From: Swapnil Sapkal Date: Fri, 20 Dec 2024 06:32:21 +0000 (+0000) Subject: sched: Report the different kinds of imbalances in /proc/schedstat X-Git-Tag: block-6.14-20240131~50^2~19 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=3b2a793ea70fd14136b442df31e53935e8095034;p=linux-block.git sched: Report the different kinds of imbalances in /proc/schedstat In /proc/schedstat, lb_imbalance reports the sum of imbalances discovered in sched domains with each call to sched_balance_rq(), which is not very useful because lb_imbalance does not mention whether the imbalance is due to load, utilization, nr_tasks or misfit_tasks. Remove this field from /proc/schedstat. Currently there is no field in /proc/schedstat to report different types of imbalances. Introduce new fields in /proc/schedstat to report the total imbalances in load, utilization, nr_tasks or misfit_tasks. Added fields to /proc/schedstat: - lb_imbalance_load: Total imbalance due to load. - lb_imbalance_util: Total imbalance due to utilization. - lb_imbalance_task: Total imbalance due to number of tasks. - lb_imbalance_misfit: Total imbalance due to misfit tasks. Signed-off-by: Swapnil Sapkal Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Shrikanth Hegde Link: https://lore.kernel.org/r/20241220063224.17767-4-swapnil.sapkal@amd.com --- diff --git a/include/linux/sched/topology.h b/include/linux/sched/topology.h index 4237daa5ac7a..76a662e1ec24 100644 --- a/include/linux/sched/topology.h +++ b/include/linux/sched/topology.h @@ -114,7 +114,10 @@ struct sched_domain { unsigned int lb_count[CPU_MAX_IDLE_TYPES]; unsigned int lb_failed[CPU_MAX_IDLE_TYPES]; unsigned int lb_balanced[CPU_MAX_IDLE_TYPES]; - unsigned int lb_imbalance[CPU_MAX_IDLE_TYPES]; + unsigned int lb_imbalance_load[CPU_MAX_IDLE_TYPES]; + unsigned int lb_imbalance_util[CPU_MAX_IDLE_TYPES]; + unsigned int lb_imbalance_task[CPU_MAX_IDLE_TYPES]; + unsigned int lb_imbalance_misfit[CPU_MAX_IDLE_TYPES]; unsigned int lb_gained[CPU_MAX_IDLE_TYPES]; unsigned int lb_hot_gained[CPU_MAX_IDLE_TYPES]; unsigned int lb_nobusyg[CPU_MAX_IDLE_TYPES]; diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index e5c0c61909b7..b3418b5d484f 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -11705,6 +11705,28 @@ static int should_we_balance(struct lb_env *env) return group_balance_cpu(sg) == env->dst_cpu; } +static void update_lb_imbalance_stat(struct lb_env *env, struct sched_domain *sd, + enum cpu_idle_type idle) +{ + if (!schedstat_enabled()) + return; + + switch (env->migration_type) { + case migrate_load: + __schedstat_add(sd->lb_imbalance_load[idle], env->imbalance); + break; + case migrate_util: + __schedstat_add(sd->lb_imbalance_util[idle], env->imbalance); + break; + case migrate_task: + __schedstat_add(sd->lb_imbalance_task[idle], env->imbalance); + break; + case migrate_misfit: + __schedstat_add(sd->lb_imbalance_misfit[idle], env->imbalance); + break; + } +} + /* * Check this_cpu to ensure it is balanced within domain. Attempt to move * tasks if there is an imbalance. @@ -11755,7 +11777,7 @@ redo: WARN_ON_ONCE(busiest == env.dst_rq); - schedstat_add(sd->lb_imbalance[idle], env.imbalance); + update_lb_imbalance_stat(&env, sd, idle); env.src_cpu = busiest->cpu; env.src_rq = busiest; diff --git a/kernel/sched/stats.c b/kernel/sched/stats.c index eb0cdcd4d921..802bd9398a2e 100644 --- a/kernel/sched/stats.c +++ b/kernel/sched/stats.c @@ -141,11 +141,14 @@ static int show_schedstat(struct seq_file *seq, void *v) seq_printf(seq, "domain%d %*pb", dcount++, cpumask_pr_args(sched_domain_span(sd))); for (itype = 0; itype < CPU_MAX_IDLE_TYPES; itype++) { - seq_printf(seq, " %u %u %u %u %u %u %u %u", + seq_printf(seq, " %u %u %u %u %u %u %u %u %u %u %u", sd->lb_count[itype], sd->lb_balanced[itype], sd->lb_failed[itype], - sd->lb_imbalance[itype], + sd->lb_imbalance_load[itype], + sd->lb_imbalance_util[itype], + sd->lb_imbalance_task[itype], + sd->lb_imbalance_misfit[itype], sd->lb_gained[itype], sd->lb_hot_gained[itype], sd->lb_nobusyq[itype],