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 --- include/linux/sched.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/sched.h b/include/linux/sched.h index 3b7f43e3b736..3a50e8222498 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1820,8 +1820,8 @@ extern unsigned int sysctl_sched_min_granularity; extern unsigned int sysctl_sched_wakeup_granularity; extern unsigned int sysctl_sched_shares_ratelimit; extern unsigned int sysctl_sched_shares_thresh; -#ifdef CONFIG_SCHED_DEBUG extern unsigned int sysctl_sched_child_runs_first; +#ifdef CONFIG_SCHED_DEBUG extern unsigned int sysctl_sched_features; extern unsigned int sysctl_sched_migration_cost; extern unsigned int sysctl_sched_nr_migrate; -- cgit v1.2.3