Kernel threads are cooperative and yield. I'd argue that preempt()
should be kept for user processes hogging CPUs. So let's be coherent
with the rest of the kernel and use sched_pause() here. ok?
Index: uvm/uvm_glue.c
===================================================================
RCS file: /cvs/src/sys/uvm/uvm_glue.c,v
retrieving revision 1.70
diff -u -p -r1.70 uvm_glue.c
--- uvm/uvm_glue.c 13 Sep 2015 17:08:03 -0000 1.70
+++ uvm/uvm_glue.c 6 Jul 2016 16:18:49 -0000
@@ -473,8 +473,7 @@ uvm_pause(void)
KERNEL_UNLOCK();
KERNEL_LOCK();
}
- if (curcpu()->ci_schedstate.spc_schedflags & SPCF_SHOULDYIELD)
- preempt(NULL);
+ sched_pause();
}
#ifndef SMALL_KERNEL
