Raise "uvm_map_entry_kmem_pool" IPL level to IPL_VM to prevent a deadlock.

A deadlock can occur when the uvm_km_thread(), running without KERNEL_LOCK()
is interrupted by and non-MPSAFE handler while holding the pool's mutex.  At
that moment if another CPU is holding the KERNEL_LOCK() and wants to grab the
pool mutex, like in sys_kbind(), kaboom!

This is a temporaty solution, a more generate approach regarding mutexes and
un-KERNEL_LOCK()ed threads is beeing discussed.

Deadlock reported by sthen@, ok kettenis@

0 files changed, 0 insertions, 0 deletions