linux.git/tools/perf/util/header.c, branch v4.17

perf record: Change warning for missing sysfs entry to debug

2018-04-13T12:59:56+00:00

Using perf on 4.16.0 kernel on s390 shows this warning:

   failed: can't open node sysfs data

each time I run command perf record ... for example:

  [root@s35lp76 perf]# ./perf record -e rB0000 -- sleep 1
  [ perf record: Woken up 1 times to write data ]
  failed: can't open node sysfs data
  [ perf record: Captured and wrote 0.001 MB perf.data (4 samples) ]
  [root@s35lp76 perf]#

It turns out commit e2091cedd51bf ("perf tools: Add MEM_TOPOLOGY feature
to perf data file") tries to open directory named /sys/devices/system/node/
which does not exist on s390.

This is the call stack:
 __cmd_record
 +---> perf_session__write_header
       +---> perf_header__adds_write
             +---> do_write_feat
	           +---> write_mem_topology
		         +---> build_mem_topology
			       prints warning

The issue starts in do_write_feat() which unconditionally loops over all
features and now includes HEADER_MEM_TOPOLOGY and calls write_mem_topology().

Function record__init_features() at the beginning of __cmd_record() sets
all features and then turns off some of them.

Fix this by changing the warning to a level 2 debug output statement.

So it is only shown when debug level 2 or higher is set.

Signed-off-by: Thomas Richter 
Cc: Heiko Carstens 
Cc: Hendrik Brueckner 
Cc: Martin Schwidefsky 
Link: http://lkml.kernel.org/r/20180412133246.92801-1-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo

perf report: Support forced leader feature in pipe mode

2018-03-16T16:56:59+00:00

Stephane reported a problem with forced leader in pipe mode, where
report does not force the group output. The reason is that we don't
force the leader in pipe mode.

This patch adds HEADER_LAST_FEATURE mark to have a point where we have
all events and features received, and force the group if requested.

  $ perf record --group -e '{cycles, instructions}' -o - kill | perf report -i - --group

  SNIP

  #         Overhead  Command  Shared Object     Symbol
  # ................  .......  ................  .......................
  #
      28.36%   0.00%  kill     libc-2.25.so      [.] __unregister_atfork
      26.32%   0.00%  kill     libc-2.25.so      [.] _dl_addr
      26.10%   0.00%  kill     ld-2.25.so        [.] _dl_relocate_object
      17.32%   0.00%  kill     ld-2.25.so        [.] __tunables_init
       1.70%   0.01%  kill     [unknown]         [k] 0xffffffffafa01a40
       0.20%   0.00%  kill     ld-2.25.so        [.] _start
       0.00%  48.77%  kill     ld-2.25.so        [.] do_lookup_x
       0.00%  42.97%  kill     libc-2.25.so      [.] _IO_getline
       0.00%   6.35%  kill     ld-2.25.so        [.] strcmp
       0.00%   1.71%  kill     ld-2.25.so        [.] _dl_sysdep_start
       0.00%   0.19%  kill     ld-2.25.so        [.] _dl_start

Signed-off-by: Jiri Olsa 
Tested-by: Arnaldo Carvalho de Melo 
Tested-by: Stephane Eranian 
Cc: Alexander Shishkin 
Cc: David Ahern 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/20180314092205.23291-2-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Add MEM_TOPOLOGY feature to perf data file

2018-03-08T14:30:46+00:00

Adding MEM_TOPOLOGY feature to perf data file,
that will carry physical memory map and its
node assignments.

The format of data in MEM_TOPOLOGY is as follows:

  0 - version          | for future changes
  8 - block_size_bytes | /sys/devices/system/memory/block_size_bytes
 16 - count            | number of nodes

 For each node we store map of physical indexes for
 each node:

 32 - node id          | node index
 40 - size             | size of bitmap
 48 - bitmap           | bitmap of memory indexes that belongs to node
                       | /sys/devices/system/node/node/memory

The MEM_TOPOLOGY could be displayed with following
report command:

  $ perf report --header-only -I
  ...
  # memory nodes (nr 1, block size 0x8000000):
  #    0 [7G]: 0-23,32-69

Signed-off-by: Jiri Olsa 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Alexander Shishkin 
Cc: David Ahern 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/20180307155020.32613-8-jolsa@kernel.org
[ Rename 'index' to 'idx', as this breaks the build in rhel5, 6 and other systems where this is used by glibc headers ]
Signed-off-by: Arnaldo Carvalho de Melo

perf report: Display perf.data header info

2018-03-08T14:30:41+00:00

Display more header info from perf.data file, following values:

  $ perf report -i perf.data --header-only
  ...
  # header version : 1
  # data offset    : 424
  # data size      : 3364280
  # feat offset    : 3364704

It's handy for debuging.

Signed-off-by: Jiri Olsa 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Alexander Shishkin 
Cc: David Ahern 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/20180307155020.32613-3-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf header: Add infrastructure to record first and last sample time

2018-01-08T14:20:51+00:00

perf report/script/... have a --time option to limit the time range of
output. That's very useful to slice large traces, e.g. when processing
the output of perf script for some analysis.

But right now --time only supports absolute time. Also there is no fast
way to get the start/end times of a given trace except for looking at
it.  This makes it hard to e.g. only decode the first half of the trace,
which is useful for parallelization of scripts

Another problem is that perf records are variable size and there is no
synchronization mechanism. So the only way to find the last sample
reliably would be to walk all samples. But we want to avoid that in perf
report/...  because it is already quite expensive. That is why storing
the first sample time and last sample time in perf record is better.

This patch creates a new header feature type HEADER_SAMPLE_TIME and
related ops. Save the first sample time and the last sample time to the
feature section in perf file header. That will be done when, for
instance, processing build-ids, where we already have to process all
samples to create the build-id table, take advantage of that to further
amortize that processing by storing HEADER_SAMPLE_TIME to make 'perf
report/script' faster when using --time.

Committer testing:

After this patch is applied the header is written with zeroes, we need
the next patch, for "perf record" to actually write the timestamps:

  # perf report -D | grep PERF_RECORD_SAMPLE\(
  22501155244406 0x44f0 [0x28]: PERF_RECORD_SAMPLE(IP, 0x4001): 25016/25016: 0xffffffffa21be8c5 period: 1 addr: 0
  
  22501155793625 0x4a30 [0x28]: PERF_RECORD_SAMPLE(IP, 0x4001): 25016/25016: 0xffffffffa21ffd50 period: 2828043 addr: 0
  # perf report --header | grep "time of "
  # time of first sample : 0.000000
  # time of last sample : 0.000000
  #

Changelog:

v7: 1. Rebase to latest perf/core branch.

    2. Add following clarification in patch description according to
       Arnaldo's suggestion.

       "That will be done when, for instance, processing build-ids,
	where we already have to process all samples to create the
	build-id table, take advantage of that to further amortize
	that processing by storing HEADER_SAMPLE_TIME to make
	'perf report/script' faster when using --time."

v4: Use perf script time style for timestamp printing. Also add with
    the printing of sample duration.

v3: Remove the definitions of first_sample_time/last_sample_time from
    perf_session. Just define them in perf_evlist

Signed-off-by: Jin Yao 
Acked-by: Jiri Olsa 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Kan Liang 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1512738826-2628-2-git-send-email-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf perf: Remove duplicate includes

2017-12-27T15:15:49+00:00

These duplicate includes have been found with scripts/checkincludes.pl
but they have been removed manually to avoid removing false positives.

Signed-off-by: Pravin Shedge 
Cc: David S. Miller 
Cc: Greg Kroah-Hartman 
Cc: Jiri Olsa 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/1512582204-6493-1-git-send-email-pravin.shedge4linux@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo

perf record: Synthesize unit/scale/... in event update

2017-11-29T21:18:00+00:00

Move the code to synthesize event updates for scale/unit/cpus to a
common utility file, and use it both from stat and record.

This allows to access scale and other extra qualifiers from perf script.

Signed-off-by: Andi Kleen 
Acked-by: Jiri Olsa 
Link: http://lkml.kernel.org/r/20171117214300.32746-2-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo

Merge branch 'linus' into perf/core, to fix conflicts

2017-11-07T09:30:18+00:00

Conflicts:
	tools/perf/arch/arm/annotate/instructions.c
	tools/perf/arch/arm64/annotate/instructions.c
	tools/perf/arch/powerpc/annotate/instructions.c
	tools/perf/arch/s390/annotate/instructions.c
	tools/perf/arch/x86/tests/intel-cqm.c
	tools/perf/ui/tui/progress.c
	tools/perf/util/zlib.c

Signed-off-by: Ingo Molnar

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55+00:00

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart 
Reviewed-by: Philippe Ombredanne 
Reviewed-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

perf tools: Add struct perf_data_file

2017-10-30T16:37:37+00:00

Add struct perf_data_file to represent a single file within a perf_data
struct.

Signed-off-by: Jiri Olsa 
Cc: Andi Kleen 
Cc: Changbin Du 
Cc: David Ahern 
Cc: Jin Yao 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Wang Nan 
Link: http://lkml.kernel.org/n/tip-c3f9p4xzykr845ktqcek6p4t@git.kernel.org
[ Fixup recent changes in 'perf script --per-event-dump' ]
Signed-off-by: Arnaldo Carvalho de Melo