Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754698AbYANUDo (ORCPT ); Mon, 14 Jan 2008 15:03:44 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753659AbYANUDd (ORCPT ); Mon, 14 Jan 2008 15:03:33 -0500 Received: from zrtps0kp.nortel.com ([47.140.192.56]:35070 "EHLO zrtps0kp.nortel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753470AbYANUDc (ORCPT ); Mon, 14 Jan 2008 15:03:32 -0500 Message-ID: <478BBFE3.9030707@nortel.com> Date: Mon, 14 Jan 2008 14:02:43 -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: Eric Dumazet CC: Ray Lee , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: questions on NAPI processing latency and dropped network packets References: <478654C3.60806@nortel.com> <2c0942db0801112137k3f3f885ek212d5cbaecb7fea0@mail.gmail.com> <478B8473.6080506@nortel.com> <478B943C.7080009@cosmosbay.com> <478BB722.1020004@nortel.com> <478BB904.3060903@cosmosbay.com> In-Reply-To: <478BB904.3060903@cosmosbay.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-OriginalArrivalTime: 14 Jan 2008 20:02:46.0944 (UTC) FILETIME=[6EAF4200:01C856E8] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1059 Lines: 29 Eric Dumazet wrote: > Chris Friesen a écrit : >> Based on the profiling information we're spending time in >> sctp_endpoint_lookup_assoc() which doesn't actually use hashes, so I >> can't see how the hash would be related. I'm pretty new to SCTP >> though, so I may be missing something. > > Well, it does use hashes :) > > hash = sctp_assoc_hashfn(ep->base.bind_addr.port, rport); > head = &sctp_assoc_hashtable[hash]; > read_lock(&head->lock); > sctp_for_each_hentry(epb, node, &head->chain) { > /* maybe your machine is traversing here a *really* long > chain */ > } The latest released kernel doesn't have this code, it was only added in November. The SCTP maintainer just pointed me to the patch, and made some other suggestions as well. 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/