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blk-iocost: Factor out the active iocgs' state check into a separate function 

Factor out the iocgs' state check into a separate function to
simplify the ioc_timer_fn().

No functional change.

Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Baolin Wang 2020-11-26 16:16:14 +08:00 committed by Jens Axboe
parent c09245f61c
commit 2474787a75
1 changed files with 77 additions and 63 deletions
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140
block/blk-iocost.c
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@ -2069,13 +2069,88 @@ static void ioc_forgive_debts(struct ioc *ioc, u64 usage_us_sum, int nr_debtors,
}
}
/*
* Check the active iocgs' state to avoid oversleeping and deactive
* idle iocgs.
*
* Since waiters determine the sleep durations based on the vrate
* they saw at the time of sleep, if vrate has increased, some
* waiters could be sleeping for too long. Wake up tardy waiters
* which should have woken up in the last period and expire idle
* iocgs.
*/
static int ioc_check_iocgs(struct ioc *ioc, struct ioc_now *now)
{
int nr_debtors = 0;
struct ioc_gq *iocg, *tiocg;
list_for_each_entry_safe(iocg, tiocg, &ioc->active_iocgs, active_list) {
if (!waitqueue_active(&iocg->waitq) && !iocg->abs_vdebt &&
!iocg->delay && !iocg_is_idle(iocg))
continue;
spin_lock(&iocg->waitq.lock);
/* flush wait and indebt stat deltas */
if (iocg->wait_since) {
iocg->local_stat.wait_us += now->now - iocg->wait_since;
iocg->wait_since = now->now;
}
if (iocg->indebt_since) {
iocg->local_stat.indebt_us +=
now->now - iocg->indebt_since;
iocg->indebt_since = now->now;
}
if (iocg->indelay_since) {
iocg->local_stat.indelay_us +=
now->now - iocg->indelay_since;
iocg->indelay_since = now->now;
}
if (waitqueue_active(&iocg->waitq) || iocg->abs_vdebt ||
iocg->delay) {
/* might be oversleeping vtime / hweight changes, kick */
iocg_kick_waitq(iocg, true, now);
if (iocg->abs_vdebt || iocg->delay)
nr_debtors++;
} else if (iocg_is_idle(iocg)) {
/* no waiter and idle, deactivate */
u64 vtime = atomic64_read(&iocg->vtime);
s64 excess;
/*
* @iocg has been inactive for a full duration and will
* have a high budget. Account anything above target as
* error and throw away. On reactivation, it'll start
* with the target budget.
*/
excess = now->vnow - vtime - ioc->margins.target;
if (excess > 0) {
u32 old_hwi;
current_hweight(iocg, NULL, &old_hwi);
ioc->vtime_err -= div64_u64(excess * old_hwi,
WEIGHT_ONE);
}
__propagate_weights(iocg, 0, 0, false, now);
list_del_init(&iocg->active_list);
}
spin_unlock(&iocg->waitq.lock);
}
commit_weights(ioc);
return nr_debtors;
}
static void ioc_timer_fn(struct timer_list *timer)
{
struct ioc *ioc = container_of(timer, struct ioc, timer);
struct ioc_gq *iocg, *tiocg;
struct ioc_now now;
LIST_HEAD(surpluses);
int nr_debtors = 0, nr_shortages = 0, nr_lagging = 0;
int nr_debtors, nr_shortages = 0, nr_lagging = 0;
u64 usage_us_sum = 0;
u32 ppm_rthr = MILLION - ioc->params.qos[QOS_RPPM];
u32 ppm_wthr = MILLION - ioc->params.qos[QOS_WPPM];
@ -2097,68 +2172,7 @@ static void ioc_timer_fn(struct timer_list *timer)
return;
}
/*
* Waiters determine the sleep durations based on the vrate they
* saw at the time of sleep. If vrate has increased, some waiters
* could be sleeping for too long. Wake up tardy waiters which
* should have woken up in the last period and expire idle iocgs.
*/
list_for_each_entry_safe(iocg, tiocg, &ioc->active_iocgs, active_list) {
if (!waitqueue_active(&iocg->waitq) && !iocg->abs_vdebt &&
!iocg->delay && !iocg_is_idle(iocg))
continue;
spin_lock(&iocg->waitq.lock);
/* flush wait and indebt stat deltas */
if (iocg->wait_since) {
iocg->local_stat.wait_us += now.now - iocg->wait_since;
iocg->wait_since = now.now;
}
if (iocg->indebt_since) {
iocg->local_stat.indebt_us +=
now.now - iocg->indebt_since;
iocg->indebt_since = now.now;
}
if (iocg->indelay_since) {
iocg->local_stat.indelay_us +=
now.now - iocg->indelay_since;
iocg->indelay_since = now.now;
}
if (waitqueue_active(&iocg->waitq) || iocg->abs_vdebt ||
iocg->delay) {
/* might be oversleeping vtime / hweight changes, kick */
iocg_kick_waitq(iocg, true, &now);
if (iocg->abs_vdebt || iocg->delay)
nr_debtors++;
} else if (iocg_is_idle(iocg)) {
/* no waiter and idle, deactivate */
u64 vtime = atomic64_read(&iocg->vtime);
s64 excess;
/*
* @iocg has been inactive for a full duration and will
* have a high budget. Account anything above target as
* error and throw away. On reactivation, it'll start
* with the target budget.
*/
excess = now.vnow - vtime - ioc->margins.target;
if (excess > 0) {
u32 old_hwi;
current_hweight(iocg, NULL, &old_hwi);
ioc->vtime_err -= div64_u64(excess * old_hwi,
WEIGHT_ONE);
}
__propagate_weights(iocg, 0, 0, false, &now);
list_del_init(&iocg->active_list);
}
spin_unlock(&iocg->waitq.lock);
}
commit_weights(ioc);
nr_debtors = ioc_check_iocgs(ioc, &now);
/*
* Wait and indebt stat are flushed above and the donation calculation