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perf tools: Fix tracing_path_mount proper path

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If there's no tracefs (RHEL7) support the tracing_path_mount
returns debugfs path which results in following fail:

  # perf probe sys_write
  kprobe_events file does not exist - please rebuild kernel with CONFIG_KPROBE_EVENTS.
  Error: Failed to add events.

In tracing_path_debugfs_mount function we need to return the
'tracing' path instead of just the mount to make it work:

  # perf probe sys_write
  Added new event:
    probe:sys_write      (on sys_write)

  You can now use it in all perf tools, such as:

          perf record -e probe:sys_write -aR sleep 1

Adding the 'return tracing_path;' also to tracing_path_tracefs_mount
function just for consistency with tracing_path_debugfs_mount.

Upstream keeps working, because it has the tracefs support.

Link: http://lkml.kernel.org/n/tip-yiwkzexq9fk1ey1xg3gnjlw4@git.kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Fixes: 23773ca18b ("perf tools: Make perf aware of tracefs")
Link: http://lkml.kernel.org/r/20181016114818.3595-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Jiri Olsa 2018-10-16 13:48:18 +02:00 committed by Arnaldo Carvalho de Melo
parent 36b8d4628d
commit c458a6206d
1 changed files with 2 additions and 2 deletions
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4
tools/lib/api/fs/tracing_path.c
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@ -36,7 +36,7 @@ static const char *tracing_path_tracefs_mount(void)
__tracing_path_set("", mnt);
return mnt;
return tracing_path;
}
static const char *tracing_path_debugfs_mount(void)
@ -49,7 +49,7 @@ static const char *tracing_path_debugfs_mount(void)
__tracing_path_set("tracing/", mnt);
return mnt;
return tracing_path;
}
const char *tracing_path_mount(void)