From mboxrd@z Thu Jan 1 00:00:00 1970 From: Juergen Gross Subject: WARNings in guest during xl save/restore Date: Fri, 21 Nov 2014 11:08:37 +0100 Message-ID: <546F0F25.4040707@suse.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: "xen-devel@lists.xensource.com" List-Id: xen-devel@lists.xenproject.org Hi, during tests of my "linear p2m list" patches I stumbled over some WARNs issued during xl save and xl restore of a pv-domU with unpatched linux 3.18-rc5: during save I saw multiple entries like: [ 176.900393] WARNING: CPU: 0 PID: 9 at arch/x86/xen/enlighten.c:968 clear_local_APIC+0xa5/0x2b0() [ 176.900393] Modules linked in: cfg80211 rfkill nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc evdev x86_pkg_temp_thermal thermal_sys snd_pcm coretemp snd_timer crc32_pclmul aesni_intel snd xts soundcore aes_i586 lrw gf128mul ablk_helper pcspkr cryptd fuse autofs4 ext4 crc16 mbcache jbd2 crc32c_intel [ 176.900393] CPU: 0 PID: 9 Comm: migration/0 Tainted: G W 3.18.0-rc5 #30 [ 176.900393] 00000009 c14c40b2 00000000 c1054b10 c1599538 00000000 00000009 c158bdc2 [ 176.900393] 000003c8 c103c925 c103c925 000003c8 00000002 00000000 c15d25eb e8867e64 [ 176.900393] c1054bd9 00000009 00000000 c103c925 00000000 c103cb54 00000002 00000000 [ 176.900393] Call Trace: [ 176.900393] [] ? dump_stack+0x3e/0x4e [ 176.900393] [] ? warn_slowpath_common+0x90/0xc0 [ 176.900393] [] ? clear_local_APIC+0xa5/0x2b0 [ 176.900393] [] ? clear_local_APIC+0xa5/0x2b0 [ 176.900393] [] ? warn_slowpath_null+0x19/0x20 [ 176.900393] [] ? clear_local_APIC+0xa5/0x2b0 [ 176.900393] [] ? disable_local_APIC+0x24/0x90 [ 176.900393] [] ? lapic_suspend+0x11e/0x170 [ 176.900393] [] ? syscore_suspend+0x79/0x220 [ 176.900393] [] ? set_next_entity+0x62/0x80 [ 176.900393] [] ? xen_suspend+0x2d/0x110 [ 176.900393] [] ? xen_mc_flush+0x13f/0x170 [ 176.900393] [] ? multi_cpu_stop+0xa9/0xd0 [ 176.900393] [] ? cpu_stop_should_run+0x50/0x50 [ 176.900393] [] ? cpu_stopper_thread+0x71/0x100 [ 176.900393] [] ? finish_task_switch+0x34/0xd0 [ 176.900393] [] ? __schedule+0x23d/0x7f0 [ 176.900393] [] ? __wake_up_common+0x44/0x70 [ 176.900393] [] ? _raw_spin_lock_irqsave+0x12/0x60 [ 176.900393] [] ? smpboot_thread_fn+0xd2/0x170 [ 176.900393] [] ? SyS_setgroups+0x110/0x110 [ 176.900393] [] ? kthread+0xa1/0xc0 [ 176.900393] [] ? ret_from_kernel_thread+0x21/0x30 [ 176.900393] [] ? kthread_create_on_node+0x120/0x120 [ 176.900393] ---[ end trace b38596d5cfdcde8d ]--- and during restore: [ 176.900393] WARNING: CPU: 0 PID: 9 at arch/x86/xen/enlighten.c:968 lapic_resume+0xc6/0x270() [ 176.900393] Modules linked in: cfg80211 rfkill nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc evdev x86_pkg_temp_thermal thermal_sys snd_pcm coretemp snd_timer crc32_pclmul aesni_intel snd xts soundcore aes_i586 lrw gf128mul ablk_helper pcspkr cryptd fuse autofs4 ext4 crc16 mbcache jbd2 crc32c_intel [ 176.900393] CPU: 0 PID: 9 Comm: migration/0 Tainted: G W 3.18.0-rc5 #30 [ 176.900393] 00000009 c14c40b2 00000000 c1054b10 c1599538 00000000 00000009 c158bdc2 [ 176.900393] 000003c8 c103c1e6 c103c1e6 000003c8 c1030020 00000002 0000001b 00000000 [ 176.900393] c1054bd9 00000009 00000000 c103c1e6 00000000 c16432c0 0108cdfe c15d25dc [ 176.900393] Call Trace: [ 176.900393] [] ? dump_stack+0x3e/0x4e [ 176.900393] [] ? warn_slowpath_common+0x90/0xc0 [ 176.900393] [] ? lapic_resume+0xc6/0x270 [ 176.900393] [] ? lapic_resume+0xc6/0x270 [ 176.900393] [] ? mcheck_cpu_init+0x170/0x4f0 [ 176.900393] [] ? warn_slowpath_null+0x19/0x20 [ 176.900393] [] ? lapic_resume+0xc6/0x270 [ 176.900393] [] ? syscore_resume+0x46/0x160 [ 176.900393] [] ? xen_timer_resume+0x42/0x60 [ 176.900393] [] ? xen_suspend+0x7c/0x110 [ 176.900393] [] ? multi_cpu_stop+0xa9/0xd0 [ 176.900393] [] ? cpu_stop_should_run+0x50/0x50 [ 176.900393] [] ? cpu_stopper_thread+0x71/0x100 [ 176.900393] [] ? finish_task_switch+0x34/0xd0 [ 176.900393] [] ? __schedule+0x23d/0x7f0 [ 176.900393] [] ? __wake_up_common+0x44/0x70 [ 176.900393] [] ? _raw_spin_lock_irqsave+0x12/0x60 [ 176.900393] [] ? smpboot_thread_fn+0xd2/0x170 [ 176.900393] [] ? SyS_setgroups+0x110/0x110 [ 176.900393] [] ? kthread+0xa1/0xc0 [ 176.900393] [] ? ret_from_kernel_thread+0x21/0x30 [ 176.900393] [] ? kthread_create_on_node+0x120/0x120 [ 176.900393] ---[ end trace b38596d5cfdcde93 ]--- While this seems not to be critical (the system is running after the restore) I assume disabling/enabling a local APIC on a pv-domain isn't something we want to happen... Juergen