From patchwork Fri Aug 13 02:16:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 12434575 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B0092C4320E for ; Fri, 13 Aug 2021 02:17:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9043C61103 for ; Fri, 13 Aug 2021 02:17:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238025AbhHMCRz (ORCPT ); Thu, 12 Aug 2021 22:17:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:44526 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237331AbhHMCRw (ORCPT ); Thu, 12 Aug 2021 22:17:52 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3093B60F35; Fri, 13 Aug 2021 02:17:26 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.94.2) (envelope-from ) id 1mEMlA-003wVw-Sa; Thu, 12 Aug 2021 22:17:24 -0400 From: Steven Rostedt To: linux-trace-devel@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Tom Zanussi , Daniel Bristot de Oliveira , Masami Hiramatsu , Namhyung Kim , linux-rt-users , Clark Williams , "Steven Rostedt (VMware)" Subject: [PATCH 3/7] libtracefs: Add API tracefs_synth_trace() Date: Thu, 12 Aug 2021 22:16:51 -0400 Message-Id: <20210813021655.939819-4-rostedt@goodmis.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210813021655.939819-1-rostedt@goodmis.org> References: <20210813021655.939819-1-rostedt@goodmis.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org From: "Steven Rostedt (VMware)" Add the API tracefs_synth_trace() that adds a "trace" action that can be attached to the onmax or the onchange handler. Note, this still can be used for onmatch, but that's the default anyway. Signed-off-by: Steven Rostedt (VMware) --- Documentation/libtracefs-synth2.txt | 17 +++++- include/tracefs.h | 2 + src/tracefs-hist.c | 91 +++++++++++++++++++++++++++++ 3 files changed, 109 insertions(+), 1 deletion(-) diff --git a/Documentation/libtracefs-synth2.txt b/Documentation/libtracefs-synth2.txt index 44693b394f29..a74e88ec0eda 100644 --- a/Documentation/libtracefs-synth2.txt +++ b/Documentation/libtracefs-synth2.txt @@ -3,7 +3,8 @@ libtracefs(3) NAME ---- -tracefs_synth_create, tracefs_synth_destroy, tracefs_synth_show - Creation of synthetic events +tracefs_synth_create, tracefs_synth_destroy, tracefs_synth_show,tracefs_synth_complete, +tracefs_synth_get_start_hist,tracefs_synth_trace - Creation of synthetic events SYNOPSIS -------- @@ -20,6 +21,8 @@ int tracefs_synth_show(struct trace_seq pass:[*]seq, struct tracefs_instance pas bool tracefs_synth_complete(struct tracefs_synth pass:[*]synth); struct tracefs_hist pass:[*]tracefs_synth_get_start_hist(struct tracefs_synth pass:[*]synth); +int tracefs_synth_trace(struct tracefs_synth pass:[*]synth, + enum tracefs_synth_handler type, const char pass:[*]var); -- DESCRIPTION @@ -60,6 +63,18 @@ a starting and ending event. *tracefs_synth_get_start_hist*() returns a struct tracefs_hist descriptor describing the histogram used to create the synthetic event. +enum tracefs_synth_handler { + TRACEFS_SYNTH_HANDLE_MATCH, + TRACEFS_SYNTH_HANDLE_MAX, + TRACEFS_SYNTH_HANDLE_CHANGE, +}; + +*tracefs_synth_trace*() Instead of doing just a trace on matching of the start and +end events, do the _type_ handler where *TRACEFS_SYNTH_HANDLE_MAX* will do a trace +when the given variable _var_ hits a new max for the matching keys. Or +*TRACEFS_SYNTH_HANDLE_CHANGE* for when the _var_ changes. _var_ must be one of +the _name_ elements used in *tracefs_synth_add_end_field*(3). + RETURN VALUE ------------ Returns zero on success or -1 on error. diff --git a/include/tracefs.h b/include/tracefs.h index d83c4e33c69a..2faa564a860f 100644 --- a/include/tracefs.h +++ b/include/tracefs.h @@ -476,6 +476,8 @@ int tracefs_synth_append_end_filter(struct tracefs_synth *synth, const char *field, enum tracefs_compare compare, const char *val); +int tracefs_synth_trace(struct tracefs_synth *synth, + enum tracefs_synth_handler type, const char *field); bool tracefs_synth_complete(struct tracefs_synth *synth); struct tracefs_hist *tracefs_synth_get_start_hist(struct tracefs_synth *synth); int tracefs_synth_create(struct tracefs_instance *instance, diff --git a/src/tracefs-hist.c b/src/tracefs-hist.c index 262db7fbb925..562ec65088a9 100644 --- a/src/tracefs-hist.c +++ b/src/tracefs-hist.c @@ -1323,6 +1323,97 @@ int tracefs_synth_append_end_filter(struct tracefs_synth *synth, type, field, compare, val); } +static int test_max_var(struct tracefs_synth *synth, const char *var) +{ + char **vars = synth->end_vars; + char *p; + int len; + int i; + + len = strlen(var); + + /* Make sure the var is defined for the end event */ + for (i = 0; vars[i]; i++) { + p = strchr(vars[i], '='); + if (!p) + continue; + if (p - vars[i] != len) + continue; + if (!strncmp(var, vars[i], len)) + return 0; + } + errno = ENODEV; + return -1; +} + +static struct action *create_action(enum tracefs_synth_handler type, + struct tracefs_synth *synth, + const char *var) +{ + struct action *action; + int ret; + + switch (type) { + case TRACEFS_SYNTH_HANDLE_MAX: + case TRACEFS_SYNTH_HANDLE_CHANGE: + ret = test_max_var(synth, var); + if (ret < 0) + return NULL; + break; + default: + break; + } + + action = calloc(1, sizeof(*action)); + if (!action) + return NULL; + + if (var) { + ret = asprintf(&action->handle_field, "$%s", var); + if (!action->handle_field) { + free(action); + return NULL; + } + } + return action; +} + +static void add_action(struct tracefs_synth *synth, struct action *action) +{ + *synth->next_action = action; + synth->next_action = &action->next; +} + +/** + * tracefs_synth_trace - Execute the trace option + * @synth: The tracefs_synth descriptor + * @type: The type of handler to attach the trace action with + * @field: The field for handlers onmax and onchange (ignored otherwise) + * + * Add the action 'trace' for handlers onmatch, onmax and onchange. + * + * Returns 0 on succes, -1 on error. + */ +int tracefs_synth_trace(struct tracefs_synth *synth, + enum tracefs_synth_handler type, const char *field) +{ + struct action *action; + + if (!synth || (!field && (type != TRACEFS_SYNTH_HANDLE_MATCH))) { + errno = EINVAL; + return -1; + } + + action = create_action(type, synth, field); + if (!action) + return -1; + + action->type = ACTION_TRACE; + action->handler = type; + add_action(synth, action); + return 0; +} + static char *create_synthetic_event(struct tracefs_synth *synth) { char *synthetic_event;