From 0ec9fab3d186d9cbb00c0f694d4a260d07c198d9 Mon Sep 17 00:00:00 2001 From: Mike Galbraith Date: Tue, 15 Sep 2009 15:07:03 +0200 Subject: sched: Improve latencies and throughput Make the idle balancer more agressive, to improve a x264 encoding workload provided by Jason Garrett-Glaser: NEXT_BUDDY NO_LB_BIAS encoded 600 frames, 252.82 fps, 22096.60 kb/s encoded 600 frames, 250.69 fps, 22096.60 kb/s encoded 600 frames, 245.76 fps, 22096.60 kb/s NO_NEXT_BUDDY LB_BIAS encoded 600 frames, 344.44 fps, 22096.60 kb/s encoded 600 frames, 346.66 fps, 22096.60 kb/s encoded 600 frames, 352.59 fps, 22096.60 kb/s NO_NEXT_BUDDY NO_LB_BIAS encoded 600 frames, 425.75 fps, 22096.60 kb/s encoded 600 frames, 425.45 fps, 22096.60 kb/s encoded 600 frames, 422.49 fps, 22096.60 kb/s Peter pointed out that this is better done via newidle_idx, not via LB_BIAS, newidle balancing should look for where there is load _now_, not where there was load 2 ticks ago. Worst-case latencies are improved as well as no buddies means less vruntime spread. (as per prior lkml discussions) This change improves kbuild-peak parallelism as well. Reported-by: Jason Garrett-Glaser Signed-off-by: Mike Galbraith Signed-off-by: Peter Zijlstra LKML-Reference: <1253011667.9128.16.camel@marge.simson.net> Signed-off-by: Ingo Molnar --- include/linux/topology.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/topology.h') diff --git a/include/linux/topology.h b/include/linux/topology.h index c87edcd87967..4298745615a5 100644 --- a/include/linux/topology.h +++ b/include/linux/topology.h @@ -151,7 +151,7 @@ int arch_update_cpu_topology(void); .cache_nice_tries = 1, \ .busy_idx = 2, \ .idle_idx = 1, \ - .newidle_idx = 2, \ + .newidle_idx = 0, \ .wake_idx = 0, \ .forkexec_idx = 1, \ \ -- cgit v1.2.1