diff options
| author | Josh Snyder <[email protected]> | 2017-12-18 16:15:10 +0000 |
|---|---|---|
| committer | Ingo Molnar <[email protected]> | 2018-01-16 03:29:36 +0100 |
| commit | c96f5471ce7d2aefd0dda560cc23f08ab00bc65d (patch) | |
| tree | 84feeca0e7b0819b55216e1fea50a3e0e79d445b /include/linux/delayacct.h | |
| parent | a8750ddca918032d6349adbf9a4b6555e7db20da (diff) | |
delayacct: Account blkio completion on the correct task
Before commit:
e33a9bba85a8 ("sched/core: move IO scheduling accounting from io_schedule_timeout() into scheduler")
delayacct_blkio_end() was called after context-switching into the task which
completed I/O.
This resulted in double counting: the task would account a delay both waiting
for I/O and for time spent in the runqueue.
With e33a9bba85a8, delayacct_blkio_end() is called by try_to_wake_up().
In ttwu, we have not yet context-switched. This is more correct, in that
the delay accounting ends when the I/O is complete.
But delayacct_blkio_end() relies on 'get_current()', and we have not yet
context-switched into the task whose I/O completed. This results in the
wrong task having its delay accounting statistics updated.
Instead of doing that, pass the task_struct being woken to delayacct_blkio_end(),
so that it can update the statistics of the correct task.
Signed-off-by: Josh Snyder <[email protected]>
Acked-by: Tejun Heo <[email protected]>
Acked-by: Balbir Singh <[email protected]>
Cc: <[email protected]>
Cc: Brendan Gregg <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Fixes: e33a9bba85a8 ("sched/core: move IO scheduling accounting from io_schedule_timeout() into scheduler")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
Diffstat (limited to 'include/linux/delayacct.h')
| -rw-r--r-- | include/linux/delayacct.h | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/include/linux/delayacct.h b/include/linux/delayacct.h index 4178d2493547..5e335b6203f4 100644 --- a/include/linux/delayacct.h +++ b/include/linux/delayacct.h @@ -71,7 +71,7 @@ extern void delayacct_init(void); extern void __delayacct_tsk_init(struct task_struct *); extern void __delayacct_tsk_exit(struct task_struct *); extern void __delayacct_blkio_start(void); -extern void __delayacct_blkio_end(void); +extern void __delayacct_blkio_end(struct task_struct *); extern int __delayacct_add_tsk(struct taskstats *, struct task_struct *); extern __u64 __delayacct_blkio_ticks(struct task_struct *); extern void __delayacct_freepages_start(void); @@ -122,10 +122,10 @@ static inline void delayacct_blkio_start(void) __delayacct_blkio_start(); } -static inline void delayacct_blkio_end(void) +static inline void delayacct_blkio_end(struct task_struct *p) { if (current->delays) - __delayacct_blkio_end(); + __delayacct_blkio_end(p); delayacct_clear_flag(DELAYACCT_PF_BLKIO); } @@ -169,7 +169,7 @@ static inline void delayacct_tsk_free(struct task_struct *tsk) {} static inline void delayacct_blkio_start(void) {} -static inline void delayacct_blkio_end(void) +static inline void delayacct_blkio_end(struct task_struct *p) {} static inline int delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) |