From mboxrd@z Thu Jan 1 00:00:00 1970 From: Denys Fedoryshchenko Subject: Re: 2.6.39-rc7-git11, x86/32, failed on ppp2897'th interface, PERCPU: allocation failed Date: Thu, 19 May 2011 09:47:38 +0300 Message-ID: References: <1305787158.3019.12.camel@edumazet-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: To: Eric Dumazet Return-path: Received: from rev-153-13.globalproof.net ([194.146.153.13]:33539 "EHLO hosting.visp.net.lb" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S932304Ab1ESGrl (ORCPT ); Thu, 19 May 2011 02:47:41 -0400 In-Reply-To: <1305787158.3019.12.camel@edumazet-laptop> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, 19 May 2011 08:39:18 +0200, Eric Dumazet wrote: > Le jeudi 19 mai 2011 =C3=A0 09:35 +0300, Denys Fedoryshchenko a =C3=A9= crit : >> Hi, again >> >> Just tried to upgrade large NAS from 2.6.38.6 to 2.6.39-rc7-git11,=20 >> and >> at same time enabling ipv6 on it. >> Got that, after ppp2897 brought up (sure it means there is other=20 >> 2896 >> available, and also few ethernet vlans, around 32). >> I am not sure it is a bug, but it looks i had free memory(the box=20 >> had >> 8GB free), and lowmem too, also i will try to enable there 64bit=20 >> kernel >> at evening. >> >> May 17 16:00:42 194.146.155.70 kernel: [14925.897799] PERCPU: >> allocation failed, size=3D2048 align=3D4, failed to allocate new ch= unk >> May 17 16:00:42 194.146.155.70 kernel: [14925.898163] Pid: 24207,=20 >> comm: >> pppd Not tainted 2.6.39-rc7-git11-build-0058 #4 > > Its a known problem : When ipv6 is enabled, we allocate percpu memory= =20 > to > hold per device snmp counters. > > make sure kernel idea of max possible cpus matches real number of=20 > cpus. > > And yes, switching to 64bit kernel helps a lot. > Yes, it matches, i guess. CONFIG_NR_CPUS=3D8 processor : 7 vendor_id : GenuineIntel cpu family : 6 model : 26 model name : Intel(R) Core(TM) i7 CPU 950 @ 3.07GHz Thanks. Then i will simply switch kernel to 64bit, but for now with=20 32bit userspace, since this semi-embedded system mass deployed, and i have to maintain it alone (cannot handle both=20 32/64 bit userspace), and some pc's don't have lm flag in cpuinfo :) I am hitting a lot lowmem limits lately, but the only application that= =20 was not working right 32bit userspace/64bit kernel - ipvsadm. Should i report it as a bug (i will check if it is still an issue)?