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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/blk-core.c
parent6c9546675864f51506af69eca388e5d922942c56 (diff)
downloadlinux-linaro-stable-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/blk-core.c')
-rw-r--r--block/blk-core.c39
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