Commit 94b5eb28 authored by Jens Axboe's avatar Jens Axboe
Browse files

block: fixup block IO unplug trace call 



It was removed with the on-stack plugging, readd it and track the
depth of requests added when flushing the plug.

Signed-off-by: default avatarJens Axboe <jaxboe@fusionio.com>
parent d9c97833

block/blk-core.c

+13 −2
Original line number Diff line number Diff line
@@ -2668,12 +2668,19 @@ static int plug_rq_cmp(void *priv, struct list_head *a, struct list_head *b) 
	return !(rqa->q <= rqb->q);

}



static void queue_unplugged(struct request_queue *q, unsigned int depth)

{

	trace_block_unplug_io(q, depth);

	__blk_run_queue(q, false);

}



static void flush_plug_list(struct blk_plug *plug)

{

	struct request_queue *q;

	unsigned long flags;

	struct request *rq;

	LIST_HEAD(list);

	unsigned int depth;



	BUG_ON(plug->magic != PLUG_MAGIC);
@@ -2688,6 +2695,7 @@ static void flush_plug_list(struct blk_plug *plug) 
	}



	q = NULL;

	depth = 0;

	local_irq_save(flags);

	while (!list_empty(&list)) {

		rq = list_entry_rq(list.next);
@@ -2696,10 +2704,11 @@ static void flush_plug_list(struct blk_plug *plug) 
		BUG_ON(!rq->q);

		if (rq->q != q) {

			if (q) {

				__blk_run_queue(q, false);

				queue_unplugged(q, depth);

				spin_unlock(q->queue_lock);

			}

			q = rq->q;

			depth = 0;

			spin_lock(q->queue_lock);

		}

		rq->cmd_flags &= ~REQ_ON_PLUG;
@@ -2711,10 +2720,12 @@ static void flush_plug_list(struct blk_plug *plug) 
			__elv_add_request(q, rq, ELEVATOR_INSERT_FLUSH);

		else

			__elv_add_request(q, rq, ELEVATOR_INSERT_SORT_MERGE);



		depth++;

	}



	if (q) {

		__blk_run_queue(q, false);

		queue_unplugged(q, depth);

		spin_unlock(q->queue_lock);

	}

include/trace/events/block.h

+6 −5
Original line number Diff line number Diff line
@@ -401,9 +401,9 @@ TRACE_EVENT(block_plug, 


DECLARE_EVENT_CLASS(block_unplug,



	TP_PROTO(struct request_queue *q),

	TP_PROTO(struct request_queue *q, unsigned int depth),



	TP_ARGS(q),

	TP_ARGS(q, depth),



	TP_STRUCT__entry(

		__field( int,		nr_rq			)
@@ -411,7 +411,7 @@ DECLARE_EVENT_CLASS(block_unplug, 
	),



	TP_fast_assign(

		__entry->nr_rq	= q->rq.count[READ] + q->rq.count[WRITE];

		__entry->nr_rq = depth;

		memcpy(__entry->comm, current->comm, TASK_COMM_LEN);

	),
@@ -421,15 +421,16 @@ DECLARE_EVENT_CLASS(block_unplug, 
/**

 * block_unplug_io - release of operations requests in request queue

 * @q: request queue to unplug

 * @depth: number of requests just added to the queue

 *

 * Unplug request queue @q because device driver is scheduled to work

 * on elements in the request queue.

 */

DEFINE_EVENT(block_unplug, block_unplug_io,



	TP_PROTO(struct request_queue *q),

	TP_PROTO(struct request_queue *q, unsigned int depth),



	TP_ARGS(q)

	TP_ARGS(q, depth)

);



/**

kernel/trace/blktrace.c

+3 −3
Original line number Diff line number Diff line
@@ -850,13 +850,13 @@ static void blk_add_trace_plug(void *ignore, struct request_queue *q) 
		__blk_add_trace(bt, 0, 0, 0, BLK_TA_PLUG, 0, 0, NULL);

}



static void blk_add_trace_unplug_io(void *ignore, struct request_queue *q)

static void blk_add_trace_unplug_io(void *ignore, struct request_queue *q,

				    unsigned int depth)

{

	struct blk_trace *bt = q->blk_trace;



	if (bt) {

		unsigned int pdu = q->rq.count[READ] + q->rq.count[WRITE];

		__be64 rpdu = cpu_to_be64(pdu);

		__be64 rpdu = cpu_to_be64(depth);



		__blk_add_trace(bt, 0, 0, 0, BLK_TA_UNPLUG_IO, 0,

				sizeof(rpdu), &rpdu);