From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965479AbbJVSPl (ORCPT ); Thu, 22 Oct 2015 14:15:41 -0400 Received: from mga14.intel.com ([192.55.52.115]:4321 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965662AbbJVSPh (ORCPT ); Thu, 22 Oct 2015 14:15:37 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,183,1444719600"; d="scan'208";a="833214977" From: Tom Zanussi To: rostedt@goodmis.org Cc: daniel.wagner@bmw-carit.de, masami.hiramatsu.pt@hitachi.com, namhyung@kernel.org, josh@joshtriplett.org, andi@firstfloor.org, mathieu.desnoyers@efficios.com, peterz@infradead.org, linux-kernel@vger.kernel.org, Tom Zanussi Subject: [PATCH v11 14/28] tracing: Add hist trigger support for clearing a trace Date: Thu, 22 Oct 2015 13:14:18 -0500 Message-Id: <48a0ac9399d67006e88b2f3d8ab5c457bc8b989c.1445530672.git.tom.zanussi@linux.intel.com> X-Mailer: git-send-email 1.9.3 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 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 Signed-off-by: Tom Zanussi Tested-by: Masami Hiramatsu --- kernel/trace/trace.c | 5 ++++- kernel/trace/trace_events_hist.c | 25 ++++++++++++++++++++++++- 2 files changed, 28 insertions(+), 2 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index a223959..6281bc9 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3802,7 +3802,7 @@ static const char readme_msg[] = "\t [:values=]\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" @@ -3822,6 +3822,9 @@ 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 8753c3b..96732c8 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -80,6 +80,7 @@ struct hist_trigger_attrs { char *sort_key_str; bool pause; bool cont; + bool clear; unsigned int map_bits; }; @@ -188,6 +189,8 @@ static struct hist_trigger_attrs *parse_hist_trigger_attrs(char *trigger_str) attrs->sort_key_str = kstrdup(str, GFP_KERNEL); else if (!strncmp(str, "pause", strlen("pause"))) attrs->pause = true; + else if (!strncmp(str, "clear", strlen("clear"))) + attrs->clear = true; else if (!strncmp(str, "continue", strlen("continue")) || !strncmp(str, "cont", strlen("cont"))) attrs->cont = true; @@ -888,6 +891,24 @@ 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); + + atomic64_set(&hist_data->total_hits, 0); + atomic64_set(&hist_data->drops, 0); + + 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) @@ -902,6 +923,8 @@ 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; @@ -1003,7 +1026,7 @@ 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) -- 1.9.3