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=-0.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,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 90A1AC4BA18 for ; Wed, 26 Feb 2020 16:58:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5D2792467F for ; Wed, 26 Feb 2020 16:58:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582736280; bh=RgNtVFk4nBO7kFebX+/FhhfnOXJq8OE999CqQl781Ao=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=DLCyJa9j+aw0THrm0D2vX659n1gv7JX6EfdLkiz8SjOUsVDhXicS7SSnoD40cRF8Q 4QJ3x0kYqCy2pqy1GCEdLaXpeVD/r4qqLx4uENXM5/fyNNbK2Owelgw6DZiHwP8rnT BsgxKw9Rh2nWCDcOjejeW2fkSXKdgugykMmo5rnY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727905AbgBZQ57 (ORCPT ); Wed, 26 Feb 2020 11:57:59 -0500 Received: from mail.kernel.org ([198.145.29.99]:36188 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727711AbgBZQ56 (ORCPT ); Wed, 26 Feb 2020 11:57:58 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 4592121556; Wed, 26 Feb 2020 16:57:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582736277; bh=RgNtVFk4nBO7kFebX+/FhhfnOXJq8OE999CqQl781Ao=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=VJJ+gOOZqXTdYl/Euf++WHSlBa7yvrHoURpyOny4vvvNxaMnMaB+l32GIEMc9ezZC JxzkSOroRr3xv5rZ2UJV9bKj8b/IFdT+JQfz3lQA8B4Sa1/7jVVWpwy211NllWO27g 5+UlQFmnLoBOPpSdNjVN4oUobb2Zxma6Kjim/cW8= Date: Wed, 26 Feb 2020 17:57:54 +0100 From: Greg KH To: Luigi Rizzo Cc: linux-kernel@vger.kernel.org, Masami Hiramatsu , akpm@linux-foundation.org, naveen.n.rao@linux.ibm.com, ardb@kernel.org, Luigi Rizzo , Paolo Abeni , Toke =?iso-8859-1?Q?H=F8iland-J=F8rgensen?= , Jesper Dangaard Brouer Subject: Re: [PATCH 0/2] quickstats, kernel sample collector Message-ID: <20200226165754.GC261747@kroah.com> References: <20200226023027.218365-1-lrizzo@google.com> <20200226081048.GC22801@kroah.com> <20200226101449.GF127655@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 26, 2020 at 03:40:27AM -0800, Luigi Rizzo wrote: > On Wed, Feb 26, 2020 at 2:15 AM Greg KH wrote: > > > > On Wed, Feb 26, 2020 at 01:52:25AM -0800, Luigi Rizzo wrote: > > > On Wed, Feb 26, 2020 at 12:10 AM Greg KH wrote: > > > > > > > > On Tue, Feb 25, 2020 at 06:30:25PM -0800, Luigi Rizzo wrote: > > > > > This patchset introduces a small library to collect per-cpu samples and > > > > > accumulate distributions to be exported through debugfs. > > > > > > > > Shouldn't this be part of the tracing infrastructure instead of being > > > > "stand-alone"? > > > > > > That's an option. My reasoning for making it standalone was that > > > there are no dependencies in the (trivial) collection/aggregation part, > > > so that code might conveniently replace/extend existing snippets of > > > code that collect distributions in ad-hoc and perhaps suboptimal ways. > > > > But that's what perf and tracing already does today, right? > > Maybe I am mistaken but I believe there are substantial performance and use case > differences between kstats and existing perf/tracing code, as described below. Then put that in the changelog text and get the perf and tracing developers to agree with you on it and sign off on the patches. Don't try to create yet-another-tracing interface without getting their approval please. That's not how to do things. thanks, greg k-h