block, bfq: fix switch back from soft-rt weitgh-raising

A bfq_queue may happen to be deemed as soft real-time while it is
still enjoying interactive weight-raising. If this happens because of
a false positive, then the bfq_queue is likely to loose its soft
real-time status soon. Upon losing such a status, the bfq_queue must
get back its interactive weight-raising, if its interactive period is
not over yet. But this case is not handled. This commit corrects this
error.

Tested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Paolo Valente 2021-01-25 20:02:45 +01:00 committed by Jens Axboe
parent 7f1995c27b
commit d1f600fa47

View file

@ -5290,8 +5290,26 @@ bfq_update_io_seektime(struct bfq_data *bfqd, struct bfq_queue *bfqq,
if (bfqq->wr_coeff > 1 &&
bfqq->wr_cur_max_time == bfqd->bfq_wr_rt_max_time &&
BFQQ_TOTALLY_SEEKY(bfqq))
bfq_bfqq_end_wr(bfqq);
BFQQ_TOTALLY_SEEKY(bfqq)) {
if (time_is_before_jiffies(bfqq->wr_start_at_switch_to_srt +
bfq_wr_duration(bfqd))) {
/*
* In soft_rt weight raising with the
* interactive-weight-raising period
* elapsed (so no switch back to
* interactive weight raising).
*/
bfq_bfqq_end_wr(bfqq);
} else { /*
* stopping soft_rt weight raising
* while still in interactive period,
* switch back to interactive weight
* raising
*/
switch_back_to_interactive_wr(bfqq, bfqd);
bfqq->entity.prio_changed = 1;
}
}
}
static void bfq_update_has_short_ttime(struct bfq_data *bfqd,