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authorThomas Gleixner <tglx@linutronix.de>2015-07-07 14:11:00 +0200
committerThomas Gleixner <tglx@linutronix.de>2015-07-07 18:46:47 +0200
commit8eb231261fdd20768db23863d00ef277de4b0543 (patch)
tree5e2e4b15ea1d0a8aaee0fa8564bdd099015a958d
parentclockevents: Allow set-state callbacks to be optional (diff)
downloadlinux-8eb231261fdd20768db23863d00ef277de4b0543.tar.xz
linux-8eb231261fdd20768db23863d00ef277de4b0543.zip
tick/broadcast: Prevent hrtimer recursion
The hrtimer based broadcast vehicle can cause a hrtimer recursion which went unnoticed until we changed the hrtimer expiry code to keep track of the currently running timer. local_timer_interrupt() local_handler() hrtimer_interrupt() expire_hrtimers() broadcast_hrtimer() send_ipis() local_handler() hrtimer_interrupt() .... Solution is simple: Prevent the local handler call from the broadcast code when the broadcast 'device' is hrtimer based. [ Split out from a larger combo patch ] Tested-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Suzuki Poulose <Suzuki.Poulose@arm.com> Cc: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com> Cc: Catalin Marinas <Catalin.Marinas@arm.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1507070929360.3916@nanos
-rw-r--r--kernel/time/tick-broadcast.c16
1 files changed, 15 insertions, 1 deletions
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index d39f32cdd1b5..a76204089f78 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -265,8 +265,22 @@ static bool tick_do_broadcast(struct cpumask *mask)
* Check, if the current cpu is in the mask
*/
if (cpumask_test_cpu(cpu, mask)) {
+ struct clock_event_device *bc = tick_broadcast_device.evtdev;
+
cpumask_clear_cpu(cpu, mask);
- local = true;
+ /*
+ * We only run the local handler, if the broadcast
+ * device is not hrtimer based. Otherwise we run into
+ * a hrtimer recursion.
+ *
+ * local timer_interrupt()
+ * local_handler()
+ * expire_hrtimers()
+ * bc_handler()
+ * local_handler()
+ * expire_hrtimers()
+ */
+ local = !(bc->features & CLOCK_EVT_FEAT_HRTIMER);
}
if (!cpumask_empty(mask)) {