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authorLin Ming <ming.m.lin@intel.com>2013-03-23 11:42:27 +0800
committerJens Axboe <axboe@kernel.dk>2013-03-22 22:22:15 -0600
commitc8158819d506a8aedeca53c52dfb709a0aabe011 (patch)
treeacabca463a1898931cd325c415a51a819eabee00 /block/elevator.c
parent6c9546675864f51506af69eca388e5d922942c56 (diff)
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.c26
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) {