linux.git/tools/perf/util/parse-events.c, branch v4.19

perf parser: Improve error message for PMU address filters

2018-08-20T11:54:58+00:00

This is the second version of a patch that improves the error message of
the perf events parser when the PMU hardware does not support address
filters.

Previously, the perf returned the following error:

  $ perf record -e intel_pt// --filter 'filter sys_write'
  --filter option should follow a -e tracepoint or HW tracer option

This implies there is some syntax error present in the command line,
which is not true. Rather, notify the user that the CPU does not have
support for this feature.

For example, Intel chips based on the Broadwell micro-archticture have
the Intel PT PMU, but do not support address filtering.

Now, perf prints the following error message:

  $ perf record -e intel_pt// --filter 'filter sys_write'
  This CPU does not support address filtering

Signed-off-by: Jack Henschel 
Tested-by: Arnaldo Carvalho de Melo 
Acked-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/20180704121345.19025-1-jackdev@mailbox.org
Signed-off-by: Arnaldo Carvalho de Melo

tools lib api fs tracing_path: Introduce opendir() method

2018-05-17T17:50:38+00:00

That takes care of using the right call to get the tracing_path
directory, the one that will end up calling tracing_path_set() to figure
out where tracefs is mounted.

One more step in doing just lazy reading of system structures to reduce
the number of operations done unconditionaly at 'perf' start.

Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: https://lkml.kernel.org/n/tip-42zzi0f274909bg9mxzl81bu@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf parse-events: Use get/put_events_file()

2018-05-17T17:49:36+00:00

Instead of accessing the trace_events_path variable directly, that may
not have been properly initialized wrt detecting where tracefs is
mounted.

Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: https://lkml.kernel.org/n/tip-id7hzn1ydgkxbumeve5wapqz@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Reuse the path to the tracepoint /events/ directory

2018-05-17T17:25:07+00:00

When using for_each_event() we needlessly rebuild the whole path to
the tracepoint directory, reuse the dir_path instead, saving some cycles
and reducing the size of the next patch.

Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: https://lkml.kernel.org/n/tip-54bcs15n0cp6gwcgpc4hptyc@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf parse-events: Handle uncore event aliases in small groups properly

2018-05-16T13:01:54+00:00

Perf stat doesn't count the uncore event aliases from the same uncore
block in a group, for example:

  perf stat -e '{unc_m_cas_count.all,unc_m_clockticks}' -a -I 1000
  #           time             counts unit events
       1.000447342            unc_m_cas_count.all
       1.000447342            unc_m_clockticks
       2.000740654            unc_m_cas_count.all
       2.000740654            unc_m_clockticks

The output is very misleading. It gives a wrong impression that the
uncore event doesn't work.

An uncore block could be composed by several PMUs. An uncore event alias
is a joint name which means the same event runs on all PMUs of a block.
Perf doesn't support mixed events from different PMUs in the same group.
It is wrong to put uncore event aliases in a big group.

The right way is to split the big group into multiple small groups which
only include the events from the same PMU.

Only uncore event aliases from the same uncore block should be specially
handled here. It doesn't make sense to mix the uncore events with other
uncore events from different blocks or even core events in a group.

With the patch:
  #           time             counts unit events
     1.001557653            140,833      unc_m_cas_count.all
     1.001557653      1,330,231,332      unc_m_clockticks
     2.002709483             85,007      unc_m_cas_count.all
     2.002709483      1,429,494,563      unc_m_clockticks

Reported-by: Andi Kleen 
Signed-off-by: Kan Liang 
Acked-by: Jiri Olsa 
Cc: Agustin Vega-Frias 
Cc: Ganapatrao Kulkarni 
Cc: Jin Yao 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Shaokun Zhang 
Cc: Will Deacon 
Link: http://lkml.kernel.org/r/1525727623-19768-1-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Add missing newline when parsing empty BPF proggie

2018-05-11T15:10:02+00:00

This is not specific to BPF but was found when parsing a .c BPF proggie
that while valid, had no events attached to tracepoints, kprobes, etc:

Very minimal file that perf's BPF code can compile:

  # cat empty.c
  char _license[] __attribute__((section("license"), used)) = "GPL";
  int _version __attribute__((section("version"), used)) = LINUX_VERSION_CODE;
  #

Before this patch:

  # perf trace -e empty.c
  WARNING: event parser found nothinginvalid or unsupported event: 'empty.c'
  Run 'perf list' for a list of valid events

   Usage: perf trace [] []
      or: perf trace [] --  []
      or: perf trace record [] []
      or: perf trace record [] --  []

      -e, --event    event/syscall selector. use 'perf list' to list available events
    #

After:

  # perf trace -e empty.c
  WARNING: event parser found nothing
  invalid or unsupported event: 'empty.c'
  Run 'perf list' for a list of valid events

   Usage: perf trace [] []
      or: perf trace [] --  []
      or: perf trace record [] []
      or: perf trace record [] --  []

      -e, --event    event/syscall selector. use 'perf list' to list available events
  #

Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: https://lkml.kernel.org/n/tip-8ysughiz00h6mjpcot04qyjj@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Fix snprint warnings for gcc 8

2018-03-19T13:00:43+00:00

With gcc 8 we get new set of snprintf() warnings that breaks the
compilation, one example:

  tests/mem.c: In function ‘check’:
  tests/mem.c:19:48: error: ‘%s’ directive output may be truncated writing \
        up to 99 bytes into a region of size 89 [-Werror=format-truncation=]
    snprintf(failure, sizeof failure, "unexpected %s", out);

The gcc docs says:

 To avoid the warning either use a bigger buffer or handle the
 function's return value which indicates whether or not its output
 has been truncated.

Given that all these warnings are harmless, because the code either
properly fails due to uncomplete file path or we don't care for
truncated output at all, I'm changing all those snprintf() calls to
scnprintf(), which actually 'checks' for the snprint return value so the
gcc stays silent.

Signed-off-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: David Ahern 
Cc: Josh Poimboeuf 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Sergey Senozhatsky 
Link: http://lkml.kernel.org/r/20180319082902.4518-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf pmu: Auto-merge PMU events created by prefix or glob match

2018-03-08T13:05:49+00:00

Auto-merge for these events was disabled when auto-merging of non-alias
events was disabled in commit 63ce844 (perf stat: Only auto-merge events
that are PMU aliases).

Non-merging of legacy events is preserved:

    $ perf stat -ag -e cache-misses,cache-misses sleep 1

     Performance counter stats for 'system wide':

                86,323      cache-misses
                86,323      cache-misses

           1.002623307 seconds time elapsed

But prefix or glob matching auto-merges the events created:

    $ perf stat -a -e l3cache/read-miss/ sleep 1

     Performance counter stats for 'system wide':

                   328      l3cache/read-miss/

           1.002627008 seconds time elapsed

    $ perf stat -a -e l3cache_0_[01]/read-miss/ sleep 1

     Performance counter stats for 'system wide':

                   172      l3cache/read-miss/

           1.002627008 seconds time elapsed

As with events created with aliases, auto-merging can be suppressed with
the --no-merge option:

    $ perf stat -a -e l3cache/read-miss/ --no-merge sleep 1

     Performance counter stats for 'system wide':

                    67      l3cache/read-miss/
                    67      l3cache/read-miss/
                    63      l3cache/read-miss/
                    60      l3cache/read-miss/

           1.002622192 seconds time elapsed

Signed-off-by: Agustin Vega-Frias 
Acked-by: Andi Kleen 
Acked-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Timur Tabi 
Cc: linux-arm-kernel@lists.infradead.org
Change-Id: I0a47eed54c05e1982ca964d743b37f50f60c508c
Link: http://lkml.kernel.org/r/1520345084-42646-4-git-send-email-agustinv@codeaurora.org
Signed-off-by: Arnaldo Carvalho de Melo

perf pmu: Display pmu name when printing unmerged events in stat

2018-03-08T13:05:49+00:00

To simplify creation of events accross multiple instances of the same
type of PMU stat supports two methods for creating multiple events from
a single event specification:

1. A prefix or glob can be used in the PMU name.
2. Aliases, which are listed immediately after the Kernel PMU events
   by perf list, are used.

When the --no-merge option is passed and these events are displayed
individually the PMU name is lost and it's not possible to see which
count corresponds to which pmu:

    $ perf stat -a -e l3cache/read-miss/ --no-merge ls > /dev/null

     Performance counter stats for 'system wide':

                    67      l3cache/read-miss/
                    67      l3cache/read-miss/
                    63      l3cache/read-miss/
                    60      l3cache/read-miss/

           0.001675706 seconds time elapsed

    $ perf stat -a -e l3cache_read_miss --no-merge ls > /dev/null

     Performance counter stats for 'system wide':

                    12      l3cache_read_miss
                    17      l3cache_read_miss
                    10      l3cache_read_miss
                     8      l3cache_read_miss

           0.001661305 seconds time elapsed

This change adds the original pmu name to the event. For dynamic pmu
events the pmu name is restored in the event name:

    $ perf stat -a -e l3cache/read-miss/ --no-merge ls > /dev/null

     Performance counter stats for 'system wide':

                    63      l3cache_0_3/read-miss/
                    74      l3cache_0_1/read-miss/
                    64      l3cache_0_2/read-miss/
                    74      l3cache_0_0/read-miss/

           0.001675706 seconds time elapsed

For alias events the name is added after the event name:

    $ perf stat -a -e l3cache_read_miss --no-merge ls > /dev/null

     Performance counter stats for 'system wide':

                    10      l3cache_read_miss [l3cache_0_3]
                    12      l3cache_read_miss [l3cache_0_1]
                    10      l3cache_read_miss [l3cache_0_2]
                    17      l3cache_read_miss [l3cache_0_0]

           0.001661305 seconds time elapsed

Signed-off-by: Agustin Vega-Frias 
Acked-by: Andi Kleen 
Acked-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Timur Tabi 
Cc: linux-arm-kernel@lists.infradead.org
Change-Id: I8056b9eda74bda33e95065056167ad96e97cb1fb
Link: http://lkml.kernel.org/r/1520345084-42646-3-git-send-email-agustinv@codeaurora.org
Signed-off-by: Arnaldo Carvalho de Melo

perf evlist: Remove fcntl.h from evlist.h

2018-01-25T09:37:30+00:00

Not needed there, fixup the places where it is needed and was getting
only by luck via evlist.h.

Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: https://lkml.kernel.org/n/tip-yxjpetn64z8vjuguu84gr6x6@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo