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 --- arch/x86/include/asm/topology.h | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'arch/x86/include') diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h index 4b1b335097b..7fafd1bc414 100644 --- a/arch/x86/include/asm/topology.h +++ b/arch/x86/include/asm/topology.h @@ -116,14 +116,12 @@ extern unsigned long node_remap_size[]; # define SD_CACHE_NICE_TRIES 1 # define SD_IDLE_IDX 1 -# define SD_NEWIDLE_IDX 2 # define SD_FORKEXEC_IDX 0 #else # define SD_CACHE_NICE_TRIES 2 # define SD_IDLE_IDX 2 -# define SD_NEWIDLE_IDX 2 # define SD_FORKEXEC_IDX 1 #endif @@ -137,7 +135,7 @@ extern unsigned long node_remap_size[]; .cache_nice_tries = SD_CACHE_NICE_TRIES, \ .busy_idx = 3, \ .idle_idx = SD_IDLE_IDX, \ - .newidle_idx = SD_NEWIDLE_IDX, \ + .newidle_idx = 0, \ .wake_idx = 0, \ .forkexec_idx = SD_FORKEXEC_IDX, \ \ -- cgit v1.2.3-18-g5258