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Commit d733ed6c authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block 

* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  block: make unplug timer trace event correspond to the schedule() unplug
  block: let io_schedule() flush the plug inline
parents 08150c53 49cac01e

block/blk-core.c

+12 −6
Original line number Diff line number Diff line
@@ -2662,17 +2662,23 @@ static int plug_rq_cmp(void *priv, struct list_head *a, struct list_head *b) 
	return !(rqa->q <= rqb->q);

}



/*

 * If 'from_schedule' is true, then postpone the dispatch of requests

 * until a safe kblockd context. We due this to avoid accidental big

 * additional stack usage in driver dispatch, in places where the originally

 * plugger did not intend it.

 */

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

			    bool force_kblockd)

			    bool from_schedule)

{

	trace_block_unplug_io(q, depth);

	__blk_run_queue(q, force_kblockd);

	trace_block_unplug(q, depth, !from_schedule);

	__blk_run_queue(q, from_schedule);



	if (q->unplugged_fn)

		q->unplugged_fn(q);

}



void blk_flush_plug_list(struct blk_plug *plug, bool force_kblockd)

void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)

{

	struct request_queue *q;

	unsigned long flags;
@@ -2707,7 +2713,7 @@ void blk_flush_plug_list(struct blk_plug *plug, bool force_kblockd) 
		BUG_ON(!rq->q);

		if (rq->q != q) {

			if (q) {

				queue_unplugged(q, depth, force_kblockd);

				queue_unplugged(q, depth, from_schedule);

				spin_unlock(q->queue_lock);

			}

			q = rq->q;
@@ -2728,7 +2734,7 @@ void blk_flush_plug_list(struct blk_plug *plug, bool force_kblockd) 
	}



	if (q) {

		queue_unplugged(q, depth, force_kblockd);

		queue_unplugged(q, depth, from_schedule);

		spin_unlock(q->queue_lock);

	}

include/linux/blkdev.h

+13 −0
Original line number Diff line number Diff line
@@ -871,6 +871,14 @@ static inline void blk_flush_plug(struct task_struct *tsk) 
{

	struct blk_plug *plug = tsk->plug;



	if (plug)

		blk_flush_plug_list(plug, false);

}



static inline void blk_schedule_flush_plug(struct task_struct *tsk)

{

	struct blk_plug *plug = tsk->plug;



	if (plug)

		blk_flush_plug_list(plug, true);

}
@@ -1317,6 +1325,11 @@ static inline void blk_flush_plug(struct task_struct *task) 
{

}



static inline void blk_schedule_flush_plug(struct task_struct *task)

{

}





static inline bool blk_needs_flush_plug(struct task_struct *tsk)

{

	return false;

include/trace/events/block.h

+7 −6
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, unsigned int depth),

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



	TP_ARGS(q, depth),

	TP_ARGS(q, depth, explicit),



	TP_STRUCT__entry(

		__field( int,		nr_rq			)
@@ -419,18 +419,19 @@ DECLARE_EVENT_CLASS(block_unplug, 
);



/**

 * block_unplug_io - release of operations requests in request queue

 * block_unplug - release of operations requests in request queue

 * @q: request queue to unplug

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

 * @explicit: whether this was an explicit unplug, or one from schedule()

 *

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

 * on elements in the request queue.

 */

DEFINE_EVENT(block_unplug, block_unplug_io,

DEFINE_EVENT(block_unplug, block_unplug,



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

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



	TP_ARGS(q, depth)

	TP_ARGS(q, depth, explicit)

);



/**

kernel/sched.c

+1 −1
Original line number Diff line number Diff line
@@ -4118,7 +4118,7 @@ need_resched: 
			 */

			if (blk_needs_flush_plug(prev)) {

				raw_spin_unlock(&rq->lock);

				blk_flush_plug(prev);

				blk_schedule_flush_plug(prev);

				raw_spin_lock(&rq->lock);

			}

		}

kernel/trace/blktrace.c

+12 −6
Original line number Diff line number Diff line
@@ -850,16 +850,21 @@ 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,

				    unsigned int depth)

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

				    unsigned int depth, bool explicit)

{

	struct blk_trace *bt = q->blk_trace;



	if (bt) {

		__be64 rpdu = cpu_to_be64(depth);

		u32 what;



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

				sizeof(rpdu), &rpdu);

		if (explicit)

			what = BLK_TA_UNPLUG_IO;

		else

			what = BLK_TA_UNPLUG_TIMER;



		__blk_add_trace(bt, 0, 0, 0, what, 0, sizeof(rpdu), &rpdu);

	}

}
@@ -1002,7 +1007,7 @@ static void blk_register_tracepoints(void) 
	WARN_ON(ret);

	ret = register_trace_block_plug(blk_add_trace_plug, NULL);

	WARN_ON(ret);

	ret = register_trace_block_unplug_io(blk_add_trace_unplug_io, NULL);

	ret = register_trace_block_unplug(blk_add_trace_unplug, NULL);

	WARN_ON(ret);

	ret = register_trace_block_split(blk_add_trace_split, NULL);

	WARN_ON(ret);
@@ -1017,7 +1022,7 @@ static void blk_unregister_tracepoints(void) 
	unregister_trace_block_rq_remap(blk_add_trace_rq_remap, NULL);

	unregister_trace_block_bio_remap(blk_add_trace_bio_remap, NULL);

	unregister_trace_block_split(blk_add_trace_split, NULL);

	unregister_trace_block_unplug_io(blk_add_trace_unplug_io, NULL);

	unregister_trace_block_unplug(blk_add_trace_unplug, NULL);

	unregister_trace_block_plug(blk_add_trace_plug, NULL);

	unregister_trace_block_sleeprq(blk_add_trace_sleeprq, NULL);

	unregister_trace_block_getrq(blk_add_trace_getrq, NULL);
@@ -1332,6 +1337,7 @@ static const struct { 
	[__BLK_TA_COMPLETE]	= {{  "C", "complete" },   blk_log_with_error },

	[__BLK_TA_PLUG]		= {{  "P", "plug" },	   blk_log_plug },

	[__BLK_TA_UNPLUG_IO]	= {{  "U", "unplug_io" },  blk_log_unplug },

	[__BLK_TA_UNPLUG_TIMER]	= {{ "UT", "unplug_timer" }, blk_log_unplug },

	[__BLK_TA_INSERT]	= {{  "I", "insert" },	   blk_log_generic },

	[__BLK_TA_SPLIT]	= {{  "X", "split" },	   blk_log_split },

	[__BLK_TA_BOUNCE]	= {{  "B", "bounce" },	   blk_log_generic },