Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754085AbYAUTyO (ORCPT ); Mon, 21 Jan 2008 14:54:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752553AbYAUTx4 (ORCPT ); Mon, 21 Jan 2008 14:53:56 -0500 Received: from zrtps0kp.nortel.com ([47.140.192.56]:44629 "EHLO zrtps0kp.nortel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752475AbYAUTxy (ORCPT ); Mon, 21 Jan 2008 14:53:54 -0500 Message-ID: <4794F848.9020402@nortel.com> Date: Mon, 21 Jan 2008 13:53:44 -0600 From: "Chris Friesen" User-Agent: Mozilla Thunderbird 1.0.2-6 (X11/20050513) X-Accept-Language: en-us, en MIME-Version: 1.0 To: netdev@vger.kernel.org CC: linux-kernel@vger.kernel.org Subject: Re: questions on NAPI processing latency and dropped network packets References: <478654C3.60806@nortel.com> In-Reply-To: <478654C3.60806@nortel.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 21 Jan 2008 19:53:47.0263 (UTC) FILETIME=[55E6B8F0:01C85C67] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 833 Lines: 21 I've done some further digging, and it appears that one of the problems we may be facing is very high instantaneous traffic rates. Instrumentation showed up to 222K packets/sec for short periods (at least 1.1 ms, possibly longer), although the long-term average is down around 14-16K packets/sec. If I bump the rx ring size up to 4096, we can handle all the packets and we still have 44% idle on cpu0 and 27% idle on cpu1. Is there anything else we can do to minimize the latency of network packet processing and avoid having to crank the rx ring size up so high? Thanks, Chris -- 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/