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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_2 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 12D24C43603 for ; Mon, 9 Dec 2019 19:31:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D7DD1206E0 for ; Mon, 9 Dec 2019 19:31:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726502AbfLITbD (ORCPT ); Mon, 9 Dec 2019 14:31:03 -0500 Received: from mail.kernel.org ([198.145.29.99]:40144 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726342AbfLITbD (ORCPT ); Mon, 9 Dec 2019 14:31:03 -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 8C863205ED; Mon, 9 Dec 2019 19:31:02 +0000 (UTC) Date: Mon, 9 Dec 2019 14:31:01 -0500 From: Steven Rostedt To: "Tzvetomir Stoyanov (VMware)" Cc: linux-trace-devel@vger.kernel.org Subject: Re: [PATCH v17 14/18] trace-cmd: Add host trace clock as guest trace argument Message-ID: <20191209143101.146cb619@gandalf.local.home> In-Reply-To: <20191203103522.482684-15-tz.stoyanov@gmail.com> References: <20191203103522.482684-1-tz.stoyanov@gmail.com> <20191203103522.482684-15-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 Tue, 3 Dec 2019 12:35:18 +0200 "Tzvetomir Stoyanov (VMware)" wrote: > When tracing host and guest machines, both should use the same > tracing clock for event timestamps. If a clock is specified > as host tracing argument, with option "-C clock_name", the same > is injected as guest tracing argument. If the user wants to use > different tracing clocks, it can specify it using "-C clock_name" > as guest tracing argument. In that case, the one specified by > the user has higher priority. > > Signed-off-by: Tzvetomir Stoyanov (VMware) > --- > tracecmd/trace-record.c | 19 +++++++++++++++++-- > 1 file changed, 17 insertions(+), 2 deletions(-) > > diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c > index 49730d6..e7fb1bd 100644 > --- a/tracecmd/trace-record.c > +++ b/tracecmd/trace-record.c > @@ -5405,6 +5405,8 @@ static void parse_record_options(int argc, > char *sav; > int name_counter = 0; > int neg_event = 0; > + struct buffer_instance *instance; > + bool guest_config = false; Should have a different name, like "clock_set", as "guest_config" doesn't let us know what this is about. > > init_common_record_context(ctx, curr_cmd); > > @@ -5562,6 +5564,7 @@ static void parse_record_options(int argc, > break; > case 'C': > ctx->instance->ftrace->clock = optarg; > + guest_config = true; > break; > case 'v': > neg_event = 1; > @@ -5779,14 +5782,26 @@ static void parse_record_options(int argc, > > /* If --date is specified, prepend it to all guest VM flags */ > if (ctx->date) { > - struct buffer_instance *instance; > - > for_all_instances(instance) { > if (is_guest(instance)) > add_argv(instance, "--date", true); > } > } > > + if (guest_config) { > + /* If -C is specified, prepend clock to all guest VM flags */ > + for_all_instances(instance) { > + if (top_instance.ftrace->clock) { > + if (is_guest(instance)) { We should only append this, if the guest didn't have a clock set already. As the change log seems to say, if the user states a "-C clock" for the guest, that should take precedence over the host clock set. That is, a user may specifically state that they are using a different clock. If we have frequency and offset set, it should still work with different clocks. -- Steve > + add_argv(instance, > + (char *)top_instance.ftrace->clock, > + true); > + add_argv(instance, "-C", true); > + } > + } > + } > + } > + > if (!ctx->filtered && ctx->instance->filter_mod) > add_func(&ctx->instance->filter_funcs, > ctx->instance->filter_mod, "*");