From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: sk98lin, jumbo frames, and memory fragmentation Date: Mon, 1 Oct 2007 14:06:27 -0700 Message-ID: <20071001140627.1e2e665f@freepuppy.rosehill> References: <47015A24.7000701@nortel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: linux@syskonnect.de, netdev@vger.kernel.org To: "Chris Friesen" Return-path: Received: from smtp2.linux-foundation.org ([207.189.120.14]:48358 "EHLO smtp2.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752300AbXJAVG6 (ORCPT ); Mon, 1 Oct 2007 17:06:58 -0400 In-Reply-To: <47015A24.7000701@nortel.com> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Mon, 01 Oct 2007 14:35:48 -0600 "Chris Friesen" wrote: > > Hi all, > > We're considering some hardware that uses the sk98lin network hardware, > and we'll be using jumbo frames. Looking at the driver, when using a > 9KB MTU it seems like it would end up trying to atomically allocate a > 16KB buffer. > > Has anyone heard of this been a problem? It would seem like trying to > atomically allocate four physically contiguous pages could become tricky > after the system has been running for a while. > > The reason I ask is that we ran into this with the e1000. Before they > added the new jumbo frame code it was trying to atomically allocate 32KB > buffers and we would start getting allocation failures after a month or > so of uptime. > > Any information anyone can provide would be appreciated. Adding fragmentation support to skge driver is on my list of possible extensions. sky2 driver already supports it (yet one more feature that the vendor sk98lin driver doesn't do). -- Stephen Hemminger