From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753393Ab3A1DLk (ORCPT ); Sun, 27 Jan 2013 22:11:40 -0500 Received: from shards.monkeyblade.net ([149.20.54.216]:38267 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752598Ab3A1DLj (ORCPT ); Sun, 27 Jan 2013 22:11:39 -0500 Date: Sun, 27 Jan 2013 22:11:37 -0500 (EST) Message-Id: <20130127.221137.1761549497221263360.davem@davemloft.net> To: mst@redhat.com Cc: romain@orebokech.com, kvm@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] vhost-net: fall back to vmalloc if high-order allocation fails From: David Miller In-Reply-To: <20130123210411.GA9055@redhat.com> References: <87k3r31vbc.fsf@silenus.orebokech.com> <20130123210411.GA9055@redhat.com> X-Mailer: Mew version 6.5 on Emacs 24.2 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Michael S. Tsirkin" Date: Wed, 23 Jan 2013 23:04:11 +0200 > Maybe we should try and reduce our memory usage, > I will look into this. As has been pointed out, 32K of the size is from those iovecs in the queues. The size of this structure is frankly offensive, and even if you add some levels of indirection even just one iovec chunk is 16K on 64-bit which is in my opinion still unacceptably large. TCP sockets aren't even %25 the size of this beast. :-) I'm not going to apply this vmalloc patch, because if I apply it the fundamental problem here just gets swept under the carpet even longer. Sorry.