Re: [PATCH 06/11] block: add polled wakeup task helper

[Jens Axboe <axboe@kernel.dk>]

On 11/13/18 8:58 AM, Jens Axboe wrote:
> On 11/13/18 8:52 AM, Keith Busch wrote:
>> On Tue, Nov 13, 2018 at 08:42:28AM -0700, Jens Axboe wrote:
>>> If we're polling for IO on a device that doesn't use interrupts, then
>>> IO completion loop (and wake of task) is done by submitting task itself.
>>> If that is the case, then we don't need to enter the wake_up_process()
>>> function, we can simply mark ourselves as TASK_RUNNING.
>>>
>>> Signed-off-by: Jens Axboe <axboe@kernel.dk>
>>> ---
>>>  fs/block_dev.c         |  6 ++----
>>>  fs/iomap.c             |  3 +--
>>>  include/linux/blkdev.h | 19 +++++++++++++++++++
>>>  3 files changed, 22 insertions(+), 6 deletions(-)
>>
>> One more for swap read:
>>
>> ---
>> diff --git a/mm/page_io.c b/mm/page_io.c
>> index d4d1c89bcddd..57572ff46016 100644
>> --- a/mm/page_io.c
>> +++ b/mm/page_io.c
>> @@ -140,7 +140,7 @@ static void end_swap_bio_read(struct bio *bio)
>>  	unlock_page(page);
>>  	WRITE_ONCE(bio->bi_private, NULL);
>>  	bio_put(bio);
>> -	wake_up_process(waiter);
>> +	blk_wake_io_task(waiter);
>>  	put_task_struct(waiter);
>>  }
>>  
> 
> Indeed, thanks Keith! I'll fold it in.

Ditto for the patch 5 changes, jfyi.

-- 
Jens Axboe