@@ -228,27 +228,19 @@ static inline bool freezer_should_skip(struct task_struct *p)
#define wait_event_freezable(wq, condition) \
({ \
int __retval; \
- for (;;) { \
- __retval = wait_event_interruptible(wq, \
- (condition) || freezing(current)); \
- if (__retval || (condition)) \
- break; \
- try_to_freeze(); \
- } \
+ freezer_do_not_count(); \
+ __retval = wait_event_interruptible(wq, (condition)); \
+ freezer_count(); \
__retval; \
})
#define wait_event_freezable_timeout(wq, condition, timeout) \
({ \
long __retval = timeout; \
- for (;;) { \
- __retval = wait_event_interruptible_timeout(wq, \
- (condition) || freezing(current), \
- __retval); \
- if (__retval <= 0 || (condition)) \
- break; \
- try_to_freeze(); \
- } \
+ freezer_do_not_count(); \
+ __retval = wait_event_interruptible_timeout(wq, (condition), \
+ __retval); \
+ freezer_count(); \
__retval; \
})
Freezing tasks will wake up almost every userspace task from where it is blocking and force it to run until it hits a call to try_to_sleep(), generally on the exit path from the syscall it is blocking in. On resume each task will run again, usually restarting the syscall and running until it hits the same blocking call as it was originally blocked in. Convert the existing wait_event_freezable* wrappers to use freezer_do_not_count(). Combined with a previous patch, these tasks will not run during suspend or resume unless they wake up for another reason, in which case they will run until they hit the try_to_freeze() in freezer_count(), and then continue processing the wakeup after tasks are thawed. This results in a small change in behavior, previously a race between freezing and a normal wakeup would be won by the wakeup, now the task will freeze and then handle the wakeup after thawing. Signed-off-by: Colin Cross <ccross@android.com> --- v3: split this out of the patch that adds new freezable helpers include/linux/freezer.h | 22 +++++++--------------- 1 file changed, 7 insertions(+), 15 deletions(-)