[PATCH] Self-adaption blkcg

[Joeytao]

---
 block/cfq-iosched.c       |   41 ++++++++++++++++++++++++++++++++++++++---
 include/linux/iocontext.h |    5 +++++
 2 files changed, 43 insertions(+), 3 deletions(-)

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 23500ac..79296de 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -288,6 +288,8 @@ struct cfq_data {
 	unsigned int cfq_group_idle;
 	unsigned int cfq_latency;
 
+    unsigned int cfq_target_latency; 
+    unsigned int cfq_write_isolation; 
 	unsigned int cic_index;
 	struct list_head cic_list;
 
@@ -589,7 +591,7 @@ cfq_group_slice(struct cfq_data *cfqd, struct cfq_group
*cfqg)
 {
 	struct cfq_rb_root *st = &cfqd->grp_service_tree;
 
-	return cfq_target_latency * cfqg->weight / st->total_weight;
+	return cfqd->cfq_target_latency * cfqg->weight / st->total_weight;
 }
 
 static inline unsigned
@@ -2028,6 +2031,14 @@ static void cfq_arm_slice_timer(struct cfq_data
*cfqd)
 			     cic->ttime_mean);
 		return;
 	}
+	
+	/* 
+	 * added by joeytao,   
+	 * If our average await_time is 0, then don't idle. This is for requests
of 
+	 * write,because if the cache of disk is on, it's no need to wait.
+	 */
+	if(!cfqd->cfq_write_isolation && sample_valid(cic->awtime_samples) &&
(cic->awtime_mean==0))
+		return;
 
 	/* There are other queues in the group, don't do group idle */
 	if (group_idle && cfqq->cfqg->nr_cfqq > 1)
@@ -2243,7 +2254,7 @@ new_workload:
 		 * 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 = cfqd->cfq_target_latency * cfqg_busy_async_queues(cfqd, cfqg);
 		tmp = tmp/cfqd->busy_queues;
 		slice = min_t(unsigned, slice, tmp);
 
@@ -3228,10 +3239,21 @@ err:
 }
 
 static void
+cfq_update_io_awaittime(struct cfq_data *cfqd, struct cfq_io_context *cic)
+{
+	unsigned long elapsed = jiffies - cic->last_end_request;
+	unsigned long awtime = min(elapsed, 2UL * 16);
+
+	cic->awtime_samples = (7*cic->awtime_samples + 256) / 8;
+	cic->awtime_total = (7*cic->awtime_total + 256*awtime) / 8;
+	cic->awtime_mean = (cic->awtime_total + 128) / cic->awtime_samples;
+}   
+
+static void
 cfq_update_io_thinktime(struct cfq_data *cfqd, struct cfq_io_context *cic)
 {
 	unsigned long elapsed = jiffies - cic->last_end_request;
-	unsigned long ttime = min(elapsed, 2UL * cfqd->cfq_slice_idle);
+	unsigned long ttime = min(elapsed, 2UL * 8);
 
 	cic->ttime_samples = (7*cic->ttime_samples + 256) / 8;
 	cic->ttime_total = (7*cic->ttime_total + 256*ttime) / 8;
@@ -3573,6 +3595,7 @@ static void cfq_completed_request(struct request_queue
*q, struct request *rq)
 	cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]--;
 
 	if (sync) {
+		cfq_update_io_awaittime(cfqd,RQ_CIC(rq)); /* added by joeytao,
2013.8.27*/
 		RQ_CIC(rq)->last_end_request = now;
 		if (!time_after(rq->start_time + cfqd->cfq_fifo_expire[1], now))
 			cfqd->last_delayed_sync = now;
@@ -4075,6 +4098,12 @@ static void *cfq_init_queue(struct request_queue *q)
 	cfqd->cfq_back_penalty = cfq_back_penalty;
 	cfqd->cfq_slice[0] = cfq_slice_async;
 	cfqd->cfq_slice[1] = cfq_slice_sync;
+	cfqd->cfq_target_latency = cfq_target_latency; /* added by joeytao,
2013.8.5 */
+#ifdef CONFIG_CFQ_GROUP_IOSCHED
+	cfqd->cfq_write_isolation = 0; /* added by joeytao, 2013.8.16 */
+#else
+	cfqd->cfq_write_isolation = 1; /* added by joeytao, 2013.8.21 */
+#endif
 	cfqd->cfq_slice_async_rq = cfq_slice_async_rq;
 	cfqd->cfq_slice_idle = cfq_slice_idle;
 	cfqd->cfq_group_idle = cfq_group_idle;
@@ -4154,6 +4183,8 @@ SHOW_FUNCTION(cfq_slice_sync_show, cfqd->cfq_slice[1],
1);
 SHOW_FUNCTION(cfq_slice_async_show, cfqd->cfq_slice[0], 1);
 SHOW_FUNCTION(cfq_slice_async_rq_show, cfqd->cfq_slice_async_rq, 0);
 SHOW_FUNCTION(cfq_low_latency_show, cfqd->cfq_latency, 0);
+SHOW_FUNCTION(cfq_target_latency_show, cfqd->cfq_target_latency, 1);
+SHOW_FUNCTION(cfq_write_isolation_show, cfqd->cfq_write_isolation, 0); 
 #undef SHOW_FUNCTION
 
 #define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV)			\
@@ -4187,6 +4218,8 @@ STORE_FUNCTION(cfq_slice_async_store,
&cfqd->cfq_slice[0], 1, UINT_MAX, 1);
 STORE_FUNCTION(cfq_slice_async_rq_store, &cfqd->cfq_slice_async_rq, 1,
 		UINT_MAX, 0);
 STORE_FUNCTION(cfq_low_latency_store, &cfqd->cfq_latency, 0, 1, 0);
+STORE_FUNCTION(cfq_target_latency_store, &cfqd->cfq_target_latency, 1,
UINT_MAX, 1);
+STORE_FUNCTION(cfq_write_isolation_store, &cfqd->cfq_write_isolation, 0,
UINT_MAX, 0); 
 #undef STORE_FUNCTION
 
 #define CFQ_ATTR(name) \
@@ -4204,6 +4237,8 @@ static struct elv_fs_entry cfq_attrs[] = {
 	CFQ_ATTR(slice_idle),
 	CFQ_ATTR(group_idle),
 	CFQ_ATTR(low_latency),
+	CFQ_ATTR(target_latency),
+	CFQ_ATTR(write_isolation),
 	__ATTR_NULL
 };
 
diff --git a/include/linux/iocontext.h b/include/linux/iocontext.h
index b2eee89..0c45b09 100644
--- a/include/linux/iocontext.h
+++ b/include/linux/iocontext.h
@@ -18,6 +18,11 @@ struct cfq_io_context {
 	unsigned long ttime_samples;
 	unsigned long ttime_mean;
 
+	/* added by joeytao */
+	unsigned long awtime_total;
+	unsigned long awtime_samples;
+	unsigned long awtime_mean;
+
 	struct list_head queue_list;
 	struct hlist_node cic_list;
 
-- 
1.7.1





--
View this message in context: http://linux-kernel.2935.n7.nabble.com/performance-drop-after-using-blkcg-tp567957p710883.html
Sent from the Linux Kernel mailing list archive at Nabble.com.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/