linux-toradex.git/include/linux/blktrace_api.h, branch v2.6.38.6

blktrace: Remove blk_fill_rwbs_rq.

2011-03-03T15:53:20+00:00

If we enable trace events to trace block actions, We use
blk_fill_rwbs_rq to analyze the corresponding actions
in request's cmd_flags, but we only choose the minor 2 bits
from it, so most of other flags(e.g, REQ_SYNC) are missing.
For example, with a sync write we get:
write_test-2409  [001]   160.013869: block_rq_insert: 3,64 W 0 () 258135 + =
8 [write_test]

Since now we have integrated the flags of both bio and request,
it is safe to pass rq->cmd_flags directly to blk_fill_rwbs and
blk_fill_rwbs_rq isn't needed any more.

With this patch, after a sync write we get:
write_test-2417  [000]   226.603878: block_rq_insert: 3,64 WS 0 () 258135 +=
 8 [write_test]

Signed-off-by: Tao Ma 
Acked-by: Jeff Moyer 
Signed-off-by: Jens Axboe

block: fix for block tracing build error

2010-08-07T16:26:29+00:00

block/compat_ioctl.c: In function 'compat_blkdev_ioctl':
block/compat_ioctl.c:754: error: 'BLKTRACESETUP32' undeclared (first use in this function)

Signed-off-by: Stephen Rothwell 
Acked-by: Arnd Bergmann 
Signed-off-by: Jens Axboe

block: push BKL into blktrace ioctls

2010-08-07T16:26:08+00:00

The blktrace driver currently needs the BKL, but
we should not need to take that in the block layer,
so just push it down into the driver itself.

It is quite likely that the BKL is not actually
required in blktrace code and could be removed
in a follow-on patch.

Signed-off-by: Arnd Bergmann 
Acked-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

block: remove wrappers for request type/flags

2010-08-07T16:17:56+00:00

Remove all the trivial wrappers for the cmd_type and cmd_flags fields in
struct requests.  This allows much easier grepping for different request
types instead of unwinding through macros.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

percpu: add __percpu sparse annotations to core kernel subsystems

2010-02-17T02:17:38+00:00

Add __percpu sparse annotations to core subsystems.

These annotations are to make sparse consider percpu variables to be
in a different address space and warn if accessed without going
through percpu accessors.  This patch doesn't affect normal builds.

Signed-off-by: Tejun Heo 
Reviewed-by: Christoph Lameter 
Acked-by: Paul E. McKenney 
Cc: Jens Axboe 
Cc: linux-mm@kvack.org
Cc: Rusty Russell 
Cc: Dipankar Sarma 
Cc: Peter Zijlstra 
Cc: Andrew Morton 
Cc: Eric Biederman

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