Re: [PATCH v6 3/4] block: implement runtime pm strategy
From: Alan Stern <stern@rowland.harvard.edu>
Date: 2013-01-07 17:21:29
Also in:
linux-scsi, lkml
On Sun, 6 Jan 2013, Aaron Lu wrote:
From: Lin Ming <redacted>
When a request is added:
If device is suspended or is suspending and the request is not a
PM request, resume the device.
When the last request finishes:
Call pm_runtime_mark_last_busy() and pm_runtime_autosuspend().
When pick a request:
If device is resuming/suspending, then only PM request is allowed to go.
Return NULL for other cases.
[aaron.lu@intel.com: PM request does not involve nr_pending counting]
[aaron.lu@intel.com: No need to check q->dev]
[aaron.lu@intel.com: Autosuspend when the last request finished]
Signed-off-by: Lin Ming <redacted>
Signed-off-by: Aaron Lu <redacted>quoted hunk ↗ jump to hunk
--- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h@@ -974,6 +974,40 @@ extern int blk_pre_runtime_suspend(struct request_queue *q); extern void blk_post_runtime_suspend(struct request_queue *q, int err); extern void blk_pre_runtime_resume(struct request_queue *q); extern void blk_post_runtime_resume(struct request_queue *q, int err); + +static inline void blk_pm_put_request(struct request *rq) +{ + if (!(rq->cmd_flags & REQ_PM) && !--rq->q->nr_pending) { + pm_runtime_mark_last_busy(rq->q->dev); + pm_runtime_autosuspend(rq->q->dev); + } +} + +static inline struct request *blk_pm_peek_request( + struct request_queue *q, struct request *rq) +{ + if (q->rpm_status == RPM_SUSPENDED || + (q->rpm_status != RPM_ACTIVE && !(rq->cmd_flags & REQ_PM))) + return NULL; + else + return rq; +} + +static inline void blk_pm_requeue_request(struct request *rq) +{ + if (!(rq->cmd_flags & REQ_PM)) + rq->q->nr_pending--; +} + +static inline void blk_pm_add_request(struct request_queue *q, + struct request *rq) +{ + if (!(rq->cmd_flags & REQ_PM) && + q->nr_pending++ == 0 && + (q->rpm_status == RPM_SUSPENDED || + q->rpm_status == RPM_SUSPENDING)) + pm_request_resume(q->dev); +}
These routines also don't belong in include/linux. And they don't need to be marked inline. Alan Stern