diff options
| -rw-r--r-- | kernel/trace/trace.c | 5 | ||||
| -rw-r--r-- | kernel/trace/trace_events_hist.c | 24 |
2 files changed, 26 insertions, 3 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 7d5c63dd410a..4097cd3763f7 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3837,7 +3837,7 @@ static const char readme_msg[] = "\t [:values=<field1[,field2,...]>]\n" "\t [:sort=<field1[,field2,...]>]\n" "\t [:size=#entries]\n" - "\t [:pause][:continue]\n" + "\t [:pause][:continue][:clear]\n" "\t [if <filter>]\n\n" "\t When a matching event is hit, an entry is added to a hash\n" "\t table using the key(s) and value(s) named, and the value of a\n" @@ -3857,6 +3857,9 @@ static const char readme_msg[] = "\t trigger or to start a hist trigger but not log any events\n" "\t until told to do so. 'continue' can be used to start or\n" "\t restart a paused hist trigger.\n\n" + "\t The 'clear' parameter will clear the contents of a running\n" + "\t hist trigger and leave its current paused/active state\n" + "\t unchanged.\n\n" #endif ; 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) |