From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lin Ming Subject: [RFC PATCH v3 3/4] block: implement runtime pm strategy Date: Tue, 22 May 2012 15:21:31 +0800 Message-ID: <1337671292-15583-4-git-send-email-ming.m.lin@intel.com> References: <1337671292-15583-1-git-send-email-ming.m.lin@intel.com> Return-path: In-Reply-To: <1337671292-15583-1-git-send-email-ming.m.lin@intel.com> Sender: linux-kernel-owner@vger.kernel.org To: Jens Axboe , Alan Stern Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linux-scsi@vger.kernel.org List-Id: linux-scsi@vger.kernel.org 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 not active, then only PM request is allowed to go. Return NULL for other request. Signed-off-by: Lin Ming --- block/blk-core.c | 10 ++++++++++ block/elevator.c | 9 +++++++++ 2 files changed, 19 insertions(+), 0 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 2d8e38e..c3a5f3a 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1130,6 +1130,10 @@ void __blk_put_request(struct request_queue *q, struct request *req) if (unlikely(--req->ref_count)) return; + /* PM request is not accounted */ + if (!(req->cmd_flags & REQ_PM) && !(--q->nr_pending) && q->dev) + pm_runtime_mark_last_busy(q->dev); + elv_completed_request(q, req); /* this is a bio leak */ @@ -1918,6 +1922,12 @@ struct request *blk_peek_request(struct request_queue *q) int ret; while ((rq = __elv_next_request(q)) != NULL) { + /* Only PM request is allowed to go if the queue is suspended */ + if (q->rpm_status != RPM_ACTIVE && !(rq->cmd_flags & REQ_PM)) { + rq = NULL; + 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 f016855..06d83c5 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -34,6 +34,7 @@ #include #include #include +#include #include @@ -546,6 +547,9 @@ void elv_requeue_request(struct request_queue *q, struct request *rq) rq->cmd_flags &= ~REQ_STARTED; + /* __elv_add_request will increment the count */ + if (!(rq->cmd_flags & REQ_PM)) + q->nr_pending--; __elv_add_request(q, rq, ELEVATOR_INSERT_REQUEUE); } @@ -587,6 +591,11 @@ void __elv_add_request(struct request_queue *q, struct request *rq, int where) { trace_block_rq_insert(q, rq); + if (!(rq->cmd_flags & REQ_PM)) + if (q->nr_pending++ == 0 && (q->rpm_status == RPM_SUSPENDED || + q->rpm_status == RPM_SUSPENDING) && q->dev) + pm_request_resume(q->dev); + rq->q = q; if (rq->cmd_flags & REQ_SOFTBARRIER) { -- 1.7.2.5