From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753494Ab3LPLAN (ORCPT ); Mon, 16 Dec 2013 06:00:13 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:23800 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753327Ab3LPLAM (ORCPT ); Mon, 16 Dec 2013 06:00:12 -0500 Message-ID: <52AEDD2F.8040704@oracle.com> Date: Mon, 16 Dec 2013 16:29:59 +0530 From: Allen Pais User-Agent: Mozilla/5.0 (X11; Linux i686; rv:16.0) Gecko/20121010 Thunderbird/16.0.1 MIME-Version: 1.0 To: Sebastian Andrzej Siewior CC: linux-kernel@vger.kernel.org, sparclinux@vger.kernel.org Subject: Re: [PATCH 2/3] sparc64: convert spinlock_t to raw_spinlock_t in mmu_context_t References: <1387166853-10782-1-git-send-email-allen.pais@oracle.com> <1387166853-10782-3-git-send-email-allen.pais@oracle.com> <52AED5BB.1060002@linutronix.de> In-Reply-To: <52AED5BB.1060002@linutronix.de> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Source-IP: acsinet21.oracle.com [141.146.126.237] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >> Issue debugged by Thomas Gleixner The kernel crashed while I attempted preempt_rt support on log at: [ 1487.027884] I7: [ 1487.027885] Call Trace: [ 1487.027887] [00000000004967dc] rt_mutex_setprio+0x3c/0x2c0 [ 1487.027892] [00000000004afe20] task_blocks_on_rt_mutex+0x180/0x200 [ 1487.027895] [0000000000819114] rt_spin_lock_slowlock+0x94/0x300 [ 1487.027897] [0000000000817ebc] __schedule+0x39c/0x53c [ 1487.027899] [00000000008185fc] schedule+0x1c/0xc0 [ 1487.027908] [000000000048fff4] smpboot_thread_fn+0x154/0x2e0 [ 1487.027913] [000000000048753c] kthread+0x7c/0xa0 [ 1487.027920] [00000000004060c4] ret_from_syscall+0x1c/0x2c [ 1487.027922] [0000000000000000] (null) Thomas debugged it and pointed me towards the fix. > > I think davem would appreciate if you add a little here than this. The > same goes for 3/3. > The same goes with 3/3 [ 2317.606015] [00000000008072f4] rt_spin_lock_slowlock+0x94/0x300 [ 2317.606020] [0000000000451d74] get_new_mmu_context+0x14/0x160 [ 2317.606026] [0000000000806394] switch_to_pc+0xd4/0x2a0 [ 2317.606029] [00000000008067dc] schedule+0x1c/0xc0 [ 2317.606031] [0000000000807364] rt_spin_lock_slowlock+0x104/0x300 [ 2317.606033] [0000000000450284] destroy_context+0x84/0x120 [ 2317.606036] [000000000045c788] __mmdrop+0x28/0xe0 [ 2317.606045] [00000000004bf290] rcu_process_callbacks+0x450/0x760 [ 2317.606049] [0000000000466d48] do_current_softirqs+0x208/0x3c0 [ 2317.606051] [0000000000466f14] run_ksoftirqd+0x14/0x40 [ 2317.606057] [000000000048c64c] smpboot_thread_fn+0x18c/0x2e0 [ 2317.606061] [0000000000483b5c] kthread+0x7c/0xa0 [ 2317.606069] [00000000004060c4] ret_from_syscall+0x1c/0x2c [ 2317.606070] [0000000000000000] (null) I am not sure if it'd be nice to put the call trace in the commit message. But if needed I can re-send them. - Allen