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| author | Sudeep Holla <sudeep.holla@arm.com> | 2018-07-11 12:24:24 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2018-08-02 14:55:53 +0200 |
| commit | fbfa9260085b5b578a049a90135e5c51928c5f7f (patch) | |
| tree | 43eadbc7349ce78a8b5b173abb068a1e2d6d5ae1 | |
| parent | 234b3840d73430564a03f53973a311b7a83a95a9 (diff) | |
| download | linux-fbfa9260085b5b578a049a90135e5c51928c5f7f.tar.bz2 | |
clockevents: Warn if cpu_all_mask is used as cpumask
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 a
boot hang due to a endless loop in clockevents_notify_released() as both
were clocksources were selected as preferred.
In order to prevent such issues in the future, warn if any clockevent
driver 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.
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lkml.kernel.org/r/1531308264-24220-3-git-send-email-sudeep.holla@arm.com
| -rw-r--r-- | kernel/time/clockevents.c | 6 |
1 files changed, 6 insertions, 0 deletions
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); |