Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752310Ab0HPE1u (ORCPT ); Mon, 16 Aug 2010 00:27:50 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:52488 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750824Ab0HPE1t convert rfc822-to-8bit (ORCPT ); Mon, 16 Aug 2010 00:27:49 -0400 MIME-Version: 1.0 In-Reply-To: <4C68B92B.3080406@myrealbox.com> References: <4C68B92B.3080406@myrealbox.com> From: Linus Torvalds Date: Sun, 15 Aug 2010 21:27:28 -0700 Message-ID: Subject: Re: Intel graphics CPU usage - SDVO detect bogosity? To: Andy Lutomirski Cc: Dave Airlie , Chris Wilson , Zhao Yakui , Jesse Barnes , Adam Jackson , DRI mailing list , linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1813 Lines: 47 On Sun, Aug 15, 2010 at 9:06 PM, Andy Lutomirski wrote: > > You might be hitting the infamous hotplug storm [1]. ?The symptoms vary by > kernel version. Hmm. I don't think it's a storm. The drm.debug=4 thing shows things just every 10 seconds. That seems pretty controlled. Of course, it seems to be several milliseconds worth of work then, so it's not _too_ controlled. I must be missing some detail. > If I'm right, the outputs of intel_bios_dumper and intel_bios_reader could > be instructive (both are in intel-gpu-tools). My version of intel-gpu-tools must be old (fedora 12). It has intel_gpu_dump and intel_reg_write and some other apps, but not the bios-dumper/reader. Not that I could read the output of them anyway, I bet ;) > You could also try intel_reg_write 0x61110 0x0 and see if the problem stops > (at least until a suspend/resume cycle). ?That command turns off output > hotplug on the card, which has the side effect that the kernel will stop > acting on bogus interrupts. # intel_reg_write 0x61110 0x0 Value before: 0x4000220 Value after: 0x0 but it doesn't seem to change any behavior. Still that sdvo probe every 10 s, and still 1% of CPU for kworker in top. But that kworker thing definitely has to be separate from the 10-second sdvo probe, because it shows up all the time (ie top updates every second). But right now the wife is using that machine, so I can't check the "it should be totally idle, what the heck is going on" behavior at the moment. Linus Linus -- 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/