linux-toradex.git/include/linux/blktrace_api.h, branch tegra-10.9.9

Add a tracepoint for block request remapping

2009-10-01T19:19:34+00:00

Since 2.6.31 now has request-based device-mapper, it's useful to have
a tracepoint for request-remapping as well as bio-remapping.
This patch adds a tracepoint for request-remapping, trace_block_rq_remap().

Signed-off-by: Kiyoshi Ueda 
Signed-off-by: Jun'ichi Nomura 
Cc: Alasdair G Kergon 
Cc: Li Zefan 
Signed-off-by: Jens Axboe

Add missing blk_trace_remove_sysfs to be in pair with blk_trace_init_sysfs

2009-10-01T19:15:46+00:00

Add missing blk_trace_remove_sysfs to be in pair with blk_trace_init_sysfs
introduced in commit 1d54ad6da9192fed5dd3b60224d9f2dfea0dcd82.
Release kobject also in case the request_fn is NULL.

Problem was noticed via kmemleak backtrace when some sysfs entries were
note properly destroyed during  device removal:

unreferenced object 0xffff88001aa76640 (size 80):
  comm "lvcreate", pid 2120, jiffies 4294885144
  hex dump (first 32 bytes):
    01 00 00 00 00 00 00 00 f0 65 a7 1a 00 88 ff ff  .........e......
    90 66 a7 1a 00 88 ff ff 86 1d 53 81 ff ff ff ff  .f........S.....
  backtrace:
    [] kmemleak_alloc+0x26/0x60
    [] kmem_cache_alloc+0x133/0x1c0
    [] sysfs_new_dirent+0x41/0x120
    [] sysfs_add_file_mode+0x3c/0xb0
    [] internal_create_group+0xc1/0x1a0
    [] sysfs_create_group+0x13/0x20
    [] blk_trace_init_sysfs+0x14/0x20
    [] blk_register_queue+0x3c/0xf0
    [] add_disk+0x94/0x160
    [] dm_create+0x598/0x6e0 [dm_mod]
    [] dev_create+0x51/0x350 [dm_mod]
    [] ctl_ioctl+0x1a3/0x240 [dm_mod]
    [] dm_compat_ctl_ioctl+0x12/0x20 [dm_mod]
    [] compat_sys_ioctl+0xcd/0x4f0
    [] sysenter_dispatch+0x7/0x2c
    [] 0xffffffffffffffff

Signed-off-by: Zdenek Kabelac 
Reviewed-by: Li Zefan 
Signed-off-by: Jens Axboe

tracing/events: convert block trace points to TRACE_EVENT(), fix !CONFIG_BLOCK

2009-06-10T09:55:06+00:00

Fix building failures when CONFIG_BLOCK == n.

Signed-off-by: Li Zefan 
LKML-Reference: <4A2F1520.8020003@cn.fujitsu.com>
Signed-off-by: Steven Rostedt 
Signed-off-by: Ingo Molnar

tracing/events: convert block trace points to TRACE_EVENT()

2009-06-09T16:34:23+00:00

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

blktrace: correct remap names

2009-05-06T12:13:00+00:00

This attempts to clarify names utilized during block I/O remap
operations (partition, volume manager). It correctly matches up the
/from/ information for both device & sector. This takes in the concept
from Kosaki Motohiro and extends it to include better naming for the
"device_from" field.

[ 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: <49FF4FAE.3000301@hp.com>
Signed-off-by: Ingo Molnar

blktrace: add trace/ to /sys/block/sda

2009-04-16T08:10:59+00:00

Impact: allow ftrace-plugin blktrace to trace device-mapper devices

To trace a single partition:
  # echo 1 > /sys/block/sda/sda1/enable

To trace the whole sda instead:
  # echo 1 > /sys/block/sda/enable

Thus we also fix an issue reported by Ted, that ftrace-plugin blktrace
can't be used to trace device-mapper devices.

Now:

  # echo 1 > /sys/block/dm-0/trace/enable
  echo: write error: No such device or address
  # mount -t ext4 /dev/dm-0 /mnt
  # echo 1 > /sys/block/dm-0/trace/enable
  # echo blk > /debug/tracing/current_tracer

Reported-by: Theodore Tso 
Signed-off-by: Li Zefan 
Acked-by: "Theodore Ts'o" 
Cc: Arnaldo Carvalho de Melo 
Cc: Shawn Du 
Cc: Jens Axboe 
LKML-Reference: <49E42665.6020506@cn.fujitsu.com>
Signed-off-by: Ingo Molnar

blktrace: support per-partition tracing

2009-04-16T08:10:57+00:00

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

Merge branch 'linus' into tracing/blktrace

2009-02-19T08:00:35+00:00

Conflicts:
	block/blktrace.c

Semantic merge:
	kernel/trace/blktrace.c

Signed-off-by: Ingo Molnar

block: fix bad definition of BIO_RW_SYNC

2009-02-18T09:32:00+00:00

We can't OR shift values, so get rid of BIO_RW_SYNC and use BIO_RW_SYNCIO
and BIO_RW_UNPLUG explicitly. This brings back the behaviour from before
213d9417fec62ef4c3675621b9364a667954d4dd.

Signed-off-by: Jens Axboe

Merge branches 'tracing/ftrace', 'tracing/kmemtrace' and 'linus' into tracing/core

2009-02-03T05:25:38+00:00