diff options
Diffstat (limited to 'sys/conf/NOTES')
| -rw-r--r-- | sys/conf/NOTES | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/sys/conf/NOTES b/sys/conf/NOTES index 60300f5ba927..43a870906202 100644 --- a/sys/conf/NOTES +++ b/sys/conf/NOTES @@ -196,12 +196,16 @@ options MUTEX_WAKE_ALL # SMP Debugging Options: # +# PREEMPTION allows the threads that are in the kernel to be preempted +# by higher priority threads. It helps with interactivity and +# allows interrupt threads to run sooner rather than waiting. +# WARNING! Only tested on alpha, amd64, and i386. # FULL_PREEMPTION instructs the kernel to preempt non-realtime kernel # threads. It sole use is to expose race conditions and other # bugs during development. Enabling this option will reduce # performance and increase the frequency of kernel panics by # design. If you aren't sure that you need it then you don't. -# DON'T TURN THIS ON. +# Relies on the PREEMPTION option. DON'T TURN THIS ON. # MUTEX_DEBUG enables various extra assertions in the mutex code. # SLEEPQUEUE_PROFILING enables rudimentary profiling of the hash table # used to hold active sleep queues. @@ -213,6 +217,7 @@ options MUTEX_WAKE_ALL # a lock hierarchy violation occurs or if locks are held when going to # sleep. # WITNESS_SKIPSPIN disables the witness checks on spin mutexes. +options PREEMPTION options FULL_PREEMPTION options MUTEX_DEBUG options WITNESS |