From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759007AbbA2XsN (ORCPT ); Thu, 29 Jan 2015 18:48:13 -0500 Received: from v094114.home.net.pl ([79.96.170.134]:59542 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1758279AbbA2XsJ (ORCPT ); Thu, 29 Jan 2015 18:48:09 -0500 From: "Rafael J. Wysocki" To: Kevin Hilman Cc: Dave Gerlach , linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, Pavel Machek , Len Brown , Nishanth Menon Subject: Re: [PATCH] PM QoS: Add debugfs support to view the list of constraints Date: Fri, 30 Jan 2015 01:10:57 +0100 Message-ID: <4174934.VKXlq5EvTQ@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/3.16.0-rc5+; KDE/4.11.5; x86_64; ; ) In-Reply-To: <7h1to0h7a0.fsf@deeprootsystems.com> References: <1417799948-48440-1-git-send-email-d-gerlach@ti.com> <7h1to0h7a0.fsf@deeprootsystems.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Monday, December 15, 2014 02:34:15 PM Kevin Hilman wrote: > Dave Gerlach writes: > > > From: Nishanth Menon > > > > PM QoS requests are notoriously hard to debug and made even > > more so due to their highly dynamic nature. Having visibility > > into the internal data representation per constraint allows > > us to have much better appreciation of potential issues or > > bad usage by drivers in the system. > > > > So introduce for all classes of PM QoS, an entry in > > /sys/kernel/debug/pm_qos that shall show all the current > > requests as well as the snapshot of the value these requests > > boil down to. For example: > > ==> /sys/kernel/debug/pm_qos/cpu_dma_latency <== > > 1: 4444: Active > > 2: 2000000000: Default > > 3: 2000000000: Default > > 4: 2000000000: Default > > Type=Minimum, Value=4444, Requests: active=1 / total=4 > > > > ==> /sys/kernel/debug/pm_qos/memory_bandwidth <== > > Empty! > > > > ... > > > > The actual value listed will have their meaning based > > on the QoS it is on, the 'Type' indicates what logic > > it would use to collate the information - Minimum, > > Maximum, or Sum. Value is the collation of all requests. > > This interface also compares the values with the defaults > > for the QoS class and marks the ones that are > > currently active. > > > > Signed-off-by: Nishanth Menon > > Signed-off-by: Dave Gerlach > > A very useful feature indeed, > > Acked-by: Kevin Hilman Queued up for 3.20, thanks! -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.