From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chegu Vinod Subject: kvm_intel: Could not allocate 42 bytes percpu data Date: Mon, 24 Jun 2013 12:01:59 -0700 Message-ID: <51C897A7.50302@hp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: KVM To: rusty@rustcorp.com.au, prarit@redhat.com, LKML , Gleb Natapov , Paolo Bonzini Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org Hello, Lots (~700+) of the following messages are showing up in the dmesg of a 3.10-rc1 based kernel (Host OS is running on a large socket count box with HT-on). [ 82.270682] PERCPU: allocation failed, size=42 align=16, alloc from reserved chunk failed [ 82.272633] kvm_intel: Could not allocate 42 bytes percpu data ... also call traces like the following... [ 101.852136] ffffc901ad5aa090 ffff88084675dd08 ffffffff81633743 ffff88084675ddc8 [ 101.860889] ffffffff81145053 ffffffff81f3fa78 ffff88084809dd40 ffff8907d1cfd2e8 [ 101.869466] ffff8907d1cfd280 ffff88087fffdb08 ffff88084675c010 ffff88084675dfd8 [ 101.878190] Call Trace: [ 101.880953] [] dump_stack+0x19/0x1e [ 101.886679] [] pcpu_alloc+0x9a3/0xa40 [ 101.892754] [] __alloc_reserved_percpu+0x13/0x20 [ 101.899733] [] load_module+0x35f/0x1a70 [ 101.905835] [] ? do_page_fault+0xe/0x10 [ 101.911953] [] SyS_init_module+0xfb/0x140 [ 101.918287] [] system_call_fastpath+0x16/0x1b [ 101.924981] kvm_intel: Could not allocate 42 bytes percpu data Wondering if anyone else has seen this with the recent [3.10] based kernels esp. on larger boxes? There was a similar issue that was reported earlier (where modules were being loaded per cpu without checking if an instance was already loaded/being-loaded). That issue seems to have been addressed in the recent past (e.g. https://lkml.org/lkml/2013/1/24/659 along with a couple of follow on cleanups) Is the above yet another variant of the original issue or perhaps some race condition that got exposed when there are lot more threads ? Vinod