Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932267AbbGPRXq (ORCPT ); Thu, 16 Jul 2015 13:23:46 -0400 Received: from mga14.intel.com ([192.55.52.115]:2451 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932244AbbGPRXo (ORCPT ); Thu, 16 Jul 2015 13:23:44 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.15,488,1432623600"; d="scan'208";a="765798544" 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, linux-kernel@vger.kernel.org, Tom Zanussi Subject: [PATCH v9 12/22] tracing: Add hist trigger support for pausing and continuing a trace Date: Thu, 16 Jul 2015 12:22:45 -0500 Message-Id: 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 Content-Length: 4160 Lines: 123 Allow users to append 'pause' or 'continue' to an existing trigger in order to have it paused or to have a paused trace continue. This expands the hist trigger syntax from this: # echo hist:keys=xxx:vals=yyy:sort=zzz.descending \ [ if filter] > event/trigger to this: # echo hist:keys=xxx:vals=yyy:sort=zzz.descending:pause or cont \ [ if filter] > event/trigger Signed-off-by: Tom Zanussi --- kernel/trace/trace.c | 5 +++++ kernel/trace/trace_events_hist.c | 26 +++++++++++++++++++++++--- 2 files changed, 28 insertions(+), 3 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 5dd1fc4..547bbc8 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3791,6 +3791,7 @@ 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. Keys and values\n" @@ -3821,6 +3822,10 @@ static const char readme_msg[] = "\t on. The default if unspecified is 'hitcount' and the.\n" "\t default sort order is 'ascending'. To sort in the opposite\n" "\t direction, append .descending' to the sort key.\n\n" + "\t The 'pause' param can be used to pause an existing hist\n" + "\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" #endif ; diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 6bf224f..3ae58e7 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -78,6 +78,8 @@ struct hist_trigger_attrs { char *keys_str; char *vals_str; char *sort_key_str; + bool pause; + bool cont; unsigned int map_bits; }; @@ -184,6 +186,11 @@ static struct hist_trigger_attrs *parse_hist_trigger_attrs(char *trigger_str) attrs->vals_str = kstrdup(str, GFP_KERNEL); else if (!strncmp(str, "sort", strlen("sort"))) attrs->sort_key_str = kstrdup(str, GFP_KERNEL); + else if (!strncmp(str, "pause", strlen("pause"))) + attrs->pause = true; + else if (!strncmp(str, "continue", strlen("continue")) || + !strncmp(str, "cont", strlen("cont"))) + attrs->cont = true; else if (!strncmp(str, "size", strlen("size"))) { int map_bits = parse_map_size(str); @@ -843,7 +850,10 @@ static int event_hist_trigger_print(struct seq_file *m, if (data->filter_str) seq_printf(m, " if %s", data->filter_str); - seq_puts(m, " [active]"); + if (data->paused) + seq_puts(m, " [paused]"); + else + seq_puts(m, " [active]"); seq_putc(m, '\n'); @@ -882,16 +892,25 @@ static int hist_register_trigger(char *glob, struct event_trigger_ops *ops, struct event_trigger_data *data, struct trace_event_file *file) { + struct hist_trigger_data *hist_data = data->private_data; struct event_trigger_data *test; int ret = 0; list_for_each_entry_rcu(test, &file->triggers, list) { if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { - ret = -EEXIST; + if (hist_data->attrs->pause) + test->paused = true; + else if (hist_data->attrs->cont) + test->paused = false; + else + ret = -EEXIST; goto out; } } + if (hist_data->attrs->pause) + data->paused = true; + if (data->ops->init) { ret = data->ops->init(data->ops, data); if (ret < 0) @@ -984,7 +1003,8 @@ static int event_hist_trigger_func(struct event_command *cmd_ops, * triggers registered a failure too. */ if (!ret) { - ret = -ENOENT; + if (!(attrs->pause || attrs->cont)) + ret = -ENOENT; goto out_free; } else if (ret < 0) goto out_free; -- 1.9.3 -- 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/