Hi all !
I wanted to try PREEMPT_RT. I added the support for it:
diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index c7880f375518..b0360167574d 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -39,6 +39,7 @@ config M68K
select OLD_SIGSUSPEND3
select UACCESS_MEMCPY if !MMU
select ZONE_DMA
+ select ARCH_SUPPORTS_RT
config CPU_BIG_ENDIAN
def_bool y
And set PREEMPT_RT then it fails to boot:
[ 6.517000] BUG: scheduling while atomic: init/1/0x00010001
[ 6.518000] Modules linked in:
[ 6.519000] CPU: 0 PID: 1 Comm: init Not tainted
6.10.0-g82c151ee715b-dirty #161
[ 6.519000] Stack from 4186dc60:
[ 6.519000] 4186dc60 414ad356 414ad356 00000001 418a0010
418a0010 413a1e6a 414ad356
[ 6.519000] 41025098 41483229 414831fb 418a0306 00000001
00010001 4186dcc4 413a2ef8
[ 6.519000] 418a0010 4186dd1c 418a0010 4186c000 413a500a
4186c000 413a2ea6 413a6934
[ 6.519000] 4102c98e 4186dcd8 413a3616 00000002 4186c000
415e9180 4186dd5c 413a7312
[ 6.519000] 00002700 00000000 00000001 413a500a d0af2266
41f31552 4186c000 415e9180
[ 6.519000] 4102e7b4 415e9180 418a0011 00000001 415e9180
413a67c6 00000000 4186dd1c
[ 6.519000] Call Trace: [<413a1e6a>] dump_stack+0xc/0x10
[ 6.519000] [<41025098>] __schedule_bug+0x50/0x64
[ 6.519000] [<413a2ef8>] __schedule+0x52/0x4ce
[ 6.519000] [<413a500a>] mutex_unlock+0x0/0x6
[ 6.519000] [<413a2ea6>] __schedule+0x0/0x4ce
[ 6.519000] [<413a6934>] try_to_take_rt_mutex+0x0/0x1ee
[ 6.519000] [<4102c98e>] __wake_up_common_lock+0x36/0x46
[ 6.519000] [<413a3616>] schedule_rtlock+0x26/0x46
[ 6.519000] [<413a7312>] rtlock_slowlock_locked+0x5f2/0x8e2
[ 6.519000] [<413a500a>] mutex_unlock+0x0/0x6
[ 6.519000] [<4102e7b4>] arch_local_irq_disable+0x0/0xc
[ 6.519000] [<413a67c6>] rt_spin_unlock+0x1c/0x48
[ 6.519000] [<412207ae>] uart_port_dtr_rts+0x18/0x26
[ 6.519000] [<41208ffc>] tty_driver_kref_put+0x0/0x10
[ 6.519000] [<412103f6>] tty_port_raise_dtr_rts+0x18/0x1c
[ 6.519000] [<413a76ec>] rt_spin_lock+0x42/0x7a
[ 6.519000] [<4122059c>] uart_insert_char+0x0/0x78
[ 6.519000] [<410340dc>] __irq_wake_thread+0x0/0x44
[ 6.519000] [<41223e10>] mcf_interrupt+0x28/0x266
[ 6.519000] [<413a500a>] mutex_unlock+0x0/0x6
[ 6.519000] [<410340dc>] __irq_wake_thread+0x0/0x44
[ 6.519000] [<41034156>] __handle_irq_event_percpu+0x36/0xc6
[ 6.519000] [<41220b76>] uart_port_deref+0x0/0x34
[ 6.519000] [<41036be4>] irqd_irq_disabled.isra.0+0x0/0xc
[ 6.519000] [<410341f6>] handle_irq_event_percpu+0x10/0x40
[ 6.519000] [<4103426e>] handle_irq_event+0x48/0x6e
[ 6.519000] [<41037756>] handle_level_irq+0x9a/0xd2
[ 6.519000] [<41220b76>] uart_port_deref+0x0/0x34
[ 6.519000] [<413a67aa>] rt_spin_unlock+0x0/0x48
[ 6.519000] [<41033b7e>] handle_irq_desc+0x1e/0x28
[ 6.519000] [<410036e2>] do_IRQ+0x22/0x34
[ 6.519000] [<410060ce>] inthandler+0x36/0x40
[ 6.519000] [<413a500a>] mutex_unlock+0x0/0x6
[ 6.519000] [<413a67aa>] rt_spin_unlock+0x0/0x48
[ 6.519000] [<4122140e>] uart_write+0x98/0xae
[ 6.519000] [<4120d1ae>] n_tty_write+0x232/0x362
[ 6.519000] [<4119bef6>] iov_iter_revert+0x0/0xb6
[ 6.519000] [<4102cbf0>] woken_wake_function+0x0/0x2e
[ 6.519000] [<412093c0>] signal_pending+0x0/0x22
[ 6.519000] [<4120a4ec>] file_tty_write.constprop.0+0x156/0x1c0
[ 6.519000] [<410aff7e>] vfs_write+0x104/0x164
[ 6.519000] [<410b00f6>] ksys_write+0x62/0x9e
[ 6.519000] [<410b0132>] sys_write+0x0/0x18
[ 6.519000] [<410b0144>] sys_write+0x12/0x18
[ 6.519000] [<41005fa4>] system_call+0x54/0xa8
[ 6.519000]
[ 6.520000] ------------[ cut here ]------------
[ 6.520000] WARNING: CPU: 0 PID: 0 at kernel/context_tracking.c:128
ct_kernel_exit.constprop.0+0x34/0x74
[ 6.520000] Modules linked in:
[ 6.520000] CPU: 0 PID: 0 Comm: swapper Tainted: G W
6.10.0-g82c151ee715b-dirty #161
[ 6.520000] Stack from 41509ef8:
[ 6.520000] 41509ef8 414ad356 414ad356 00000000 00000009
413997d2 413a1e6a 414ad356
[ 6.520000] 4139919c 4147f834 413a2700 41487ce2 41582928
41028f28 41009894 41487ce2
[ 6.520000] 00000080 413a2604 00000009 00000000 00000000
413a2776 00000000 4101f954
[ 6.520000] 00000001 00000002 41508000 418a0010 41508000
413a27b0 413a2604 41487ce2
[ 6.520000] 00000080 00000009 00000000 413a27c8 4102ad8a
00000002 4102ad24 4101e6f6
[ 6.520000] 4103b6ca 41509ff8 4102afda 4103f09c 413a287c
000000ec 415b524a 418740b0
[ 6.520000] Call Trace: [<413997d2>] _printk+0x0/0x18
[ 6.520000] [<413a1e6a>] dump_stack+0xc/0x10
[ 6.520000] [<4139919c>] __warn+0x74/0xc2
[ 6.520000] [<413a2700>] ct_nmi_enter+0x14/0x7e
[ 6.520000] [<41028f28>] arch_local_irq_disable+0x0/0xc
[ 6.520000] [<41009894>] warn_slowpath_fmt+0x6e/0xc6
[ 6.520000] [<413a2604>] ct_kernel_exit.constprop.0+0x34/0x74
[ 6.520000] [<413a2776>] cpu_idle_poll.isra.0+0x0/0x3a
[ 6.520000] [<4101f954>] parse_args+0x0/0x31a
[ 6.520000] [<413a27b0>] default_idle_call+0x0/0x2a
[ 6.520000] [<413a2604>] ct_kernel_exit.constprop.0+0x34/0x74
[ 6.520000] [<413a27c8>] default_idle_call+0x18/0x2a
[ 6.520000] [<4102ad8a>] do_idle+0x66/0x9e
[ 6.520000] [<4102ad24>] do_idle+0x0/0x9e
[ 6.520000] [<4101e6f6>] find_task_by_pid_ns+0x0/0x1e
[ 6.520000] [<4103b6ca>] __rcu_read_lock+0x0/0xc
[ 6.520000] [<4102afda>] cpu_startup_entry+0x14/0x16
[ 6.520000] [<4103f09c>] __rcu_read_unlock+0x0/0x106
[ 6.520000] [<413a287c>] kernel_init+0x0/0xf6
[ 6.520000] [<41392654>] strlen+0x0/0x14
[ 6.520000] [<41398ba0>] arch_local_irq_disable+0x0/0xc
[ 6.520000] [<415a29c8>] console_on_rootfs+0x0/0x58
[ 6.520000] [<41003100>] _exit+0x0/0x4
Any idea, thoughts :-) ?
Thanks a lot !
JM
