From 2bba22c50b06abe9fd0d23933b1e64d35b419262 Mon Sep 17 00:00:00 2001 From: Mike Galbraith Date: Wed, 9 Sep 2009 15:41:37 +0200 Subject: sched: Turn off child_runs_first Set child_runs_first default to off. It hurts 'optimal' make -j workloads as make jobs get preempted by child tasks, reducing parallelism. Note, this patch might make existing races in user applications more prominent than before - so breakages might be bisected to this commit. Child-runs-first is broken on SMP to begin with, and we already had it off briefly in v2.6.23 so most of the offenders ought to be fixed. Would be nice not to revert this commit but fix those apps finally ... Signed-off-by: Mike Galbraith Acked-by: Peter Zijlstra LKML-Reference: <1252486344.28645.18.camel@marge.simson.net> [ made the sysctl independent of CONFIG_SCHED_DEBUG, in case people want to work around broken apps. ] Signed-off-by: Ingo Molnar --- kernel/sysctl.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) (limited to 'kernel/sysctl.c') diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 6c9836ef4b4..25d6bf3383b 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -246,6 +246,14 @@ static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */ #endif static struct ctl_table kern_table[] = { + { + .ctl_name = CTL_UNNUMBERED, + .procname = "sched_child_runs_first", + .data = &sysctl_sched_child_runs_first, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = &proc_dointvec, + }, #ifdef CONFIG_SCHED_DEBUG { .ctl_name = CTL_UNNUMBERED, @@ -298,14 +306,6 @@ static struct ctl_table kern_table[] = { .strategy = &sysctl_intvec, .extra1 = &zero, }, - { - .ctl_name = CTL_UNNUMBERED, - .procname = "sched_child_runs_first", - .data = &sysctl_sched_child_runs_first, - .maxlen = sizeof(unsigned int), - .mode = 0644, - .proc_handler = &proc_dointvec, - }, { .ctl_name = CTL_UNNUMBERED, .procname = "sched_features", -- cgit v1.2.3