From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752987AbbC3NDY (ORCPT ); Mon, 30 Mar 2015 09:03:24 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:24687 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752597AbbC3NDU (ORCPT ); Mon, 30 Mar 2015 09:03:20 -0400 Message-ID: <5519497D.5030909@oracle.com> Date: Mon, 30 Mar 2015 07:02:53 -0600 From: David Ahern User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: Peter Zijlstra CC: efault@gmx.de, mingo@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH] sched: Add cpu based entries to debugfs References: <1427681613-98163-1-git-send-email-david.ahern@oracle.com> <20150330074452.GM23123@twins.programming.kicks-ass.net> In-Reply-To: <20150330074452.GM23123@twins.programming.kicks-ass.net> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Source-IP: userv0022.oracle.com [156.151.31.74] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/30/15 1:44 AM, Peter Zijlstra wrote: > On Sun, Mar 29, 2015 at 10:13:33PM -0400, David Ahern wrote: >> Before spending too much time formalizing this I wanted to see if you guys >> would entertain the idea of making this info available via debugfs. It does >> move the existing sched_features file to sched/features -- not sure how >> acceptable it is to move files in debugfs. > > There also already is a /proc/sys/kernel/sched_domain/ sysctl thing that > has much of the stuff in. > > I'm not opposed to a debugfs thing, but only if we can take the sysctl > thing out. > Related files I aware of; perhaps there are others: - /sys/devices/system/cpu entries. e.g., for cpu topology (physical package id, core id, sibling cores and threads) - debufs file for sched_features - /proc/sys/kernel/sched_domain for tweaking scheduling parameters I could not find anything that shows the sched_domain information. The proposal here was to create read-only debugfs files to dump the same info (but with better readability for large systems) that comes with the sched_debug parameter. I chose debugfs because a) sched_features is there and b) it is debug information about the scheduler. I could just as easily out it under /proc/sys/kernel/sched_domain or create a sched subdir under /sys/devices/system/cpu/cpu$n if one of those is preferred. David