[tip:sched/urgent] sched/numa: Fix numa balancing stats in /proc/ pid/sched

From: tip-bot for Srikar Dronamraju
Date: Fri Jul 03 2015 - 03:48:42 EST


Commit-ID: 46fb6b9762d13fdeeefb3a9e9c317ebcd344f578
Gitweb: http://git.kernel.org/tip/46fb6b9762d13fdeeefb3a9e9c317ebcd344f578
Author: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>
AuthorDate: Thu, 25 Jun 2015 22:51:43 +0530
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Wed, 1 Jul 2015 10:31:28 +0200

sched/numa: Fix numa balancing stats in /proc/pid/sched

Commit 44dba3d5d6a1 ("sched: Refactor task_struct to use
numa_faults instead of numa_* pointers") modified the way
tsk->numa_faults stats are accounted.

However that commit never touched show_numa_stats() that is displayed
in /proc/pid/sched and thus the numbers displayed in /proc/pid/sched
don't match the actual numbers.

Fix it by making sure that /proc/pid/sched reflects the task
fault numbers. Also add group fault stats too.

Also couple of more modifications are added here:

1. Format changes:

- Previously we would list two entries per node, one for private
and one for shared. Also the home node info was listed in each entry.

- Now preferred node, total_faults and current node are
displayed separately.

- Now there is one entry per node, that lists private,shared task and
group faults.

2. Unit changes:

- p->numa_pages_migrated was getting reset after every read of
/proc/pid/sched. It's more useful to have absolute numbers since
differential migrations between two accesses can be more easily
calculated.

Signed-off-by: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>
Acked-by: Rik van Riel <riel@xxxxxxxxxx>
Cc: Iulia Manda <iulia.manda21@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1435252903-1081-4-git-send-email-srikar@xxxxxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
kernel/sched/debug.c | 38 +++++++++++++++++---------------------
kernel/sched/fair.c | 22 +++++++++++++++++++++-
kernel/sched/sched.h | 10 +++++++++-
3 files changed, 47 insertions(+), 23 deletions(-)

diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index f1dcd1d..4222ec5 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -517,11 +517,21 @@ __initcall(init_sched_debug_procfs);
SEQ_printf(m, "%-45s:%14Ld.%06ld\n", #F, SPLIT_NS((long long)p->F))


+#ifdef CONFIG_NUMA_BALANCING
+void print_numa_stats(struct seq_file *m, int node, unsigned long tsf,
+ unsigned long tpf, unsigned long gsf, unsigned long gpf)
+{
+ SEQ_printf(m, "numa_faults node=%d ", node);
+ SEQ_printf(m, "task_private=%lu task_shared=%lu ", tsf, tpf);
+ SEQ_printf(m, "group_private=%lu group_shared=%lu\n", gsf, gpf);
+}
+#endif
+
+
static void sched_show_numa(struct task_struct *p, struct seq_file *m)
{
#ifdef CONFIG_NUMA_BALANCING
struct mempolicy *pol;
- int node, i;

if (p->mm)
P(mm->numa_scan_seq);
@@ -533,26 +543,12 @@ static void sched_show_numa(struct task_struct *p, struct seq_file *m)
mpol_get(pol);
task_unlock(p);

- SEQ_printf(m, "numa_migrations, %ld\n", xchg(&p->numa_pages_migrated, 0));
-
- for_each_online_node(node) {
- for (i = 0; i < 2; i++) {
- unsigned long nr_faults = -1;
- int cpu_current, home_node;
-
- if (p->numa_faults)
- nr_faults = p->numa_faults[2*node + i];
-
- cpu_current = !i ? (task_node(p) == node) :
- (pol && node_isset(node, pol->v.nodes));
-
- home_node = (p->numa_preferred_nid == node);
-
- SEQ_printf(m, "numa_faults_memory, %d, %d, %d, %d, %ld\n",
- i, node, cpu_current, home_node, nr_faults);
- }
- }
-
+ P(numa_pages_migrated);
+ P(numa_preferred_nid);
+ P(total_numa_faults);
+ SEQ_printf(m, "current_node=%d, numa_group_id=%d\n",
+ task_node(p), task_numa_group_id(p));
+ show_numa_stats(p, m);
mpol_put(pol);
#endif
}
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 40a7fcb..7245039 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -8468,7 +8468,27 @@ void print_cfs_stats(struct seq_file *m, int cpu)
print_cfs_rq(m, cpu, cfs_rq);
rcu_read_unlock();
}
-#endif
+
+#ifdef CONFIG_NUMA_BALANCING
+void show_numa_stats(struct task_struct *p, struct seq_file *m)
+{
+ int node;
+ unsigned long tsf = 0, tpf = 0, gsf = 0, gpf = 0;
+
+ for_each_online_node(node) {
+ if (p->numa_faults) {
+ tsf = p->numa_faults[task_faults_idx(NUMA_MEM, node, 0)];
+ tpf = p->numa_faults[task_faults_idx(NUMA_MEM, node, 1)];
+ }
+ if (p->numa_group) {
+ gsf = p->numa_group->faults[task_faults_idx(NUMA_MEM, node, 0)],
+ gpf = p->numa_group->faults[task_faults_idx(NUMA_MEM, node, 1)];
+ }
+ print_numa_stats(m, node, tsf, tpf, gsf, gpf);
+ }
+}
+#endif /* CONFIG_NUMA_BALANCING */
+#endif /* CONFIG_SCHED_DEBUG */

__init void init_sched_fair_class(void)
{
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 7d58952..7ef5968 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1675,7 +1675,15 @@ extern void print_rt_stats(struct seq_file *m, int cpu);
extern void print_dl_stats(struct seq_file *m, int cpu);
extern void
print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
-#endif
+
+#ifdef CONFIG_NUMA_BALANCING
+extern void
+show_numa_stats(struct task_struct *p, struct seq_file *m);
+extern void
+print_numa_stats(struct seq_file *m, int node, unsigned long tsf,
+ unsigned long tpf, unsigned long gsf, unsigned long gpf);
+#endif /* CONFIG_NUMA_BALANCING */
+#endif /* CONFIG_SCHED_DEBUG */

extern void init_cfs_rq(struct cfs_rq *cfs_rq);
extern void init_rt_rq(struct rt_rq *rt_rq);
--
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