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authorSudeep Holla <sudeep.holla@arm.com>2018-07-11 12:24:24 +0100
committerThomas Gleixner <tglx@linutronix.de>2018-08-02 14:55:53 +0200
commitfbfa9260085b5b578a049a90135e5c51928c5f7f (patch)
tree43eadbc7349ce78a8b5b173abb068a1e2d6d5ae1
parent234b3840d73430564a03f53973a311b7a83a95a9 (diff)
downloadlinux-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.c6
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);