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| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2015-07-09 22:59:49 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2015-07-09 22:59:49 +0200 |
| commit | ae0afb4f5d44d17a0fd135ae000e2acf12c53617 (patch) | |
| tree | 35b7a32ed8fc9d2b6ca219e3b4769f7fb165c455 /drivers/cpuidle | |
| parent | d770e558e21961ad6cfdf0ff7df0eb5d7d4f0754 (diff) | |
| download | lwn-ae0afb4f5d44d17a0fd135ae000e2acf12c53617.tar.gz lwn-ae0afb4f5d44d17a0fd135ae000e2acf12c53617.zip | |
suspend-to-idle: Prevent RCU from complaining about tick_freeze()
Put tick_freeze() under RCU_NONIDLE() to prevent RCU from complaining
about suspicious RCU usage in idle by trace_suspend_resume() called
from there.
While at it, fix a comment related to another usage of RCU_NONIDLE()
in enter_freeze_proper().
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'drivers/cpuidle')
| -rw-r--r-- | drivers/cpuidle/cpuidle.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index e8e2775c3821..48b7228563ad 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -112,7 +112,12 @@ int cpuidle_find_deepest_state(struct cpuidle_driver *drv, static void enter_freeze_proper(struct cpuidle_driver *drv, struct cpuidle_device *dev, int index) { - tick_freeze(); + /* + * trace_suspend_resume() called by tick_freeze() for the last CPU + * executing it contains RCU usage regarded as invalid in the idle + * context, so tell RCU about that. + */ + RCU_NONIDLE(tick_freeze()); /* * The state used here cannot be a "coupled" one, because the "coupled" * cpuidle mechanism enables interrupts and doing that with timekeeping @@ -122,7 +127,7 @@ static void enter_freeze_proper(struct cpuidle_driver *drv, WARN_ON(!irqs_disabled()); /* * timekeeping_resume() that will be called by tick_unfreeze() for the - * last CPU executing it calls functions containing RCU read-side + * first CPU executing it calls functions containing RCU read-side * critical sections, so tell RCU about that. */ RCU_NONIDLE(tick_unfreeze()); |