On 12/21/2017 01:46 PM, Keith Busch wrote: > When a request completion is polled, the completion task wakes itself > up. This is unnecessary, as the task can just set itself back to > running. > > Signed-off-by: Keith Busch <keith.busch@xxxxxxxxx> > --- > fs/block_dev.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/fs/block_dev.c b/fs/block_dev.c > index 4a181fcb5175..ce67ffe73430 100644 > --- a/fs/block_dev.c > +++ b/fs/block_dev.c > @@ -181,7 +181,10 @@ static void blkdev_bio_end_io_simple(struct bio *bio) > struct task_struct *waiter = bio->bi_private; > > WRITE_ONCE(bio->bi_private, NULL); > - wake_up_process(waiter); > + if (current != waiter) > + wake_up_process(waiter); > + else > + __set_current_state(TASK_RUNNING); Do we actually need to set this to TASK_RUNNING? If we get here we're already running, right? Everywhere I see uses of __set_current_state(TASK_RUNNING) it's after we've done a set_current_state(TASK_INTERRUPTIBLE).
