[LITMUS^RT] prop/sched-domains

[Björn Brandenburg]

Hi Glenn,

I’m seeing warnings that seem to be related to the sched-domain patch. This happens when I activate the P-FP plugin and requires LOCKDEP to be active.

litmus-rt login: Switching to LITMUS^RT plugin P-FP.
------------[ cut here ]------------
WARNING: at kernel/lockdep.c:2740 lockdep_trace_alloc+0xec/0x100()
DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags))
CPU: 0 PID: 7 Comm: migration/0 Not tainted 3.10.5-litmus2013.1+ #1122
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
 ffffffff81682f05 ffff88007a125aa8 ffffffff8150e94e ffff88007a125ae8
 ffffffff81033f76 ffff88007a125ad8 0000000000000046 ffff88007a0db210
 00000000000080d0 00000000000080d0 00000000000000b2 ffff88007a125b48
Call Trace:
 [<ffffffff8150e94e>] dump_stack+0x19/0x1b
 [<ffffffff81033f76>] warn_slowpath_common+0x66/0x90
 [<ffffffff81034041>] warn_slowpath_fmt+0x41/0x50
 [<ffffffff8107f56c>] lockdep_trace_alloc+0xec/0x100
 [<ffffffff810fa82c>] __kmalloc+0x4c/0x1d0
 [<ffffffff81155ae2>] ? __proc_create+0xb2/0x120
 [<ffffffff81155ae2>] __proc_create+0xb2/0x120
 [<ffffffff811565bc>] proc_create_data+0x8c/0xc0
 [<ffffffff81265e8a>] activate_domain_proc+0xca/0x150
 [<ffffffff812646a1>] do_plugin_switch+0x61/0xc0
 [<ffffffff8108c4a2>] stop_machine_cpu_stop+0xb2/0x150
 [<ffffffff8108c3f0>] ? queue_stop_cpus_work+0x160/0x160
 [<ffffffff8108c00d>] cpu_stopper_thread+0x8d/0x170
 [<ffffffff81512625>] ? _raw_spin_unlock_irqrestore+0x65/0x80
 [<ffffffff81060aae>] smpboot_thread_fn+0x1ce/0x310
 [<ffffffff810608e0>] ? smpboot_register_percpu_thread+0xe0/0xe0
 [<ffffffff810583a6>] kthread+0xd6/0xe0
 [<ffffffff81066175>] ? schedule_tail+0xd5/0x210
 [<ffffffff810582d0>] ? __init_kthread_worker+0x70/0x70
 [<ffffffff8151346c>] ret_from_fork+0x7c/0xb0
 [<ffffffff810582d0>] ? __init_kthread_worker+0x70/0x70
---[ end trace 2f7c7abc2a2e4492 ]—

It seems the code is somehow calling kmalloc(), which can sleep, with interrupts disabled. I don’t think this is related to rebasing the patch. Can you please have a look?

Thanks,
Björn