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=-11.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 2C753C433E7 for ; Tue, 21 Jul 2020 16:43:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1558F20720 for ; Tue, 21 Jul 2020 16:43:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730880AbgGUQnr (ORCPT ); Tue, 21 Jul 2020 12:43:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:43648 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730391AbgGUQno (ORCPT ); Tue, 21 Jul 2020 12:43:44 -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 BA78C207BB; Tue, 21 Jul 2020 16:43:43 +0000 (UTC) Date: Tue, 21 Jul 2020 12:43:42 -0400 From: Steven Rostedt To: Tingwei Zhang Cc: Ingo Molnar , tsoni@codeaurora.org, Sai Prakash Ranjan , Mao Jinlong , linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/4] tracing: add trace_export support for event trace Message-ID: <20200721124342.422ee784@oasis.local.home> In-Reply-To: <20200721123733.1a87568a@oasis.local.home> References: <20200720022117.9375-1-tingwei@codeaurora.org> <20200720022117.9375-3-tingwei@codeaurora.org> <20200721123733.1a87568a@oasis.local.home> 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-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 21 Jul 2020 12:37:33 -0400 Steven Rostedt wrote: > On Mon, 20 Jul 2020 10:21:15 +0800 > Tingwei Zhang wrote: > > > Only function traces can be exported to other destinations currently. > > This patch exports event trace as well. > > > > Signed-off-by: Tingwei Zhang > > --- > > kernel/trace/trace.c | 24 +++++++++++++----------- > > 1 file changed, 13 insertions(+), 11 deletions(-) > > > > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > > index bb62269724d5..aef6330836e2 100644 > > --- a/kernel/trace/trace.c > > +++ b/kernel/trace/trace.c > > @@ -2697,17 +2697,6 @@ int tracepoint_printk_sysctl(struct ctl_table *table, int write, > > return ret; > > } > > > > -void trace_event_buffer_commit(struct trace_event_buffer *fbuffer) > > -{ > > - if (static_key_false(&tracepoint_printk_key.key)) > > - output_printk(fbuffer); > > - > > - event_trigger_unlock_commit_regs(fbuffer->trace_file, fbuffer->buffer, > > - fbuffer->event, fbuffer->entry, > > - fbuffer->flags, fbuffer->pc, fbuffer->regs); > > -} > > -EXPORT_SYMBOL_GPL(trace_event_buffer_commit); > > - > > Please move the ftrace_exports routines up, instead of moving the > trace_event_buffer_commit() down. As it fits better where it is (next > to the other buffer_commit code). > > -- Steve > > > > /* > > * Skip 3: > > * > > @@ -2868,6 +2857,19 @@ int unregister_ftrace_export(struct > > trace_export *export) } > > EXPORT_SYMBOL_GPL(unregister_ftrace_export); > > > > +void trace_event_buffer_commit(struct trace_event_buffer *fbuffer) > > +{ > > + if (static_key_false(&tracepoint_printk_key.key)) > > + output_printk(fbuffer); > > + > > + if (static_branch_unlikely(&ftrace_exports_enabled)) > > + ftrace_exports(fbuffer->event); I would also recommend making each static branch a separate variable. That way you could pick and choose what you want to enable. If you only want events, and functions are being traced, it will add a bit of overhead to handle the functions to just ignore them. That is: ftrace_exports_enabled, trace_event_exports_enabled, trace_marker_exports_enabled. -- Steve > > + event_trigger_unlock_commit_regs(fbuffer->trace_file, > > fbuffer->buffer, > > + fbuffer->event, fbuffer->entry, > > + fbuffer->flags, fbuffer->pc, > > fbuffer->regs); +} > > +EXPORT_SYMBOL_GPL(trace_event_buffer_commit); > > + > > void > > trace_function(struct trace_array *tr, > > unsigned long ip, unsigned long parent_ip, unsigned > > long flags, >