diff options
| author | Anton Vorontsov <anton.vorontsov@linaro.org> | 2012-07-17 14:26:15 -0700 |
|---|---|---|
| committer | Anton Vorontsov <anton.vorontsov@linaro.org> | 2012-09-06 22:16:58 -0700 |
| commit | 65f8c95e46a1827ae8bbc52a817ea308dd7d65ae (patch) | |
| tree | adc856e8b50441b055350d8f1d83e3f641c77456 /Documentation/ramoops.txt | |
| parent | b4a871bce619dc5ca03cc6c78e1c467ceacb8e7e (diff) | |
pstore/ftrace: Convert to its own enable/disable debugfs knob
With this patch we no longer reuse function tracer infrastructure, now
we register our own tracer back-end via a debugfs knob.
It's a bit more code, but that is the only downside. On the bright side we
have:
- Ability to make persistent_ram module removable (when needed, we can
move ftrace_ops struct into a module). Note that persistent_ram is still
not removable for other reasons, but with this patch it's just one
thing less to worry about;
- Pstore part is more isolated from the generic function tracer. We tried
it already by registering our own tracer in available_tracers, but that
way we're loosing ability to see the traces while we record them to
pstore. This solution is somewhere in the middle: we only register
"internal ftracer" back-end, but not the "front-end";
- When there is only pstore tracing enabled, the kernel will only write
to the pstore buffer, omitting function tracer buffer (which, of course,
still can be enabled via 'echo function > current_tracer').
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Diffstat (limited to 'Documentation/ramoops.txt')
| -rw-r--r-- | Documentation/ramoops.txt | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/Documentation/ramoops.txt b/Documentation/ramoops.txt index 197ad59ab9bf..69b3cac4749d 100644 --- a/Documentation/ramoops.txt +++ b/Documentation/ramoops.txt @@ -102,9 +102,7 @@ related hangs. The functions call chain log is stored in a "ftrace-ramoops" file. Here is an example of usage: # mount -t debugfs debugfs /sys/kernel/debug/ - # cd /sys/kernel/debug/tracing - # echo function > current_tracer - # echo 1 > options/func_pstore + # echo 1 > /sys/kernel/debug/pstore/record_ftrace # reboot -f [...] # mount -t pstore pstore /mnt/ |