On 3/25/19 10:39 AM, Bart Van Assche wrote:
> On Mon, 2019-03-25 at 10:22 -0600, Jens Axboe wrote:
>> We now wrap sbitmap waitqueues in an active counter, so we can avoid
>> iterating wakeups unless we have waiters there. This works as long as
>> everyone that's manipulating the waitqueues use the proper helpers. For
>> the tag wait case for shared tags, however, we add ourselves to the
>> waitqueue without incrementing/decrementing the ->ws_active count. This
>> means that wakeups can take a long time to happen.
>>
>> Fix this by manually doing the inc/dec as needed for the wait queue
>> handling.
>>
>> Fixes: 5d2ee7122c73 ("sbitmap: optimize wakeup check")
>> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
>
> Hi Jens,
>
> Since commit 5d2ee7122c73 went upstream in kernel v5.0, does this patch need
> a "Cc: stable" tag?
I guess it does, I'll add it.
--
Jens Axboe
