Implement idle zeroing of pages. I've been tinkering with this

on and off since John Dyson left his work-in-progress.

It is off by default for now.  sysctl vm.zeroidle_enable=1 to turn it on.

There are some hacks here to deal with the present lack of preemption - we
yield after doing a small number of pages since we wont preempt otherwise.

This is basically Matt's algorithm [with hysteresis] with an idle process
to call it in a similar way it used to be called from the idle loop.

I cleaned up the includes a fair bit here too.

1 files changed, 1 insertions, 0 deletions

diff --git a/sys/vm/vm_page.h b/sys/vm/vm_page.h
index c31aa49..a2e67df 100644
--- a/sys/vm/vm_page.h
+++ b/sys/vm/vm_page.h
@@ -386,6 +386,7 @@ int vm_page_asleep(vm_page_t m, char *msg, char *busy);
 #endif
 void vm_page_zero_invalid(vm_page_t m, boolean_t setvalid);
 void vm_page_free_toq(vm_page_t m);
+void vm_page_zero_idle_wakeup(void);
 
 #endif				/* _KERNEL */
 #endif				/* !_VM_PAGE_ */