From: Yafang Shao Date: Fri, 3 Jan 2025 02:24:08 +0000 (+0800) Subject: sched, psi: Don't account irq time if sched_clock_irqtime is disabled X-Git-Tag: v6.14-rc1~184^2~2 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=a6fd16148fdd7e9da143037106956a3447c247a8;p=thirdparty%2Fkernel%2Flinux.git sched, psi: Don't account irq time if sched_clock_irqtime is disabled sched_clock_irqtime may be disabled due to the clock source. When disabled, irq_time_read() won't change over time, so there is nothing to account. We can save iterating the whole hierarchy on every tick and context switch. Signed-off-by: Yafang Shao Signed-off-by: Yafang Shao Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Michal Koutný Acked-by: Johannes Weiner Link: https://lore.kernel.org/r/20250103022409.2544-4-laoar.shao@gmail.com --- diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c index 84dad1511d1e4..bb56805e3d476 100644 --- a/kernel/sched/psi.c +++ b/kernel/sched/psi.c @@ -998,7 +998,7 @@ void psi_account_irqtime(struct rq *rq, struct task_struct *curr, struct task_st s64 delta; u64 irq; - if (static_branch_likely(&psi_disabled)) + if (static_branch_likely(&psi_disabled) || !irqtime_enabled()) return; if (!curr->pid) @@ -1240,6 +1240,11 @@ int psi_show(struct seq_file *m, struct psi_group *group, enum psi_res res) if (static_branch_likely(&psi_disabled)) return -EOPNOTSUPP; +#ifdef CONFIG_IRQ_TIME_ACCOUNTING + if (!irqtime_enabled() && res == PSI_IRQ) + return -EOPNOTSUPP; +#endif + /* Update averages before reporting them */ mutex_lock(&group->avgs_lock); now = sched_clock();