fix:
[ 0.184011] ------------[ cut here ]------------
[ 0.188011] WARNING: at kernel/fork.c:918 copy_process+0x1c0/0x1084()
[ 0.192011] Pid: 0, comm: swapper Not tainted 2.6.26-tip-00351-g01d4a50-dirty #14521
[ 0.196011] [<
c0135d48>] warn_on_slowpath+0x3c/0x60
[ 0.200012] [<
c016f805>] ? __alloc_pages_internal+0x92/0x36b
[ 0.208012] [<
c033de5e>] ? __spin_lock_init+0x24/0x4a
[ 0.212012] [<
c01347e3>] copy_process+0x1c0/0x1084
[ 0.216013] [<
c013575f>] do_fork+0xb8/0x1ad
[ 0.220013] [<
c034f75e>] ? acpi_os_release_lock+0x8/0xa
[ 0.228013] [<
c034ff7a>] ? acpi_os_vprintf+0x20/0x24
[ 0.232014] [<
c01129ee>] kernel_thread+0x75/0x7d
[ 0.236014] [<
c0a491eb>] ? kernel_init+0x0/0x24a
[ 0.240014] [<
c0a491eb>] ? kernel_init+0x0/0x24a
[ 0.244014] [<
c01151b0>] ? kernel_thread_helper+0x0/0x10
[ 0.252015] [<
c06c6ac0>] rest_init+0x14/0x50
[ 0.256015] [<
c0a498ce>] start_kernel+0x2b9/0x2c0
[ 0.260015] [<
c0a4904f>] __init_begin+0x4f/0x57
[ 0.264016] =======================
[ 0.268016] ---[ end trace
4eaa2a86a8e2da22 ]---
[ 0.272016] enabled ExtINT on CPU#0
which occurs if CONFIG_TRACE_IRQFLAGS=y, CONFIG_DEBUG_LOCKDEP=y,
but CONFIG_PROVE_LOCKING is disabled.
Signed-off-by: Ingo Molnar <mingo@elte.hu>