slub: BUG: Invalid wait context

[Jens Axboe]

Hi,

Booting current -git yields the below splat. I'm assuming this is
related to the new RT stuff, where spin_lock() can sleep. This obviously
won't fly off IPI.

I'll leave the actual fix to others.

[    1.430398] =============================
[    1.430398] [ BUG: Invalid wait context ]
[    1.430398] 5.14.0+ #11360 Not tainted
[    1.430398] -----------------------------
[    1.430533] swapper/0/0 is trying to lock:
[    1.430743] ffff888100050918 (&n->list_lock){....}-{3:3}, at: deactivate_slab+0x213/0x540
[    1.431171] other info that might help us debug this:
[    1.431430] context-{2:2}
[    1.431567] no locks held by swapper/0/0.
[    1.431774] stack backtrace:
[    1.431923] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.14.0+ #11360
[    1.432246] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[    1.432826] Call Trace:
[    1.432961]  <IRQ>
[    1.433071]  dump_stack_lvl+0x45/0x59
[    1.433273]  __lock_acquire.cold+0x21a/0x34d
[    1.433504]  ? lock_chain_count+0x20/0x20
[    1.433722]  ? lockdep_hardirqs_on_prepare+0x1f0/0x1f0
[    1.433990]  ? __lock_acquire+0x86b/0x30b0
[    1.434206]  lock_acquire+0x157/0x3e0
[    1.434399]  ? deactivate_slab+0x213/0x540
[    1.434615]  ? lock_release+0x410/0x410
[    1.434815]  ? lockdep_hardirqs_on_prepare+0x1f0/0x1f0
[    1.435081]  ? mark_held_locks+0x65/0x90
[    1.435286]  ? lock_is_held_type+0x98/0x110
[    1.435509]  ? lock_is_held_type+0x98/0x110
[    1.435728]  _raw_spin_lock+0x2c/0x40
[    1.435922]  ? deactivate_slab+0x213/0x540
[    1.436136]  deactivate_slab+0x213/0x540
[    1.436341]  ? sched_clock_tick+0x49/0x80
[    1.436556]  ? lock_is_held_type+0x98/0x110
[    1.436774]  flush_cpu_slab+0x34/0x50
[    1.436966]  flush_smp_call_function_queue+0xf6/0x2c0
[    1.437228]  ? slub_cpu_dead+0xe0/0xe0
[    1.437426]  __sysvec_call_function_single+0x6b/0x280
[    1.437691]  sysvec_call_function_single+0x65/0x90
[    1.437940]  </IRQ>
[    1.438053]  asm_sysvec_call_function_single+0xf/0x20
[    1.438314] RIP: 0010:default_idle+0x10/0x20
[    1.438539] Code: ff f0 80 63 02 df 5b 41 5c c3 0f ae f0 0f ae 3b 0f ae f0 eb 90 0f 1f 44 00 00 0f 1f 44 00 00 eb 07 0f 00 2d 92 5d 45 00 fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 0f 1f 44 00 00 41
[    1.439481] RSP: 0000:ffffffff82a07e60 EFLAGS: 00000206
[    1.439605] RAX: 0000000000001811 RBX: ffffffff82a1f400 RCX: ffffffff81dbddc5
[    1.439605] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff81dce145
[    1.439605] RBP: 0000000000000000 R08: 0000000000000001 R09: ffff8881f7630b0b
[    1.439605] R10: ffffed103eec6161 R11: 0000000000000000 R12: ffffffff8306c7b0
[    1.439605] R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff0540fd1
[    1.439605]  ? rcu_eqs_enter.constprop.0+0xa5/0xc0
[    1.439605]  ? default_idle_call+0x45/0xb0
[    1.439605]  default_idle_call+0x7d/0xb0
[    1.439605]  do_idle+0x31c/0x3d0
[    1.439605]  ? lock_downgrade+0x390/0x390
[    1.439605]  ? arch_cpu_idle_exit+0x40/0x40
[    1.439605]  cpu_startup_entry+0x19/0x20
[    1.439605]  start_kernel+0x38d/0x3ab
[    1.439605]  secondary_startup_64_no_verify+0xb0/0xbb


-- 
Jens Axboe