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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 78759C433EF for ; Wed, 24 Nov 2021 21:38:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352025AbhKXVmF (ORCPT ); Wed, 24 Nov 2021 16:42:05 -0500 Received: from mail.kernel.org ([198.145.29.99]:49180 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352145AbhKXVlL (ORCPT ); Wed, 24 Nov 2021 16:41:11 -0500 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 830AC60F5B; Wed, 24 Nov 2021 21:38:00 +0000 (UTC) Date: Wed, 24 Nov 2021 16:37:59 -0500 From: Steven Rostedt To: Daniel Bristot de Oliveira Cc: Tao Zhou , Ingo Molnar , Tom Zanussi , Masami Hiramatsu , Juri Lelli , Clark Williams , John Kacur , Peter Zijlstra , Thomas Gleixner , Sebastian Andrzej Siewior , linux-rt-users@vger.kernel.org, linux-trace-devel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH V7 02/14] rtla: Helper functions for rtla Message-ID: <20211124163759.6d118d96@gandalf.local.home> In-Reply-To: <1eb27af1d8356d17d1f8a69a362da46ae8594ab0.1635535309.git.bristot@kernel.org> References: <1eb27af1d8356d17d1f8a69a362da46ae8594ab0.1635535309.git.bristot@kernel.org> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org On Fri, 29 Oct 2021 21:26:05 +0200 Daniel Bristot de Oliveira wrote: > +/* > + * enable_tracer_by_name - enable a tracer on the given instance > + */ > +int enable_tracer_by_name(struct tracefs_instance *inst, const char *tracer) > +{ > + enum tracefs_tracers t; > + int retval; > + > + t = TRACEFS_TRACER_CUSTOM; > + > + debug_msg("enabling %s tracer\n", tracer); > + > + retval = tracefs_tracer_set(inst, t, tracer); Interesting. We had discussions about having the custom option (which I fought for, for this very reason). > + if (retval < 0) { > + if (errno == ENODEV) > + err_msg("tracer %s not found!\n", tracer); > + > + err_msg("failed to enable the tracer %s\n", tracer); > + return -1; > + } > + > + return 0; > +} > + > +/* > + * disable_tracer - set nop tracer to the insta > + */ > +void disable_tracer(struct tracefs_instance *inst) > +{ > + enum tracefs_tracers t = TRACEFS_TRACER_NOP; > + int retval; > + > + retval = tracefs_tracer_set(inst, t); > + if (retval < 0) > + err_msg("oops, error disabling tracer\n"); > +} > + > +/* > + * create_instance - create a trace instance with *instance_name > + */ > +struct tracefs_instance *create_instance(char *instance_name) > +{ > + return tracefs_instance_create(instance_name); > +} > + > +/* > + * destroy_instance - remove a trace instance and free the data > + */ > +void destroy_instance(struct tracefs_instance *inst) > +{ > + tracefs_instance_destroy(inst); > + tracefs_instance_free(inst); > +} > + > +/* > + * save_trace_to_file - save the trace output of the instance to the file > + */ > +int save_trace_to_file(struct tracefs_instance *inst, const char *filename) > +{ > + const char *file = "trace"; > + mode_t mode = 0644; > + char *buffer[4096]; Did you really mean to have buffer be 4096 strings? Or did you mean: char buffer[4096]; (i.e. a single string of 4096 size)? -- Steve > + int out_fd, in_fd; > + int retval = -1; > + > + in_fd = tracefs_instance_file_open(inst, file, O_RDONLY); > + if (in_fd < 0) { > + err_msg("Failed to open trace file\n"); > + return -1; > + } > + > + out_fd = creat(filename, mode); > + if (out_fd < 0) { > + err_msg("Failed to create output file %s\n", filename); > + goto out_close_in; > + } > + > + do { > + retval = read(in_fd, buffer, sizeof(buffer)); > + if (retval <= 0) > + goto out_close; > + > + retval = write(out_fd, buffer, retval); > + if (retval < 0) > + goto out_close; > + } while (retval > 0); > + > + retval = 0; > +out_close: > + close(out_fd); > +out_close_in: > + close(in_fd); > + return retval; > +} > + > +/*