From: Shrikanth Hegde <sshegde@linux.ibm.com>
To: linux-kernel@vger.kernel.org, mingo@kernel.org,
peterz@infradead.org, juri.lelli@redhat.com,
vincent.guittot@linaro.org, tglx@linutronix.de,
yury.norov@gmail.com, gregkh@linuxfoundation.org
Cc: sshegde@linux.ibm.com, pbonzini@redhat.com, seanjc@google.com,
kprateek.nayak@amd.com, vschneid@redhat.com, iii@linux.ibm.com,
huschle@linux.ibm.com, rostedt@goodmis.org,
dietmar.eggemann@arm.com, mgorman@suse.de, bsegall@google.com,
maddy@linux.ibm.com, srikar@linux.ibm.com, hdanton@sina.com,
chleroy@kernel.org, vineeth@bitbyteword.org,
joelagnelf@nvidia.com
Subject: [PATCH v2 11/17] sched/debug: Add migration stats due to non preferred CPUs
Date: Wed, 8 Apr 2026 00:49:44 +0530 [thread overview]
Message-ID: <20260407191950.643549-12-sshegde@linux.ibm.com> (raw)
In-Reply-To: <20260407191950.643549-1-sshegde@linux.ibm.com>
Add new stats.
- nr_migrations_cpu_non_preferred: number of migrations happened since
a CPU was marked as non preferred due to high steal time.
Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
---
include/linux/sched.h | 1 +
kernel/sched/core.c | 1 +
kernel/sched/debug.c | 1 +
3 files changed, 3 insertions(+)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 1eb3825bcaeb..6c0d5d36f21c 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -554,6 +554,7 @@ struct sched_statistics {
u64 nr_failed_migrations_running;
u64 nr_failed_migrations_hot;
u64 nr_forced_migrations;
+ u64 nr_migrations_cpu_non_preferred;
u64 nr_wakeups;
u64 nr_wakeups_sync;
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index b375c500d49e..7a9442439eb2 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -11321,6 +11321,7 @@ void sched_push_current_non_preferred_cpu(struct rq *rq)
local_irq_save(flags);
get_task_struct(push_task);
+ schedstat_inc(push_task->stats.nr_migrations_cpu_non_preferred);
rq_lock(rq, &rf);
rq->push_task_work_done = 1;
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index f8a43fc13564..482c86a0ff80 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -1305,6 +1305,7 @@ 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);
+ P_SCHEDSTAT(nr_migrations_cpu_non_preferred);
P_SCHEDSTAT(nr_wakeups);
P_SCHEDSTAT(nr_wakeups_sync);
P_SCHEDSTAT(nr_wakeups_migrate);
--
2.47.3
next prev parent reply other threads:[~2026-04-07 19:21 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-07 19:19 [PATCH v2 00/17] sched/paravirt: Introduce cpu_preferred_mask and steal-driven vCPU backoff Shrikanth Hegde
2026-04-07 19:19 ` [PATCH v2 01/17] sched/debug: Remove unused schedstats Shrikanth Hegde
2026-04-07 19:19 ` [PATCH v2 02/17] sched/docs: Document cpu_preferred_mask and Preferred CPU concept Shrikanth Hegde
2026-04-07 19:19 ` [PATCH v2 03/17] cpumask: Introduce cpu_preferred_mask Shrikanth Hegde
2026-04-07 20:27 ` Yury Norov
2026-04-08 9:16 ` Shrikanth Hegde
2026-04-08 17:57 ` Yury Norov
2026-04-07 19:19 ` [PATCH v2 04/17] sysfs: Add preferred CPU file Shrikanth Hegde
2026-04-07 19:19 ` [PATCH v2 05/17] sched/core: allow only preferred CPUs in is_cpu_allowed Shrikanth Hegde
2026-04-08 1:05 ` Yury Norov
2026-04-08 12:56 ` Shrikanth Hegde
2026-04-08 18:09 ` Yury Norov
2026-04-07 19:19 ` [PATCH v2 06/17] sched/fair: Select preferred CPU at wakeup when possible Shrikanth Hegde
2026-04-07 19:19 ` [PATCH v2 07/17] sched/fair: load balance only among preferred CPUs Shrikanth Hegde
2026-04-07 19:19 ` [PATCH v2 08/17] sched/rt: Select a preferred CPU for wakeup and pulling rt task Shrikanth Hegde
2026-04-07 19:19 ` [PATCH v2 09/17] sched/core: Keep tick on non-preferred CPUs until tasks are out Shrikanth Hegde
2026-04-07 19:19 ` [PATCH v2 10/17] sched/core: Push current task from non preferred CPU Shrikanth Hegde
2026-04-07 19:19 ` Shrikanth Hegde [this message]
2026-04-07 19:19 ` [PATCH v2 12/17] sched/feature: Add STEAL_MONITOR feature Shrikanth Hegde
2026-04-07 19:19 ` [PATCH v2 13/17] sched/core: Introduce a simple steal monitor Shrikanth Hegde
2026-04-07 19:19 ` [PATCH v2 14/17] sched/core: Compute steal values at regular intervals Shrikanth Hegde
2026-04-07 19:19 ` [PATCH v2 15/17] sched/core: Handle steal values and mark CPUs as preferred Shrikanth Hegde
2026-04-07 19:19 ` [PATCH v2 16/17] sched/core: Mark the direction of steal values to avoid oscillations Shrikanth Hegde
2026-04-07 19:19 ` [PATCH v2 17/17] sched/debug: Add debug knobs for steal monitor Shrikanth Hegde
2026-04-07 19:50 ` [PATCH v2 00/17] sched/paravirt: Introduce cpu_preferred_mask and steal-driven vCPU backoff Shrikanth Hegde
2026-04-08 10:14 ` Hillf Danton
2026-04-08 13:49 ` Shrikanth Hegde
2026-04-09 5:15 ` Hillf Danton
2026-04-09 10:27 ` Shrikanth Hegde
2026-04-10 9:47 ` Shrikanth Hegde
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