From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755040Ab1JEGxy (ORCPT ); Wed, 5 Oct 2011 02:53:54 -0400 Received: from mail-ww0-f44.google.com ([74.125.82.44]:63041 "EHLO mail-ww0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750925Ab1JEGxx (ORCPT ); Wed, 5 Oct 2011 02:53:53 -0400 Subject: Re: big picture UDP/IP performance question re 2.6.18 -> 2.6.32 From: Eric Dumazet To: starlight@binnacle.cx Cc: linux-kernel@vger.kernel.org, netdev , Willy Tarreau , Peter Zijlstra , Stephen Hemminger In-Reply-To: <6.2.5.6.2.20111003140010.05a70ed0@binnacle.cx> References: <6.2.5.6.2.20111003140010.05a70ed0@binnacle.cx> Content-Type: text/plain; charset="UTF-8" Date: Wed, 05 Oct 2011 08:53:47 +0200 Message-ID: <1317797627.3099.1.camel@edumazet-laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.32.2 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le lundi 03 octobre 2011 à 14:02 -0400, starlight@binnacle.cx a écrit : > At 06:16 PM 10/3/2011 +0200, Eric Dumazet wrote: > > > >It seems you use 4096 2MB hugepages, and your > >machine has 1GB pages availabe, you could > >try to use them. > > > >(boot cmd : hugepagesz=1GB hugepages=8 ) > > Tried it and got errno 12 on the segment > allocations. None were allocated, though > the count is six and the largest is exactly > 1GB. Don't have time to dig into it. > Thats pretty normal ;) With 2MB pages, your segment size must be a 2MB multiple. With 1GB pages, your segment size must be a .... 1GB multiple. So only applicable is say you handle one big 8GB segment for example, or 2 4GB segments... Well you see the picture.