On -rt, allocators don't work from atomic context any more,
and the maximum size of the array is known at compile time.

Call trace on a -rt kernel:

oprofile: using NMI interrupt.
BUG: sleeping function called from invalid context at kernel/rtmutex.c:645
in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: kworker/0:1
Pid: 0, comm: kworker/0:1 Tainted: G         C  3.0.0-rt3-patser+ #39
Call Trace:
 <IRQ>  [<ffffffff8103fc0a>] __might_sleep+0xca/0xf0
 [<ffffffff8160d424>] rt_spin_lock+0x24/0x40
 [<ffffffff811476c7>] __kmalloc+0xc7/0x370
 [<ffffffffa0275c85>] ? ppro_setup_ctrs+0x215/0x260 [oprofile]
 [<ffffffffa0273de0>] ? oprofile_cpu_notifier+0x60/0x60 [oprofile]
 [<ffffffffa0275c85>] ppro_setup_ctrs+0x215/0x260 [oprofile]
 [<ffffffffa0273de0>] ? oprofile_cpu_notifier+0x60/0x60 [oprofile]
 [<ffffffffa0273de0>] ? oprofile_cpu_notifier+0x60/0x60 [oprofile]
 [<ffffffffa0273ea4>] nmi_cpu_setup+0xc4/0x110 [oprofile]
 [<ffffffff81094455>] generic_smp_call_function_interrupt+0x95/0x190
 [<ffffffff8101df77>] smp_call_function_interrupt+0x27/0x40
 [<ffffffff81615093>] call_function_interrupt+0x13/0x20
 <EOI>  [<ffffffff8131d0c4>] ? plist_check_head+0x54/0xc0
 [<ffffffff81371fe8>] ? intel_idle+0xc8/0x120
 [<ffffffff81371fc7>] ? intel_idle+0xa7/0x120
 [<ffffffff814a57b0>] cpuidle_idle_call+0xb0/0x230
 [<ffffffff810011db>] cpu_idle+0x8b/0xe0
 [<ffffffff815fc82f>] start_secondary+0x1d3/0x1d8
Signed-off-by: Maarten Lankhorst <m.b.lankhorst@gmail.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>