Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757717AbcCUUJS (ORCPT ); Mon, 21 Mar 2016 16:09:18 -0400 Received: from exsmtp03.microchip.com ([198.175.253.49]:25271 "EHLO email.microchip.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755746AbcCUUJQ convert rfc822-to-8bit (ORCPT ); Mon, 21 Mar 2016 16:09:16 -0400 From: To: CC: , , , , , , , , , Subject: RE: [PATCH] lan78xx: Protect runtime_auto check by #ifdef CONFIG_PM Thread-Topic: [PATCH] lan78xx: Protect runtime_auto check by #ifdef CONFIG_PM Thread-Index: AQHRgpVrRdyRALUs2keEkS6lXb+y9Z9kCZOAgABqqICAACvLAIAADd2A//+N0tCAAIPAAP//lPlw Date: Mon, 21 Mar 2016 20:09:13 +0000 Message-ID: <9235D6609DB808459E95D78E17F2E43D404CC1EF@CHN-SV-EXMX02.mchp-main.com> References: <9235D6609DB808459E95D78E17F2E43D404CC166@CHN-SV-EXMX02.mchp-main.com> In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.10.76.4] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 907 Lines: 21 > > > But this leaves open the issue that querying the device too often will > > > prevent it from going into autosuspend. It seems to me that the best > > > way to deal with this is to make sure that the autosuspend timeout is > > > shorter than the interal between queries, not to make the querying > > > conditional on !runtime_auto. > > > > Short autosuspend timeout can affect performance. For instance our > experiments showed that > > shorter than 10sec timeout made Ethernet performance degrade because > of wakeup delays. > > So, just putting shorter timeout may have some side effects. > > Sure. This just means that you need a long statistics interval -- > longer than the autosuspend timeout. That's why I suggested making the > interval adjustable. What do you mean statistics interval? Interval calling ndo_get_stats64 or another thread/timer or else getting statistics? Thanks. Woojung