blk-iocost: make iocg_kick_waitq() call iocg_kick_delay() after paying debt

iocg_kick_waitq() is the function which pays debt and iocg_kick_delay()
updates the actual delay status accordingly. If iocg_kick_delay() is not
called after iocg_kick_delay() updated debt, unnecessarily large delays can
be applied temporarily.

Let's make sure such conditions don't occur by making iocg_kick_waitq()
always call iocg_kick_delay() after paying debt.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-iocost.c b/block/blk-iocost.c
index ac22d76..b2b8dfb 100644 (file)
--- a/block/blk-iocost.c
+++ b/block/blk-iocost.c
@@ -1226,6 +1226,8 @@ static void iocg_kick_waitq(struct ioc_gq *iocg, struct ioc_now *now)
                atomic64_add(delta, &iocg->vtime);
                atomic64_add(delta, &iocg->done_vtime);
                iocg->abs_vdebt -= abs_delta;
+
+               iocg_kick_delay(iocg, now);
        }
 
        /*
@@ -1383,7 +1385,6 @@ static void ioc_timer_fn(struct timer_list *timer)
                if (waitqueue_active(&iocg->waitq) || iocg->abs_vdebt) {
                        /* might be oversleeping vtime / hweight changes, kick */
                        iocg_kick_waitq(iocg, &now);
-                       iocg_kick_delay(iocg, &now);
                } else if (iocg_is_idle(iocg)) {
                        /* no waiter and idle, deactivate */
                        iocg->last_inuse = iocg->inuse;