diff options
| author | Lin Ming <ming.m.lin@intel.com> | 2013-03-23 11:42:27 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2013-03-22 22:22:15 -0600 |
| commit | c8158819d506a8aedeca53c52dfb709a0aabe011 (patch) | |
| tree | acabca463a1898931cd325c415a51a819eabee00 /block/elevator.c | |
| parent | 6c9546675864f51506af69eca388e5d922942c56 (diff) | |
| download | linux-c8158819d506a8aedeca53c52dfb709a0aabe011.tar.gz | |
block: implement runtime pm strategy
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().
When pick a request:
If device is resuming/suspending, then only PM request is allowed
to go.
The idea and API is designed by Alan Stern and described here:
http://marc.info/?l=linux-scsi&m=133727953625963&w=2
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/elevator.c')
| -rw-r--r-- | block/elevator.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/block/elevator.c b/block/elevator.c index a0ffdd943c98..eba5b04c29b1 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -34,6 +34,7 @@ #include <linux/blktrace_api.h> #include <linux/hash.h> #include <linux/uaccess.h> +#include <linux/pm_runtime.h> #include <trace/events/block.h> @@ -536,6 +537,27 @@ void elv_bio_merged(struct request_queue *q, struct request *rq, e->type->ops.elevator_bio_merged_fn(q, rq, bio); } +#ifdef CONFIG_PM_RUNTIME +static void blk_pm_requeue_request(struct request *rq) +{ + if (rq->q->dev && !(rq->cmd_flags & REQ_PM)) + rq->q->nr_pending--; +} + +static void blk_pm_add_request(struct request_queue *q, struct request *rq) +{ + if (q->dev && !(rq->cmd_flags & REQ_PM) && q->nr_pending++ == 0 && + (q->rpm_status == RPM_SUSPENDED || q->rpm_status == RPM_SUSPENDING)) + pm_request_resume(q->dev); +} +#else +static inline void blk_pm_requeue_request(struct request *rq) {} +static inline void blk_pm_add_request(struct request_queue *q, + struct request *rq) +{ +} +#endif + void elv_requeue_request(struct request_queue *q, struct request *rq) { /* @@ -550,6 +572,8 @@ void elv_requeue_request(struct request_queue *q, struct request *rq) rq->cmd_flags &= ~REQ_STARTED; + blk_pm_requeue_request(rq); + __elv_add_request(q, rq, ELEVATOR_INSERT_REQUEUE); } @@ -572,6 +596,8 @@ 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); + rq->q = q; if (rq->cmd_flags & REQ_SOFTBARRIER) { |