diff mbox series

[v6,10/12] block: Change the runtime power management approach (1/2)

Message ID 20180809194149.15285-11-bart.vanassche@wdc.com (mailing list archive)
State New, archived
Headers show
Series blk-mq: Implement runtime power management | expand

Commit Message

Bart Van Assche Aug. 9, 2018, 7:41 p.m. UTC
Instead of scheduling runtime resume of a request queue after a
request has been queued, schedule asynchronous resume during request
allocation. The new pm_request_resume() calls occur after
blk_queue_enter() has increased the q_usage_counter request queue
member. This change is needed for a later patch that will make request
allocation block while the queue status is not RPM_ACTIVE.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Jianchao Wang <jianchao.w.wang@oracle.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Alan Stern <stern@rowland.harvard.edu>
---
 block/blk-core.c | 2 ++
 block/blk-mq.c   | 2 ++
 block/elevator.c | 1 -
 3 files changed, 4 insertions(+), 1 deletion(-)

Comments

jianchao.wang Aug. 10, 2018, 1:59 a.m. UTC | #1
Hi Bart

On 08/10/2018 03:41 AM, Bart Van Assche wrote:
> Instead of scheduling runtime resume of a request queue after a
> request has been queued, schedule asynchronous resume during request
> allocation. The new pm_request_resume() calls occur after
> blk_queue_enter() has increased the q_usage_counter request queue
                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> member. This change is needed for a later patch that will make request
> allocation block while the queue status is not RPM_ACTIVE.

Is it "after getting q->q_usage_counter fails" ?
And also this blk_pm_request_resume  will not affect the normal path. ;)

Thanks
Jianchao
Bart Van Assche Aug. 10, 2018, 3:20 p.m. UTC | #2
On Fri, 2018-08-10 at 09:59 +0800, jianchao.wang wrote:
> On 08/10/2018 03:41 AM, Bart Van Assche wrote:
> > Instead of scheduling runtime resume of a request queue after a
> > request has been queued, schedule asynchronous resume during request
> > allocation. The new pm_request_resume() calls occur after
> > blk_queue_enter() has increased the q_usage_counter request queue
> 
>                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > member. This change is needed for a later patch that will make request
> > allocation block while the queue status is not RPM_ACTIVE.
> 
> Is it "after getting q->q_usage_counter fails" ?
> And also this blk_pm_request_resume  will not affect the normal path. ;)

Right, the commit message needs to be brought in sync with the code.

Bart.
diff mbox series

Patch

diff --git a/block/blk-core.c b/block/blk-core.c
index 59dd98585eb0..f30545fb2de2 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -972,6 +972,8 @@  int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags)
 		if (success)
 			return 0;
 
+		blk_pm_request_resume(q);
+
 		if (flags & BLK_MQ_REQ_NOWAIT)
 			return -EBUSY;
 
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 2a0eb058ba5a..24439735f20b 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -33,6 +33,7 @@ 
 #include "blk-mq.h"
 #include "blk-mq-debugfs.h"
 #include "blk-mq-tag.h"
+#include "blk-pm.h"
 #include "blk-stat.h"
 #include "blk-mq-sched.h"
 #include "blk-rq-qos.h"
@@ -473,6 +474,7 @@  static void __blk_mq_free_request(struct request *rq)
 	struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu);
 	const int sched_tag = rq->internal_tag;
 
+	blk_pm_mark_last_busy(rq);
 	if (rq->tag != -1)
 		blk_mq_put_tag(hctx, hctx->tags, ctx, rq->tag);
 	if (sched_tag != -1)
diff --git a/block/elevator.c b/block/elevator.c
index 00c5d8dbce16..4c15f0240c99 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -601,7 +601,6 @@  void __elv_add_request(struct request_queue *q, struct request *rq, int where)
 	trace_block_rq_insert(q, rq);
 
 	blk_pm_add_request(q, rq);
-	blk_pm_request_resume(q);
 
 	rq->q = q;