Lock reservations with a dedicated lock in each reservation. Protect the

vmd_free_count with atomics.

This allows us to allocate and free from reservations without the free lock
except where a superpage is allocated from the physical layer, which is
roughly 1/512 of the operations on amd64.

Use the counter api to eliminate cache conention on counters.

Reviewed by:	markj
Tested by:	pho
Sponsored by:	Netflix, Dell/EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D14707

1 files changed, 1 insertions, 18 deletions

diff --git a/sys/vm/vm_pagequeue.h b/sys/vm/vm_pagequeue.h
index b13657072717..894b4b57d31b 100644
--- a/sys/vm/vm_pagequeue.h
+++ b/sys/vm/vm_pagequeue.h
@@ -180,7 +180,7 @@ vm_pagequeue_cnt_add(struct vm_pagequeue *pq, int addend)
 
 void vm_domain_set(struct vm_domain *vmd);
 void vm_domain_clear(struct vm_domain *vmd);
-int vm_domain_available(struct vm_domain *vmd, int req, int npages);
+int vm_domain_allocate(struct vm_domain *vmd, int req, int npages);
 
 /*
  *      vm_pagequeue_domain:
@@ -266,22 +266,5 @@ vm_domain_freecnt_inc(struct vm_domain *vmd, int adj)
 		vm_domain_clear(vmd);
 }
 
-static inline void
-vm_domain_freecnt_dec(struct vm_domain *vmd, int adj)
-{
-	u_int old, new;
-
-	old = atomic_fetchadd_int(&vmd->vmd_free_count, -adj);
-	new = old - adj;
-	KASSERT(new >= 0, ("vm_domain_freecnt_dec: free count underflow"));
-	if (vm_paging_needed(vmd, new) && !vm_paging_needed(vmd, old))
-		pagedaemon_wakeup(vmd->vmd_domain);
-	/* Only update bitsets on transitions. */
-	if ((old >= vmd->vmd_free_min && new < vmd->vmd_free_min) ||
-	    (old >= vmd->vmd_free_severe && new < vmd->vmd_free_severe))
-		vm_domain_set(vmd);
-}
-
-
 #endif	/* _KERNEL */
 #endif				/* !_VM_PAGEQUEUE_ */