From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rick Jones Subject: Re: [PATCH net-next] net/mlx4: use one page fragment per incoming frame Date: Mon, 03 Jun 2013 11:24:48 -0700 Message-ID: <51ACDF70.4050301@hp.com> References: <1370282095.24311.171.camel@edumazet-glaptop> <51ACDAF5.2040008@hp.com> <1370283150.24311.179.camel@edumazet-glaptop> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: David Miller , netdev , Amir Vadai To: Eric Dumazet Return-path: Received: from g4t0014.houston.hp.com ([15.201.24.17]:41924 "EHLO g4t0014.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754821Ab3FCSYu (ORCPT ); Mon, 3 Jun 2013 14:24:50 -0400 In-Reply-To: <1370283150.24311.179.camel@edumazet-glaptop> Sender: netdev-owner@vger.kernel.org List-ID: On 06/03/2013 11:12 AM, Eric Dumazet wrote: > On Mon, 2013-06-03 at 11:05 -0700, Rick Jones wrote: > >> I take it this is a > 10 Gbit/s NIC? >> > > Well, I guess so ! > > Or something is really strange with this NIC ! Indeed. >> What if any is the downside to an incoming stream of small packets? > > These kind of NIC are aimed for performance, I was told. > > 1) It would be strange to use them on memory constrained machines. > > 2) using 1536 bytes fragments is better than most other NIC drivers, as > they usually use 2048 or 4096 bytes frags > > 3) Current memory allocations done in mlx4 uses order-2 pages, and > nobody yet complained that these allocation might fail... I was thinking more about getting up to a socket and finding insufficient overhead remaining to hold the packet. rick