The following oops' occur with the new -rt kernel (branch standard/preempt-rt/intel) with an intel-corei7-64 MACHINE: [ 6.845236] ------------[ cut here ]------------ [ 6.845253] ------------[ cut here ]------------ [ 6.845277] WARNING: CPU: 1 PID: 491 at /home/pokybuild/yocto-autobuilder/yocto-worker/intel-corei7-64-rt/build/build/tmp/work-shared/intel-cor ei7-64/kernel-source/kernel/sched/core.c:3384 migrate_disable+0xef/0x100 [ 6.845285] Modules linked in: [ 6.845296] CPU: 1 PID: 491 Comm: udhcpc Not tainted 4.8.0-rc7-rt1-yocto-preempt-rt #1 [ 6.845301] Hardware name: ADI Minnowboard Turbot D0 PLATFORM/MinnowBoard Turbot, BIOS MNW2MAX1.X64.0090.R01.1603151016 03/15/2016 [ 6.845318] 0000000000000000 ffff8800378e7a38 ffffffff814061ef 0000000000000000 [ 6.845330] 0000000000000000 ffff8800378e7a78 ffffffff8107b344 00000d38000ce5b4 [ 6.845341] ffff880037a754c0 0000000000000034 0000000000000034 ffffffff820cce40 [ 6.845344] Call Trace: [ 6.845362] [<ffffffff814061ef>] dump_stack+0x4f/0x70 [ 6.845374] [<ffffffff8107b344>] __warn+0xe4/0x100 [ 6.845385] [<ffffffff8107b42d>] warn_slowpath_null+0x1d/0x20 [ 6.845393] [<ffffffff810a0f4f>] migrate_disable+0xef/0x100 [ 6.845406] [<ffffffff810c9a6a>] call_console_drivers.isra.21.constprop.30+0xda/0x160 [ 6.845417] [<ffffffff810cae62>] console_unlock+0x252/0x630 [ 6.845428] [<ffffffff810cb4bf>] vprintk_emit+0x27f/0x500 [ 6.845439] [<ffffffff810a108f>] ? migrate_enable+0x12f/0x170 [ 6.845449] [<ffffffff810cb8af>] vprintk_default+0x1f/0x30 [ 6.845459] [<ffffffff8114e566>] printk+0x48/0x50 [ 6.845471] [<ffffffff81869147>] ? __alloc_skb+0x97/0x1c0 [ 6.845479] [<ffffffff810a108f>] ? migrate_enable+0x12f/0x170 [ 6.845489] [<ffffffff8107b299>] __warn+0x39/0x100 [ 6.845499] [<ffffffff8107b42d>] warn_slowpath_null+0x1d/0x20 [ 6.845507] [<ffffffff810a108f>] migrate_enable+0x12f/0x170 [ 6.845519] [<ffffffff819ed607>] rt_spin_unlock+0x27/0x40 [ 6.845528] [<ffffffff81880725>] __dev_queue_xmit+0x415/0x690 [ 6.845538] [<ffffffff818809b0>] dev_queue_xmit+0x10/0x20 [ 6.845549] [<ffffffff8196c0a7>] packet_sendmsg+0xb87/0x13e0 [ 6.845560] [<ffffffff819eaf1a>] ? wait_for_completion+0x3a/0xd0 [ 6.845572] [<ffffffff810d529c>] ? __wait_rcu_gp+0xac/0xd0 [ 6.845588] [<ffffffff81860ecf>] SYSC_sendto+0xff/0x180 [ 6.845603] [<ffffffff811d5ec5>] ? fd_install+0x25/0x30 [ 6.845612] [<ffffffff8185fd54>] ? sock_map_fd+0x44/0x70 [ 6.845624] [<ffffffff8186156e>] SyS_sendto+0xe/0x10 [ 6.845633] [<ffffffff819ed8db>] entry_SYSCALL_64_fastpath+0x13/0x8f [ 6.845641] ---[ end trace 0000000000000002 ]--- [ 7.245277] WARNING: CPU: 1 PID: 491 at /home/pokybuild/yocto-autobuilder/yocto-worker/intel-corei7-64-rt/build/build/tmp/work-shared/intel-cor ei7-64/kernel-source/kernel/sched/core.c:3415 migrate_enable+0x12f/0x170 [ 7.273397] Modules linked in: [ 7.280198] CPU: 1 PID: 491 Comm: udhcpc Tainted: G W 4.8.0-rc7-rt1-yocto-preempt-rt #1 [ 7.280200] Hardware name: ADI Minnowboard Turbot D0 PLATFORM/MinnowBoard Turbot, BIOS MNW2MAX1.X64.0090.R01.1603151016 03/15/2016 [ 7.280206] 0000000000000000 ffff8800378e7c18 ffffffff814061ef 0000000000000000 [ 7.280211] 0000000000000000 ffff8800378e7c58 ffffffff8107b344 00000d578107cea0 [ 7.280215] ffff880037a754c0 0000000000000002 ffff8800372db600 ffffffff81f00b20 [ 7.280216] Call Trace: [ 7.280223] [<ffffffff814061ef>] dump_stack+0x4f/0x70 [ 7.280227] [<ffffffff8107b344>] __warn+0xe4/0x100 [ 7.280231] [<ffffffff8107b42d>] warn_slowpath_null+0x1d/0x20 [ 7.280234] [<ffffffff810a108f>] migrate_enable+0x12f/0x170 [ 7.280239] [<ffffffff819ed607>] rt_spin_unlock+0x27/0x40 [ 7.280242] [<ffffffff81880725>] __dev_queue_xmit+0x415/0x690 [ 7.280246] [<ffffffff818809b0>] dev_queue_xmit+0x10/0x20 [ 7.280250] [<ffffffff8196c0a7>] packet_sendmsg+0xb87/0x13e0 [ 7.280254] [<ffffffff819eaf1a>] ? wait_for_completion+0x3a/0xd0 [ 7.280258] [<ffffffff810d529c>] ? __wait_rcu_gp+0xac/0xd0 [ 7.280264] [<ffffffff81860ecf>] SYSC_sendto+0xff/0x180 [ 7.280269] [<ffffffff811d5ec5>] ? fd_install+0x25/0x30 [ 7.280273] [<ffffffff8185fd54>] ? sock_map_fd+0x44/0x70 [ 7.280277] [<ffffffff8186156e>] SyS_sendto+0xe/0x10 [ 7.280280] [<ffffffff819ed8db>] entry_SYSCALL_64_fastpath+0x13/0x8f [ 7.280315] ---[ end trace 0000000000000003 ]--- This is from a MinnowBoard Turbot, but I have also reproduced it on the NUC6.
I don't have any hardware to reproduce this. Qemux86* is booting fine.
Can you attach your local.conf and bblayers.conf? And I think you have some local changes in meta-intel that are not on master branch. Currently there is no 4.8-rt bbappend in meta-intel ; just the 4.1 and 4.4 versions so this currently isn't even a valid bug. I had to hack around and put COMPATIBLE_MACHINE_corei7-64-intel-common = "${MACHINE}" into my local.conf but now I've not no confidence I'm building and configuring what you were. Also please include full dmesg output showing the kernel bootargs ; at the moment I'm guessing you were using NFS root due to the relatively early timestamps on the kernel messages -- but again I don't want to have to guess at the relevant steps in attempting to create a reproducer so I can test any prospective fix(es).
Created attachment 3448 [details] dmesg log
Created attachment 3449 [details] local.conf
Created attachment 3450 [details] bblayers.conf
My changes that add the 4.8 preempt-rt kernel recipe are here: https://git.yoctoproject.org/cgit/cgit.cgi/meta-intel-contrib/log/?h=clsulliv/master-test This was originally found building on the autobuilder, but I also verified it occurs with the above local.conf and bblayers.conf in a local build.
I believe I've an understanding of the issue here; it is fixed by dropping a patch from the -rt series as I did here: https://git.kernel.org/cgit/linux/kernel/git/paulg/4.8-rt-patches.git/commit/?h=v4.8-rt Bruce has integrated the above change into the 4.8 kernel release he just did.
As of Bruce's integration patch I can confirm this no longer occurs. https://git.yoctoproject.org/cgit/cgit.cgi/linux-yocto-4.8/commit/?h=standard/preempt-rt/base&id=cd97b2cf4bc73316204a5148d2b0f5fc5d2ecc19