From mboxrd@z Thu Jan 1 00:00:00 1970 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=-8.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_2 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 A4F18C433E2 for ; Fri, 17 Jul 2020 14:06:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8C8B122B49 for ; Fri, 17 Jul 2020 14:06:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726938AbgGQOGI (ORCPT ); Fri, 17 Jul 2020 10:06:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:54238 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726715AbgGQOGH (ORCPT ); Fri, 17 Jul 2020 10:06:07 -0400 Received: from oasis.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 D0369207EA; Fri, 17 Jul 2020 14:06:06 +0000 (UTC) Date: Fri, 17 Jul 2020 10:06:05 -0400 From: Steven Rostedt To: "Tzvetomir Stoyanov (VMware)" Cc: linux-trace-devel@vger.kernel.org Subject: Re: [PATCH 2/2] trace-cmd: Enhance "trace-cmd clear" to be instance aware Message-ID: <20200717100605.3540f840@oasis.local.home> In-Reply-To: <20200717080326.82151-3-tz.stoyanov@gmail.com> References: <20200717080326.82151-1-tz.stoyanov@gmail.com> <20200717080326.82151-3-tz.stoyanov@gmail.com> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-trace-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org On Fri, 17 Jul 2020 11:03:26 +0300 "Tzvetomir Stoyanov (VMware)" wrote: > --- /dev/null > +++ b/tracecmd/trace-clear.c > @@ -0,0 +1,124 @@ > +// SPDX-License-Identifier: LGPL-2.1 > +/* > + * Copyright (C) 2008, 2009, 2010 Red Hat Inc, Steven Rostedt > + * > + * Updates: > + * Copyright (C) 2020, VMware, Tzvetomir Stoyanov > + * > + */ > +#include > +#include > +#include > + > +#include "tracefs.h" > +#include "trace-local.h" > + > +struct instances_list { > + struct instances_list *next; > + struct tracefs_instance *instance; > +}; > + > +static int add_new_instance(struct instances_list **list, char *name) > +{ > + struct instances_list *new; > + > + new = calloc(1, sizeof(*new)); > + if (!new) > + return -1; > + new->instance = tracefs_instance_alloc(name); > + if (!new->instance) { > + free(new); > + return -1; > + } > + > + new->next = *list; > + *list = new; > + return 0; > +} > + > +static int add_instance_walk(const char *name, void *data) > +{ > + return add_new_instance((struct instances_list **)data, (char *)name); > +} > + > +static void clear_list(struct instances_list *list) > +{ > + struct instances_list *del; > + > + while (list) { > + del = list; > + list = list->next; > + tracefs_instance_free(del->instance); > + free(del); > + } > +} BTW, why create this list? (see below). > + > +static void clear_instance_trace(struct tracefs_instance *instance) > +{ > + FILE *fp; > + char *path; > + > + /* reset the trace */ > + path = tracefs_instance_get_file(instance, "trace"); > + fp = fopen(path, "w"); > + if (!fp) > + die("writing to '%s'", path); > + tracefs_put_tracing_file(path); > + fwrite("0", 1, 1, fp); > + fclose(fp); > +} > + > +static void clear_trace(struct instances_list *instances) > +{ > + if (instances) { > + while (instances) { > + clear_instance_trace(instances->instance); > + instances = instances->next; > + } > + } else > + clear_instance_trace(NULL); > +} > + > +void trace_clear(int argc, char **argv) > +{ > + struct instances_list *instances = NULL; > + bool all = false; > + int c; > + > + for (;;) { > + int option_index = 0; > + static struct option long_options[] = { > + {"all", no_argument, NULL, 'a'}, > + {"help", no_argument, NULL, '?'}, > + {NULL, 0, NULL, 0} > + }; > + > + c = getopt_long (argc-1, argv+1, "+haB:", > + long_options, &option_index); > + if (c == -1) > + break; > + switch (c) { > + case 'B': > + if (add_new_instance(&instances, optarg)) > + die("Failed to allocate instance %s", optarg); > + break; > + case 'a': > + all = true; All you need to do is set the flag, and don't create the list here. > + if (tracefs_instances_walk(add_instance_walk, &instances)) > + die("Failed to add all instances"); > + break; > + case 'h': > + case '?': > + default: > + usage(argv); > + break; > + } > + } > + > + clear_trace(instances); > + if (all) Then here, you would just do: tracefs_instances_iterate(clear_instance_iter, NULL); Where we have: static int clear_instance_iter(const char *name, void *data) { tracefs_clear(name); } No need for the creating of the list. -- Steve > + clear_trace(NULL); > + clear_list(instances); > + exit(0); > +} > + > diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c > index bd004574..5009eaa1 100644 > --- a/tracecmd/trace-record.c > +++ b/tracecmd/trace-record.c > @@ -835,21 +835,6 @@ static void clear_trace_instances(void) > __clear_trace(instance); > } > > -static void clear_trace(void) > -{ > - FILE *fp; > - char *path; > - > - /* reset the trace */ > - path = tracefs_get_tracing_file("trace"); > - fp = fopen(path, "w"); > - if (!fp) > - die("writing to '%s'", path); > - tracefs_put_tracing_file(path); > - fwrite("0", 1, 1, fp); > - fclose(fp); > -} > - > static void reset_max_latency(struct buffer_instance *instance) > { > tracefs_instance_file_write(instance->tracefs, > @@ -6704,15 +6689,6 @@ void trace_profile(int argc, char **argv) > exit(0); > } > > -void trace_clear(int argc, char **argv) > -{ > - if (argc > 2) > - usage(argv); > - else > - clear_trace(); > - exit(0); > -} > - > void trace_record(int argc, char **argv) > { > struct common_record_context ctx; > diff --git a/tracecmd/trace-usage.c b/tracecmd/trace-usage.c > index 3f0b2d07..79610bd3 100644 > --- a/tracecmd/trace-usage.c > +++ b/tracecmd/trace-usage.c > @@ -180,7 +180,9 @@ static struct usage_help usage_help[] = { > { > "clear", > "clear the trace buffers", > - " %s clear\n" > + " %s clear [-B buf][-a]\n" > + " -B clear the given buffer (may specify multiple -B)\n" > + " -a clear all existing buffers, including the top level one\n" > }, > { > "report",