linux-stable.git/tools/perf/util/header.c, branch v5.8

perf session: Try to read pipe data from file

2020-05-28T13:03:25+00:00

Ian came with the idea of having support to read the pipe data also from
file. Currently pipe mode files fail like:

  $ perf record -o - sleep 1 > /tmp/perf.pipe.data
  $ perf report -i /tmp/perf.pipe.data
  incompatible file format (rerun with -v to learn more)

This patch adds the support to do that by trying the pipe header first,
and if its successfully detected, switching the perf data to pipe mode.

Committer testing:

  # ls
  # perf record -a -o - sleep 1 > /tmp/perf.pipe.data
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.000 MB - ]
  # ls
  # perf report -i /tmp/perf.pipe.data | head -25
  # To display the perf.data header info, please use --header/--header-only options.
  #
  #
  # Total Lost Samples: 0
  #
  # Samples: 511  of event 'cycles'
  # Event count (approx.): 178447276
  #
  # Overhead  Command   Shared Object      Symbol
  # ........  ........  .................  ...........................................................................................
  #
      65.49%  swapper   [kernel.kallsyms]  [k] native_safe_halt
       6.45%  chromium  libblink_core.so   [.] blink::SelectorChecker::CheckOne
       4.08%  chromium  libblink_core.so   [.] blink::SelectorQuery::ExecuteForTraverseRoot
       2.25%  chromium  libblink_core.so   [.] blink::SelectorQuery::FindTraverseRootsAndExecute
       2.11%  chromium  libblink_core.so   [.] blink::SelectorChecker::MatchSelector
       1.91%  chromium  libblink_core.so   [.] blink::Node::OwnerShadowHost
       1.31%  chromium  libblink_core.so   [.] blink::Node::parentNode@plt
       1.22%  chromium  libblink_core.so   [.] blink::Node::parentNode
       0.59%  chromium  libblink_core.so   [.] blink::AnyAttributeMatches
       0.58%  chromium  libv8.so           [.] v8::internal::GlobalHandles::Create
       0.58%  chromium  libblink_core.so   [.] blink::NodeTraversal::NextAncestorSibling
       0.55%  chromium  libv8.so           [.] v8::internal::RegExpGlobalCache::RegExpGlobalCache
       0.55%  chromium  libblink_core.so   [.] blink::Node::ContainingShadowRoot
       0.55%  chromium  libblink_core.so   [.] blink::NodeTraversal::NextAncestorSibling@plt
  #

Original-patch-by: Ian Rogers 
Signed-off-by: Jiri Olsa 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Alexander Shishkin 
Cc: Ian Rogers 
Cc: Michael Petlan 
Cc: Namhyung Kim 
Cc: Paul Khuong 
Cc: Peter Zijlstra 
Link: http://lore.kernel.org/lkml/20200507095024.2789147-4-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Do not seek in pipe fd during tracing data processing

2020-05-28T13:03:25+00:00

There's no need to set 'fd' position in pipe mode, the file descriptor
is already in proper place. Moreover the lseek will fail on pipe
descriptor and that's why it's been working properly.

I was tempted to remove the lseek calls completely, because it seems
that tracing data event was always synthesized only in pipe mode, so
there's no need for 'file' mode handling. But I guess there was a reason
behind this and there might (however unlikely) be a perf.data that we
could break processing for.

Signed-off-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Ian Rogers 
Cc: Michael Petlan 
Cc: Namhyung Kim 
Cc: Paul Khuong 
Cc: Peter Zijlstra 
Link: http://lore.kernel.org/lkml/20200507095024.2789147-3-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf evsel: Rename perf_evsel__is_() to evsel__is()

2020-05-05T19:35:31+00:00

As those are 'struct evsel' methods, not part of tools/lib/perf/, aka
libperf, to whom the perf_ prefix belongs.

Cc: Adrian Hunter 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Signed-off-by: Arnaldo Carvalho de Melo

perf evsel: Rename perf_evselname() to evselname()

2020-05-05T19:35:30+00:00

As they are 'struct evsel' methods or related routines, not part of
tools/lib/perf/, aka libperf, to whom the perf_ prefix belongs.

Cc: Adrian Hunter 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Signed-off-by: Arnaldo Carvalho de Melo

perf header: Support CPU PMU capabilities

2020-04-18T12:05:00+00:00

To stitch LBR call stack, the max LBR information is required. So the
CPU PMU capabilities information has to be stored in perf header.

Add a new feature HEADER_CPU_PMU_CAPS for CPU PMU capabilities.
Retrieve all CPU PMU capabilities, not just max LBR information.

Add variable max_branches to facilitate future usage.

Committer testing:

  # ls -la /sys/devices/cpu/caps/
  total 0
  drwxr-xr-x. 2 root root    0 Apr 17 10:53 .
  drwxr-xr-x. 6 root root    0 Apr 17 07:02 ..
  -r--r--r--. 1 root root 4096 Apr 17 10:53 max_precise
  #
  # cat /sys/devices/cpu/caps/max_precise
  0
  # perf record sleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.033 MB perf.data (7 samples) ]
  #
  # perf report --header-only | egrep 'cpu(desc|.*capabilities)'
  # cpudesc : AMD Ryzen 5 3600X 6-Core Processor
  # cpu pmu capabilities: max_precise=0
  #

And then on an Intel machine:

  $ ls -la /sys/devices/cpu/caps/
  total 0
  drwxr-xr-x. 2 root root    0 Apr 17 10:51 .
  drwxr-xr-x. 6 root root    0 Apr 17 10:04 ..
  -r--r--r--. 1 root root 4096 Apr 17 11:37 branches
  -r--r--r--. 1 root root 4096 Apr 17 10:51 max_precise
  -r--r--r--. 1 root root 4096 Apr 17 11:37 pmu_name
  $ cat /sys/devices/cpu/caps/max_precise
  3
  $ cat /sys/devices/cpu/caps/branches
  32
  $ cat /sys/devices/cpu/caps/pmu_name
  skylake
  $ perf record sleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.001 MB perf.data (8 samples) ]
  $ perf report --header-only | egrep 'cpu(desc|.*capabilities)'
  # cpudesc : Intel(R) Core(TM) i5-7500 CPU @ 3.40GHz
  # cpu pmu capabilities: branches=32, max_precise=3, pmu_name=skylake
  $

Signed-off-by: Kan Liang 
Reviewed-by: Andi Kleen 
Acked-by: Jiri Olsa 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Adrian Hunter 
Cc: Alexey Budankov 
Cc: Mathieu Poirier 
Cc: Michael Ellerman 
Cc: Namhyung Kim 
Cc: Pavel Gerasimov 
Cc: Peter Zijlstra 
Cc: Ravi Bangoria 
Cc: Stephane Eranian 
Cc: Vitaly Slobodskoy 
Link: http://lore.kernel.org/lkml/20200319202517.23423-3-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf header: Add check for unexpected use of reserved membrs in event attr

2020-03-10T00:43:24+00:00

The perf.data may be generated by a newer version of perf tool, which
support new input bits in attr, e.g. new bit for branch_sample_type.

The perf.data may be parsed by an older version of perf tool later.  The
old perf tool may parse the perf.data incorrectly. There is no warning
message for this case.

Current perf header never check for unknown input bits in attr.

When read the event desc from header, check the stored event attr.  The
reserved bits, sample type, read format and branch sample type will be
checked.

Signed-off-by: Kan Liang 
Cc: Adrian Hunter 
Cc: Alexey Budankov 
Cc: Andi Kleen 
Cc: Jiri Olsa 
Cc: Mathieu Poirier 
Cc: Michael Ellerman 
Cc: Namhyung Kim 
Cc: Pavel Gerasimov 
Cc: Peter Zijlstra 
Cc: Ravi Bangoria 
Cc: Stephane Eranian 
Cc: Vitaly Slobodskoy 
Link: http://lkml.kernel.org/r/20200228163011.19358-4-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf header: Use last modification time for timestamp

2020-01-15T13:17:20+00:00

Using .st_ctime clobbers the timestamp information in perf report header
whenever any operation is done with the file. Even tar-ing and untar-ing
the perf.data file (which preserves the file last modification timestamp)
doesn't prevent that:

    [Michael@Diego tmp]$ ls -l perf.data
->	-rw-------. 1 Michael Michael 169888 Dec  2 15:23 perf.data

	[Michael@Diego tmp]$ perf report --header-only
	# ========
->	# captured on    : Mon Dec  2 15:23:42 2019
	 [...]

	[Michael@Diego tmp]$ tar c perf.data | xz > perf.data.tar.xz
	[Michael@Diego tmp]$ mkdir aaa
	[Michael@Diego tmp]$ cd aaa
	[Michael@Diego aaa]$ xzcat ../perf.data.tar.xz | tar x
	[Michael@Diego aaa]$ ls -l -a
	total 172
	drwxrwxr-x. 2 Michael Michael     23 Jan 14 11:26 .
	drwxrwxr-x. 6 Michael Michael   4096 Jan 14 11:26 ..
->	-rw-------. 1 Michael Michael 169888 Dec  2 15:23 perf.data

	[Michael@Diego aaa]$ perf report --header-only
	# ========
->	# captured on    : Tue Jan 14 11:26:16 2020
	 [...]

When using .st_mtime instead, correct information is printed:

	[Michael@Diego aaa]$ ~/acme/tools/perf/perf report --header-only
	# ========
->	# captured on    : Mon Dec  2 15:23:42 2019
	 [...]

Signed-off-by: Michael Petlan 
Acked-by: Jiri Olsa 
LPU-Reference: 20200114104236.31555-1-mpetlan@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo

perf header: Fix false warning when there are no duplicate cache entries

2019-12-11T15:28:14+00:00

Before this patch, perf expected that there might be NPROC*4 unique
cache entries at max, however, it also expected that some of them would
be shared and/or of the same size, thus the final number of entries
would be reduced to be lower than NPROC*4. In case the number of entries
hadn't been reduced (was NPROC*4), the warning was printed.

However, some systems might have unusual cache topology, such as the
following two-processor KVM guest:

	cpu  level  shared_cpu_list  size
	  0     1         0           32K
	  0     1         0           64K
	  0     2         0           512K
	  0     3         0           8192K
	  1     1         1           32K
	  1     1         1           64K
	  1     2         1           512K
	  1     3         1           8192K

This KVM guest has 8 (NPROC*4) unique cache entries, which used to make
perf printing the message, although there actually aren't "way too many
cpu caches".

v2: Removing unused argument.

v3: Unifying the way we obtain number of cpus.

v4: Removed '& UINT_MAX' construct which is redundant.

Signed-off-by: Michael Petlan 
Acked-by: Jiri Olsa 
LPU-Reference: 20191208162056.20772-1-mpetlan@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo

perf arch: Make the default get_cpuid() return compatible error

2019-12-11T15:25:14+00:00

Some of the functions calling get_cpuid() propagate back the error it
returns, and all are using errno (positive) values, make the weak
default get_cpuid() function return ENOSYS to be consistent and to allow
checking if this is an arch not providing this function or if a provided
one is having trouble getting the cpuid, to decide if the warning should
be provided to the user or just a debug message should be emitted.

Reviewed-by: Mark Rutland 
Tested-by: Mark Rutland 
Tested-by: John Garry  # arm64
Acked-by: Jiri Olsa 
Cc: Adrian Hunter 
Cc: Namhyung Kim 
Cc: Will Deacon 
Link: https://lkml.kernel.org/n/tip-lxwjr0cd2eggzx04a780ffrv@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Fix resource leak of closedir() on the error paths

2019-10-15T14:54:11+00:00

Both build_mem_topology() and rm_rf_depth_pat() have resource leaks of
closedir() on the error paths.

Fix this by calling closedir() before function returns.

Fixes: e2091cedd51b ("perf tools: Add MEM_TOPOLOGY feature to perf data file")
Fixes: cdb6b0235f17 ("perf tools: Add pattern name checking to rm_rf")
Signed-off-by: Yunfeng Ye 
Acked-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Alexei Starovoitov 
Cc: Alexey Budankov 
Cc: Andi Kleen 
Cc: Daniel Borkmann 
Cc: Feilong Lin 
Cc: Hu Shiyuan 
Cc: Igor Lubashev 
Cc: Kan Liang 
Cc: Mark Rutland 
Cc: Martin KaFai Lau 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Song Liu 
Cc: Yonghong Song 
Link: http://lore.kernel.org/lkml/cd5f7cd2-b80d-6add-20a1-32f4f43e0744@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo