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-rw-r--r--block/cfq-iosched.c36
1 files changed, 31 insertions, 5 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 1cc10489eaf0..b9e483d9031e 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -408,6 +408,13 @@ static inline int cfq_group_busy_queues_wl(enum wl_prio_t wl,
+ cfqg->service_trees[wl][SYNC_WORKLOAD].count;
}
+static inline int cfqg_busy_async_queues(struct cfq_data *cfqd,
+ struct cfq_group *cfqg)
+{
+ return cfqg->service_trees[RT_WORKLOAD][ASYNC_WORKLOAD].count
+ + cfqg->service_trees[BE_WORKLOAD][ASYNC_WORKLOAD].count;
+}
+
static void cfq_dispatch_insert(struct request_queue *, struct request *);
static struct cfq_queue *cfq_get_queue(struct cfq_data *, bool,
struct io_context *, gfp_t);
@@ -895,13 +902,19 @@ static void cfq_group_served(struct cfq_data *cfqd, struct cfq_group *cfqg,
struct cfq_queue *cfqq)
{
struct cfq_rb_root *st = &cfqd->grp_service_tree;
- unsigned int used_sl;
+ unsigned int used_sl, charge_sl;
+ int nr_sync = cfqg->nr_cfqq - cfqg_busy_async_queues(cfqd, cfqg)
+ - cfqg->service_tree_idle.count;
+
+ BUG_ON(nr_sync < 0);
+ used_sl = charge_sl = cfq_cfqq_slice_usage(cfqq);
- used_sl = cfq_cfqq_slice_usage(cfqq);
+ if (!cfq_cfqq_sync(cfqq) && !nr_sync)
+ charge_sl = cfqq->allocated_slice;
/* Can't update vdisktime while group is on service tree */
cfq_rb_erase(&cfqg->rb_node, st);
- cfqg->vdisktime += cfq_scale_slice(used_sl, cfqg);
+ cfqg->vdisktime += cfq_scale_slice(charge_sl, cfqg);
__cfq_group_service_tree_add(st, cfqg);
/* This group is being expired. Save the context */
@@ -2016,11 +2029,24 @@ static void choose_service_tree(struct cfq_data *cfqd, struct cfq_group *cfqg)
max_t(unsigned, cfqg->busy_queues_avg[cfqd->serving_prio],
cfq_group_busy_queues_wl(cfqd->serving_prio, cfqd, cfqg));
- if (cfqd->serving_type == ASYNC_WORKLOAD)
+ if (cfqd->serving_type == ASYNC_WORKLOAD) {
+ unsigned int tmp;
+
+ /*
+ * Async queues are currently system wide. Just taking
+ * proportion of queues with-in same group will lead to higher
+ * async ratio system wide as generally root group is going
+ * to have higher weight. A more accurate thing would be to
+ * calculate system wide asnc/sync ratio.
+ */
+ tmp = cfq_target_latency * cfqg_busy_async_queues(cfqd, cfqg);
+ tmp = tmp/cfqd->busy_queues;
+ slice = min_t(unsigned, slice, tmp);
+
/* async workload slice is scaled down according to
* the sync/async slice ratio. */
slice = slice * cfqd->cfq_slice[0] / cfqd->cfq_slice[1];
- else
+ } else
/* sync workload slice is at least 2 * cfq_slice_idle */
slice = max(slice, 2 * cfqd->cfq_slice_idle);