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| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2015-04-10 11:50:22 +0200 |
|---|---|---|
| committer | Anders Roxell <anders.roxell@linaro.org> | 2015-06-01 12:03:39 +0200 |
| commit | 0545bb2edf4c723d64c106b8bcac7a965deec53b (patch) | |
| tree | efea82f7ce2a990b72cac7b17a689cf63714e85a /arch/powerpc/crypto | |
| parent | 873c6bc22569e32fa14f6310599f9a42d172c1a7 (diff) | |
kernel/irq_work: fix no_hz deadlock
Invoking NO_HZ's irq_work callback from timer irq is not working very
well if the callback decides to invoke hrtimer_cancel():
|hrtimer_try_to_cancel+0x55/0x5f
|hrtimer_cancel+0x16/0x28
|tick_nohz_restart+0x17/0x72
|__tick_nohz_full_check+0x8e/0x93
|nohz_full_kick_work_func+0xe/0x10
|irq_work_run_list+0x39/0x57
|irq_work_tick+0x60/0x67
|update_process_times+0x57/0x67
|tick_sched_handle+0x4a/0x59
|tick_sched_timer+0x3b/0x64
|__run_hrtimer+0x7a/0x149
|hrtimer_interrupt+0x1cc/0x2c5
and here we deadlock while waiting for the lock which we are holding.
To fix this I'm doing the same thing that upstream is doing: is the
irq_work dedicated IRQ and use it only for what is marked as "hirq"
which should only be the FULL_NO_HZ related work.
Cc: stable-rt@vger.kernel.org
Reported-by: Carsten Emde <C.Emde@osadl.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
[ Added back in_irq() check for non PREEMPT_RT configs ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'arch/powerpc/crypto')
0 files changed, 0 insertions, 0 deletions