar 9 18:50:49 2012 (r232739) +++ head/sys/kern/sched_ule.c Fri Mar 9 19:09:08 2012 (r232740) @@ -212,7 +212,7 @@ static int preempt_thresh = 0; #endif static int static_boost = PRI_MIN_BATCH; static int sched_idlespins = 10000; -static int sched_idlespinthresh = 16; +static int sched_idlespinthresh = -1; /* * tdq - per processor runqs and statistics. All fields are protected by the @@ -1390,6 +1390,8 @@ sched_initticks(void *dummy) steal_thresh = min(fls(mp_ncpus) - 1, 3); affinity = SCHED_AFFINITY_DEFAULT; #endif + if (sched_idlespinthresh < 0) + sched_idlespinthresh = max(16, 2 * hz / realstathz); }
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