Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757211Ab0GIPLK (ORCPT ); Fri, 9 Jul 2010 11:11:10 -0400 Received: from iolanthe.rowland.org ([192.131.102.54]:46898 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1754839Ab0GIPLI (ORCPT ); Fri, 9 Jul 2010 11:11:08 -0400 Date: Fri, 9 Jul 2010 11:11:06 -0400 (EDT) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: Arjan van de Ven cc: linux-pm@lists.linux-foundation.org, Subject: Re: [linux-pm] [PATCH] pm: Add runtime PM statistics to sysfs In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2079 Lines: 58 On Fri, 9 Jul 2010, Alan Stern wrote: > On Thu, 8 Jul 2010, Arjan van de Ven wrote: > > > From: Arjan van de Ven > > Subject: pm: Add runtime PM statistics to sysfs > > > > In order for PowerTOP to be able to report how well the new runtime PM is working > > for the various drivers, the kernel needs to export some basic statistics in sysfs. > > > > This patch adds two sysfs files in the runtime PM domain that expose the > > total time a device has been active, and the time a device has been suspended. > > > > With this PowerTOP can compute the activity percentage > > > > Active %age = 100 * (delta active) / (delta active + delta suspended) > > > > and present the information to the user. > > > > I've written the PowerTOP code (slated for version 1.12) already, and the output looks > > like this: > > > > Runtime Device Power Management statistics > > Active Device name > > 10.0% 06:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8101E/RTL8102E > > > > @@ -411,6 +433,7 @@ int __pm_runtime_resume(struct device *dev, bool from_wq) > > } > > > > if (retval) { > > + update_pm_runtime_accounting(dev); > > dev->power.runtime_status = RPM_SUSPENDED; > > pm_runtime_cancel_pending(dev); > > } else { > > This line was added in the wrong place. It belongs either before the > "if (retval) {" or after the "} else {". Whoops, sorry, my mistake. It doesn't belong here at all. It belongs considerably earlier in the function, before the line: dev->power.runtime_status = RPM_RESUMING; This is because update_pm_runtime_accounting() doesn't take into account the existence of the RPM_RESUMING and RPM_SUSPENDING states; it treats them all the same as RPM_ACTIVE. Also, it looks like you forgot to add a call in __pm_runtime_set_status(). Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/