Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762992AbYALFhb (ORCPT ); Sat, 12 Jan 2008 00:37:31 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751551AbYALFhW (ORCPT ); Sat, 12 Jan 2008 00:37:22 -0500 Received: from fg-out-1718.google.com ([72.14.220.154]:18799 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751348AbYALFhU (ORCPT ); Sat, 12 Jan 2008 00:37:20 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:sender:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references:x-google-sender-auth; b=XLFHwqfodMzg8mj7uyD9GSNK74gb5JzYWzb2X0sVmebF/Qv3d94Gy+5ZmkNFBA1U70wObz3sGHdLWZNRZZVPDdjVdmjSuom3DzAugUACMfxNcepVNxTqofZODV6kFeZVGbP4EKcdiKwFk/ZUYpm5DFslO5bIfYeA2dZ5ARaNNwI= Message-ID: <2c0942db0801112137k3f3f885ek212d5cbaecb7fea0@mail.gmail.com> Date: Fri, 11 Jan 2008 21:37:18 -0800 From: "Ray Lee" To: "Chris Friesen" Subject: Re: questions on NAPI processing latency and dropped network packets Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <478654C3.60806@nortel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <478654C3.60806@nortel.com> X-Google-Sender-Auth: 23e736aa56d7bbe9 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1021 Lines: 24 On Jan 10, 2008 9:24 AM, Chris Friesen wrote: > After a recent userspace app change, we've started seeing packets being > dropped by the ethernet hardware (e1000, NAPI is enabled). The > error/dropped/fifo counts are going up in ethtool: (These are perhaps too obvious, but I didn't see the questions or answers in the thread.) Can you reproduce it with a simple userspace cpu hog? (Two, really, one per cpu.) Can you reproduce it with the newer e1000? Can you reproduce it with git head? If the answer to the first one is yes, the last no, then bisect until you get a kernel that doesn't show the problem. Backport the fix, unless the fix happens to be CFS. However, I suspect that your userpace app is just starving the system from time to time. -- 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/