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 A40A7C433EF for ; Tue, 24 May 2022 15:53:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235697AbiEXPxV (ORCPT ); Tue, 24 May 2022 11:53:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39430 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234881AbiEXPxU (ORCPT ); Tue, 24 May 2022 11:53:20 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 04DF991549 for ; Tue, 24 May 2022 08:53:19 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 8904061724 for ; Tue, 24 May 2022 15:53:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 86F8EC34113; Tue, 24 May 2022 15:53:18 +0000 (UTC) Date: Tue, 24 May 2022 11:53:17 -0400 From: Steven Rostedt To: Vineeth Pillai Cc: linux-trace-devel@vger.kernel.org, Joel Fernandes Subject: Re: [PATCH] trace-cmd: rework of the pid detection of vcpus Message-ID: <20220524115317.62efeeb0@gandalf.local.home> In-Reply-To: References: <20220504010242.1388192-1-vineethrp@google.com> <20220520160842.75d0ecbe@gandalf.local.home> <20220523094700.26eb2a05@gandalf.local.home> 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 Tue, 24 May 2022 11:35:40 -0400 Vineeth Pillai wrote: > On Mon, May 23, 2022 at 9:47 AM Steven Rostedt wrote: > > > > > I think we should also think about versioning the guest/host protocols > > > > We actually have that. We are currently at version 3. If this becomes too > > much of an issue, we can always move to v4. But to do that would require a > > lot more thinking, as I like to support all versions, and I don't want to > > have a lot of them. Thus, if we need to update to v4. It would likely be a > > entirely new protocol to fix and extend the issues of v3. > > > Thanks for the details.. Yeah, doesn't make sense to have a version > change for this. But there may be other reasons to update to v4 ;-) > > > > Sure, I will have a look at this again and see if/how we can fix this without > > > touching existing protocol. I was thinking about adding the pid details to > > > debugfs and then reading it from there. Its not optimal as we would need a > > > supporting kernel, but it would be accurate if we have kernel support and we > > > need not rely on trace messages to get the pids. > > > > That would be useful too, in more than just trace-cmd I believe. > > > Posted a patch upstream for exposing pid in debugfs: > https://www.spinics.net/lists/kvm/msg278146.html Saw that. > > I shall work on trace-cmd changes as well once the above patch > is finalized.. Thanks, -- Steve