From b5d978e0c7e79a7ff842e895c85a86b38c71f1cd Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 1 Sep 2009 10:34:33 +0200 Subject: [PATCH] sched: Add SD_PREFER_SIBLING Do the placement thing using SD flags. Signed-off-by: Peter Zijlstra Tested-by: Andreas Herrmann Acked-by: Andreas Herrmann Acked-by: Gautham R Shenoy Cc: Balbir Singh LKML-Reference: <20090901083825.897028974@chello.nl> Signed-off-by: Ingo Molnar --- include/linux/sched.h | 29 +++++++++++++++-------------- kernel/sched.c | 14 +++++++++++++- 2 files changed, 28 insertions(+), 15 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 9c96ef2..651dded 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -798,18 +798,19 @@ enum cpu_idle_type { #define SCHED_LOAD_SCALE_FUZZ SCHED_LOAD_SCALE #ifdef CONFIG_SMP -#define SD_LOAD_BALANCE 1 /* Do load balancing on this domain. */ -#define SD_BALANCE_NEWIDLE 2 /* Balance when about to become idle */ -#define SD_BALANCE_EXEC 4 /* Balance on exec */ -#define SD_BALANCE_FORK 8 /* Balance on fork, clone */ -#define SD_WAKE_IDLE 16 /* Wake to idle CPU on task wakeup */ -#define SD_WAKE_AFFINE 32 /* Wake task to waking CPU */ -#define SD_WAKE_BALANCE 64 /* Perform balancing at task wakeup */ -#define SD_SHARE_CPUPOWER 128 /* Domain members share cpu power */ -#define SD_POWERSAVINGS_BALANCE 256 /* Balance for power savings */ -#define SD_SHARE_PKG_RESOURCES 512 /* Domain members share cpu pkg resources */ -#define SD_SERIALIZE 1024 /* Only a single load balancing instance */ -#define SD_WAKE_IDLE_FAR 2048 /* Gain latency sacrificing cache hit */ +#define SD_LOAD_BALANCE 0x0001 /* Do load balancing on this domain. */ +#define SD_BALANCE_NEWIDLE 0x0002 /* Balance when about to become idle */ +#define SD_BALANCE_EXEC 0x0004 /* Balance on exec */ +#define SD_BALANCE_FORK 0x0008 /* Balance on fork, clone */ +#define SD_WAKE_IDLE 0x0010 /* Wake to idle CPU on task wakeup */ +#define SD_WAKE_AFFINE 0x0020 /* Wake task to waking CPU */ +#define SD_WAKE_BALANCE 0x0040 /* Perform balancing at task wakeup */ +#define SD_SHARE_CPUPOWER 0x0080 /* Domain members share cpu power */ +#define SD_POWERSAVINGS_BALANCE 0x0100 /* Balance for power savings */ +#define SD_SHARE_PKG_RESOURCES 0x0200 /* Domain members share cpu pkg resources */ +#define SD_SERIALIZE 0x0400 /* Only a single load balancing instance */ +#define SD_WAKE_IDLE_FAR 0x0800 /* Gain latency sacrificing cache hit */ +#define SD_PREFER_SIBLING 0x1000 /* Prefer to place tasks in a sibling domain */ enum powersavings_balance_level { POWERSAVINGS_BALANCE_NONE = 0, /* No power saving load balance */ @@ -829,7 +830,7 @@ static inline int sd_balance_for_mc_power(void) if (sched_smt_power_savings) return SD_POWERSAVINGS_BALANCE; - return 0; + return SD_PREFER_SIBLING; } static inline int sd_balance_for_package_power(void) @@ -837,7 +838,7 @@ static inline int sd_balance_for_package_power(void) if (sched_mc_power_savings | sched_smt_power_savings) return SD_POWERSAVINGS_BALANCE; - return 0; + return SD_PREFER_SIBLING; } /* diff --git a/kernel/sched.c b/kernel/sched.c index 584a122..9d64cec 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -3811,9 +3811,13 @@ static inline void update_sd_lb_stats(struct sched_domain *sd, int this_cpu, const struct cpumask *cpus, int *balance, struct sd_lb_stats *sds) { + struct sched_domain *child = sd->child; struct sched_group *group = sd->groups; struct sg_lb_stats sgs; - int load_idx; + int load_idx, prefer_sibling = 0; + + if (child && child->flags & SD_PREFER_SIBLING) + prefer_sibling = 1; init_sd_power_savings_stats(sd, sds, idle); load_idx = get_sd_load_idx(sd, idle); @@ -3833,6 +3837,14 @@ static inline void update_sd_lb_stats(struct sched_domain *sd, int this_cpu, sds->total_load += sgs.group_load; sds->total_pwr += group->__cpu_power; + /* + * In case the child domain prefers tasks go to siblings + * first, lower the group capacity to one so that we'll try + * and move all the excess tasks away. + */ + if (prefer_sibling) + sgs.group_capacity = 1; + if (local_group) { sds->this_load = sgs.avg_load; sds->this = group; -- 2.7.4