On Tue, Jul 31, 2012 at 8:43 AM, Srivatsa S. Bhat <[email protected]> wrote: > On 07/26/2012 02:50 AM, Colin Cross wrote: >> The cpu hotplug notifier gets called in both atomic and non-atomic >> contexts, it is not always safe to lock a mutex. Filter out all events >> except the six necessary ones, which are all sleepable, before taking >> the mutex. >> >> Signed-off-by: Colin Cross <[email protected]> >> --- >> drivers/cpuidle/coupled.c | 12 ++++++++++++ >> 1 files changed, 12 insertions(+), 0 deletions(-) >> >> diff --git a/drivers/cpuidle/coupled.c b/drivers/cpuidle/coupled.c >> index 2c9bf26..c24dda0 100644 >> --- a/drivers/cpuidle/coupled.c >> +++ b/drivers/cpuidle/coupled.c >> @@ -678,6 +678,18 @@ static int cpuidle_coupled_cpu_notify(struct >> notifier_block *nb, >> int cpu = (unsigned long)hcpu; >> struct cpuidle_device *dev; >> >> + switch (action & ~CPU_TASKS_FROZEN) { >> + case CPU_UP_PREPARE: >> + case CPU_DOWN_PREPARE: >> + case CPU_ONLINE: >> + case CPU_DEAD: >> + case CPU_UP_CANCELED: >> + case CPU_DOWN_FAILED: >> + break; >> + default: >> + return NOTIFY_OK; >> + } >> + > > Instead, wouldn't it be better to have case statements for the > 2 cases that imply atomic context and return immediately? > > Something like: > switch (action & ~CPU_TASKS_FROZEN) { > case CPU_STARTING: > case CPU_DYING: > return NOTIFY_OK; > }
No, because then it would need updating whenever a new notification event was added. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
