<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/git/stable/linux.git/tools/perf/util, branch linux-6.0.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<id>https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/atom?h=linux-6.0.y</id>
<link rel='self' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/atom?h=linux-6.0.y'/>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/'/>
<updated>2023-01-12T11:00:41+00:00</updated>
<entry>
<title>perf stat: Fix handling of --for-each-cgroup with --bpf-counters to match non BPF mode</title>
<updated>2023-01-12T11:00:41+00:00</updated>
<author>
<name>Namhyung Kim</name>
<email>namhyung@kernel.org</email>
</author>
<published>2023-01-04T06:44:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=314f50ce4e82338fc47a4ca68a53e5d0ebd6b24d'/>
<id>urn:sha1:314f50ce4e82338fc47a4ca68a53e5d0ebd6b24d</id>
<content type='text'>
[ Upstream commit 54b353a20c7e8be98414754f5aff98c8a68fcc1f ]

The --for-each-cgroup can have the same cgroup multiple times, but this
confuses BPF counters (since they have the same cgroup id), making only
the last cgroup events to be counted.

Let's check the cgroup name before adding a new entry to the cgroups
list.

Before:

  $ sudo ./perf stat -a --bpf-counters --for-each-cgroup /,/ sleep 1

   Performance counter stats for 'system wide':

       &lt;not counted&gt; msec cpu-clock                        /
       &lt;not counted&gt;      context-switches                 /
       &lt;not counted&gt;      cpu-migrations                   /
       &lt;not counted&gt;      page-faults                      /
       &lt;not counted&gt;      cycles                           /
       &lt;not counted&gt;      instructions                     /
       &lt;not counted&gt;      branches                         /
       &lt;not counted&gt;      branch-misses                    /
            8,016.04 msec cpu-clock                        /                #    7.998 CPUs utilized
               6,152      context-switches                 /                #  767.461 /sec
                 250      cpu-migrations                   /                #   31.187 /sec
                 442      page-faults                      /                #   55.139 /sec
         613,111,487      cycles                           /                #    0.076 GHz
         280,599,604      instructions                     /                #    0.46  insn per cycle
          57,692,724      branches                         /                #    7.197 M/sec
           3,385,168      branch-misses                    /                #    5.87% of all branches

         1.002220125 seconds time elapsed

After it becomes similar to the non-BPF mode:

  $ sudo ./perf stat -a --bpf-counters --for-each-cgroup /,/  sleep 1

   Performance counter stats for 'system wide':

            8,013.38 msec cpu-clock                        /                #    7.998 CPUs utilized
               6,859      context-switches                 /                #  855.944 /sec
                 334      cpu-migrations                   /                #   41.680 /sec
                 345      page-faults                      /                #   43.053 /sec
         782,326,119      cycles                           /                #    0.098 GHz
         471,645,724      instructions                     /                #    0.60  insn per cycle
          94,963,430      branches                         /                #   11.851 M/sec
           3,685,511      branch-misses                    /                #    3.88% of all branches

         1.001864539 seconds time elapsed

Committer notes:

As a reminder, to test with BPF counters one has to use BUILD_BPF_SKEL=1
in the make command line and have clang/llvm installed when building
perf, otherwise the --bpf-counters option will not be available:

  # perf stat -a --bpf-counters --for-each-cgroup /,/ sleep 1
  Error: unknown option `bpf-counters'

   Usage: perf stat [&lt;options&gt;] [&lt;command&gt;]

      -a, --all-cpus        system-wide collection from all CPUs
  &lt;SNIP&gt;
  #

Fixes: bb1c15b60b981d10 ("perf stat: Support regex pattern in --for-each-cgroup")
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: bpf@vger.kernel.org
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Song Liu &lt;songliubraving@fb.com&gt;
Link: https://lore.kernel.org/r/20230104064402.1551516-5-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>perf stat: Fix handling of unsupported cgroup events when using BPF counters</title>
<updated>2023-01-12T11:00:41+00:00</updated>
<author>
<name>Namhyung Kim</name>
<email>namhyung@kernel.org</email>
</author>
<published>2023-01-04T06:44:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c1bb59435614ccde0caaba91564bbe050b05bf53'/>
<id>urn:sha1:c1bb59435614ccde0caaba91564bbe050b05bf53</id>
<content type='text'>
[ Upstream commit 2d656b0f81b22101db0447f890e39fdd736b745e ]

When --for-each-cgroup option is used, it fails when any of events is
not supported and exits immediately.  This is not how 'perf stat'
handles unsupported events.

Let's ignore the failure and proceed with others so that the output is
similar to when BPF counters are not used:

Before:

  $ sudo ./perf stat -a --bpf-counters -e L1-icache-loads,L1-dcache-loads --for-each-cgroup system.slice,user.slice sleep 1
  Failed to open first cgroup events
  $

After it shows output similat to when --bpf-counters isn't specified:

  $ sudo ./perf stat -a --bpf-counters -e L1-icache-loads,L1-dcache-loads --for-each-cgroup system.slice,user.slice sleep 1

   Performance counter stats for 'system wide':

     &lt;not supported&gt;      L1-icache-loads                  system.slice
          29,892,418      L1-dcache-loads                  system.slice
     &lt;not supported&gt;      L1-icache-loads                  user.slice
          52,497,220      L1-dcache-loads                  user.slice
  $

Fixes: 944138f048f7d759 ("perf stat: Enable BPF counter with --for-each-cgroup")
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Song Liu &lt;songliubraving@fb.com&gt;
Link: https://lore.kernel.org/r/20230104064402.1551516-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>perf tools: Fix resources leak in perf_data__open_dir()</title>
<updated>2023-01-12T11:00:40+00:00</updated>
<author>
<name>Miaoqian Lin</name>
<email>linmq006@gmail.com</email>
</author>
<published>2022-12-29T09:09:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=d89805f8fdedcf8efd645ff2e9d81d15a3b43313'/>
<id>urn:sha1:d89805f8fdedcf8efd645ff2e9d81d15a3b43313</id>
<content type='text'>
[ Upstream commit 0a6564ebd953c4590663c9a3c99a3ea9920ade6f ]

In perf_data__open_dir(), opendir() opens the directory stream.  Add
missing closedir() to release it after use.

Fixes: eb6176709b235b96 ("perf data: Add perf_data__open_dir_data function")
Reviewed-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Signed-off-by: Miaoqian Lin &lt;linmq006@gmail.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Alexey Bayduraev &lt;alexey.v.bayduraev@linux.intel.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: https://lore.kernel.org/r/20221229090903.1402395-1-linmq006@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>perf probe: Fix to get the DW_AT_decl_file and DW_AT_call_file as unsinged data</title>
<updated>2023-01-12T11:00:28+00:00</updated>
<author>
<name>Masami Hiramatsu (Google)</name>
<email>mhiramat@kernel.org</email>
</author>
<published>2022-11-05T03:01:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=749fa62e49279876e11c5fb85720b7befb3f4a9d'/>
<id>urn:sha1:749fa62e49279876e11c5fb85720b7befb3f4a9d</id>
<content type='text'>
[ Upstream commit a9dfc46c67b52ad43b8e335e28f4cf8002c67793 ]

DWARF version 5 standard Sec 2.14 says that

  Any debugging information entry representing the declaration of an object,
  module, subprogram or type may have DW_AT_decl_file, DW_AT_decl_line and
  DW_AT_decl_column attributes, each of whose value is an unsigned integer
  constant.

So it should be an unsigned integer data. Also, even though the standard
doesn't clearly say the DW_AT_call_file is signed or unsigned, the
elfutils (eu-readelf) interprets it as unsigned integer data and it is
natural to handle it as unsigned integer data as same as DW_AT_decl_file.
This changes the DW_AT_call_file as unsigned integer data too.

Fixes: 3f4460a28fb2f73d ("perf probe: Filter out redundant inline-instances")
Signed-off-by: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Acked-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Masami Hiramatsu &lt;masami.hiramatsu.pt@hitachi.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: stable@vger.kernel.org
Cc: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
Link: https://lore.kernel.org/r/166761727445.480106.3738447577082071942.stgit@devnote3
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>perf probe: Use dwarf_attr_integrate as generic DWARF attr accessor</title>
<updated>2023-01-12T11:00:28+00:00</updated>
<author>
<name>Masami Hiramatsu (Google)</name>
<email>mhiramat@kernel.org</email>
</author>
<published>2022-11-01T13:48:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b0d8f117079e1d0c6c067f41ec21610857086759'/>
<id>urn:sha1:b0d8f117079e1d0c6c067f41ec21610857086759</id>
<content type='text'>
[ Upstream commit f828929ab7f0dc3353e4a617f94f297fa8f3dec3 ]

Use dwarf_attr_integrate() instead of dwarf_attr() for generic attribute
acccessor functions, so that it can find the specified attribute from
abstact origin DIE etc.

Signed-off-by: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Acked-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
Link: https://lore.kernel.org/r/166731051988.2100653.13595339994343449770.stgit@devnote3
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Stable-dep-of: a9dfc46c67b5 ("perf probe: Fix to get the DW_AT_decl_file and DW_AT_call_file as unsinged data")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>perf debug: Set debug_peo_args and redirect_to_stderr variable to correct values in perf_quiet_option()</title>
<updated>2022-12-31T12:26:50+00:00</updated>
<author>
<name>Yang Jihong</name>
<email>yangjihong1@huawei.com</email>
</author>
<published>2022-12-20T03:57:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=5f2f72b7b5aca5801c3b4d0caf878786fbf69a37'/>
<id>urn:sha1:5f2f72b7b5aca5801c3b4d0caf878786fbf69a37</id>
<content type='text'>
[ Upstream commit 188ac720d364035008a54d249cf47b4cc100f819 ]

When perf uses quiet mode, perf_quiet_option() sets the 'debug_peo_args'
variable to -1, and display_attr() incorrectly determines the value of
'debug_peo_args'.  As a result, unexpected information is displayed.

Before:

  # perf record --quiet -- ls &gt; /dev/null
  ------------------------------------------------------------
  perf_event_attr:
    size                             128
    { sample_period, sample_freq }   4000
    sample_type                      IP|TID|TIME|PERIOD
    read_format                      ID|LOST
    disabled                         1
    inherit                          1
    mmap                             1
    comm                             1
    freq                             1
    enable_on_exec                   1
    task                             1
    precise_ip                       3
    sample_id_all                    1
    exclude_guest                    1
    mmap2                            1
    comm_exec                        1
    ksymbol                          1
    bpf_event                        1
  ------------------------------------------------------------
  ...

After:
  # perf record --quiet -- ls &gt; /dev/null
  #

redirect_to_stderr is a similar problem.

Fixes: f78eaef0e0493f60 ("perf tools: Allow to force redirect pr_debug to stderr.")
Fixes: ccd26741f5e6bdf2 ("perf tool: Provide an option to print perf_event_open args and return value")
Suggested-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Reviewed-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Signed-off-by: Yang Jihong &lt;yangjihong1@huawei.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Carsten Haitzler &lt;carsten.haitzler@arm.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Leo Yan &lt;leo.yan@linaro.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: martin.lau@kernel.org
Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Ravi Bangoria &lt;ravi.bangoria@amd.com&gt;
Cc: Ravi Bangoria &lt;ravi.bangoria@linux.ibm.com&gt;
Link: https://lore.kernel.org/r/20221220035702.188413-2-yangjihong1@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>perf off_cpu: Fix a typo in BTF tracepoint name, it should be 'btf_trace_sched_switch'</title>
<updated>2022-12-31T12:26:31+00:00</updated>
<author>
<name>Namhyung Kim</name>
<email>namhyung@kernel.org</email>
</author>
<published>2022-12-08T18:26:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a4abe5e2e7b804e9d972121e547cc9c4ff0e2894'/>
<id>urn:sha1:a4abe5e2e7b804e9d972121e547cc9c4ff0e2894</id>
<content type='text'>
[ Upstream commit 167b266bf66c5b93171011ef9d1f09b070c2c537 ]

In BTF, tracepoint definitions have the "btf_trace_" prefix.  The
off-cpu profiler needs to check the signature of the sched_switch event
using that definition.  But there's a typo (s/bpf/btf/) so it failed
always.

Fixes: b36888f71c8542cd ("perf record: Handle argument change in sched_switch")
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: bpf@vger.kernel.org
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Song Liu &lt;song@kernel.org&gt;
Link: https://lore.kernel.org/r/20221208182636.524139-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>perf symbol: correction while adjusting symbol</title>
<updated>2022-12-31T12:26:30+00:00</updated>
<author>
<name>Ajay Kaher</name>
<email>akaher@vmware.com</email>
</author>
<published>2022-11-23T10:18:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=37f84cec5d51693fbb808203ab3e97de6b312235'/>
<id>urn:sha1:37f84cec5d51693fbb808203ab3e97de6b312235</id>
<content type='text'>
[ Upstream commit 6f520ce17920b3cdfbd2479b3ccf27f9706219d0 ]

perf doesn't provide proper symbol information for specially crafted
.debug files.

Sometimes .debug file may not have similar program header as runtime
ELF file. For example if we generate .debug file using objcopy
--only-keep-debug resulting file will not contain .text, .data and
other runtime sections. That means corresponding program headers will
have zero FileSiz and modified Offset.

Example: program header of text section of libxxx.so:

Type           Offset             VirtAddr           PhysAddr
               FileSiz            MemSiz              Flags  Align
LOAD        0x00000000003d3000 0x00000000003d3000 0x00000000003d3000
            0x000000000055ae80 0x000000000055ae80  R E    0x1000

Same program header after executing:
objcopy --only-keep-debug libxxx.so libxxx.so.debug

LOAD        0x0000000000001000 0x00000000003d3000 0x00000000003d3000
            0x0000000000000000 0x000000000055ae80  R E    0x1000

Offset and FileSiz have been changed.

Following formula will not provide correct value, if program header
taken from .debug file (syms_ss):

    sym.st_value -= phdr.p_vaddr - phdr.p_offset;

Correct program header information is located inside runtime ELF
file (runtime_ss).

Fixes: 2d86612aacb7805f ("perf symbol: Correct address for bss symbols")
Signed-off-by: Ajay Kaher &lt;akaher@vmware.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Alexey Makhalov &lt;amakhalov@vmware.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Leo Yan &lt;leo.yan@linaro.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Srivatsa S. Bhat &lt;srivatsab@vmware.com&gt;
Cc: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
Cc: Vasavi Sirnapalli &lt;vsirnapalli@vmware.com&gt;
Link: http://lore.kernel.org/lkml/1669198696-50547-1-git-send-email-akaher@vmware.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>perf test: Fix skipping branch stack sampling test</title>
<updated>2022-11-16T09:03:59+00:00</updated>
<author>
<name>James Clark</name>
<email>james.clark@arm.com</email>
</author>
<published>2022-10-28T12:19:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=94bb0a6bdb142539f854f19eefdeeb2e58f116cc'/>
<id>urn:sha1:94bb0a6bdb142539f854f19eefdeeb2e58f116cc</id>
<content type='text'>
[ Upstream commit 20ebc4a649b82e6ad892684c76ea1e8dd786d336 ]

Commit f4a2aade6809c657 ("perf tests powerpc: Fix branch stack sampling
test to include sanity check for branch filter") added a skip if certain
branch options aren't available.

But the change added both -b (--branch-any) and --branch-filter options
at the same time, which will always result in a failure on any platform
because the arguments can't be used together.

Fix this by removing -b (--branch-any) and leaving --branch-filter which
already specifies 'any'. Also add warning messages to the test and perf
tool.

Output on x86 before this fix:

   $ sudo ./perf test branch
   108: Check branch stack sampling         : Skip

After:

   $ sudo ./perf test branch
   108: Check branch stack sampling         : Ok

Fixes: f4a2aade6809c657 ("perf tests powerpc: Fix branch stack sampling test to include sanity check for branch filter")
Signed-off-by: James Clark &lt;james.clark@arm.com&gt;
Tested-by: Athira Jajeev &lt;atrajeev@linux.vnet.ibm.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Anshuman.Khandual@arm.com
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Kajol Jain &lt;kjain@linux.ibm.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: https://lore.kernel.org/r/20221028121913.745307-1-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>perf stat: Fix printing os-&gt;prefix in CSV metrics output</title>
<updated>2022-11-16T09:03:58+00:00</updated>
<author>
<name>Athira Rajeev</name>
<email>atrajeev@linux.vnet.ibm.com</email>
</author>
<published>2022-10-18T08:56:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.rulkc.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=82f88249451ac6259509c896e6f534ddb0ac566f'/>
<id>urn:sha1:82f88249451ac6259509c896e6f534ddb0ac566f</id>
<content type='text'>
[ Upstream commit ad353b710c7493df3d4fc2d3a51819126bed2e81 ]

'perf stat' with CSV output option prints an extra empty string as first
field in metrics output line.  Sample output below:

	# ./perf stat -x, --per-socket -a -C 1 ls
	S0,1,1.78,msec,cpu-clock,1785146,100.00,0.973,CPUs utilized
	S0,1,26,,context-switches,1781750,100.00,0.015,M/sec
	S0,1,1,,cpu-migrations,1780526,100.00,0.561,K/sec
	S0,1,1,,page-faults,1779060,100.00,0.561,K/sec
	S0,1,875807,,cycles,1769826,100.00,0.491,GHz
	S0,1,85281,,stalled-cycles-frontend,1767512,100.00,9.74,frontend cycles idle
	S0,1,576839,,stalled-cycles-backend,1766260,100.00,65.86,backend cycles idle
	S0,1,288430,,instructions,1762246,100.00,0.33,insn per cycle
====&gt;	,S0,1,,,,,,,2.00,stalled cycles per insn

The above command line uses field separator as "," via "-x," option and
per-socket option displays socket value as first field. But here the
last line for "stalled cycles per insn" has "," in the beginning.

Sample output using interval mode:

	# ./perf stat -I 1000 -x, --per-socket -a -C 1 ls
	0.001813453,S0,1,1.87,msec,cpu-clock,1872052,100.00,0.002,CPUs utilized
	0.001813453,S0,1,2,,context-switches,1868028,100.00,1.070,K/sec
	------
	0.001813453,S0,1,85379,,instructions,1856754,100.00,0.32,insn per cycle
====&gt;	0.001813453,,S0,1,,,,,,,1.34,stalled cycles per insn

Above result also has an extra CSV separator after
the timestamp. Patch addresses extra field separator
in the beginning of the metric output line.

The counter stats are displayed by function
"perf_stat__print_shadow_stats" in code
"util/stat-shadow.c". While printing the stats info
for "stalled cycles per insn", function "new_line_csv"
is used as new_line callback.

The new_line_csv function has check for "os-&gt;prefix"
and if prefix is not null, it will be printed along
with cvs separator.
Snippet from "new_line_csv":
	if (os-&gt;prefix)
               fprintf(os-&gt;fh, "%s%s", os-&gt;prefix, config-&gt;csv_sep);

Here os-&gt;prefix gets printed followed by ","
which is the cvs separator. The os-&gt;prefix is
used in interval mode option ( -I ), to print
time stamp on every new line. But prefix is
already set to contain CSV separator when used
in interval mode for CSV option.

Reference: Function "static void print_interval"
Snippet:
	sprintf(prefix, "%6lu.%09lu%s", ts-&gt;tv_sec, ts-&gt;tv_nsec, config-&gt;csv_sep);

Also if prefix is not assigned (if not used with
-I option), it gets set to empty string.
Reference: function printout() in util/stat-display.c
Snippet:
	.prefix = prefix ? prefix : "",

Since prefix already set to contain cvs_sep in interval
option, patch removes printing config-&gt;csv_sep in
new_line_csv function to avoid printing extra field.

After the patch:

	# ./perf stat -x, --per-socket -a -C 1 ls
	S0,1,2.04,msec,cpu-clock,2045202,100.00,1.013,CPUs utilized
	S0,1,2,,context-switches,2041444,100.00,979.289,/sec
	S0,1,0,,cpu-migrations,2040820,100.00,0.000,/sec
	S0,1,2,,page-faults,2040288,100.00,979.289,/sec
	S0,1,254589,,cycles,2036066,100.00,0.125,GHz
	S0,1,82481,,stalled-cycles-frontend,2032420,100.00,32.40,frontend cycles idle
	S0,1,113170,,stalled-cycles-backend,2031722,100.00,44.45,backend cycles idle
	S0,1,88766,,instructions,2030942,100.00,0.35,insn per cycle
	S0,1,,,,,,,1.27,stalled cycles per insn

Fixes: 92a61f6412d3a09d ("perf stat: Implement CSV metrics output")
Reported-by: Disha Goel &lt;disgoel@linux.vnet.ibm.com&gt;
Reviewed-By: Kajol Jain &lt;kjain@linux.ibm.com&gt;
Signed-off-by: Athira Jajeev &lt;atrajeev@linux.vnet.ibm.com&gt;
Tested-by: Disha Goel &lt;disgoel@linux.vnet.ibm.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: James Clark &lt;james.clark@arm.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Madhavan Srinivasan &lt;maddy@linux.vnet.ibm.com&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Nageswara R Sastry &lt;rnsastry@linux.ibm.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Link: https://lore.kernel.org/r/20221018085605.63834-1-atrajeev@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
</feed>
