From: Mike Galbraith Date: Tue, 15 Sep 2009 13:07:03 +0000 (+0200) Subject: sched: Improve latencies and throughput X-Git-Tag: v2.6.32-rc1~652^2~22 X-Git-Url: http://ftp.safe.ca/?p=safe%2Fjmp%2Flinux-2.6;a=commitdiff_plain;h=0ec9fab3d186d9cbb00c0f694d4a260d07c198d9 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 --- diff --git a/arch/ia64/include/asm/topology.h b/arch/ia64/include/asm/topology.h index 47f3c51..42f1673 100644 --- a/arch/ia64/include/asm/topology.h +++ b/arch/ia64/include/asm/topology.h @@ -61,7 +61,7 @@ void build_cpu_to_node_map(void); .cache_nice_tries = 2, \ .busy_idx = 2, \ .idle_idx = 1, \ - .newidle_idx = 2, \ + .newidle_idx = 0, \ .wake_idx = 0, \ .forkexec_idx = 1, \ .flags = SD_LOAD_BALANCE \ @@ -87,10 +87,11 @@ void build_cpu_to_node_map(void); .cache_nice_tries = 2, \ .busy_idx = 3, \ .idle_idx = 2, \ - .newidle_idx = 2, \ + .newidle_idx = 0, \ .wake_idx = 0, \ .forkexec_idx = 1, \ .flags = SD_LOAD_BALANCE \ + | SD_BALANCE_NEWIDLE \ | SD_BALANCE_EXEC \ | SD_BALANCE_FORK \ | SD_BALANCE_WAKE \ diff --git a/arch/powerpc/include/asm/topology.h b/arch/powerpc/include/asm/topology.h index a6b220a..1a2c9eb 100644 --- a/arch/powerpc/include/asm/topology.h +++ b/arch/powerpc/include/asm/topology.h @@ -57,7 +57,7 @@ static inline int pcibus_to_node(struct pci_bus *bus) .cache_nice_tries = 1, \ .busy_idx = 3, \ .idle_idx = 1, \ - .newidle_idx = 2, \ + .newidle_idx = 0, \ .wake_idx = 0, \ .flags = SD_LOAD_BALANCE \ | SD_BALANCE_EXEC \ diff --git a/arch/sh/include/asm/topology.h b/arch/sh/include/asm/topology.h index 9054e5c..c843677 100644 --- a/arch/sh/include/asm/topology.h +++ b/arch/sh/include/asm/topology.h @@ -15,13 +15,14 @@ .cache_nice_tries = 2, \ .busy_idx = 3, \ .idle_idx = 2, \ - .newidle_idx = 2, \ + .newidle_idx = 0, \ .wake_idx = 0, \ .forkexec_idx = 1, \ .flags = SD_LOAD_BALANCE \ | SD_BALANCE_FORK \ | SD_BALANCE_EXEC \ | SD_BALANCE_WAKE \ + | SD_BALANCE_NEWIDLE \ | SD_SERIALIZE, \ .last_balance = jiffies, \ .balance_interval = 1, \ diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h index 4b1b335..7fafd1b 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, \ \ diff --git a/include/linux/topology.h b/include/linux/topology.h index c87edcd..4298745 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, \ \ diff --git a/kernel/sched_features.h b/kernel/sched_features.h index 891ea0f..e98c2e8 100644 --- a/kernel/sched_features.h +++ b/kernel/sched_features.h @@ -67,7 +67,7 @@ SCHED_FEAT(AFFINE_WAKEUPS, 1) * wakeup-preemption), since its likely going to consume data we * touched, increases cache locality. */ -SCHED_FEAT(NEXT_BUDDY, 1) +SCHED_FEAT(NEXT_BUDDY, 0) /* * Prefer to schedule the task that ran last (when we did