Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758895Ab0FPLm1 (ORCPT ); Wed, 16 Jun 2010 07:42:27 -0400 Received: from mail-gx0-f174.google.com ([209.85.161.174]:41531 "EHLO mail-gx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758870Ab0FPLm0 convert rfc822-to-8bit (ORCPT ); Wed, 16 Jun 2010 07:42:26 -0400 X-Greylist: delayed 303 seconds by postgrey-1.27 at vger.kernel.org; Wed, 16 Jun 2010 07:42:25 EDT DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type :content-transfer-encoding; b=NEVe7p9EhgEfADt1ZBe7V36ZYQ3197PKgs3a89YMWychgP9gT9fauh868aaZIEpKQ3 6ieOvPzdG9ag7x4FrhSH1UvnZydcxoFCm42w2EMhdMhxHV8gX95rOzSgqMeb/5qhtE8H 1iJvm5iUjywzYd/NnxVp18kwTBmvySyQJRpZs= MIME-Version: 1.0 In-Reply-To: <18402.1276625268@redhat.com> References: <20100613194949.GC8055@thunk.org> <20100614184244.GA11480@elliptictech.com> <20100614214646.GF6666@thunk.org> <18402.1276625268@redhat.com> Date: Wed, 16 Jun 2010 12:37:22 +0100 X-Google-Sender-Auth: 0hUdrIgRj_2ZGI1Gp2-nqDstyCI Message-ID: Subject: Re: Why is kslowd accumulating so much CPU time? From: Andy Whitcroft To: David Howells Cc: tytso@mit.edu, Dave Airlie , Dave Airlie , 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: 895 Lines: 24 > Can you see what they're doing? > > ? ? ? ?watch -n0 cat /sys/kernel/debug/slow_work/runqueue Turned on the debugging and applied the patch from Ted, and when things are bad I see constant cycling of all four threads in the output showing similar to the below, note only one thread shows at a time: Every 0.1s: cat /sys/kernel/debug/slow_work/runqueue Wed Jun 16 12:34:52 2010 THR PID ITEM ADDR FL MARK DESC === ===== ================ == ===== ========== 0 897 ffff88012bb07510 12 20ms DRM_CRTC_HELPER: i915@pci:0000:00:02.0 When things are working well I see the same output appearing for one update, about every 10s. -apw -- 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/