From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753305AbaEWQqN (ORCPT ); Fri, 23 May 2014 12:46:13 -0400 Received: from shards.monkeyblade.net ([149.20.54.216]:53585 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753178AbaEWQqL (ORCPT ); Fri, 23 May 2014 12:46:11 -0400 Date: Fri, 23 May 2014 12:46:04 -0400 (EDT) Message-Id: <20140523.124604.1978823006121667147.davem@davemloft.net> To: jim_baxter@mentor.com Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, kamal@canonical.com, bhutchings@solarflare.com, edumazet@google.com, mszeredi@suse.cz, fw@strlen.de Subject: Re: skbuff truesize incorrect. From: David Miller In-Reply-To: <537F130F.6080901@mentor.com> References: <537E5C63.7080607@mentor.com> <20140522.165833.414855217799383878.davem@davemloft.net> <537F130F.6080901@mentor.com> X-Mailer: Mew version 6.5 on Emacs 24.1 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.7 (shards.monkeyblade.net [149.20.54.216]); Fri, 23 May 2014 09:46:11 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jim Baxter Date: Fri, 23 May 2014 10:21:19 +0100 > On 22/05/14 21:58, David Miller wrote: >> From: Jim Baxter >> Date: Thu, 22 May 2014 21:21:55 +0100 >> >>> If there are multiple clones for an skb all pointing at the same data, >>> will that distort the memory used when they all have the same truesize? >> >> What is distorted about it? >> >> Each clone references exactly that much backing memory. >> > > Thank you for you help, I think distorted was the wrong word. > > > I think I am confused what truesize is used for it looks like it is used > to deallocate memory, is this correct? It's used to determine how much to charge sockets against their read and write memory limits.