blk-throttle: detect completed idle cgroup

[mirror_ubuntu-bionic-kernel.git] / block / blk-throttle.c

diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index d00c1c1e99e478099056eb2e592cddece6fe8a1a..014b2e96a423da2e4526b78f2b537595d613c8e2 100644 (file)
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -149,6 +149,8 @@ struct throtl_grp {
 
        unsigned long last_check_time;
 
+       unsigned long last_dispatch_time[2];
+
        /* When did we start a new slice */
        unsigned long slice_start[2];
        unsigned long slice_end[2];
@@ -445,11 +447,14 @@ static void tg_update_has_rules(struct throtl_grp *tg)
 
 static void throtl_pd_online(struct blkg_policy_data *pd)
 {
+       struct throtl_grp *tg = pd_to_tg(pd);
        /*
         * We don't want new groups to escape the limits of its ancestors.
         * Update has_rules[] after a new group is brought online.
         */
-       tg_update_has_rules(pd_to_tg(pd));
+       tg_update_has_rules(tg);
+       tg->last_dispatch_time[READ] = jiffies;
+       tg->last_dispatch_time[WRITE] = jiffies;
 }
 
 static void blk_throtl_update_limit_valid(struct throtl_data *td)
@@ -1615,6 +1620,12 @@ static bool throtl_tg_can_upgrade(struct throtl_grp *tg)
        if (write_limit && sq->nr_queued[WRITE] &&
            (!read_limit || sq->nr_queued[READ]))
                return true;
+
+       if (time_after_eq(jiffies,
+            tg->last_dispatch_time[READ] + tg->td->throtl_slice) &&
+           time_after_eq(jiffies,
+            tg->last_dispatch_time[WRITE] + tg->td->throtl_slice))
+               return true;
        return false;
 }
 
@@ -1692,6 +1703,11 @@ static bool throtl_tg_can_downgrade(struct throtl_grp *tg)
        struct throtl_data *td = tg->td;
        unsigned long now = jiffies;
 
+       if (time_after_eq(now, tg->last_dispatch_time[READ] +
+                                       td->throtl_slice) &&
+           time_after_eq(now, tg->last_dispatch_time[WRITE] +
+                                       td->throtl_slice))
+               return false;
        /*
         * If cgroup is below low limit, consider downgrade and throttle other
         * cgroups
@@ -1800,6 +1816,7 @@ bool blk_throtl_bio(struct request_queue *q, struct blkcg_gq *blkg,
 
 again:
        while (true) {
+               tg->last_dispatch_time[rw] = jiffies;
                if (tg->last_low_overflow_time[rw] == 0)
                        tg->last_low_overflow_time[rw] = jiffies;
                throtl_downgrade_check(tg);