From d0deef5b14af7d5bbd0003a0a2a1a32326e20a6d Mon Sep 17 00:00:00 2001 From: Shawn Du Date: Tue, 14 Apr 2009 13:58:56 +0800 Subject: blktrace: support per-partition tracing Though one can specify '-d /dev/sda1' when using blktrace, it still traces the whole sda. To support per-partition tracing, when we start tracing, we initialize bt->start_lba and bt->end_lba to the start and end sector of that partition. Note some actions are per device, thus we don't filter 0-sector events. The original patch and discussion can be found here: http://marc.info/?l=linux-btrace&m=122949374214540&w=2 Signed-off-by: Shawn Du Signed-off-by: Li Zefan Acked-by: "Theodore Ts'o" Cc: Arnaldo Carvalho de Melo Cc: Jens Axboe LKML-Reference: <49E42620.4050701@cn.fujitsu.com> Signed-off-by: Ingo Molnar --- drivers/scsi/sg.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers') diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 82312df9b0b..49c98730bb8 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -1065,6 +1065,7 @@ sg_ioctl(struct inode *inode, struct file *filp, return blk_trace_setup(sdp->device->request_queue, sdp->disk->disk_name, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), + NULL, (char *)arg); case BLKTRACESTART: return blk_trace_startstop(sdp->device->request_queue, 1); -- cgit v1.2.3 From 22a7c31a9659deaddafbbcec6562d44141e84474 Mon Sep 17 00:00:00 2001 From: "Alan D. Brunelle" Date: Mon, 4 May 2009 16:35:08 -0400 Subject: blktrace: from-sector redundant in trace_block_remap Remove redundant from-sector parameter: it's /always/ the bio's sector passed in. [ Impact: cleanup ] Signed-off-by: Alan D. Brunelle Reviewed-by: Li Zefan Reviewed-by: KOSAKI Motohiro Cc: Jens Axboe Cc: Arnaldo Carvalho de Melo LKML-Reference: <49FF517C.7000503@hp.com> Signed-off-by: Ingo Molnar --- drivers/md/dm.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 8a994be035b..b01514afb6b 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -657,8 +657,7 @@ static void __map_bio(struct dm_target *ti, struct bio *clone, /* the bio has been remapped so dispatch it */ trace_block_remap(bdev_get_queue(clone->bi_bdev), clone, - tio->io->bio->bi_bdev->bd_dev, - clone->bi_sector, sector); + tio->io->bio->bi_bdev->bd_dev, sector); generic_make_request(clone); } else if (r < 0 || r == DM_MAPIO_REQUEUE) { -- cgit v1.2.3 From 55782138e47d9baf2f7d3a7af9e7cf42adf72c56 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Tue, 9 Jun 2009 13:43:05 +0800 Subject: tracing/events: convert block trace points to TRACE_EVENT() TRACE_EVENT is a more generic way to define tracepoints. Doing so adds these new capabilities to this tracepoint: - zero-copy and per-cpu splice() tracing - binary tracing without printf overhead - structured logging records exposed under /debug/tracing/events - trace events embedded in function tracer output and other plugins - user-defined, per tracepoint filter expressions ... Cons: - no dev_t info for the output of plug, unplug_timer and unplug_io events. no dev_t info for getrq and sleeprq events if bio == NULL. no dev_t info for rq_abort,...,rq_requeue events if rq->rq_disk == NULL. This is mainly because we can't get the deivce from a request queue. But this may change in the future. - A packet command is converted to a string in TP_assign, not TP_print. While blktrace do the convertion just before output. Since pc requests should be rather rare, this is not a big issue. - In blktrace, an event can have 2 different print formats, but a TRACE_EVENT has a unique format, which means we have some unused data in a trace entry. The overhead is minimized by using __dynamic_array() instead of __array(). I've benchmarked the ioctl blktrace vs the splice based TRACE_EVENT tracing: dd dd + ioctl blktrace dd + TRACE_EVENT (splice) 1 7.36s, 42.7 MB/s 7.50s, 42.0 MB/s 7.41s, 42.5 MB/s 2 7.43s, 42.3 MB/s 7.48s, 42.1 MB/s 7.43s, 42.4 MB/s 3 7.38s, 42.6 MB/s 7.45s, 42.2 MB/s 7.41s, 42.5 MB/s So the overhead of tracing is very small, and no regression when using those trace events vs blktrace. And the binary output of TRACE_EVENT is much smaller than blktrace: # ls -l -h -rw-r--r-- 1 root root 8.8M 06-09 13:24 sda.blktrace.0 -rw-r--r-- 1 root root 195K 06-09 13:24 sda.blktrace.1 -rw-r--r-- 1 root root 2.7M 06-09 13:25 trace_splice.out Following are some comparisons between TRACE_EVENT and blktrace: plug: kjournald-480 [000] 303.084981: block_plug: [kjournald] kjournald-480 [000] 303.084981: 8,0 P N [kjournald] unplug_io: kblockd/0-118 [000] 300.052973: block_unplug_io: [kblockd/0] 1 kblockd/0-118 [000] 300.052974: 8,0 U N [kblockd/0] 1 remap: kjournald-480 [000] 303.085042: block_remap: 8,0 W 102736992 + 8 <- (8,8) 33384 kjournald-480 [000] 303.085043: 8,0 A W 102736992 + 8 <- (8,8) 33384 bio_backmerge: kjournald-480 [000] 303.085086: block_bio_backmerge: 8,0 W 102737032 + 8 [kjournald] kjournald-480 [000] 303.085086: 8,0 M W 102737032 + 8 [kjournald] getrq: kjournald-480 [000] 303.084974: block_getrq: 8,0 W 102736984 + 8 [kjournald] kjournald-480 [000] 303.084975: 8,0 G W 102736984 + 8 [kjournald] bash-2066 [001] 1072.953770: 8,0 G N [bash] bash-2066 [001] 1072.953773: block_getrq: 0,0 N 0 + 0 [bash] rq_complete: konsole-2065 [001] 300.053184: block_rq_complete: 8,0 W () 103669040 + 16 [0] konsole-2065 [001] 300.053191: 8,0 C W 103669040 + 16 [0] ksoftirqd/1-7 [001] 1072.953811: 8,0 C N (5a 00 08 00 00 00 00 00 24 00) [0] ksoftirqd/1-7 [001] 1072.953813: block_rq_complete: 0,0 N (5a 00 08 00 00 00 00 00 24 00) 0 + 0 [0] rq_insert: kjournald-480 [000] 303.084985: block_rq_insert: 8,0 W 0 () 102736984 + 8 [kjournald] kjournald-480 [000] 303.084986: 8,0 I W 102736984 + 8 [kjournald] Changelog from v2 -> v3: - use the newly introduced __dynamic_array(). Changelog from v1 -> v2: - use __string() instead of __array() to minimize the memory required to store hex dump of rq->cmd(). - support large pc requests. - add missing blk_fill_rwbs_rq() in block_rq_requeue TRACE_EVENT. - some cleanups. Signed-off-by: Li Zefan LKML-Reference: <4A2DF669.5070905@cn.fujitsu.com> Signed-off-by: Steven Rostedt --- drivers/md/dm.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'drivers') diff --git a/drivers/md/dm.c b/drivers/md/dm.c index e2ee4a79ea2..3fd8b1e6548 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -20,7 +20,8 @@ #include #include #include -#include + +#include #define DM_MSG_PREFIX "core" @@ -53,8 +54,6 @@ struct dm_target_io { union map_info info; }; -DEFINE_TRACE(block_bio_complete); - /* * For request-based dm. * One of these is allocated per request. -- cgit v1.2.3