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 38BA4C433F5 for ; Tue, 24 May 2022 15:35:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234011AbiEXPfx (ORCPT ); Tue, 24 May 2022 11:35:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32998 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231731AbiEXPfx (ORCPT ); Tue, 24 May 2022 11:35:53 -0400 Received: from mail-oa1-x32.google.com (mail-oa1-x32.google.com [IPv6:2001:4860:4864:20::32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 508E4580E1 for ; Tue, 24 May 2022 08:35:52 -0700 (PDT) Received: by mail-oa1-x32.google.com with SMTP id 586e51a60fabf-f233f06563so11076002fac.7 for ; Tue, 24 May 2022 08:35:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=X7cNaM55JAWOKA1/w809k8ceGl1bJ3qVly9hGwnlUVE=; b=cUaaNC9E80HPon0FTF7XpXKTg1DodCuFOLJzVa6sBz2y9jhzjU32ZLbSTe/QkcH7g1 RI5/GZC5sX45WKX16iKxxFAmmv3p88qHyaqaJ3wgS9h9KcJtJecyiaiImvbfXC8RosHk njJt18XdeJUfF/v0N3eDlCL3B18EsdZN2+GzHvs8AHUS4pk7WmjjeC88kXlNeFrXzqCu /VHrJNgdyc43SsKnEdm3FwiGQo4158CGmtsgD2Rvf+vZzFY+kmX1wbqHQmo4ulNLHffv t6pjCMFFpOEmdlvCAd7R6WfIjc/iQihYgK4pFGIYQu31QvW2KoCJpOv5nvO/71i+udTN lciw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=X7cNaM55JAWOKA1/w809k8ceGl1bJ3qVly9hGwnlUVE=; b=c32qoslNGv7UafUe8oNMJMEcIru4/ErtDbAw8BKgPYZ9e6W+4mYiWxodxmq+7mGrNQ TnNU1DRVUchLRLZcqgYBeZixvJDq0E5pQGVfq9ngv/ZMtzp6s2rA6V21UCGGnP8MM4IQ ACl6v28QIk7ibFxGWghjVAimYSTLcSdGW0IPm0Fo8vfnoF+WjQzlwx+b9Rw96+PtrYYk YYZEASRcMdYo9zbA2xvV/qO+xY5p0hIBhJGPhL8BpibFReBJgw0FWDw0PJcTWWqemdDv ieoK5aRioXeDonrNit8BtUChvaXhLsqGDV/LNk4qcneB0j1tQSKoadOYOSslq8qYTQMR 4X8g== X-Gm-Message-State: AOAM531B/1aWbPaAMlsZqDahuA+w5vo0tO1XY0Kfc7RX9spZigjHsbpE IfhY0UlsybHBwwLsPRqPujMMCzEO9AXRv7nXDTfhOsQdQ+N/vQ== X-Google-Smtp-Source: ABdhPJwj3xkcjDqDwCCfKbYPmb8bh15f8XJV6kB3U8NPiiK4B3wMqtWDNtikFBdvSsbHb+yyPwQMtub+4cwt+5uB+U8= X-Received: by 2002:a05:6870:461b:b0:e9:a015:36a6 with SMTP id z27-20020a056870461b00b000e9a01536a6mr2646679oao.185.1653406551415; Tue, 24 May 2022 08:35:51 -0700 (PDT) MIME-Version: 1.0 References: <20220504010242.1388192-1-vineethrp@google.com> <20220520160842.75d0ecbe@gandalf.local.home> <20220523094700.26eb2a05@gandalf.local.home> In-Reply-To: <20220523094700.26eb2a05@gandalf.local.home> From: Vineeth Pillai Date: Tue, 24 May 2022 11:35:40 -0400 Message-ID: Subject: Re: [PATCH] trace-cmd: rework of the pid detection of vcpus To: Steven Rostedt Cc: linux-trace-devel@vger.kernel.org, Joel Fernandes Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org 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. > > 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 I shall work on trace-cmd changes as well once the above patch is finalized.. Thanks, Vineeth