Messages in this thread | | | Date | Tue, 16 Oct 2018 12:18:13 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH] perf tools: Fix tracing_path_mount proper path |
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Em Tue, Oct 16, 2018 at 01:48:18PM +0200, Jiri Olsa escreveu: > 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> > --- > tools/lib/api/fs/tracing_path.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/tools/lib/api/fs/tracing_path.c b/tools/lib/api/fs/tracing_path.c > index 120037496f77..5afb11b30fca 100644 > --- a/tools/lib/api/fs/tracing_path.c > +++ b/tools/lib/api/fs/tracing_path.c > @@ -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;
Humm, colour me confused, by the name of the function I expected tracing_path_debugfs_mount() to return the debugfs mount.
tracing_path_tracefs_mount() would return the tracefs mount point, so, there, returning tracing_path would be ok.
Is there some other way to figure out that tracefs isn't available and thus we should use debugfs_mount + "/tracing/" for the "tracefs" mount?
This may well be just the naming confusion... lemme read this a bit more...
- Arnaldo
> } > > const char *tracing_path_mount(void) > -- > 2.17.2
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