linux.git/tools/perf/Documentation, branch v2.6.35

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

perf tools: Fixup minor doc formatting issues

2010-05-05T14:23:27+00:00

Cc: Frédéric Weisbecker 
Cc: Mike Galbraith 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Tom Zanussi 
LKML-Reference: 
Signed-off-by: Arnaldo Carvalho de Melo

perf list: Add explanation about raw hardware event descriptors

2010-05-05T14:20:05+00:00

Using explanation given by Ingo Molnar in the oprofile mailing list.

Suggested-by: Nick Black 
Cc: Frédéric Weisbecker 
Cc: Mike Galbraith 
Cc: Nick Black 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Tom Zanussi 
LKML-Reference: 
Signed-off-by: Arnaldo Carvalho de Melo

Merge branch 'perf' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux-2.6 into perf/core

2010-05-04T16:31:47+00:00

perf inject: Add missing bits

2010-05-04T13:48:22+00:00

New commands need to have Documentation and be added to command-list.txt
so that they can appear when 'perf' is called withouth any subcommand:

[root@doppio linux-2.6-tip]# perf

 usage: perf [--version] [--help] COMMAND [ARGS]

 The most commonly used perf commands are:
   annotate        Read perf.data (created by perf record) and display annotated code
   archive         Create archive with object files with build-ids found in perf.data file
   bench           General framework for benchmark suites
   buildid-cache   Manage build-id cache.
   buildid-list    List the buildids in a perf.data file
   diff            Read two perf.data files and display the differential profile
   inject          Filter to augment the events stream with additional information
   kmem            Tool to trace/measure kernel memory(slab) properties
   kvm             Tool to trace/measure kvm guest os
   list            List all symbolic event types
   lock            Analyze lock events
   probe           Define new dynamic tracepoints
   record          Run a command and record its profile into perf.data
   report          Read perf.data (created by perf record) and display the profile
   sched           Tool to trace/measure scheduler properties (latencies)
   stat            Run a command and gather performance counter statistics
   test            Runs sanity tests.
   timechart       Tool to visualize total system behavior during a workload
   top             System profiling tool.
   trace           Read perf.data (created by perf record) and display trace output

 See 'perf help COMMAND' for more information on a specific command.

[root@doppio linux-2.6-tip]#

The new 'perf inject' command hadn't so it wasn't appearing on that list.

Also fix the long option, that should have no spaces in it, rename the faulty one
to be '--build-ids', instead of '--inject build-ids'.

Reported-by: Ingo Molnar 
Cc: Frédéric Weisbecker 
Cc: Mike Galbraith 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Tom Zanussi 
LKML-Reference: 
Signed-off-by: Arnaldo Carvalho de Melo

perf: Remove leftover useless options to record trace events from scripts

2010-04-30T17:55:00+00:00

-f, -c 1, -R are now useless for trace events recording, moreover
-M is useless and event hurts.

Remove them from the documentation examples and from record scripts.

Signed-off-by: Frederic Weisbecker 
Cc: Ingo Molnar 
Cc: Peter Zijlstra 
Cc: Arnaldo Carvalho de Melo 
Cc: Paul Mackerras 
Cc: Tom Zanussi

perf test: Initial regression testing command

2010-04-29T21:59:23+00:00

First an example with the first internal test:

[acme@doppio linux-2.6-tip]$ perf test
 1: vmlinux symtab matches kallsyms: Ok

So it run just one test, that is "vmlinux symtab matches kallsyms", and it was
successful.

If we run it in verbose mode, we'll see details about errors and extra warnings
for non-fatal problems:

[acme@doppio linux-2.6-tip]$ perf test -v
 1: vmlinux symtab matches kallsyms:
--- start ---
Looking at the vmlinux_path (5 entries long)
No build_id in vmlinux, ignoring it
No build_id in /boot/vmlinux, ignoring it
No build_id in /boot/vmlinux-2.6.34-rc4-tip+, ignoring it
Using /lib/modules/2.6.34-rc4-tip+/build/vmlinux for symbols
Maps only in vmlinux:
 ffffffff81cb81b1-ffffffff81e1149b 0 [kernel].init.text
 ffffffff81e1149c-ffffffff9fffffff 0 [kernel].exit.text
 ffffffffff600000-ffffffffff6000ff 0 [kernel].vsyscall_0
 ffffffffff600100-ffffffffff6003ff 0 [kernel].vsyscall_fn
 ffffffffff600400-ffffffffff6007ff 0 [kernel].vsyscall_1
 ffffffffff600800-ffffffffffffffff 0 [kernel].vsyscall_2
Maps in vmlinux with a different name in kallsyms:
 ffffffffff600000-ffffffffff6000ff 0 [kernel].vsyscall_0 in kallsyms as [kernel].0
 ffffffffff600100-ffffffffff6003ff 0 [kernel].vsyscall_fn in kallsyms as:
*ffffffffff600100-ffffffffff60012f 0 [kernel].2
 ffffffffff600400-ffffffffff6007ff 0 [kernel].vsyscall_1 in kallsyms as [kernel].6
 ffffffffff600800-ffffffffffffffff 0 [kernel].vsyscall_2 in kallsyms as [kernel].8
Maps only in kallsyms:
 ffffffffff600130-ffffffffff6003ff 0 [kernel].4
---- end ----
vmlinux symtab matches kallsyms: Ok
[acme@doppio linux-2.6-tip]$

In the above case we only know the name of the non contiguous kernel ranges in
the address space when reading the symbol information from the ELF symtab in
vmlinux.

The /proc/kallsyms file lack this, we only notice they are separate because
there are modules after the kernel and after that more kernel functions, so we
need to have a module rbtree backed by the module .ko path to get symtabs in
the vmlinux case.

The tool uses it to match by address to emit appropriate warning, but don't
considers this fatal.

The .init.text and .exit.text ines, of course, aren't in kallsyms, so I left
these cases just as extra info in verbose mode.

The end of the sections also aren't in kallsyms, so we the symbols layer does
another pass and sets the end addresses as the next map start minus one, which
sometimes pads, causing harmless mismatches.

But at least the symbols match, tested it by copying /proc/kallsyms to
/tmp/kallsyms and doing changes to see if they were detected.

This first test also should serve as a first stab at documenting the
symbol library by providing a self contained example that exercises it
together with comments about what is being done.

More tests to check if actions done on a monitored app, like doing mmaps, etc,
makes the kernel generate the expected events should be added next.

Cc: Frédéric Weisbecker 
Cc: Mike Galbraith 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
LKML-Reference: 
Signed-off-by: Arnaldo Carvalho de Melo