From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH net] bna: page allocation during interrupts to use a mempool. Date: Mon, 06 Oct 2014 18:52:15 -0700 Message-ID: <1412646735.11091.93.camel@edumazet-glaptop2.roam.corp.google.com> References: <20140929092833.6c2cb7e9@urahara> <262CB373A6D1F14F9B81E82F74F77D5A4704FAE7@avmb2.qlogic.org> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Shahed Shaikh , Stephen Hemminger , netdev , "rmody@brocade.com" , Rasesh Mody To: Eric Wheeler Return-path: Received: from mail-pa0-f47.google.com ([209.85.220.47]:61632 "EHLO mail-pa0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751482AbaJGBwS (ORCPT ); Mon, 6 Oct 2014 21:52:18 -0400 Received: by mail-pa0-f47.google.com with SMTP id rd3so6291680pab.20 for ; Mon, 06 Oct 2014 18:52:18 -0700 (PDT) In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On Mon, 2014-10-06 at 18:57 -0700, Eric Wheeler wrote: > This patch fixes an order:2 memory allocation error backtrace by > guaranteeing that memory is available during simultaneous high memory > pressure and packet rates when using 9k jumbo frames. > > Tests between two systems (one patched, one not) succeeded with ~1TB of > data transferred over DRBD. As expected, the unpatched host gave > warn_alloc_failed's, and the patched host worked correctly. This patch > increases kernel memory usage by 32 order-2 allocation when this module is > loaded (512k on x86) which should be negligible on hosts that use 10GbE > cards. This is highly suspect to me. Most likely yet another truesize lie. At a first glance, bnad_cq_setup_skb_frags() is buggy here : skb->truesize += totlen; With this kind of lies, system can OOM very fast.