From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [PATCH 1/1] via-rhine: Fix hanging with high CPU load on low-end broads. Date: Wed, 28 Dec 2011 10:17:10 -0800 Message-ID: <20111228101710.51c4893f@nehalam.linuxnetplumber.net> References: <1325075319-13464-1-git-send-email-gurligebis@gentoo.org> <1325083051.2327.47.camel@deadeye> <1325092423.2327.70.camel@deadeye> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: Ben Hutchings , linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Roger Luethi To: Bjarke Istrup Pedersen Return-path: Received: from mail.vyatta.com ([76.74.103.46]:48731 "EHLO mail.vyatta.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754045Ab1L1SRN (ORCPT ); Wed, 28 Dec 2011 13:17:13 -0500 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: Looks like the hardware isn't really disabling interrupts correctly to support NAPI. NAPI is supposed to be friendly and under load the work should move to ksoftirqd. I suspect the IRQ management in this driver is borked. There is some stupid spin loops in the IRQ handler that happen when looking for Tx IRQ. I would run with debug set and see if this is triggering.