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| 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/blk-core.c | |
| parent | 6c9546675864f51506af69eca388e5d922942c56 (diff) | |
| download | linux-c8158819d506a8aedeca53c52dfb709a0aabe011.tar.gz linux-c8158819d506a8aedeca53c52dfb709a0aabe011.tar.bz2 linux-c8158819d506a8aedeca53c52dfb709a0aabe011.zip | |
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/blk-core.c')
| -rw-r--r-- | block/blk-core.c | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index 123d240132bf..441f3488a766 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1264,6 +1264,16 @@ void part_round_stats(int cpu, struct hd_struct *part) } EXPORT_SYMBOL_GPL(part_round_stats); +#ifdef CONFIG_PM_RUNTIME +static void blk_pm_put_request(struct request *rq) +{ + if (rq->q->dev && !(rq->cmd_flags & REQ_PM) && !--rq->q->nr_pending) + pm_runtime_mark_last_busy(rq->q->dev); +} +#else +static inline void blk_pm_put_request(struct request *rq) {} +#endif + /* * queue lock must be held */ @@ -1274,6 +1284,8 @@ void __blk_put_request(struct request_queue *q, struct request *req) if (unlikely(--req->ref_count)) return; + blk_pm_put_request(req); + elv_completed_request(q, req); /* this is a bio leak */ @@ -2053,6 +2065,28 @@ static void blk_account_io_done(struct request *req) } } +#ifdef CONFIG_PM_RUNTIME +/* + * Don't process normal requests when queue is suspended + * or in the process of suspending/resuming + */ +static struct request *blk_pm_peek_request(struct request_queue *q, + struct request *rq) +{ + if (q->dev && (q->rpm_status == RPM_SUSPENDED || + (q->rpm_status != RPM_ACTIVE && !(rq->cmd_flags & REQ_PM)))) + return NULL; + else + return rq; +} +#else +static inline struct request *blk_pm_peek_request(struct request_queue *q, + struct request *rq) +{ + return rq; +} +#endif + /** * blk_peek_request - peek at the top of a request queue * @q: request queue to peek at @@ -2075,6 +2109,11 @@ struct request *blk_peek_request(struct request_queue *q) int ret; while ((rq = __elv_next_request(q)) != NULL) { + + rq = blk_pm_peek_request(q, rq); + if (!rq) + break; + if (!(rq->cmd_flags & REQ_STARTED)) { /* * This is the first time the device driver |