| Message ID | 1531308264-24220-3-git-send-email-sudeep.holla@arm.com |
|---|---|
| State | Accepted |
| Commit | fbfa9260085b5b578a049a90135e5c51928c5f7f |
| Headers | show |
| Series | [1/3] clocksource: drivers: set clockevent device cpumask to cpu_possible_mask | expand |
Hi Thomas, On 11/07/18 12:24, Sudeep Holla wrote: > Using cpu_all_mask in clockevents cpumask may result in issues while > comparing multiple clockevent devices to choose the preferred one. > On one of the platforms with 2 system(i.e. non per-CPU) timers with > different ratings, having cpu_all_mask for one of the device resulted > in boot hang with forever loop in clockevents_notify_released as both > were being selected as preferred. > > In order to prevent such issues in future, let's warn if any clockevent > drivers sets cpu_all_mask as it's cpumask and just override it to use > cpu_possible_mask. All the existing occurrences of cpu_all_mask are > already replaced with cpu_possible_mask. > Daniel has picked up patch 1/3, do you want me to resend this patch 2 and 3 again or you happy to pick them ? -- Regards, Sudeep
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c index 16c027e9cc73..8c0e4092f661 100644 --- a/kernel/time/clockevents.c +++ b/kernel/time/clockevents.c @@ -463,6 +463,12 @@ void clockevents_register_device(struct clock_event_device *dev) dev->cpumask = cpumask_of(smp_processor_id()); } + if (dev->cpumask == cpu_all_mask) { + WARN(1, "%s cpumask == cpu_all_mask, using cpu_possible_mask instead\n", + dev->name); + dev->cpumask = cpu_possible_mask; + } + raw_spin_lock_irqsave(&clockevents_lock, flags); list_add(&dev->list, &clockevent_devices);
Using cpu_all_mask in clockevents cpumask may result in issues while comparing multiple clockevent devices to choose the preferred one. On one of the platforms with 2 system(i.e. non per-CPU) timers with different ratings, having cpu_all_mask for one of the device resulted in boot hang with forever loop in clockevents_notify_released as both were being selected as preferred. In order to prevent such issues in future, let's warn if any clockevent drivers sets cpu_all_mask as it's cpumask and just override it to use cpu_possible_mask. All the existing occurrences of cpu_all_mask are already replaced with cpu_possible_mask. Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> --- kernel/time/clockevents.c | 6 ++++++ 1 file changed, 6 insertions(+) -- 2.7.4