From patchwork Fri Aug 13 02:16:53 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 12434577 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=unavailable 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 70ADEC4320A 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 59F796113C for ; Fri, 13 Aug 2021 02:17:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237946AbhHMCRz (ORCPT ); Thu, 12 Aug 2021 22:17:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:44556 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237630AbhHMCRw (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 37778610CF; 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-003wW0-UQ; 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 5/7] libtracefs: Add API tracefs_synth_save() Date: Thu, 12 Aug 2021 22:16:53 -0400 Message-Id: <20210813021655.939819-6-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 an API tracefs_synth_save() that will save fields when onmax() or onchange() handlers are executed. Signed-off-by: Steven Rostedt (VMware) --- Documentation/libtracefs-synth2.txt | 9 ++++ include/tracefs.h | 3 ++ src/tracefs-hist.c | 73 ++++++++++++++++++++++++++++- 3 files changed, 83 insertions(+), 2 deletions(-) diff --git a/Documentation/libtracefs-synth2.txt b/Documentation/libtracefs-synth2.txt index 194a4e021f62..cfcae7411f58 100644 --- a/Documentation/libtracefs-synth2.txt +++ b/Documentation/libtracefs-synth2.txt @@ -25,6 +25,9 @@ int tracefs_synth_trace(struct tracefs_synth pass:[*]synth, enum tracefs_synth_handler type, const char pass:[*]var); int tracefs_synth_snapshot(struct tracefs_synth pass:[*]synth, enum tracefs_synth_handler type, const char pass:[*]var); +int tracefs_synth_save(struct tracefs_synth pass:[*]synth, + enum tracefs_synth_handler type, const char pass:[*]var, + char pass:[**]save_fields); -- DESCRIPTION @@ -84,6 +87,12 @@ into a "snapshot" buffer, that can be accessed via the "snapshot" file in the top level tracefs directory, or one of the instances. _var_ changes. _var_ must be one of the _name_ elements used in *tracefs_synth_add_end_field*(3). +*tracefs_synth_save*() When the given variable _var_ is either a new max if +_handler_ is TRACEFS_SYNTH_HANDLE_MAX_ or simpy changed if TRACEFS_SYNTH_HANDLE_CHANGE_ +then saven the given _save_fields_ list. The fields will be stored in the histogram +"hist" file of the event that can be retrieved with *tracefs_event_file_read*(3). +_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 45a5bb2df2de..25abbdc10ebf 100644 --- a/include/tracefs.h +++ b/include/tracefs.h @@ -480,6 +480,9 @@ int tracefs_synth_trace(struct tracefs_synth *synth, enum tracefs_synth_handler type, const char *field); int tracefs_synth_snapshot(struct tracefs_synth *synth, enum tracefs_synth_handler type, const char *field); +int tracefs_synth_save(struct tracefs_synth *synth, + enum tracefs_synth_handler type, const char *field, + char **save_fields); 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 2c9c37b8ec23..003715fa693c 100644 --- a/src/tracefs-hist.c +++ b/src/tracefs-hist.c @@ -525,6 +525,7 @@ enum action_type { ACTION_NONE, ACTION_TRACE, ACTION_SNAPSHOT, + ACTION_SAVE, }; struct action { @@ -532,6 +533,7 @@ struct action { enum action_type type; enum tracefs_synth_handler handler; char *handle_field; + char *save; }; /* @@ -580,6 +582,13 @@ struct tracefs_synth { int arg_cnt; }; +static void action_free(struct action *action) +{ + free(action->handle_field); + free(action->save); + free(action); +} + /** * tracefs_synth_free - free the resources alloced to a synth * @synth: The tracefs_synth descriptor @@ -610,8 +619,7 @@ void tracefs_synth_free(struct tracefs_synth *synth) while ((action = synth->actions)) { synth->actions = action->next; - free(action->handle_field); - free(action); + action_free(action); } free(synth); @@ -1445,6 +1453,64 @@ int tracefs_synth_snapshot(struct tracefs_synth *synth, return 0; } +/** + * tracefs_synth_save - create a save command to the histogram + * @synth: The tracefs_synth descriptor + * @type: The type of handler to attach the save action + * @max_field: The field for handlers onmax and onchange + * @fields: The fields to save for the end variable + * + * Add the action to save fields for handlers onmax and onchange. + * + * Returns 0 on succes, -1 on error. + */ +int tracefs_synth_save(struct tracefs_synth *synth, + enum tracefs_synth_handler type, const char *max_field, + char **fields) +{ + struct action *action; + char *save; + int i; + + if (!synth || !max_field || (type == TRACEFS_SYNTH_HANDLE_MATCH)) { + errno = EINVAL; + return -1; + } + + action = create_action(type, synth, max_field); + if (!action) + return -1; + + action->type = ACTION_SAVE; + action->handler = type; + *synth->next_action = action; + synth->next_action = &action->next; + + save = strdup(".save("); + if (!save) + goto error; + + for (i = 0; fields[i]; i++) { + char *delim = i ? "," : NULL; + + if (!trace_verify_event_field(synth->end_event, fields[i], NULL)) + goto error; + save = append_string(save, delim, fields[i]); + } + save = append_string(save, NULL, ")"); + if (!save) + goto error; + + action->save = save; + add_action(synth, action); + return 0; + error: + action_free(action); + free(save); + return -1; + return 0; +} + static char *create_synthetic_event(struct tracefs_synth *synth) { char *synthetic_event; @@ -1596,6 +1662,9 @@ static char *create_actions(char *hist, struct tracefs_synth *synth) case ACTION_SNAPSHOT: hist = append_string(hist, NULL, ".snapshot()"); break; + case ACTION_SAVE: + hist = append_string(hist, NULL, action->save); + break; default: continue; }