litmus-rt.git/tools/perf/Documentation, branch wip-default-clustering

perf man pages: Fix cut'n'paste error

2010-07-28T14:30:10+00:00

We remove files _from_ the cache.

Cc: Frederic Weisbecker 
Cc: Mike Galbraith 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
LKML-Reference: 
Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Support tracing an entry of array

2010-07-05T21:50:27+00:00

Add array-entry tracing support to perf probe. This enables to trace an entry
of array which is indexed by constant value, e.g. array[0].

For example:

  $ perf probe -a 'bio_split bi->bi_io_vec[0]'

Cc: Paul Mackerras 
Cc: Ingo Molnar 
Cc: Peter Zijlstra 
Cc: Mike Galbraith 
Cc: Frederic Weisbecker 
LKML-Reference: <20100519195742.2885.5344.stgit@localhost6.localdomain6>
Signed-off-by: Masami Hiramatsu 
Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Support "string" type

2010-07-05T21:47:28+00:00

Support string type casting to event argument. If perf-probe finds an argument
casted as string, it ensures the target variable is "(unsigned/signed) char
*(or []). perf-probe also adds dereference if the target is a pointer.

So, both of 'char buf[10];' and 'char *buf;' can be accessed by 'buf:string'

Cc: Ingo Molnar 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Mike Galbraith 
Cc: Frederic Weisbecker 
LKML-Reference: <20100519195734.2885.1666.stgit@localhost6.localdomain6>
Signed-off-by: Masami Hiramatsu 
Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Add kernel source path option

2010-06-17T13:27:57+00:00

The probe plugin requires access to the source code for some operations.  The
source code must be in the exact same location as specified by the DWARF tags,
but sometimes the location is an absolute path that cannot be replicated by a
normal user. This change adds the -s|--source option to allow the user to
specify the root of the kernel source tree.

Cc: Ingo Molnar 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Masami Hiramatsu 
LKML-Reference: <1276543590-10486-1-git-send-email-chase.douglas@canonical.com>
Signed-off-by: Chase Douglas 
Signed-off-by: Arnaldo Carvalho de Melo

perf record: Add option to avoid updating buildid cache

2010-06-17T13:20:44+00:00

There are situations where there is enough information in the perf.data
to process the samples. Updating the buildid cache may add unecessary
overhead in terms of disk space and time (copying large elf images).

A persistent option to do this already exists via the perfconfig file,
simply do:

[buildid]
dir = /dev/null

This patch provides a way to suppress builid cache updates on a per-run
basis.  It addds a new option, -N, to perf record. Buildids are still
generated in the perf.data file.

Cc: David S. Miller 
Cc: Frédéric Weisbecker 
Cc: Ingo Molnar 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
LKML-Reference: <4c19ef89.93ecd80a.40dc.fffff8e9@mx.google.com>
Signed-off-by: Stephane Eranian 
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Add the ability to specify list of cpus to monitor

2010-06-05T12:33:01+00:00

This patch adds a -C option to stat, record, top to designate a list of CPUs to
monitor. CPUs can be specified as a comma-separated list or ranges, no space
allowed.

Examples:
$ perf record -a -C0-1,4-7 sleep 1
$ perf top -C0-4
$ perf stat -a -C1,2,3,4 sleep 1

With perf record in per-thread mode with inherit mode on, samples are collected
only when the thread runs on the designated CPUs.

The -C option does not turn on system-wide mode automatically.

Cc: David S. Miller 
Cc: Frédéric Weisbecker 
Cc: Ingo Molnar 
Cc: Mike Galbraith 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: Tom Zanussi 
LKML-Reference: <4bff9496.d345d80a.41fe.7b00@mx.google.com>
Signed-off-by: Stephane Eranian 
Signed-off-by: Arnaldo Carvalho de Melo

perf stat: add perf stat -B to pretty print large numbers

2010-05-19T02:03:22+00:00

It is hard to read very large numbers so provide an option to perf stat
to separate thousands using a separator. The patch leverages the locale
support of stdio. You need to set your LC_NUMERIC appropriately, for
instance LC_NUMERIC=en_US.UTF8. You need to pass -B to activate this
feature. This way existing scripts parsing the output do not need to be
changed. Here is an example.

$ perf stat noploop 2
noploop for 2 seconds

 Performance counter stats for 'noploop 2':

        1998.347031  task-clock-msecs         #      0.998 CPUs
                 61  context-switches         #      0.000 M/sec
                  0  CPU-migrations           #      0.000 M/sec
                118  page-faults              #      0.000 M/sec
      4,138,410,900  cycles                   #   2070.917 M/sec  (scaled from 70.01%)
      2,062,650,268  instructions             #      0.498 IPC    (scaled from 70.01%)
      2,057,653,466  branches                 #   1029.678 M/sec  (scaled from 70.01%)
             40,267  branch-misses            #      0.002 %      (scaled from 30.04%)
      2,055,961,348  cache-references         #   1028.831 M/sec  (scaled from 30.03%)
             53,725  cache-misses             #      0.027 M/sec  (scaled from 30.02%)

        2.001393933  seconds time elapsed

$ perf stat -B  noploop 2
noploop for 2 seconds

 Performance counter stats for 'noploop 2':

        1998.297883  task-clock-msecs         #      0.998 CPUs
                 59  context-switches         #      0.000 M/sec
                  0  CPU-migrations           #      0.000 M/sec
                119  page-faults              #      0.000 M/sec
      4,131,380,160  cycles                   #   2067.450 M/sec  (scaled from 70.01%)
      2,059,096,507  instructions             #      0.498 IPC    (scaled from 70.01%)
      2,054,681,303  branches                 #   1028.216 M/sec  (scaled from 70.01%)
             25,650  branch-misses            #      0.001 %      (scaled from 30.05%)
      2,056,283,014  cache-references         #   1029.017 M/sec  (scaled from 30.03%)
             47,097  cache-misses             #      0.024 M/sec  (scaled from 30.02%)

        2.001391016  seconds time elapsed

Cc: David S. Miller 
Cc: Frédéric Weisbecker 
Cc: Ingo Molnar 
Cc: Mike Galbraith 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Tom Zanussi 
LKML-Reference: <4bf28fe8.914ed80a.01ca.fffff5f5@mx.google.com>
Signed-off-by: Stephane Eranian 
Signed-off-by: Arnaldo Carvalho de Melo

perf trace scripts: Fix typos in perf-trace-python.txt

2010-05-13T20:10:40+00:00

option option   -> option
special special -> special

Signed-off-by: Kirill Smelkov 
Cc: Tom Zanussi 
LKML-Reference: <1273747165-17242-1-git-send-email-kirr@mns.spb.ru>
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: change event inheritance logic in stat and record

2010-05-13T19:39:12+00:00

By default, event inheritance across fork and pthread_create was on but the -i
option of stat and record, which enabled inheritance, led to believe it was off
by default.

This patch fixes this logic by inverting the meaning of the -i option.  By
default inheritance is on whether you attach to a process (-p), a thread (-t)
or start a process. If you pass -i, then you turn off inheritance. Turning off
inheritance if you don't need it, helps limit perf resource usage as well.

The patch also fixes perf stat -t xxxx and perf record -t xxxx which did not
start the counters.

Acked-by: Frederic Weisbecker 
Cc: David S. Miller 
Cc: Frédéric Weisbecker 
Cc: Ingo Molnar 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
LKML-Reference: <4bea9d2f.d60ce30a.0b5b.08e1@mx.google.com>
Signed-off-by: Stephane Eranian 
Signed-off-by: Arnaldo Carvalho de Melo

perf list: Improve the raw hw event descriptor documentation

2010-05-07T17:07:05+00:00

It was x86 specific and imcomplete at that, improve the situation by
making it clear where the example provided applies and by adding the
URLs for the Intel and AMD manuals where this is discussed in depth.

Acked-by: Robert Richter 
Cc: Cyrill Gorcunov 
Cc: Frédéric Weisbecker 
Cc: Mike Galbraith 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Tom Zanussi 
Cc: Robert Richter 
Reported-by: Robert Richter 
Signed-off-by: Arnaldo Carvalho de Melo