On Fri, 2012-07-06 at 12:04 +0800, Lin Ming wrote:
> When a request is added:
> If device is suspended or is suspending and the request is not a
> PM request, resume the device.
>
> When a 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.
> Return NULL for other cases.
This is a complete reinvention of the quiesce state, just with new names
and moved up to block in part ... why do we have to have two separate
systems for stopping a device and sending special commands when the
device is suspended, why not just one?
James
> Signed-off-by: Lin Ming <ming.m.lin@xxxxxxxxx>
> ---
> block/blk-core.c | 7 +++++++
> block/elevator.c | 4 ++++
> include/linux/blkdev.h | 37 +++++++++++++++++++++++++++++++++++++
> 3 files changed, 48 insertions(+)
>
> diff --git a/block/blk-core.c b/block/blk-core.c
> index 1cc80ae..cb93501 100644
> --- a/block/blk-core.c
> +++ b/block/blk-core.c
> @@ -1224,6 +1224,8 @@ void __blk_put_request(struct request_queue *q, struct request *req)
> if (unlikely(--req->ref_count))
> return;
>
> + blk_pm_put_request(q);
> +
> elv_completed_request(q, req);
>
> /* this is a bio leak */
> @@ -2012,6 +2014,11 @@ 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
> diff --git a/block/elevator.c b/block/elevator.c
> index 6a55d41..37c1a2b 100644
> --- a/block/elevator.c
> +++ b/block/elevator.c
> @@ -536,6 +536,8 @@ void elv_requeue_request(struct request_queue *q, struct request *rq)
>
> rq->cmd_flags &= ~REQ_STARTED;
>
> + blk_pm_requeue_request(q);
> +
> __elv_add_request(q, rq, ELEVATOR_INSERT_REQUEUE);
> }
>
> @@ -558,6 +560,8 @@ 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) {
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index 9395d39..c8c5951 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -908,6 +908,36 @@ 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_queue *q)
> +{
> + if (!(--q->nr_pending) && q->dev)
> + pm_runtime_mark_last_busy(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_queue *q)
> +{
> + q->nr_pending--;
> +}
> +
> +static inline void blk_pm_add_request(struct request_queue *q,
> + struct request *rq)
> +{
> + if (q->nr_pending++ == 0 && !(rq->cmd_flags & REQ_PM) &&
> + (q->rpm_status == RPM_SUSPENDED ||
> + q->rpm_status == RPM_SUSPENDING) && q->dev)
> + pm_request_resume(q->dev);
> +}
> #else
> static inline void blk_pm_runtime_init(struct request_queue *q,
> struct device *dev) {}
> @@ -918,6 +948,13 @@ static inline int blk_pre_runtime_suspend(struct request_queue *q)
> static inline void blk_post_runtime_suspend(struct request_queue *q, int err) {}
> static inline void blk_pre_runtime_resume(struct request_queue *q) {}
> static inline void blk_post_runtime_resume(struct request_queue *q, int err) {}
> +
> +static inline void blk_pm_put_request(struct request_queue *q) {}
> +static inline struct request *blk_pm_peek_request(
> + struct request_queue *q, struct request *rq) { return rq; }
> +static inline void blk_pm_requeue_request(struct request_queue *q) {}
> +static inline void blk_pm_add_request(struct request_queue *q,
> + struct request *req) {}
> #endif
>
> /*
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