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| author |   Jiri Olsa <jolsa@kernel.org> | 2015-09-19 16:47:07 +0200 |
|---|---|---|
| committer |   Arnaldo Carvalho de Melo <acme@redhat.com> | 2015-09-28 15:50:54 -0300 |
| commit | dc240c5dc2a02e335c5bcb50ad3a1274818c8609 (patch) | |
| tree | eddd6aeca2ce858c2beaba83bf392db6fe6aadfe /tools/lib | |
| parent | perf tools: Use __map__is_kernel() when synthesizing kernel module mmap records (diff) | |
| download | linux-dev-dc240c5dc2a02e335c5bcb50ad3a1274818c8609.tar.xz linux-dev-dc240c5dc2a02e335c5bcb50ad3a1274818c8609.zip | |
tools lib api fs: Store tracing mountpoint for better error message
Storing the actual tracing path mountpoint to display correct
error message hint ('Hint:' line). The error hint rediscovers
mountpoints, but it could be different from what we actually
used in tracing path.
Before we'd display debugfs mount even though tracefs was used:
$ perf record -e sched:sched_krava ls
event syntax error: 'sched:sched_krava'
\___ can't access trace events
Error: No permissions to read /sys/kernel/debug/tracing/events/sched/sched_krava
Hint: Try 'sudo mount -o remount,mode=755 /sys/kernel/debug'
...
After this change, correct mountpoint is displayed:
$ perf record -e sched:sched_krava ls
event syntax error: 'sched:sched_krava'
\___ can't access trace events
Error: No permissions to read /sys/kernel/debug/tracing/events/sched/sched_krava
Hint: Try 'sudo mount -o remount,mode=755 /sys/kernel/debug/tracing'
...
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Raphael Beamonte <raphael.beamonte@gmail.com>
Link: http://lkml.kernel.org/r/1442674027-19427-1-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/lib')
| -rw-r--r-- | tools/lib/api/fs/tracing_path.c | 13 |
1 files changed, 3 insertions, 10 deletions
diff --git a/tools/lib/api/fs/tracing_path.c b/tools/lib/api/fs/tracing_path.c index 38aca2dd1946..0406a7d5c891 100644 --- a/tools/lib/api/fs/tracing_path.c +++ b/tools/lib/api/fs/tracing_path.c @@ -12,12 +12,14 @@ #include "tracing_path.h" +char tracing_mnt[PATH_MAX + 1] = "/sys/kernel/debug"; char tracing_path[PATH_MAX + 1] = "/sys/kernel/debug/tracing"; char tracing_events_path[PATH_MAX + 1] = "/sys/kernel/debug/tracing/events"; static void __tracing_path_set(const char *tracing, const char *mountpoint) { + snprintf(tracing_mnt, sizeof(tracing_mnt), "%s", mountpoint); snprintf(tracing_path, sizeof(tracing_path), "%s/%s", mountpoint, tracing); snprintf(tracing_events_path, sizeof(tracing_events_path), "%s/%s%s", @@ -109,19 +111,10 @@ static int strerror_open(int err, char *buf, size_t size, const char *filename) "Hint:\tTry 'sudo mount -t debugfs nodev /sys/kernel/debug'"); break; case EACCES: { - const char *mountpoint = debugfs__mountpoint(); - - if (!access(mountpoint, R_OK) && strncmp(filename, "tracing/", 8) == 0) { - const char *tracefs_mntpoint = tracefs__mountpoint(); - - if (tracefs_mntpoint) - mountpoint = tracefs__mountpoint(); - } - snprintf(buf, size, "Error:\tNo permissions to read %s/%s\n" "Hint:\tTry 'sudo mount -o remount,mode=755 %s'\n", - tracing_events_path, filename, mountpoint); + tracing_events_path, filename, tracing_mnt); } break; default: |