From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: still seeing network freezes with rtl8139 nic Date: Mon, 25 Feb 2008 10:54:46 +0200 Message-ID: <47C28256.7020908@qumranet.com> References: <47BDC414.30301@cisco.com> <47C14371.9040405@qumranet.com> <47C1CA4F.3020605@cisco.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel To: david ahern Return-path: In-Reply-To: <47C1CA4F.3020605@cisco.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces@lists.sourceforge.net Errors-To: kvm-devel-bounces@lists.sourceforge.net List-Id: kvm.vger.kernel.org david ahern wrote: > I've run a lot more tests: > > > - if I remove the "if (!change) return" optimization from pci_set_irq the > rtl8139 nic worked fine for 16+ hours. I'm not recommending this as a fix, just > confirming that the problem goes away. > > Interesting. What can cause this to happen? - some non-pci device shares the same irq (unlikely) - the pci link sharing is broken. Is the eth0 irq shared? Please post /proc/interrupts. - the in-kernel ioapic is buggy and needs the extra kicking the optimization prevents. Can be checked by re-adding the optimization to kvm_ioapic_set_irq() (keeping it removed in qemu). If it works, the problem is in userspace. If it fails, the problem is in the kernel. Something like static int old_level[16]; if (level == old_level[irq]) return; old_level[irq] = level; -- Do not meddle in the internals of kernels, for they are subtle and quick to panic. ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/