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=-5.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 19C95C2B9F4 for ; Thu, 17 Jun 2021 11:34:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EFF2D61403 for ; Thu, 17 Jun 2021 11:34:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232395AbhFQLgz (ORCPT ); Thu, 17 Jun 2021 07:36:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:57814 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231250AbhFQLgz (ORCPT ); Thu, 17 Jun 2021 07:36:55 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id EB320613FF; Thu, 17 Jun 2021 11:34:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1623929687; bh=cMOB9S+2dYw6yIe3QIWUKtCOd2frCSqtDIIs3dUr138=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Kx8OmuUL4tJIAHyPAWkrARJ0Ir7zyF+ick79boaurToJaLA8Hk8ty/lIedsm9DsF5 qIfaxY49IOKm7frb9PPKRl36QiLCiTcNC1AHjX42ul5zUDe02zv6pxMJtN20AB5eIc Gd09aT5sOD4ToZgHiuHVuYc9NKGjP4ARo9UVwiR0= Date: Thu, 17 Jun 2021 13:34:45 +0200 From: Greg KH To: Paolo Bonzini Cc: Jing Zhang , KVM , KVMARM , LinuxMIPS , KVMPPC , LinuxS390 , Linuxkselftest , Marc Zyngier , James Morse , Julien Thierry , Suzuki K Poulose , Will Deacon , Huacai Chen , Aleksandar Markovic , Thomas Bogendoerfer , Paul Mackerras , Christian Borntraeger , Janosch Frank , David Hildenbrand , Cornelia Huck , Claudio Imbrenda , Sean Christopherson , Vitaly Kuznetsov , Jim Mattson , Peter Shier , Oliver Upton , David Rientjes , Emanuele Giuseppe Esposito , David Matlack , Ricardo Koller , Krish Sadhukhan , Fuad Tabba Subject: Re: [PATCH v10 3/5] KVM: stats: Add documentation for binary statistics interface Message-ID: References: <20210617044146.2667540-1-jingzhangos@google.com> <20210617044146.2667540-4-jingzhangos@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-s390@vger.kernel.org On Thu, Jun 17, 2021 at 01:19:50PM +0200, Paolo Bonzini wrote: > On 17/06/21 08:07, Greg KH wrote: > > > The statistics data itself could be read out by userspace telemetry > > > periodically without any extra parsing or setup effort. > > Do you have a pointer to userspace code that can do such a thing that > > others can use? We do not like adding apis to the kernel without at > > least seeing the user of those apis, especially for complex things like > > this. > > > > Ideally you would include some library code in the kernel tree itself > > that everyone can use for this for their own programs. You have > > provided a test which is great, but how do we know it works for "real" > > usages? > > I am pretty sure that Google is using this internally, but we are also going > to work on QEMU and Libvirt support for this. We need an "external user" for something as complex as this to be able to see if it actually works or not. Otherwise we have to just guess :( thanks, greg k-h 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=-3.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 0EB48C48BE5 for ; Thu, 17 Jun 2021 11:34:53 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id A05FA61403 for ; Thu, 17 Jun 2021 11:34:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A05FA61403 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 4675A40895; Thu, 17 Jun 2021 07:34:52 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Authentication-Results: mm01.cs.columbia.edu (amavisd-new); dkim=softfail (fail, message has been altered) header.i=@linuxfoundation.org Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 1jWQDWz3yUt9; Thu, 17 Jun 2021 07:34:51 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 1CA3249FB7; Thu, 17 Jun 2021 07:34:51 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id BA0C240895 for ; Thu, 17 Jun 2021 07:34:49 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id reszemqr5Zv7 for ; Thu, 17 Jun 2021 07:34:48 -0400 (EDT) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id 90F4540874 for ; Thu, 17 Jun 2021 07:34:48 -0400 (EDT) Received: by mail.kernel.org (Postfix) with ESMTPSA id EB320613FF; Thu, 17 Jun 2021 11:34:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1623929687; bh=cMOB9S+2dYw6yIe3QIWUKtCOd2frCSqtDIIs3dUr138=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Kx8OmuUL4tJIAHyPAWkrARJ0Ir7zyF+ick79boaurToJaLA8Hk8ty/lIedsm9DsF5 qIfaxY49IOKm7frb9PPKRl36QiLCiTcNC1AHjX42ul5zUDe02zv6pxMJtN20AB5eIc Gd09aT5sOD4ToZgHiuHVuYc9NKGjP4ARo9UVwiR0= Date: Thu, 17 Jun 2021 13:34:45 +0200 From: Greg KH To: Paolo Bonzini Subject: Re: [PATCH v10 3/5] KVM: stats: Add documentation for binary statistics interface Message-ID: References: <20210617044146.2667540-1-jingzhangos@google.com> <20210617044146.2667540-4-jingzhangos@google.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: Cc: KVM , David Hildenbrand , Paul Mackerras , Linuxkselftest , Claudio Imbrenda , Will Deacon , KVMARM , Emanuele Giuseppe Esposito , LinuxS390 , Janosch Frank , Marc Zyngier , Huacai Chen , Christian Borntraeger , Aleksandar Markovic , David Rientjes , KVMPPC , Krish Sadhukhan , David Matlack , Jim Mattson , Thomas Bogendoerfer , Sean Christopherson , Cornelia Huck , Peter Shier , LinuxMIPS , Vitaly Kuznetsov X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu On Thu, Jun 17, 2021 at 01:19:50PM +0200, Paolo Bonzini wrote: > On 17/06/21 08:07, Greg KH wrote: > > > The statistics data itself could be read out by userspace telemetry > > > periodically without any extra parsing or setup effort. > > Do you have a pointer to userspace code that can do such a thing that > > others can use? We do not like adding apis to the kernel without at > > least seeing the user of those apis, especially for complex things like > > this. > > > > Ideally you would include some library code in the kernel tree itself > > that everyone can use for this for their own programs. You have > > provided a test which is great, but how do we know it works for "real" > > usages? > > I am pretty sure that Google is using this internally, but we are also going > to work on QEMU and Libvirt support for this. We need an "external user" for something as complex as this to be able to see if it actually works or not. Otherwise we have to just guess :( thanks, greg k-h _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg KH Date: Thu, 17 Jun 2021 11:34:45 +0000 Subject: Re: [PATCH v10 3/5] KVM: stats: Add documentation for binary statistics interface Message-Id: List-Id: References: <20210617044146.2667540-1-jingzhangos@google.com> <20210617044146.2667540-4-jingzhangos@google.com> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Paolo Bonzini Cc: Jing Zhang , KVM , KVMARM , LinuxMIPS , KVMPPC , LinuxS390 , Linuxkselftest , Marc Zyngier , James Morse , Julien Thierry , Suzuki K Poulose , Will Deacon , Huacai Chen , Aleksandar Markovic , Thomas Bogendoerfer , Paul Mackerras , Christian Borntraeger , Janosch Frank , David Hildenbrand , Cornelia Huck , Claudio Imbrenda , Sean Christopherson , Vitaly Kuznetsov , Jim Mattson , Peter Shier , Oliver Upton , David Rientjes , Emanuele Giuseppe Esposito , David Matlack , Ricardo Koller , Krish Sadhukhan , Fuad Tabba On Thu, Jun 17, 2021 at 01:19:50PM +0200, Paolo Bonzini wrote: > On 17/06/21 08:07, Greg KH wrote: > > > The statistics data itself could be read out by userspace telemetry > > > periodically without any extra parsing or setup effort. > > Do you have a pointer to userspace code that can do such a thing that > > others can use? We do not like adding apis to the kernel without at > > least seeing the user of those apis, especially for complex things like > > this. > > > > Ideally you would include some library code in the kernel tree itself > > that everyone can use for this for their own programs. You have > > provided a test which is great, but how do we know it works for "real" > > usages? > > I am pretty sure that Google is using this internally, but we are also going > to work on QEMU and Libvirt support for this. We need an "external user" for something as complex as this to be able to see if it actually works or not. Otherwise we have to just guess :( thanks, greg k-h