diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2015-07-07 15:11:00 +0300 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2015-07-07 19:46:47 +0300 |
| commit | 8eb231261fdd20768db23863d00ef277de4b0543 (patch) | |
| tree | 5e2e4b15ea1d0a8aaee0fa8564bdd099015a958d | |
| parent | 7c4a976cd55972b68c75a978f171b6db5df4ce66 (diff) | |
| download | linux-8eb231261fdd20768db23863d00ef277de4b0543.tar.xz | |
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.c | 16 |
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)) { |