4 commits

Author	SHA1	Message	Date
Omar Sandoval	efd4b81abb	blk-stat: fix blk_stat_sum() if all samples are batched ... We need to flush the batch _before_ we check the number of samples, otherwise we'll miss all of the batched samples. Fixes: cf43e6b ("block: add scalable completion tracking of requests") Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>	2017-03-16 09:46:14 -06:00
Jens Axboe	7cd54aa843	blk-stat: fix a few cases of missing batch flushing ... Everytime we need to read ->nr_samples, we should have flushed the batch first. The non-mq read path also needs to flush the batch. Signed-off-by: Jens Axboe <axboe@fb.com>	2016-12-09 13:08:35 -07:00
Shaohua Li	209200efa3	blk-stat: fix a typo ... Signed-off-by: Shaohua Li <shli@fb.com> Fixes: cf43e6be86 ("block: add scalable completion tracking of requests") Signed-off-by: Jens Axboe <axboe@fb.com>	2016-12-02 20:17:43 -07:00
Jens Axboe	cf43e6be86	block: add scalable completion tracking of requests ... For legacy block, we simply track them in the request queue. For blk-mq, we track them on a per-sw queue basis, which we can then sum up through the hardware queues and finally to a per device state. The stats are tracked in, roughly, 0.1s interval windows. Add sysfs files to display the stats. The feature is off by default, to avoid any extra overhead. In-kernel users of it can turn it on by setting QUEUE_FLAG_STATS in the queue flags. We currently don't turn it on if someone just reads any of the stats files, that is something we could add as well. Signed-off-by: Jens Axboe <axboe@fb.com>	2016-11-10 13:53:26 -07:00