From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755486Ab1BHCBK (ORCPT ); Mon, 7 Feb 2011 21:01:10 -0500 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.124]:60035 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754912Ab1BHB7e (ORCPT ); Mon, 7 Feb 2011 20:59:34 -0500 X-Authority-Analysis: v=1.1 cv=3uSaImBeuprzHBlOOPjkqgu+7PcxSRW0m2Aphm9Zmck= c=1 sm=0 a=tzsyC8EBcMQA:10 a=bbbx4UPp9XUA:10 a=OPBmh+XkhLl+Enan7BmTLg==:17 a=20KFwNOVAAAA:8 a=pGLkceISAAAA:8 a=meVymXHHAAAA:8 a=MbP_AqgZFaudCkinbc4A:9 a=k61h7L677-4K8Oh3iegA:7 a=ttE5PYYxOZC6UBI6cWgIKzPQ17AA:4 a=jEp0ucaQiEUA:10 a=MSl-tDqOz04A:10 a=jeBq3FmKZ4MA:10 a=OPBmh+XkhLl+Enan7BmTLg==:117 X-Cloudmark-Score: 0 X-Originating-IP: 67.242.120.143 Message-Id: <20110208015931.648196481@goodmis.org> User-Agent: quilt/0.48-1 Date: Mon, 07 Feb 2011 20:56:21 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Thomas Gleixner , Frederic Weisbecker , Mathieu Desnoyers , Lai Jiangshan , Li Zefan , Masami Hiramatsu , Tom Zanussi Subject: [PATCH 04/14] tracing/filter: Call synchronize_sched() just once for system filters References: <20110208015617.902200587@goodmis.org> Content-Disposition: inline; filename=0004-tracing-filter-Call-synchronize_sched-just-once-for-.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Steven Rostedt By separating out the reseting of the filter->n_preds to zero from the reallocation of preds for the filter, we can reset groups of filters first, call synchronize_sched() just once, and then reallocate each of the filters in the system group. Cc: Tom Zanussi Signed-off-by: Steven Rostedt --- kernel/trace/trace_events_filter.c | 80 ++++++++++++++++++++++++++++-------- 1 files changed, 63 insertions(+), 17 deletions(-) diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index aac6a61..8f00a11 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -570,17 +570,28 @@ static void __free_preds(struct event_filter *filter) filter->n_preds = 0; } +static void reset_preds(struct event_filter *filter) +{ + struct filter_pred *pred; + int n_preds = filter->n_preds; + int i; + + filter->n_preds = 0; + if (!filter->preds) + return; + + for (i = 0; i < n_preds; i++) { + pred = filter->preds[i]; + pred->fn = filter_pred_none; + } +} + static void filter_disable_preds(struct ftrace_event_call *call) { struct event_filter *filter = call->filter; - int i; call->flags &= ~TRACE_EVENT_FL_FILTERED; - if (filter->preds) { - for (i = 0; i < filter->n_preds; i++) - filter->preds[i]->fn = filter_pred_none; - } - filter->n_preds = 0; + reset_preds(filter); } static void __free_filter(struct event_filter *filter) @@ -620,15 +631,17 @@ static int __alloc_preds(struct event_filter *filter, int n_preds) if (filter->preds) { if (filter->a_preds < n_preds) { - /* We need to reallocate */ - filter->n_preds = 0; /* - * It is possible that the filter is currently - * being used. We need to zero out the number - * of preds, wait on preemption and then free - * the preds. + * We need to reallocate. + * We should have already have zeroed out + * the pred count and called synchronized_sched() + * to make sure no one is using the preds. */ - synchronize_sched(); + if (WARN_ON_ONCE(filter->n_preds)) { + /* We need to reset it now */ + filter->n_preds = 0; + synchronize_sched(); + } __free_preds(filter); } } @@ -1328,6 +1341,30 @@ static int replace_system_preds(struct event_subsystem *system, /* try to see if the filter can be applied */ err = replace_preds(call, filter, ps, filter_string, true); if (err) + goto fail; + } + + /* set all filter pred counts to zero */ + list_for_each_entry(call, &ftrace_events, list) { + struct event_filter *filter = call->filter; + + if (strcmp(call->class->system, system->name) != 0) + continue; + + reset_preds(filter); + } + + /* + * Since some of the preds may be used under preemption + * we need to wait for them to finish before we may + * reallocate them. + */ + synchronize_sched(); + + list_for_each_entry(call, &ftrace_events, list) { + struct event_filter *filter = call->filter; + + if (strcmp(call->class->system, system->name) != 0) continue; /* really apply the filter */ @@ -1342,11 +1379,13 @@ static int replace_system_preds(struct event_subsystem *system, fail = false; } - if (fail) { - parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0); - return -EINVAL; - } + if (fail) + goto fail; + return 0; + fail: + parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0); + return -EINVAL; } int apply_event_filter(struct ftrace_event_call *call, char *filter_string) @@ -1381,6 +1420,13 @@ int apply_event_filter(struct ftrace_event_call *call, char *filter_string) goto out; } + /* + * Make sure all the pred counts are zero so that + * no task is using it when we reallocate the preds array. + */ + reset_preds(call->filter); + synchronize_sched(); + err = replace_preds(call, call->filter, ps, filter_string, false); if (err) append_filter_err(ps, call->filter); -- 1.7.2.3