Messages in this thread | | | Date | Tue, 22 Feb 2022 10:32:32 -0600 | Subject | Re: [PATCH] kernel/sched: Update schedstats when migrating threads | From | Carlos Bilbao <> |
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Hi,
On 1/26/2022 9:22 AM, Carlos Bilbao wrote: > The kernel manages per-task scheduler statistics or schedstats. Such > counters should be reinitialized when the thread is migrated to a > different core rq, except for the values recording number of migrations. > > Signed-off-by: Carlos Bilbao <carlos.bilbao@amd.com> > --- > kernel/sched/core.c | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > > diff --git a/kernel/sched/core.c b/kernel/sched/core.c > index fe53e510e711..d64c2a290176 100644 > --- a/kernel/sched/core.c > +++ b/kernel/sched/core.c > @@ -8757,6 +8757,7 @@ bool sched_smp_initialized __read_mostly; > int migrate_task_to(struct task_struct *p, int target_cpu) > { > struct migration_arg arg = { p, target_cpu }; > + uint64_t forced_migrations, migrations_cold; > int curr_cpu = task_cpu(p); > > if (curr_cpu == target_cpu) > @@ -8765,7 +8766,14 @@ 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 */ > + if (schedstat_enabled()) { > + forced_migrations = schedstat_val(p->stats.nr_forced_migrations); > + migrations_cold = schedstat_val(p->stats.nr_migrations_cold); > + memset(&p->stats, 0, sizeof(p->stats)); > + schedstat_set(p->stats.nr_forced_migrations, forced_migrations); > + schedstat_set(p->stats.nr_migrations_cold, migrations_cold); > + schedstat_inc(p->stats.nr_migrations_cold); > + } > > trace_sched_move_numa(p, curr_cpu, target_cpu); > return stop_one_cpu(curr_cpu, migration_cpu_stop, &arg);
I would love to hear some thoughts on this.
Thanks, Carlos
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