| Message ID | 20190626195919.107425-1-dianders@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | block, bfq: Init saved_wr_start_at_switch_to_srt in unlikely case | expand |
On Wed, Jun 26, 2019 at 1:00 PM Douglas Anderson <dianders@chromium.org> wrote: > > Some debug code suggested by Paolo was tripping when I did reboot > stress tests. Specifically in bfq_bfqq_resume_state() > "bic->saved_wr_start_at_switch_to_srt" was later than the current > value of "jiffies". A bit of debugging showed that > "bic->saved_wr_start_at_switch_to_srt" was actually 0 and a bit more > debugging showed that was because we had run through the "unlikely" > case in the bfq_bfqq_save_state() function. > > Let's init "saved_wr_start_at_switch_to_srt" in the unlikely case to > something sane. > > NOTE: this fixes no known real-world errors. > > Signed-off-by: Douglas Anderson <dianders@chromium.org> > Reviewed-by: Paolo Valente <paolo.valente@linaro.org> Reviewed-by: Guenter Roeck <groeck@chromium.org> > > --- > Paolo said to add his Reviewed-by in https://crrev.com/c/1678756. > > block/bfq-iosched.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c > index 72840ebf953e..008c93d6b8d7 100644 > --- a/block/bfq-iosched.c > +++ b/block/bfq-iosched.c > @@ -2678,6 +2678,7 @@ static void bfq_bfqq_save_state(struct bfq_queue *bfqq) > * to enjoy weight raising if split soon. > */ > bic->saved_wr_coeff = bfqq->bfqd->bfq_wr_coeff; > + bic->saved_wr_start_at_switch_to_srt = bfq_smallest_from_now(); > bic->saved_wr_cur_max_time = bfq_wr_duration(bfqq->bfqd); > bic->saved_last_wr_start_finish = jiffies; > } else { > -- > 2.22.0.410.gd8fdbe21b5-goog >
On 6/26/19 1:59 PM, Douglas Anderson wrote: > Some debug code suggested by Paolo was tripping when I did reboot > stress tests. Specifically in bfq_bfqq_resume_state() > "bic->saved_wr_start_at_switch_to_srt" was later than the current > value of "jiffies". A bit of debugging showed that > "bic->saved_wr_start_at_switch_to_srt" was actually 0 and a bit more > debugging showed that was because we had run through the "unlikely" > case in the bfq_bfqq_save_state() function. > > Let's init "saved_wr_start_at_switch_to_srt" in the unlikely case to > something sane. > > NOTE: this fixes no known real-world errors. Applied, thanks.
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 72840ebf953e..008c93d6b8d7 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -2678,6 +2678,7 @@ static void bfq_bfqq_save_state(struct bfq_queue *bfqq) * to enjoy weight raising if split soon. */ bic->saved_wr_coeff = bfqq->bfqd->bfq_wr_coeff; + bic->saved_wr_start_at_switch_to_srt = bfq_smallest_from_now(); bic->saved_wr_cur_max_time = bfq_wr_duration(bfqq->bfqd); bic->saved_last_wr_start_finish = jiffies; } else {