Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754691Ab3HVX1p (ORCPT ); Thu, 22 Aug 2013 19:27:45 -0400 Received: from mga11.intel.com ([192.55.52.93]:17464 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754660Ab3HVX1m (ORCPT ); Thu, 22 Aug 2013 19:27:42 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.89,937,1367996400"; d="scan'208";a="390634287" From: Tom Zanussi To: rostedt@goodmis.org Cc: masami.hiramatsu.pt@hitachi.com, linux-kernel@vger.kernel.org, Tom Zanussi Subject: [PATCH v6 03/10] tracing: add 'traceon' and 'traceoff' event trigger commands Date: Thu, 22 Aug 2013 18:27:19 -0500 Message-Id: <3ed99e1081ecef175dbbbad884355ea3e4108775.1377213245.git.tom.zanussi@linux.intel.com> X-Mailer: git-send-email 1.7.11.4 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6341 Lines: 244 Add 'traceon' and 'traceoff' ftrace_func_command commands. traceon and traceoff event triggers are added by the user via these commands in a similar way and using practically the same syntax as the analagous 'traceon' and 'traceoff' ftrace function commands, but instead of writing to the set_ftrace_filter file, the traceon and traceoff triggers are written to the per-event 'trigger' files: echo 'traceon' > .../tracing/events/somesys/someevent/trigger echo 'traceoff' > .../tracing/events/somesys/someevent/trigger The above command will turn tracing on or off whenever someevent is hit. This also adds a 'count' version that limits the number of times the command will be invoked: echo 'traceon:N' > .../tracing/events/somesys/someevent/trigger echo 'traceoff:N' > .../tracing/events/somesys/someevent/trigger Where N is the number of times the command will be invoked. The above commands will will turn tracing on or off whenever someevent is hit, but only N times. Signed-off-by: Tom Zanussi --- include/linux/ftrace_event.h | 1 + kernel/trace/trace_events_trigger.c | 182 ++++++++++++++++++++++++++++++++++++ 2 files changed, 183 insertions(+) diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h index 0765d3d..4c8f7c1 100644 --- a/include/linux/ftrace_event.h +++ b/include/linux/ftrace_event.h @@ -318,6 +318,7 @@ struct ftrace_event_file { enum trigger_mode { TM_NONE = (0), + TM_TRACE_ONOFF = (1 << 0), }; extern void destroy_preds(struct ftrace_event_call *call); diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c index 7a52109..d5a10ed 100644 --- a/kernel/trace/trace_events_trigger.c +++ b/kernel/trace/trace_events_trigger.c @@ -564,7 +564,189 @@ event_trigger_callback(struct event_command *cmd_ops, goto out; } +static void +traceon_trigger(void **_data) +{ + struct event_trigger_data **p = (struct event_trigger_data **)_data; + struct event_trigger_data *data = *p; + + if (!data) + return; + + if (tracing_is_on()) + return; + + tracing_on(); +} + +static void +traceon_count_trigger(void **_data) +{ + struct event_trigger_data **p = (struct event_trigger_data **)_data; + struct event_trigger_data *data = *p; + + if (!data) + return; + + if (!data->count) + return; + + if (data->count != -1) + (data->count)--; + + traceon_trigger(_data); +} + +static void +traceoff_trigger(void **_data) +{ + struct event_trigger_data **p = (struct event_trigger_data **)_data; + struct event_trigger_data *data = *p; + + if (!data) + return; + + if (!tracing_is_on()) + return; + + tracing_off(); +} + +static void +traceoff_count_trigger(void **_data) +{ + struct event_trigger_data **p = (struct event_trigger_data **)_data; + struct event_trigger_data *data = *p; + + if (!data) + return; + + if (!data->count) + return; + + if (data->count != -1) + (data->count)--; + + traceoff_trigger(_data); +} + +static int +traceon_trigger_print(struct seq_file *m, struct event_trigger_ops *ops, + void *_data) +{ + struct event_trigger_data *data = _data; + + return event_trigger_print("traceon", m, (void *)data->count, + data->filter_str); +} + +static int +traceoff_trigger_print(struct seq_file *m, struct event_trigger_ops *ops, + void *_data) +{ + struct event_trigger_data *data = _data; + + return event_trigger_print("traceoff", m, (void *)data->count, + data->filter_str); +} + +static struct event_trigger_ops traceon_trigger_ops = { + .func = traceon_trigger, + .print = traceon_trigger_print, + .init = event_trigger_init, + .free = event_trigger_free, +}; + +static struct event_trigger_ops traceon_count_trigger_ops = { + .func = traceon_count_trigger, + .print = traceon_trigger_print, + .init = event_trigger_init, + .free = event_trigger_free, +}; + +static struct event_trigger_ops traceoff_trigger_ops = { + .func = traceoff_trigger, + .print = traceoff_trigger_print, + .init = event_trigger_init, + .free = event_trigger_free, +}; + +static struct event_trigger_ops traceoff_count_trigger_ops = { + .func = traceoff_count_trigger, + .print = traceoff_trigger_print, + .init = event_trigger_init, + .free = event_trigger_free, +}; + +static struct event_trigger_ops * +onoff_get_trigger_ops(char *cmd, char *param) +{ + struct event_trigger_ops *ops; + + /* we register both traceon and traceoff to this callback */ + if (strcmp(cmd, "traceon") == 0) + ops = param ? &traceon_count_trigger_ops : + &traceon_trigger_ops; + else + ops = param ? &traceoff_count_trigger_ops : + &traceoff_trigger_ops; + + return ops; +} + +static struct event_command trigger_traceon_cmd = { + .name = "traceon", + .trigger_mode = TM_TRACE_ONOFF, + .func = event_trigger_callback, + .reg = register_trigger, + .unreg = unregister_trigger, + .get_trigger_ops = onoff_get_trigger_ops, +}; + +static struct event_command trigger_traceoff_cmd = { + .name = "traceoff", + .trigger_mode = TM_TRACE_ONOFF, + .func = event_trigger_callback, + .reg = register_trigger, + .unreg = unregister_trigger, + .get_trigger_ops = onoff_get_trigger_ops, +}; + +static __init void unregister_trigger_traceon_traceoff_cmds(void) +{ + unregister_event_command(&trigger_traceon_cmd, + &trigger_commands, + &trigger_cmd_mutex); + unregister_event_command(&trigger_traceoff_cmd, + &trigger_commands, + &trigger_cmd_mutex); +} + +static __init int register_trigger_traceon_traceoff_cmds(void) +{ + int ret; + + ret = register_event_command(&trigger_traceon_cmd, &trigger_commands, + &trigger_cmd_mutex); + if (WARN_ON(ret < 0)) + return ret; + ret = register_event_command(&trigger_traceoff_cmd, &trigger_commands, + &trigger_cmd_mutex); + if (WARN_ON(ret < 0)) + unregister_trigger_traceon_traceoff_cmds(); + + return ret; +} + __init int register_trigger_cmds(void) { + int ret; + + ret = register_trigger_traceon_traceoff_cmds(); + if (ret) { + unregister_trigger_traceon_traceoff_cmds(); + return ret; + } + return 0; } -- 1.7.11.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/