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>

diff --git a/block/blk-iocost.c b/block/blk-iocost.c
index 09f22f9a6ba4a7c58db39ba80503cc165c1f7d75..7dd1424d5833cf24ae3df82cf7df4840fc1a60f9 100644 (file)
--- a/block/blk-iocost.c
+++ b/block/blk-iocost.c
@@ -2069,40 +2069,21 @@ static void ioc_forgive_debts(struct ioc *ioc, u64 usage_us_sum, int nr_debtors,
        }
 }
 
-static void ioc_timer_fn(struct timer_list *timer)
+/*
+ * 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)
 {
-       struct ioc *ioc = container_of(timer, struct ioc, timer);
+       int nr_debtors = 0;
        struct ioc_gq *iocg, *tiocg;
-       struct ioc_now now;
-       LIST_HEAD(surpluses);
-       int nr_debtors = 0, 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];
-       u32 missed_ppm[2], rq_wait_pct;
-       u64 period_vtime;
-       int prev_busy_level;
-
-       /* how were the latencies during the period? */
-       ioc_lat_stat(ioc, missed_ppm, &rq_wait_pct);
 
-       /* take care of active iocgs */
-       spin_lock_irq(&ioc->lock);
-
-       ioc_now(ioc, &now);
-
-       period_vtime = now.vnow - ioc->period_at_vtime;
-       if (WARN_ON_ONCE(!period_vtime)) {
-               spin_unlock_irq(&ioc->lock);
-               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))
@@ -2112,24 +2093,24 @@ static void ioc_timer_fn(struct timer_list *timer)
 
                /* 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;
+                       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;
+                               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;
+                               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);
+                       iocg_kick_waitq(iocg, true, now);
                        if (iocg->abs_vdebt || iocg->delay)
                                nr_debtors++;
                } else if (iocg_is_idle(iocg)) {
@@ -2143,7 +2124,7 @@ static void ioc_timer_fn(struct timer_list *timer)
                         * error and throw away. On reactivation, it'll start
                         * with the target budget.
                         */
-                       excess = now.vnow - vtime - ioc->margins.target;
+                       excess = now->vnow - vtime - ioc->margins.target;
                        if (excess > 0) {
                                u32 old_hwi;
 
@@ -2152,13 +2133,46 @@ static void ioc_timer_fn(struct timer_list *timer)
                                                            WEIGHT_ONE);
                        }
 
-                       __propagate_weights(iocg, 0, 0, false, &now);
+                       __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, 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];
+       u32 missed_ppm[2], rq_wait_pct;
+       u64 period_vtime;
+       int prev_busy_level;
+
+       /* how were the latencies during the period? */
+       ioc_lat_stat(ioc, missed_ppm, &rq_wait_pct);
+
+       /* take care of active iocgs */
+       spin_lock_irq(&ioc->lock);
+
+       ioc_now(ioc, &now);
+
+       period_vtime = now.vnow - ioc->period_at_vtime;
+       if (WARN_ON_ONCE(!period_vtime)) {
+               spin_unlock_irq(&ioc->lock);
+               return;
+       }
+
+       nr_debtors = ioc_check_iocgs(ioc, &now);
 
        /*
         * Wait and indebt stat are flushed above and the donation calculation