cfq: set workload as expired if it doesn't have any slice left

When a group is resumed, if it doesn't have workload slice left,
we should set workload_expires as expired. Otherwise, we might
start from where we left in previous group by error.
Thanks the idea from Corrado.

Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index f3f62394b986..e2f80463ed0d 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -2113,7 +2113,9 @@ static void cfq_choose_cfqg(struct cfq_data *cfqd)
                 cfqd->workload_expires = jiffies + cfqg->saved_workload_slice;
                 cfqd->serving_type = cfqg->saved_workload;
                 cfqd->serving_prio = cfqg->saved_serving_prio;
-        }
+        } else
+                cfqd->workload_expires = jiffies - 1;
+
         choose_service_tree(cfqd, cfqg);
 }