From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754956AbcAOJUd (ORCPT ); Fri, 15 Jan 2016 04:20:33 -0500 Received: from mail.microcatalog.org.uk ([217.6.246.34]:42116 "EHLO root.phytec.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753986AbcAOJTy (ORCPT ); Fri, 15 Jan 2016 04:19:54 -0500 Message-ID: <1452849530.3483.30.camel@lws-tremmet.phytec.de> Subject: Re: phy: SMSC LAN8710/LAN8720 high load From: Teresa Remmet To: David Laight Cc: Igor Plyatov , "David S. Miller" , Florian Fainelli , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" Date: Fri, 15 Jan 2016 10:18:50 +0100 In-Reply-To: <063D6719AE5E284EB5DD2968C1650D6D1CCC42AE@AcuExch.aculab.com> References: <1452498115.7467.23.camel@lws-tremmet.phytec.de> <063D6719AE5E284EB5DD2968C1650D6D1CCC42AE@AcuExch.aculab.com> X-Mailer: Evolution 3.10.4-0ubuntu2 Mime-Version: 1.0 X-MIMETrack: Itemize by SMTP Server on Idefix/Phytec(Release 9.0.1FP4|June 07, 2015) at 15.01.2016 10:19:50, Serialize by Router on Idefix/Phytec(Release 9.0.1FP4|June 07, 2015) at 15.01.2016 10:19:50, Serialize complete at 15.01.2016 10:19:50 X-TNEFEvaluated: 1 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 Hello David, Am Dienstag, den 12.01.2016, 11:33 +0000 schrieb David Laight: > From: Teresa Remmet > > Sent: 11 January 2016 07:42 > > we have noticed load issues on our AM335x boards with a LAN8710 phy while > > cpu is idling using 4.4-rc8. > > > > CPU: 0% usr 0% sys 0% nic 99% idle 0% io 0% irq 0% sirq > > Load average: 1.21 1.16 1.00 1/84 372 > > The 'Load average' value is mostly meaningless. > It includes any process/thread that is sleeping uninterruptably - even > if the process is never woken (or is only woken for short periods). > > If you have a kernel thread that you don't want affected by signals > (exits on some request to the driver) then you end up increasing the > 'load average'. thank you for your explanation. But I'm still worried that waiting so long in this function might be a problem. When I look at the function duration of lan87xx_read_status it takes in average about 1277869 us. When disabling the the power detect mode the time drops down to 555.326 us. As disabling over device tree does not work correct for lan87xx a patch follows. Teresa > > David >