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| author | Tom Zanussi <tom.zanussi@linux.intel.com> | 2016-03-03 12:54:47 -0600 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2016-04-19 12:17:35 -0400 |
| commit | e86ae9baacfa9efe957df4fc037f079772636d76 (patch) | |
| tree | e07aea609d84ed0aa32db8307b2d5c5cdc453f11 /kernel/trace/trace_events_hist.c | |
| parent | 83e99914c9e2677d8a80f2a23eca0d215d5bfb0f (diff) | |
| download | linux-e86ae9baacfa9efe957df4fc037f079772636d76.tar.gz linux-e86ae9baacfa9efe957df4fc037f079772636d76.tar.bz2 linux-e86ae9baacfa9efe957df4fc037f079772636d76.zip | |
tracing: Add hist trigger support for clearing a trace
Allow users to append 'clear' to an existing trigger in order to have
the hash table cleared.
This expands the hist trigger syntax from this:
# echo hist:keys=xxx:vals=yyy:sort=zzz.descending:pause/cont \
[ if filter] >> event/trigger
to this:
# echo hist:keys=xxx:vals=yyy:sort=zzz.descending:pause/cont/clear \
[ if filter] >> event/trigger
Link: http://lkml.kernel.org/r/ae15dd0d9b2f7af07a37c1ff682063e2dbcdf160.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace_events_hist.c')
| -rw-r--r-- | kernel/trace/trace_events_hist.c | 24 |
1 files changed, 22 insertions, 2 deletions
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index e3fa9c89f125..83cb25e067ad 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -88,6 +88,7 @@ struct hist_trigger_attrs { char *sort_key_str; bool pause; bool cont; + bool clear; unsigned int map_bits; }; @@ -200,6 +201,8 @@ static struct hist_trigger_attrs *parse_hist_trigger_attrs(char *trigger_str) else if ((strcmp(str, "cont") == 0) || (strcmp(str, "continue") == 0)) attrs->cont = true; + else if (strcmp(str, "clear") == 0) + attrs->clear = true; else if (strncmp(str, "size=", strlen("size=")) == 0) { int map_bits = parse_map_size(str); @@ -916,6 +919,21 @@ static struct event_trigger_ops *event_hist_get_trigger_ops(char *cmd, return &event_hist_trigger_ops; } +static void hist_clear(struct event_trigger_data *data) +{ + struct hist_trigger_data *hist_data = data->private_data; + bool paused; + + paused = data->paused; + data->paused = true; + + synchronize_sched(); + + tracing_map_clear(hist_data->map); + + data->paused = paused; +} + static int hist_register_trigger(char *glob, struct event_trigger_ops *ops, struct event_trigger_data *data, struct trace_event_file *file) @@ -930,13 +948,15 @@ static int hist_register_trigger(char *glob, struct event_trigger_ops *ops, test->paused = true; else if (hist_data->attrs->cont) test->paused = false; + else if (hist_data->attrs->clear) + hist_clear(test); else ret = -EEXIST; goto out; } } - if (hist_data->attrs->cont) { + if (hist_data->attrs->cont || hist_data->attrs->clear) { ret = -ENOENT; goto out; } @@ -1035,7 +1055,7 @@ static int event_hist_trigger_func(struct event_command *cmd_ops, * triggers registered a failure too. */ if (!ret) { - if (!(attrs->pause || attrs->cont)) + if (!(attrs->pause || attrs->cont || attrs->clear)) ret = -ENOENT; goto out_free; } else if (ret < 0) |