@@ -1652,6 +1652,12 @@ The following nested keys are defined.
numa_hint_faults (npn)
Number of NUMA hinting faults.
+ numa_task_migrated (npn)
+ Number of task migration by NUMA balancing.
+
+ numa_task_swapped (npn)
+ Number of task swap by NUMA balancing.
+
pgdemote_kswapd
Number of pages demoted by kswapd.
@@ -549,6 +549,10 @@ struct sched_statistics {
u64 nr_failed_migrations_running;
u64 nr_failed_migrations_hot;
u64 nr_forced_migrations;
+#ifdef CONFIG_NUMA_BALANCING
+ u64 numa_task_migrated;
+ u64 numa_task_swapped;
+#endif
u64 nr_wakeups;
u64 nr_wakeups_sync;
@@ -64,6 +64,8 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT,
NUMA_HINT_FAULTS,
NUMA_HINT_FAULTS_LOCAL,
NUMA_PAGE_MIGRATE,
+ NUMA_TASK_MIGRATE,
+ NUMA_TASK_SWAP,
#endif
#ifdef CONFIG_MIGRATION
PGMIGRATE_SUCCESS, PGMIGRATE_FAIL,
@@ -3352,6 +3352,11 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
#ifdef CONFIG_NUMA_BALANCING
static void __migrate_swap_task(struct task_struct *p, int cpu)
{
+ __schedstat_inc(p->stats.numa_task_swapped);
+
+ if (p->mm)
+ count_memcg_events_mm(p->mm, NUMA_TASK_SWAP, 1);
+
if (task_on_rq_queued(p)) {
struct rq *src_rq, *dst_rq;
struct rq_flags srf, drf;
@@ -7955,8 +7960,9 @@ int migrate_task_to(struct task_struct *p, int target_cpu)
if (!cpumask_test_cpu(target_cpu, p->cpus_ptr))
return -EINVAL;
- /* TODO: This is not properly updating schedstats */
-
+ __schedstat_inc(p->stats.numa_task_migrated);
+ if (p->mm)
+ count_memcg_events_mm(p->mm, NUMA_TASK_MIGRATE, 1);
trace_sched_move_numa(p, curr_cpu, target_cpu);
return stop_one_cpu(curr_cpu, migration_cpu_stop, &arg);
}
@@ -1206,6 +1206,10 @@ void proc_sched_show_task(struct task_struct *p, struct pid_namespace *ns,
P_SCHEDSTAT(nr_failed_migrations_running);
P_SCHEDSTAT(nr_failed_migrations_hot);
P_SCHEDSTAT(nr_forced_migrations);
+#ifdef CONFIG_NUMA_BALANCING
+ P_SCHEDSTAT(numa_task_migrated);
+ P_SCHEDSTAT(numa_task_swapped);
+#endif
P_SCHEDSTAT(nr_wakeups);
P_SCHEDSTAT(nr_wakeups_sync);
P_SCHEDSTAT(nr_wakeups_migrate);
@@ -460,6 +460,8 @@ static const unsigned int memcg_vm_event_stat[] = {
NUMA_PAGE_MIGRATE,
NUMA_PTE_UPDATES,
NUMA_HINT_FAULTS,
+ NUMA_TASK_MIGRATE,
+ NUMA_TASK_SWAP,
#endif
};
@@ -1342,6 +1342,8 @@ const char * const vmstat_text[] = {
"numa_hint_faults",
"numa_hint_faults_local",
"numa_pages_migrated",
+ "numa_task_migrated",
+ "numa_task_swapped",
#endif
#ifdef CONFIG_MIGRATION
"pgmigrate_success",
On systems with NUMA balancing enabled, it is found that tracking the task activities due to NUMA balancing is helpful. NUMA balancing has two mechanisms for task migration: one is to migrate the task to an idle CPU in its preferred node, the other is to swap tasks on different nodes if they are on each other's preferred node. The kernel already has NUMA page migration statistics in /sys/fs/cgroup/mytest/memory.stat and /proc/{PID}/sched, but does not have statistics for task migration/swap. Add the task migration and swap count accordingly. The following two new fields: numa_task_migrated numa_task_swapped will be displayed in both /sys/fs/cgroup/{GROUP}/memory.stat and /proc/{PID}/sched Introducing both pertask and permemcg NUMA balancing statistics helps to quickly evaluate the performance and resource usage of the target workload. For example, the user can first identify the container which has high NUMA balance activity and then narrow down to a specific task within that group, and tune the memory policy of that task. In summary, it is plausible to iterate the /proc/$pid/sched to find the offending task, but the introduction of per memcg tasks' Numa balancing aggregated activity can further help users identify the task in a divide-and-conquer way. Tested-by: K Prateek Nayak <kprateek.nayak@amd.com> Tested-by: Madadi Vineeth Reddy <vineethr@linux.ibm.com> Signed-off-by: Chen Yu <yu.c.chen@intel.com> --- v1->v2: Update the Documentation/admin-guide/cgroup-v2.rst. (Michal) --- Documentation/admin-guide/cgroup-v2.rst | 6 ++++++ include/linux/sched.h | 4 ++++ include/linux/vm_event_item.h | 2 ++ kernel/sched/core.c | 10 ++++++++-- kernel/sched/debug.c | 4 ++++ mm/memcontrol.c | 2 ++ mm/vmstat.c | 2 ++ 7 files changed, 28 insertions(+), 2 deletions(-)