From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: TCPBacklogDrops during aggressive bursts of traffic Date: Wed, 23 May 2012 18:39:49 +0200 Message-ID: <1337791189.3361.3029.camel@edumazet-glaptop> References: <1337092718.1689.45.camel@kjm-desktop.uk.level5networks.com> <1337093776.8512.1089.camel@edumazet-glaptop> <1337099368.1689.47.camel@kjm-desktop.uk.level5networks.com> <1337099641.8512.1102.camel@edumazet-glaptop> <1337100454.2544.25.camel@bwh-desktop.uk.solarflarecom.com> <1337101280.8512.1108.camel@edumazet-glaptop> <1337272292.1681.16.camel@kjm-desktop.uk.level5networks.com> <1337272654.3403.20.camel@edumazet-glaptop> <1337674831.1698.7.camel@kjm-desktop.uk.level5networks.com> <1337678759.3361.147.camel@edumazet-glaptop> <1337679045.3361.154.camel@edumazet-glaptop> <1337699379.1698.30.camel@kjm-desktop.uk.level5networks.com> <1337703170.3361.217.camel@edumazet-glaptop> <1337704382.1698.53.camel@kjm-desktop.uk.level5networks.com> <1337705135.3361.226.camel@edumazet-glaptop> <1337720076.3361.667.camel@edumazet-glaptop> <1337766246.3361.2447.camel@edumazet-glaptop> <1337774978.3361.2744.camel@edumazet-glaptop> <4FBD0A85.4040407@intel.com> <1337789530.3361.2992.camel@edumazet-glaptop> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Kieran Mansley , Jeff Kirsher , Ben Hutchings , netdev@vger.kernel.org To: Alexander Duyck Return-path: Received: from mail-ey0-f174.google.com ([209.85.215.174]:43889 "EHLO mail-ey0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751351Ab2EWQjy (ORCPT ); Wed, 23 May 2012 12:39:54 -0400 Received: by eaak11 with SMTP id k11so2136466eaa.19 for ; Wed, 23 May 2012 09:39:53 -0700 (PDT) In-Reply-To: <1337789530.3361.2992.camel@edumazet-glaptop> Sender: netdev-owner@vger.kernel.org List-ID: On Wed, 2012-05-23 at 18:12 +0200, Eric Dumazet wrote: > With current driver, a MTU=1500 frame uses : > > sk_buff (256 bytes) > skb->head : 1024 bytes (or more exaclty now : 512 + 384) By the way, NET_SKB_PAD adds 64 bytes so its 64 + 512 + 384 = 960