sched/numa: Fix NUMA_PULL_BIAS
Commit-ID: 5b1e7a5858fd9cbf5b2062d845db54b1750c6ca6 Gitweb: http://git.kernel.org/tip/5b1e7a5858fd9cbf5b2062d845db54b1750c6ca6 Author: Peter Zijlstra <[email protected]> AuthorDate: Fri, 5 Oct 2012 15:57:54 +0200 Committer: Ingo Molnar <[email protected]> CommitDate: Fri, 12 Oct 2012 12:07:17 +0200
sched/numa: Fix NUMA_PULL_BIAS
PULL_BIAS is broken, the intent was to only attempt a small bias when the machine was otherwise balanced, hence the out_balanced label.
The problem is that a number of branches that decide we're completely unbalanced also jump to the out_balanced label, causing undue numa bias. The end result was that an unbalanced system of 8:1 would try and move the 1 task towards the 8.
Signed-off-by Peter Zijlstra <[email protected]>
Signed-off-by Ingo Molnar <[email protected]>
--- kernel/sched/fair.c | 6 +++--- 1 files changed, 3 insertions(+), 3 deletions(-)
kernel/sched/fair.c +3 -3
@@ -4569,7 +4569,7 @@ find_busiest_group(struct lb_env *env, int *balance)/* There is no busy sibling group to pull tasks from */ if (!sds.busiest || sds.busiest_nr_running ==0 ) - goto out_balanced; + goto ret; sds.avg_load = (SCHED_POWER_SCALE * sds.total_load) / sds.total_pwr;
@@ -4591,14 +4591,14 @@ find_busiest_group(struct lb_env *env, int *balance)* don't try and pull any tasks. */ if (sds.this_load >= sds.max_load) - goto out_balanced; + goto ret;/* * Don't pull any tasks if this group is already above the domain * average load. */ if (sds.this_load >= sds.avg_load) - goto out_balanced; + goto ret;if (env->idle ==CPU_IDLE ) {/*