Messages in this thread Patch in this message | | | Date | Tue, 11 Apr 2023 04:25:11 +0000 | Subject | [PATCH v3 14/14] sched: Fix runtime accounting w/ proxy-execution | From | John Stultz <> |
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The idea here is we want to charge the selected task's vruntime but charge the executed task's sum_exec_runtime.
This way cputime accounting goes against the task actually running but vruntime accounting goes against the selected task so we get proper fairness.
Cc: Joel Fernandes <joelaf@google.com> Cc: Qais Yousef <qyousef@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ben Segall <bsegall@google.com> Cc: Zimuzo Ezeozue <zezeozue@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Will Deacon <will@kernel.org> Cc: Waiman Long <longman@redhat.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: "Paul E . McKenney" <paulmck@kernel.org> Signed-off-by: John Stultz <jstultz@google.com> --- kernel/sched/fair.c | 24 +++++++++++++++++++----- 1 file changed, 19 insertions(+), 5 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index acb8155f40c3..3abb48b3515c 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -891,22 +891,36 @@ static void update_tg_load_avg(struct cfs_rq *cfs_rq) } #endif /* CONFIG_SMP */ -static s64 update_curr_se(struct rq *rq, struct sched_entity *curr) +static s64 update_curr_se(struct rq *rq, struct sched_entity *se) { u64 now = rq_clock_task(rq); s64 delta_exec; - delta_exec = now - curr->exec_start; + /* Calculate the delta from selected se */ + delta_exec = now - se->exec_start; if (unlikely(delta_exec <= 0)) return delta_exec; - curr->exec_start = now; - curr->sum_exec_runtime += delta_exec; + /* Update selected se's exec_start */ + se->exec_start = now; + if (entity_is_task(se)) { + struct task_struct *running = rq_curr(rq); + /* + * If se is a task, we account the time + * against the running task, as w/ proxy-exec + * they may not be the same. + */ + running->se.exec_start = now; + running->se.sum_exec_runtime += delta_exec; + } else { + /* If not task, account the time against se */ + se->sum_exec_runtime += delta_exec; + } if (schedstat_enabled()) { struct sched_statistics *stats; - stats = __schedstats_from_se(curr); + stats = __schedstats_from_se(se); __schedstat_set(stats->exec_max, max(delta_exec, stats->exec_max)); } -- 2.40.0.577.gac1e443424-goog
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