Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753450AbdHOJan (ORCPT ); Tue, 15 Aug 2017 05:30:43 -0400 Received: from mail-pg0-f51.google.com ([74.125.83.51]:34773 "EHLO mail-pg0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753377AbdHOJam (ORCPT ); Tue, 15 Aug 2017 05:30:42 -0400 MIME-Version: 1.0 In-Reply-To: References:

From: Dmitry Vyukov Date: Tue, 15 Aug 2017 11:30:20 +0200 Message-ID: Subject: Re: drm/mtrr: possible deadlock To: Dou Liyang Cc: daniel.vetter@intel.com, jani.nikula@linux.intel.com, seanpaul@chromium.org, David Airlie , dri-devel@lists.freedesktop.org, LKML , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , "x86@kernel.org" , syzkaller Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1054 Lines: 35 On Tue, Aug 15, 2017 at 11:20 AM, Dou Liyang wrote: > Hi Dmitry, > > At 08/15/2017 03:18 PM, Dmitry Vyukov wrote: >> >> Hello, >> >> I am getting the following deadlock report while booting linux-next on >> 91dfed74eabcdae9378131546c446442c29bf769 in qemu. Config is attached. >> >> >> WARNING: possible recursive locking detected >> 4.13.0-rc4-next-20170811 #2 Not tainted >> -------------------------------------------- >> swapper/0/1 is trying to acquire lock: >> (cpu_hotplug_lock.rw_sem){++++}, at: [] >> stop_machine+0x1c/0x40 kernel/stop_machine.c:596 >> >> but task is already holding lock: >> (cpu_hotplug_lock.rw_sem){++++}, at: [] >> get_online_cpus include/linux/cpu.h:126 [inline] >> (cpu_hotplug_lock.rw_sem){++++}, at: [] >> mtrr_add_page+0x1bd/0xe80 arch/x86/kernel/cpu/mtrr/main.c:328 >> > > I guess you may want this. > > https://lkml.org/lkml/2017/8/14/7 > > and the solution by Thomas > > https://lkml.org/lkml/2017/8/14/64 Will try that. Thanks!