From 9482fd71dbb8f0d1a61821a83e467dc0a9d7b429 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 12 Aug 2021 22:31:24 +0200 Subject: [PATCH] hrtimer: Use raw_cpu_ptr() in clock_was_set() clock_was_set() can be invoked from preemptible context. Use raw_cpu_ptr() to check whether high resolution mode is active or not. It does not matter whether the task migrates after acquiring the pointer. Fixes: e71a4153b7c2 ("hrtimer: Force clock_was_set() handling for the HIGHRES=n, NOHZ=y case") Reported-by: Mike Galbraith Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/875ywacsmb.ffs@tglx --- kernel/time/hrtimer.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 88aefc35f7d2..33b00e213e07 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -944,10 +944,11 @@ static bool update_needs_ipi(struct hrtimer_cpu_base *cpu_base, */ void clock_was_set(unsigned int bases) { + struct hrtimer_cpu_base *cpu_base = raw_cpu_ptr(&hrtimer_bases); cpumask_var_t mask; int cpu; - if (!hrtimer_hres_active() && !tick_nohz_active) + if (!__hrtimer_hres_active(cpu_base) && !tick_nohz_active) goto out_timerfd; if (!zalloc_cpumask_var(&mask, GFP_KERNEL)) { @@ -958,9 +959,9 @@ void clock_was_set(unsigned int bases) /* Avoid interrupting CPUs if possible */ cpus_read_lock(); for_each_online_cpu(cpu) { - struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu); unsigned long flags; + cpu_base = &per_cpu(hrtimer_bases, cpu); raw_spin_lock_irqsave(&cpu_base->lock, flags); if (update_needs_ipi(cpu_base, bases)) -- 2.20.1