From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: big picture UDP/IP performance question re 2.6.18 -> 2.6.32 Date: Wed, 05 Oct 2011 08:53:47 +0200 Message-ID: <1317797627.3099.1.camel@edumazet-laptop> References: <6.2.5.6.2.20111003140010.05a70ed0@binnacle.cx> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: linux-kernel@vger.kernel.org, netdev , Willy Tarreau , Peter Zijlstra , Stephen Hemminger To: starlight@binnacle.cx Return-path: In-Reply-To: <6.2.5.6.2.20111003140010.05a70ed0@binnacle.cx> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Le lundi 03 octobre 2011 =C3=A0 14:02 -0400, starlight@binnacle.cx a =C3= =A9crit : > 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=3D1GB hugepages=3D8 ) >=20 > 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. >=20 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, o= r 2 4GB segments... Well you see the picture.