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authorLinus Torvalds <torvalds@linux-foundation.org>2008-12-28 15:21:10 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2008-12-28 15:21:10 -0500
commitb0f4b285d7ed174804658539129a834270f4829a (patch)
treebe7f8dca58075aba2c6a137fcfd4d44c5c333efc /block/blktrace.c
parentbe9c5ae4eeec2e85527e95647348b8ea4eb25128 (diff)
parent5250d329e38cdf7580faeb9c53c17d3588d7d19c (diff)
Merge branch 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (241 commits) sched, trace: update trace_sched_wakeup() tracing/ftrace: don't trace on early stage of a secondary cpu boot, v3 Revert "x86: disable X86_PTRACE_BTS" ring-buffer: prevent false positive warning ring-buffer: fix dangling commit race ftrace: enable format arguments checking x86, bts: memory accounting x86, bts: add fork and exit handling ftrace: introduce tracing_reset_online_cpus() helper tracing: fix warnings in kernel/trace/trace_sched_switch.c tracing: fix warning in kernel/trace/trace.c tracing/ring-buffer: remove unused ring_buffer size trace: fix task state printout ftrace: add not to regex on filtering functions trace: better use of stack_trace_enabled for boot up code trace: add a way to enable or disable the stack tracer x86: entry_64 - introduce FTRACE_ frame macro v2 tracing/ftrace: add the printk-msg-only option tracing/ftrace: use preempt_enable_no_resched_notrace in ring_buffer_time_stamp() x86, bts: correctly report invalid bts records ... Fixed up trivial conflict in scripts/recordmcount.pl due to SH bits being already partly merged by the SH merge.
Diffstat (limited to 'block/blktrace.c')
-rw-r--r--block/blktrace.c332
1 files changed, 329 insertions, 3 deletions
diff --git a/block/blktrace.c b/block/blktrace.c
index 85049a7e7a17..b0a2cae886db 100644
--- a/block/blktrace.c
+++ b/block/blktrace.c
@@ -23,10 +23,18 @@
23#include <linux/mutex.h> 23#include <linux/mutex.h>
24#include <linux/debugfs.h> 24#include <linux/debugfs.h>
25#include <linux/time.h> 25#include <linux/time.h>
26#include <trace/block.h>
26#include <asm/uaccess.h> 27#include <asm/uaccess.h>
27 28
28static unsigned int blktrace_seq __read_mostly = 1; 29static unsigned int blktrace_seq __read_mostly = 1;
29 30
31/* Global reference count of probes */
32static DEFINE_MUTEX(blk_probe_mutex);
33static atomic_t blk_probes_ref = ATOMIC_INIT(0);
34
35static int blk_register_tracepoints(void);
36static void blk_unregister_tracepoints(void);
37
30/* 38/*
31 * Send out a notify message. 39 * Send out a notify message.
32 */ 40 */
@@ -119,7 +127,7 @@ static u32 ddir_act[2] __read_mostly = { BLK_TC_ACT(BLK_TC_READ), BLK_TC_ACT(BLK
119 * The worker for the various blk_add_trace*() types. Fills out a 127 * The worker for the various blk_add_trace*() types. Fills out a
120 * blk_io_trace structure and places it in a per-cpu subbuffer. 128 * blk_io_trace structure and places it in a per-cpu subbuffer.
121 */ 129 */
122void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes, 130static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
123 int rw, u32 what, int error, int pdu_len, void *pdu_data) 131 int rw, u32 what, int error, int pdu_len, void *pdu_data)
124{ 132{
125 struct task_struct *tsk = current; 133 struct task_struct *tsk = current;
@@ -177,8 +185,6 @@ void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
177 local_irq_restore(flags); 185 local_irq_restore(flags);
178} 186}
179 187
180EXPORT_SYMBOL_GPL(__blk_add_trace);
181
182static struct dentry *blk_tree_root; 188static struct dentry *blk_tree_root;
183static DEFINE_MUTEX(blk_tree_mutex); 189static DEFINE_MUTEX(blk_tree_mutex);
184static unsigned int root_users; 190static unsigned int root_users;
@@ -237,6 +243,10 @@ static void blk_trace_cleanup(struct blk_trace *bt)
237 free_percpu(bt->sequence); 243 free_percpu(bt->sequence);
238 free_percpu(bt->msg_data); 244 free_percpu(bt->msg_data);
239 kfree(bt); 245 kfree(bt);
246 mutex_lock(&blk_probe_mutex);
247 if (atomic_dec_and_test(&blk_probes_ref))
248 blk_unregister_tracepoints();
249 mutex_unlock(&blk_probe_mutex);
240} 250}
241 251
242int blk_trace_remove(struct request_queue *q) 252int blk_trace_remove(struct request_queue *q)
@@ -428,6 +438,14 @@ int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
428 bt->pid = buts->pid; 438 bt->pid = buts->pid;
429 bt->trace_state = Blktrace_setup; 439 bt->trace_state = Blktrace_setup;
430 440
441 mutex_lock(&blk_probe_mutex);
442 if (atomic_add_return(1, &blk_probes_ref) == 1) {
443 ret = blk_register_tracepoints();
444 if (ret)
445 goto probe_err;
446 }
447 mutex_unlock(&blk_probe_mutex);
448
431 ret = -EBUSY; 449 ret = -EBUSY;
432 old_bt = xchg(&q->blk_trace, bt); 450 old_bt = xchg(&q->blk_trace, bt);
433 if (old_bt) { 451 if (old_bt) {
@@ -436,6 +454,9 @@ int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
436 } 454 }
437 455
438 return 0; 456 return 0;
457probe_err:
458 atomic_dec(&blk_probes_ref);
459 mutex_unlock(&blk_probe_mutex);
439err: 460err:
440 if (dir) 461 if (dir)
441 blk_remove_tree(dir); 462 blk_remove_tree(dir);
@@ -562,3 +583,308 @@ void blk_trace_shutdown(struct request_queue *q)
562 blk_trace_remove(q); 583 blk_trace_remove(q);
563 } 584 }
564} 585}
586
587/*
588 * blktrace probes
589 */
590
591/**
592 * blk_add_trace_rq - Add a trace for a request oriented action
593 * @q: queue the io is for
594 * @rq: the source request
595 * @what: the action
596 *
597 * Description:
598 * Records an action against a request. Will log the bio offset + size.
599 *
600 **/
601static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
602 u32 what)
603{
604 struct blk_trace *bt = q->blk_trace;
605 int rw = rq->cmd_flags & 0x03;
606
607 if (likely(!bt))
608 return;
609
610 if (blk_discard_rq(rq))
611 rw |= (1 << BIO_RW_DISCARD);
612
613 if (blk_pc_request(rq)) {
614 what |= BLK_TC_ACT(BLK_TC_PC);
615 __blk_add_trace(bt, 0, rq->data_len, rw, what, rq->errors,
616 sizeof(rq->cmd), rq->cmd);
617 } else {
618 what |= BLK_TC_ACT(BLK_TC_FS);
619 __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9,
620 rw, what, rq->errors, 0, NULL);
621 }
622}
623
624static void blk_add_trace_rq_abort(struct request_queue *q, struct request *rq)
625{
626 blk_add_trace_rq(q, rq, BLK_TA_ABORT);
627}
628
629static void blk_add_trace_rq_insert(struct request_queue *q, struct request *rq)
630{
631 blk_add_trace_rq(q, rq, BLK_TA_INSERT);
632}
633
634static void blk_add_trace_rq_issue(struct request_queue *q, struct request *rq)
635{
636 blk_add_trace_rq(q, rq, BLK_TA_ISSUE);
637}
638
639static void blk_add_trace_rq_requeue(struct request_queue *q, struct request *rq)
640{
641 blk_add_trace_rq(q, rq, BLK_TA_REQUEUE);
642}
643
644static void blk_add_trace_rq_complete(struct request_queue *q, struct request *rq)
645{
646 blk_add_trace_rq(q, rq, BLK_TA_COMPLETE);
647}
648
649/**
650 * blk_add_trace_bio - Add a trace for a bio oriented action
651 * @q: queue the io is for
652 * @bio: the source bio
653 * @what: the action
654 *
655 * Description:
656 * Records an action against a bio. Will log the bio offset + size.
657 *
658 **/
659static void blk_add_trace_bio(struct request_queue *q, struct bio *bio,
660 u32 what)
661{
662 struct blk_trace *bt = q->blk_trace;
663
664 if (likely(!bt))
665 return;
666
667 __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what,
668 !bio_flagged(bio, BIO_UPTODATE), 0, NULL);
669}
670
671static void blk_add_trace_bio_bounce(struct request_queue *q, struct bio *bio)
672{
673 blk_add_trace_bio(q, bio, BLK_TA_BOUNCE);
674}
675
676static void blk_add_trace_bio_complete(struct request_queue *q, struct bio *bio)
677{
678 blk_add_trace_bio(q, bio, BLK_TA_COMPLETE);
679}
680
681static void blk_add_trace_bio_backmerge(struct request_queue *q, struct bio *bio)
682{
683 blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE);
684}
685
686static void blk_add_trace_bio_frontmerge(struct request_queue *q, struct bio *bio)
687{
688 blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE);
689}
690
691static void blk_add_trace_bio_queue(struct request_queue *q, struct bio *bio)
692{
693 blk_add_trace_bio(q, bio, BLK_TA_QUEUE);
694}
695
696static void blk_add_trace_getrq(struct request_queue *q, struct bio *bio, int rw)
697{
698 if (bio)
699 blk_add_trace_bio(q, bio, BLK_TA_GETRQ);
700 else {
701 struct blk_trace *bt = q->blk_trace;
702
703 if (bt)
704 __blk_add_trace(bt, 0, 0, rw, BLK_TA_GETRQ, 0, 0, NULL);
705 }
706}
707
708
709static void blk_add_trace_sleeprq(struct request_queue *q, struct bio *bio, int rw)
710{
711 if (bio)
712 blk_add_trace_bio(q, bio, BLK_TA_SLEEPRQ);
713 else {
714 struct blk_trace *bt = q->blk_trace;
715
716 if (bt)
717 __blk_add_trace(bt, 0, 0, rw, BLK_TA_SLEEPRQ, 0, 0, NULL);
718 }
719}
720
721static void blk_add_trace_plug(struct request_queue *q)
722{
723 struct blk_trace *bt = q->blk_trace;
724
725 if (bt)
726 __blk_add_trace(bt, 0, 0, 0, BLK_TA_PLUG, 0, 0, NULL);
727}
728
729static void blk_add_trace_unplug_io(struct request_queue *q)
730{
731 struct blk_trace *bt = q->blk_trace;
732
733 if (bt) {
734 unsigned int pdu = q->rq.count[READ] + q->rq.count[WRITE];
735 __be64 rpdu = cpu_to_be64(pdu);
736
737 __blk_add_trace(bt, 0, 0, 0, BLK_TA_UNPLUG_IO, 0,
738 sizeof(rpdu), &rpdu);
739 }
740}
741
742static void blk_add_trace_unplug_timer(struct request_queue *q)
743{
744 struct blk_trace *bt = q->blk_trace;
745
746 if (bt) {
747 unsigned int pdu = q->rq.count[READ] + q->rq.count[WRITE];
748 __be64 rpdu = cpu_to_be64(pdu);
749
750 __blk_add_trace(bt, 0, 0, 0, BLK_TA_UNPLUG_TIMER, 0,
751 sizeof(rpdu), &rpdu);
752 }
753}
754
755static void blk_add_trace_split(struct request_queue *q, struct bio *bio,
756 unsigned int pdu)
757{
758 struct blk_trace *bt = q->blk_trace;
759
760 if (bt) {
761 __be64 rpdu = cpu_to_be64(pdu);
762
763 __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw,
764 BLK_TA_SPLIT, !bio_flagged(bio, BIO_UPTODATE),
765 sizeof(rpdu), &rpdu);
766 }
767}
768
769/**
770 * blk_add_trace_remap - Add a trace for a remap operation
771 * @q: queue the io is for
772 * @bio: the source bio
773 * @dev: target device
774 * @from: source sector
775 * @to: target sector
776 *
777 * Description:
778 * Device mapper or raid target sometimes need to split a bio because
779 * it spans a stripe (or similar). Add a trace for that action.
780 *
781 **/
782static void blk_add_trace_remap(struct request_queue *q, struct bio *bio,
783 dev_t dev, sector_t from, sector_t to)
784{
785 struct blk_trace *bt = q->blk_trace;
786 struct blk_io_trace_remap r;
787
788 if (likely(!bt))
789 return;
790
791 r.device = cpu_to_be32(dev);
792 r.device_from = cpu_to_be32(bio->bi_bdev->bd_dev);
793 r.sector = cpu_to_be64(to);
794
795 __blk_add_trace(bt, from, bio->bi_size, bio->bi_rw, BLK_TA_REMAP,
796 !bio_flagged(bio, BIO_UPTODATE), sizeof(r), &r);
797}
798
799/**
800 * blk_add_driver_data - Add binary message with driver-specific data
801 * @q: queue the io is for
802 * @rq: io request
803 * @data: driver-specific data
804 * @len: length of driver-specific data
805 *
806 * Description:
807 * Some drivers might want to write driver-specific data per request.
808 *
809 **/
810void blk_add_driver_data(struct request_queue *q,
811 struct request *rq,
812 void *data, size_t len)
813{
814 struct blk_trace *bt = q->blk_trace;
815
816 if (likely(!bt))
817 return;
818
819 if (blk_pc_request(rq))
820 __blk_add_trace(bt, 0, rq->data_len, 0, BLK_TA_DRV_DATA,
821 rq->errors, len, data);
822 else
823 __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9,
824 0, BLK_TA_DRV_DATA, rq->errors, len, data);
825}
826EXPORT_SYMBOL_GPL(blk_add_driver_data);
827
828static int blk_register_tracepoints(void)
829{
830 int ret;
831
832 ret = register_trace_block_rq_abort(blk_add_trace_rq_abort);
833 WARN_ON(ret);
834 ret = register_trace_block_rq_insert(blk_add_trace_rq_insert);
835 WARN_ON(ret);
836 ret = register_trace_block_rq_issue(blk_add_trace_rq_issue);
837 WARN_ON(ret);
838 ret = register_trace_block_rq_requeue(blk_add_trace_rq_requeue);
839 WARN_ON(ret);
840 ret = register_trace_block_rq_complete(blk_add_trace_rq_complete);
841 WARN_ON(ret);
842 ret = register_trace_block_bio_bounce(blk_add_trace_bio_bounce);
843 WARN_ON(ret);
844 ret = register_trace_block_bio_complete(blk_add_trace_bio_complete);
845 WARN_ON(ret);
846 ret = register_trace_block_bio_backmerge(blk_add_trace_bio_backmerge);
847 WARN_ON(ret);
848 ret = register_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge);
849 WARN_ON(ret);
850 ret = register_trace_block_bio_queue(blk_add_trace_bio_queue);
851 WARN_ON(ret);
852 ret = register_trace_block_getrq(blk_add_trace_getrq);
853 WARN_ON(ret);
854 ret = register_trace_block_sleeprq(blk_add_trace_sleeprq);
855 WARN_ON(ret);
856 ret = register_trace_block_plug(blk_add_trace_plug);
857 WARN_ON(ret);
858 ret = register_trace_block_unplug_timer(blk_add_trace_unplug_timer);
859 WARN_ON(ret);
860 ret = register_trace_block_unplug_io(blk_add_trace_unplug_io);
861 WARN_ON(ret);
862 ret = register_trace_block_split(blk_add_trace_split);
863 WARN_ON(ret);
864 ret = register_trace_block_remap(blk_add_trace_remap);
865 WARN_ON(ret);
866 return 0;
867}
868
869static void blk_unregister_tracepoints(void)
870{
871 unregister_trace_block_remap(blk_add_trace_remap);
872 unregister_trace_block_split(blk_add_trace_split);
873 unregister_trace_block_unplug_io(blk_add_trace_unplug_io);
874 unregister_trace_block_unplug_timer(blk_add_trace_unplug_timer);
875 unregister_trace_block_plug(blk_add_trace_plug);
876 unregister_trace_block_sleeprq(blk_add_trace_sleeprq);
877 unregister_trace_block_getrq(blk_add_trace_getrq);
878 unregister_trace_block_bio_queue(blk_add_trace_bio_queue);
879 unregister_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge);
880 unregister_trace_block_bio_backmerge(blk_add_trace_bio_backmerge);
881 unregister_trace_block_bio_complete(blk_add_trace_bio_complete);
882 unregister_trace_block_bio_bounce(blk_add_trace_bio_bounce);
883 unregister_trace_block_rq_complete(blk_add_trace_rq_complete);
884 unregister_trace_block_rq_requeue(blk_add_trace_rq_requeue);
885 unregister_trace_block_rq_issue(blk_add_trace_rq_issue);
886 unregister_trace_block_rq_insert(blk_add_trace_rq_insert);
887 unregister_trace_block_rq_abort(blk_add_trace_rq_abort);
888
889 tracepoint_synchronize_unregister();
890}