Index: head/sys/vm/vm_kern.c
===================================================================
--- head/sys/vm/vm_kern.c	(revision 364819)
+++ head/sys/vm/vm_kern.c	(revision 364820)
@@ -1,885 +1,899 @@
 /*-
  * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
  *
  * Copyright (c) 1991, 1993
  *	The Regents of the University of California.  All rights reserved.
  *
  * This code is derived from software contributed to Berkeley by
  * The Mach Operating System project at Carnegie-Mellon University.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  * 3. Neither the name of the University nor the names of its contributors
  *    may be used to endorse or promote products derived from this software
  *    without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
  *	from: @(#)vm_kern.c	8.3 (Berkeley) 1/12/94
  *
  *
  * Copyright (c) 1987, 1990 Carnegie-Mellon University.
  * All rights reserved.
  *
  * Authors: Avadis Tevanian, Jr., Michael Wayne Young
  *
  * Permission to use, copy, modify and distribute this software and
  * its documentation is hereby granted, provided that both the copyright
  * notice and this permission notice appear in all copies of the
  * software, derivative works or modified versions, and any portions
  * thereof, and that both notices appear in supporting documentation.
  *
  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  *
  * Carnegie Mellon requests users of this software to return to
  *
  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  *  School of Computer Science
  *  Carnegie Mellon University
  *  Pittsburgh PA 15213-3890
  *
  * any improvements or extensions that they make and grant Carnegie the
  * rights to redistribute these changes.
  */
 
 /*
  *	Kernel memory management.
  */
 
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
 #include "opt_vm.h"
 
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/kernel.h>		/* for ticks and hz */
 #include <sys/domainset.h>
 #include <sys/eventhandler.h>
 #include <sys/lock.h>
 #include <sys/proc.h>
 #include <sys/malloc.h>
 #include <sys/rwlock.h>
 #include <sys/sysctl.h>
 #include <sys/vmem.h>
 #include <sys/vmmeter.h>
 
 #include <vm/vm.h>
 #include <vm/vm_param.h>
 #include <vm/vm_domainset.h>
 #include <vm/vm_kern.h>
 #include <vm/pmap.h>
 #include <vm/vm_map.h>
 #include <vm/vm_object.h>
 #include <vm/vm_page.h>
 #include <vm/vm_pageout.h>
 #include <vm/vm_phys.h>
 #include <vm/vm_pagequeue.h>
 #include <vm/vm_radix.h>
 #include <vm/vm_extern.h>
 #include <vm/uma.h>
 
 struct vm_map kernel_map_store;
 struct vm_map exec_map_store;
 struct vm_map pipe_map_store;
 
 const void *zero_region;
 CTASSERT((ZERO_REGION_SIZE & PAGE_MASK) == 0);
 
 /* NB: Used by kernel debuggers. */
 const u_long vm_maxuser_address = VM_MAXUSER_ADDRESS;
 
 u_int exec_map_entry_size;
 u_int exec_map_entries;
 
 SYSCTL_ULONG(_vm, OID_AUTO, min_kernel_address, CTLFLAG_RD,
     SYSCTL_NULL_ULONG_PTR, VM_MIN_KERNEL_ADDRESS, "Min kernel address");
 
 SYSCTL_ULONG(_vm, OID_AUTO, max_kernel_address, CTLFLAG_RD,
 #if defined(__arm__)
     &vm_max_kernel_address, 0,
 #else
     SYSCTL_NULL_ULONG_PTR, VM_MAX_KERNEL_ADDRESS,
 #endif
     "Max kernel address");
 
 #if VM_NRESERVLEVEL > 0
 #define	KVA_QUANTUM_SHIFT	(VM_LEVEL_0_ORDER + PAGE_SHIFT)
 #else
 /* On non-superpage architectures we want large import sizes. */
 #define	KVA_QUANTUM_SHIFT	(8 + PAGE_SHIFT)
 #endif
 #define	KVA_QUANTUM		(1 << KVA_QUANTUM_SHIFT)
+#define	KVA_NUMA_IMPORT_QUANTUM	(KVA_QUANTUM * 128)
 
 extern void     uma_startup2(void);
 
 /*
  *	kva_alloc:
  *
  *	Allocate a virtual address range with no underlying object and
  *	no initial mapping to physical memory.  Any mapping from this
  *	range to physical memory must be explicitly created prior to
  *	its use, typically with pmap_qenter().  Any attempt to create
  *	a mapping on demand through vm_fault() will result in a panic. 
  */
 vm_offset_t
 kva_alloc(vm_size_t size)
 {
 	vm_offset_t addr;
 
 	size = round_page(size);
 	if (vmem_alloc(kernel_arena, size, M_BESTFIT | M_NOWAIT, &addr))
 		return (0);
 
 	return (addr);
 }
 
 /*
  *	kva_free:
  *
  *	Release a region of kernel virtual memory allocated
  *	with kva_alloc, and return the physical pages
  *	associated with that region.
  *
  *	This routine may not block on kernel maps.
  */
 void
 kva_free(vm_offset_t addr, vm_size_t size)
 {
 
 	size = round_page(size);
 	vmem_free(kernel_arena, addr, size);
 }
 
 static vm_page_t
 kmem_alloc_contig_pages(vm_object_t object, vm_pindex_t pindex, int domain,
     int pflags, u_long npages, vm_paddr_t low, vm_paddr_t high,
     u_long alignment, vm_paddr_t boundary, vm_memattr_t memattr)
 {
 	vm_page_t m;
 	int tries;
 	bool wait;
 
 	VM_OBJECT_ASSERT_WLOCKED(object);
 
 	wait = (pflags & VM_ALLOC_WAITOK) != 0;
 	pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL);
 	pflags |= VM_ALLOC_NOWAIT;
 	for (tries = wait ? 3 : 1;; tries--) {
 		m = vm_page_alloc_contig_domain(object, pindex, domain, pflags,
 		    npages, low, high, alignment, boundary, memattr);
 		if (m != NULL || tries == 0)
 			break;
 
 		VM_OBJECT_WUNLOCK(object);
 		if (!vm_page_reclaim_contig_domain(domain, pflags, npages,
 		    low, high, alignment, boundary) && wait)
 			vm_wait_domain(domain);
 		VM_OBJECT_WLOCK(object);
 	}
 	return (m);
 }
 
 /*
  *	Allocates a region from the kernel address map and physical pages
  *	within the specified address range to the kernel object.  Creates a
  *	wired mapping from this region to these pages, and returns the
  *	region's starting virtual address.  The allocated pages are not
  *	necessarily physically contiguous.  If M_ZERO is specified through the
  *	given flags, then the pages are zeroed before they are mapped.
  */
 static vm_offset_t
 kmem_alloc_attr_domain(int domain, vm_size_t size, int flags, vm_paddr_t low,
     vm_paddr_t high, vm_memattr_t memattr)
 {
 	vmem_t *vmem;
 	vm_object_t object;
 	vm_offset_t addr, i, offset;
 	vm_page_t m;
 	int pflags;
 	vm_prot_t prot;
 
 	object = kernel_object;
 	size = round_page(size);
 	vmem = vm_dom[domain].vmd_kernel_arena;
 	if (vmem_alloc(vmem, size, M_BESTFIT | flags, &addr))
 		return (0);
 	offset = addr - VM_MIN_KERNEL_ADDRESS;
 	pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED;
 	prot = (flags & M_EXEC) != 0 ? VM_PROT_ALL : VM_PROT_RW;
 	VM_OBJECT_WLOCK(object);
 	for (i = 0; i < size; i += PAGE_SIZE) {
 		m = kmem_alloc_contig_pages(object, atop(offset + i),
 		    domain, pflags, 1, low, high, PAGE_SIZE, 0, memattr);
 		if (m == NULL) {
 			VM_OBJECT_WUNLOCK(object);
 			kmem_unback(object, addr, i);
 			vmem_free(vmem, addr, size);
 			return (0);
 		}
 		KASSERT(vm_phys_domain(m) == domain,
 		    ("kmem_alloc_attr_domain: Domain mismatch %d != %d",
 		    vm_phys_domain(m), domain));
 		if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0)
 			pmap_zero_page(m);
 		vm_page_valid(m);
 		pmap_enter(kernel_pmap, addr + i, m, prot,
 		    prot | PMAP_ENTER_WIRED, 0);
 	}
 	VM_OBJECT_WUNLOCK(object);
 	return (addr);
 }
 
 vm_offset_t
 kmem_alloc_attr(vm_size_t size, int flags, vm_paddr_t low, vm_paddr_t high,
     vm_memattr_t memattr)
 {
 
 	return (kmem_alloc_attr_domainset(DOMAINSET_RR(), size, flags, low,
 	    high, memattr));
 }
 
 vm_offset_t
 kmem_alloc_attr_domainset(struct domainset *ds, vm_size_t size, int flags,
     vm_paddr_t low, vm_paddr_t high, vm_memattr_t memattr)
 {
 	struct vm_domainset_iter di;
 	vm_offset_t addr;
 	int domain;
 
 	vm_domainset_iter_policy_init(&di, ds, &domain, &flags);
 	do {
 		addr = kmem_alloc_attr_domain(domain, size, flags, low, high,
 		    memattr);
 		if (addr != 0)
 			break;
 	} while (vm_domainset_iter_policy(&di, &domain) == 0);
 
 	return (addr);
 }
 
 /*
  *	Allocates a region from the kernel address map and physically
  *	contiguous pages within the specified address range to the kernel
  *	object.  Creates a wired mapping from this region to these pages, and
  *	returns the region's starting virtual address.  If M_ZERO is specified
  *	through the given flags, then the pages are zeroed before they are
  *	mapped.
  */
 static vm_offset_t
 kmem_alloc_contig_domain(int domain, vm_size_t size, int flags, vm_paddr_t low,
     vm_paddr_t high, u_long alignment, vm_paddr_t boundary,
     vm_memattr_t memattr)
 {
 	vmem_t *vmem;
 	vm_object_t object;
 	vm_offset_t addr, offset, tmp;
 	vm_page_t end_m, m;
 	u_long npages;
 	int pflags;
 
 	object = kernel_object;
 	size = round_page(size);
 	vmem = vm_dom[domain].vmd_kernel_arena;
 	if (vmem_alloc(vmem, size, flags | M_BESTFIT, &addr))
 		return (0);
 	offset = addr - VM_MIN_KERNEL_ADDRESS;
 	pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED;
 	npages = atop(size);
 	VM_OBJECT_WLOCK(object);
 	m = kmem_alloc_contig_pages(object, atop(offset), domain,
 	    pflags, npages, low, high, alignment, boundary, memattr);
 	if (m == NULL) {
 		VM_OBJECT_WUNLOCK(object);
 		vmem_free(vmem, addr, size);
 		return (0);
 	}
 	KASSERT(vm_phys_domain(m) == domain,
 	    ("kmem_alloc_contig_domain: Domain mismatch %d != %d",
 	    vm_phys_domain(m), domain));
 	end_m = m + npages;
 	tmp = addr;
 	for (; m < end_m; m++) {
 		if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0)
 			pmap_zero_page(m);
 		vm_page_valid(m);
 		pmap_enter(kernel_pmap, tmp, m, VM_PROT_RW,
 		    VM_PROT_RW | PMAP_ENTER_WIRED, 0);
 		tmp += PAGE_SIZE;
 	}
 	VM_OBJECT_WUNLOCK(object);
 	return (addr);
 }
 
 vm_offset_t
 kmem_alloc_contig(vm_size_t size, int flags, vm_paddr_t low, vm_paddr_t high,
     u_long alignment, vm_paddr_t boundary, vm_memattr_t memattr)
 {
 
 	return (kmem_alloc_contig_domainset(DOMAINSET_RR(), size, flags, low,
 	    high, alignment, boundary, memattr));
 }
 
 vm_offset_t
 kmem_alloc_contig_domainset(struct domainset *ds, vm_size_t size, int flags,
     vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary,
     vm_memattr_t memattr)
 {
 	struct vm_domainset_iter di;
 	vm_offset_t addr;
 	int domain;
 
 	vm_domainset_iter_policy_init(&di, ds, &domain, &flags);
 	do {
 		addr = kmem_alloc_contig_domain(domain, size, flags, low, high,
 		    alignment, boundary, memattr);
 		if (addr != 0)
 			break;
 	} while (vm_domainset_iter_policy(&di, &domain) == 0);
 
 	return (addr);
 }
 
 /*
  *	kmem_subinit:
  *
  *	Initializes a map to manage a subrange
  *	of the kernel virtual address space.
  *
  *	Arguments are as follows:
  *
  *	parent		Map to take range from
  *	min, max	Returned endpoints of map
  *	size		Size of range to find
  *	superpage_align	Request that min is superpage aligned
  */
 void
 kmem_subinit(vm_map_t map, vm_map_t parent, vm_offset_t *min, vm_offset_t *max,
     vm_size_t size, bool superpage_align)
 {
 	int ret;
 
 	size = round_page(size);
 
 	*min = vm_map_min(parent);
 	ret = vm_map_find(parent, NULL, 0, min, size, 0, superpage_align ?
 	    VMFS_SUPER_SPACE : VMFS_ANY_SPACE, VM_PROT_ALL, VM_PROT_ALL,
 	    MAP_ACC_NO_CHARGE);
 	if (ret != KERN_SUCCESS)
 		panic("kmem_subinit: bad status return of %d", ret);
 	*max = *min + size;
 	vm_map_init(map, vm_map_pmap(parent), *min, *max);
 	if (vm_map_submap(parent, *min, *max, map) != KERN_SUCCESS)
 		panic("kmem_subinit: unable to change range to submap");
 }
 
 /*
  *	kmem_malloc_domain:
  *
  *	Allocate wired-down pages in the kernel's address space.
  */
 static vm_offset_t
 kmem_malloc_domain(int domain, vm_size_t size, int flags)
 {
 	vmem_t *arena;
 	vm_offset_t addr;
 	int rv;
 
 	if (__predict_true((flags & M_EXEC) == 0))
 		arena = vm_dom[domain].vmd_kernel_arena;
 	else
 		arena = vm_dom[domain].vmd_kernel_rwx_arena;
 	size = round_page(size);
 	if (vmem_alloc(arena, size, flags | M_BESTFIT, &addr))
 		return (0);
 
 	rv = kmem_back_domain(domain, kernel_object, addr, size, flags);
 	if (rv != KERN_SUCCESS) {
 		vmem_free(arena, addr, size);
 		return (0);
 	}
 	return (addr);
 }
 
 vm_offset_t
 kmem_malloc(vm_size_t size, int flags)
 {
 
 	return (kmem_malloc_domainset(DOMAINSET_RR(), size, flags));
 }
 
 vm_offset_t
 kmem_malloc_domainset(struct domainset *ds, vm_size_t size, int flags)
 {
 	struct vm_domainset_iter di;
 	vm_offset_t addr;
 	int domain;
 
 	vm_domainset_iter_policy_init(&di, ds, &domain, &flags);
 	do {
 		addr = kmem_malloc_domain(domain, size, flags);
 		if (addr != 0)
 			break;
 	} while (vm_domainset_iter_policy(&di, &domain) == 0);
 
 	return (addr);
 }
 
 /*
  *	kmem_back_domain:
  *
  *	Allocate physical pages from the specified domain for the specified
  *	virtual address range.
  */
 int
 kmem_back_domain(int domain, vm_object_t object, vm_offset_t addr,
     vm_size_t size, int flags)
 {
 	vm_offset_t offset, i;
 	vm_page_t m, mpred;
 	vm_prot_t prot;
 	int pflags;
 
 	KASSERT(object == kernel_object,
 	    ("kmem_back_domain: only supports kernel object."));
 
 	offset = addr - VM_MIN_KERNEL_ADDRESS;
 	pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED;
 	pflags &= ~(VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | VM_ALLOC_WAITFAIL);
 	if (flags & M_WAITOK)
 		pflags |= VM_ALLOC_WAITFAIL;
 	prot = (flags & M_EXEC) != 0 ? VM_PROT_ALL : VM_PROT_RW;
 
 	i = 0;
 	VM_OBJECT_WLOCK(object);
 retry:
 	mpred = vm_radix_lookup_le(&object->rtree, atop(offset + i));
 	for (; i < size; i += PAGE_SIZE, mpred = m) {
 		m = vm_page_alloc_domain_after(object, atop(offset + i),
 		    domain, pflags, mpred);
 
 		/*
 		 * Ran out of space, free everything up and return. Don't need
 		 * to lock page queues here as we know that the pages we got
 		 * aren't on any queues.
 		 */
 		if (m == NULL) {
 			if ((flags & M_NOWAIT) == 0)
 				goto retry;
 			VM_OBJECT_WUNLOCK(object);
 			kmem_unback(object, addr, i);
 			return (KERN_NO_SPACE);
 		}
 		KASSERT(vm_phys_domain(m) == domain,
 		    ("kmem_back_domain: Domain mismatch %d != %d",
 		    vm_phys_domain(m), domain));
 		if (flags & M_ZERO && (m->flags & PG_ZERO) == 0)
 			pmap_zero_page(m);
 		KASSERT((m->oflags & VPO_UNMANAGED) != 0,
 		    ("kmem_malloc: page %p is managed", m));
 		vm_page_valid(m);
 		pmap_enter(kernel_pmap, addr + i, m, prot,
 		    prot | PMAP_ENTER_WIRED, 0);
 		if (__predict_false((prot & VM_PROT_EXECUTE) != 0))
 			m->oflags |= VPO_KMEM_EXEC;
 	}
 	VM_OBJECT_WUNLOCK(object);
 
 	return (KERN_SUCCESS);
 }
 
 /*
  *	kmem_back:
  *
  *	Allocate physical pages for the specified virtual address range.
  */
 int
 kmem_back(vm_object_t object, vm_offset_t addr, vm_size_t size, int flags)
 {
 	vm_offset_t end, next, start;
 	int domain, rv;
 
 	KASSERT(object == kernel_object,
 	    ("kmem_back: only supports kernel object."));
 
 	for (start = addr, end = addr + size; addr < end; addr = next) {
 		/*
 		 * We must ensure that pages backing a given large virtual page
 		 * all come from the same physical domain.
 		 */
 		if (vm_ndomains > 1) {
 			domain = (addr >> KVA_QUANTUM_SHIFT) % vm_ndomains;
 			while (VM_DOMAIN_EMPTY(domain))
 				domain++;
 			next = roundup2(addr + 1, KVA_QUANTUM);
 			if (next > end || next < start)
 				next = end;
 		} else {
 			domain = 0;
 			next = end;
 		}
 		rv = kmem_back_domain(domain, object, addr, next - addr, flags);
 		if (rv != KERN_SUCCESS) {
 			kmem_unback(object, start, addr - start);
 			break;
 		}
 	}
 	return (rv);
 }
 
 /*
  *	kmem_unback:
  *
  *	Unmap and free the physical pages underlying the specified virtual
  *	address range.
  *
  *	A physical page must exist within the specified object at each index
  *	that is being unmapped.
  */
 static struct vmem *
 _kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size)
 {
 	struct vmem *arena;
 	vm_page_t m, next;
 	vm_offset_t end, offset;
 	int domain;
 
 	KASSERT(object == kernel_object,
 	    ("kmem_unback: only supports kernel object."));
 
 	if (size == 0)
 		return (NULL);
 	pmap_remove(kernel_pmap, addr, addr + size);
 	offset = addr - VM_MIN_KERNEL_ADDRESS;
 	end = offset + size;
 	VM_OBJECT_WLOCK(object);
 	m = vm_page_lookup(object, atop(offset)); 
 	domain = vm_phys_domain(m);
 	if (__predict_true((m->oflags & VPO_KMEM_EXEC) == 0))
 		arena = vm_dom[domain].vmd_kernel_arena;
 	else
 		arena = vm_dom[domain].vmd_kernel_rwx_arena;
 	for (; offset < end; offset += PAGE_SIZE, m = next) {
 		next = vm_page_next(m);
 		vm_page_xbusy_claim(m);
 		vm_page_unwire_noq(m);
 		vm_page_free(m);
 	}
 	VM_OBJECT_WUNLOCK(object);
 
 	return (arena);
 }
 
 void
 kmem_unback(vm_object_t object, vm_offset_t addr, vm_size_t size)
 {
 
 	(void)_kmem_unback(object, addr, size);
 }
 
 /*
  *	kmem_free:
  *
  *	Free memory allocated with kmem_malloc.  The size must match the
  *	original allocation.
  */
 void
 kmem_free(vm_offset_t addr, vm_size_t size)
 {
 	struct vmem *arena;
 
 	size = round_page(size);
 	arena = _kmem_unback(kernel_object, addr, size);
 	if (arena != NULL)
 		vmem_free(arena, addr, size);
 }
 
 /*
  *	kmap_alloc_wait:
  *
  *	Allocates pageable memory from a sub-map of the kernel.  If the submap
  *	has no room, the caller sleeps waiting for more memory in the submap.
  *
  *	This routine may block.
  */
 vm_offset_t
 kmap_alloc_wait(vm_map_t map, vm_size_t size)
 {
 	vm_offset_t addr;
 
 	size = round_page(size);
 	if (!swap_reserve(size))
 		return (0);
 
 	for (;;) {
 		/*
 		 * To make this work for more than one map, use the map's lock
 		 * to lock out sleepers/wakers.
 		 */
 		vm_map_lock(map);
 		addr = vm_map_findspace(map, vm_map_min(map), size);
 		if (addr + size <= vm_map_max(map))
 			break;
 		/* no space now; see if we can ever get space */
 		if (vm_map_max(map) - vm_map_min(map) < size) {
 			vm_map_unlock(map);
 			swap_release(size);
 			return (0);
 		}
 		map->needs_wakeup = TRUE;
 		vm_map_unlock_and_wait(map, 0);
 	}
 	vm_map_insert(map, NULL, 0, addr, addr + size, VM_PROT_RW, VM_PROT_RW,
 	    MAP_ACC_CHARGED);
 	vm_map_unlock(map);
 	return (addr);
 }
 
 /*
  *	kmap_free_wakeup:
  *
  *	Returns memory to a submap of the kernel, and wakes up any processes
  *	waiting for memory in that map.
  */
 void
 kmap_free_wakeup(vm_map_t map, vm_offset_t addr, vm_size_t size)
 {
 
 	vm_map_lock(map);
 	(void) vm_map_delete(map, trunc_page(addr), round_page(addr + size));
 	if (map->needs_wakeup) {
 		map->needs_wakeup = FALSE;
 		vm_map_wakeup(map);
 	}
 	vm_map_unlock(map);
 }
 
 void
 kmem_init_zero_region(void)
 {
 	vm_offset_t addr, i;
 	vm_page_t m;
 
 	/*
 	 * Map a single physical page of zeros to a larger virtual range.
 	 * This requires less looping in places that want large amounts of
 	 * zeros, while not using much more physical resources.
 	 */
 	addr = kva_alloc(ZERO_REGION_SIZE);
 	m = vm_page_alloc(NULL, 0, VM_ALLOC_NORMAL |
 	    VM_ALLOC_NOOBJ | VM_ALLOC_WIRED | VM_ALLOC_ZERO);
 	if ((m->flags & PG_ZERO) == 0)
 		pmap_zero_page(m);
 	for (i = 0; i < ZERO_REGION_SIZE; i += PAGE_SIZE)
 		pmap_qenter(addr + i, &m, 1);
 	pmap_protect(kernel_pmap, addr, addr + ZERO_REGION_SIZE, VM_PROT_READ);
 
 	zero_region = (const void *)addr;
 }
 
 /*
  * Import KVA from the kernel map into the kernel arena.
  */
 static int
 kva_import(void *unused, vmem_size_t size, int flags, vmem_addr_t *addrp)
 {
 	vm_offset_t addr;
 	int result;
 
 	KASSERT((size % KVA_QUANTUM) == 0,
 	    ("kva_import: Size %jd is not a multiple of %d",
 	    (intmax_t)size, (int)KVA_QUANTUM));
 	addr = vm_map_min(kernel_map);
 	result = vm_map_find(kernel_map, NULL, 0, &addr, size, 0,
 	    VMFS_SUPER_SPACE, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT);
 	if (result != KERN_SUCCESS)
                 return (ENOMEM);
 
 	*addrp = addr;
 
 	return (0);
 }
 
 /*
  * Import KVA from a parent arena into a per-domain arena.  Imports must be
  * KVA_QUANTUM-aligned and a multiple of KVA_QUANTUM in size.
  */
 static int
 kva_import_domain(void *arena, vmem_size_t size, int flags, vmem_addr_t *addrp)
 {
 
 	KASSERT((size % KVA_QUANTUM) == 0,
 	    ("kva_import_domain: Size %jd is not a multiple of %d",
 	    (intmax_t)size, (int)KVA_QUANTUM));
 	return (vmem_xalloc(arena, size, KVA_QUANTUM, 0, 0, VMEM_ADDR_MIN,
 	    VMEM_ADDR_MAX, flags, addrp));
 }
 
 /*
  * 	kmem_init:
  *
  *	Create the kernel map; insert a mapping covering kernel text, 
  *	data, bss, and all space allocated thus far (`boostrap' data).  The 
  *	new map will thus map the range between VM_MIN_KERNEL_ADDRESS and 
  *	`start' as allocated, and the range between `start' and `end' as free.
  *	Create the kernel vmem arena and its per-domain children.
  */
 void
 kmem_init(vm_offset_t start, vm_offset_t end)
 {
+	vm_size_t quantum;
 	int domain;
 
 	vm_map_init(kernel_map, kernel_pmap, VM_MIN_KERNEL_ADDRESS, end);
 	kernel_map->system_map = 1;
 	vm_map_lock(kernel_map);
 	/* N.B.: cannot use kgdb to debug, starting with this assignment ... */
 	(void)vm_map_insert(kernel_map, NULL, 0,
 #ifdef __amd64__
 	    KERNBASE,
 #else		     
 	    VM_MIN_KERNEL_ADDRESS,
 #endif
 	    start, VM_PROT_ALL, VM_PROT_ALL, MAP_NOFAULT);
 	/* ... and ending with the completion of the above `insert' */
 
 #ifdef __amd64__
 	/*
 	 * Mark KVA used for the page array as allocated.  Other platforms
 	 * that handle vm_page_array allocation can simply adjust virtual_avail
 	 * instead.
 	 */
 	(void)vm_map_insert(kernel_map, NULL, 0, (vm_offset_t)vm_page_array,
 	    (vm_offset_t)vm_page_array + round_2mpage(vm_page_array_size *
 	    sizeof(struct vm_page)),
 	    VM_PROT_RW, VM_PROT_RW, MAP_NOFAULT);
 #endif
 	vm_map_unlock(kernel_map);
 
 	/*
+	 * Use a large import quantum on NUMA systems.  This helps minimize
+	 * interleaving of superpages, reducing internal fragmentation within
+	 * the per-domain arenas.
+	 */
+	if (vm_ndomains > 1 && PMAP_HAS_DMAP)
+		quantum = KVA_NUMA_IMPORT_QUANTUM;
+	else
+		quantum = KVA_QUANTUM;
+
+	/*
 	 * Initialize the kernel_arena.  This can grow on demand.
 	 */
 	vmem_init(kernel_arena, "kernel arena", 0, 0, PAGE_SIZE, 0, 0);
-	vmem_set_import(kernel_arena, kva_import, NULL, NULL, KVA_QUANTUM);
+	vmem_set_import(kernel_arena, kva_import, NULL, NULL, quantum);
 
 	for (domain = 0; domain < vm_ndomains; domain++) {
 		/*
 		 * Initialize the per-domain arenas.  These are used to color
 		 * the KVA space in a way that ensures that virtual large pages
 		 * are backed by memory from the same physical domain,
 		 * maximizing the potential for superpage promotion.
 		 */
 		vm_dom[domain].vmd_kernel_arena = vmem_create(
 		    "kernel arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK);
 		vmem_set_import(vm_dom[domain].vmd_kernel_arena,
-		    kva_import_domain, NULL, kernel_arena, KVA_QUANTUM);
+		    kva_import_domain, NULL, kernel_arena, quantum);
 
 		/*
 		 * In architectures with superpages, maintain separate arenas
 		 * for allocations with permissions that differ from the
 		 * "standard" read/write permissions used for kernel memory,
 		 * so as not to inhibit superpage promotion.
+		 *
+		 * Use the base import quantum since this arena is rarely used.
 		 */
 #if VM_NRESERVLEVEL > 0
 		vm_dom[domain].vmd_kernel_rwx_arena = vmem_create(
 		    "kernel rwx arena domain", 0, 0, PAGE_SIZE, 0, M_WAITOK);
 		vmem_set_import(vm_dom[domain].vmd_kernel_rwx_arena,
 		    kva_import_domain, (vmem_release_t *)vmem_xfree,
 		    kernel_arena, KVA_QUANTUM);
 #else
 		vm_dom[domain].vmd_kernel_rwx_arena =
 		    vm_dom[domain].vmd_kernel_arena;
 #endif
 	}
 
 	/*
 	 * This must be the very first call so that the virtual address
 	 * space used for early allocations is properly marked used in
 	 * the map.
 	 */
 	uma_startup2();
 }
 
 /*
  *	kmem_bootstrap_free:
  *
  *	Free pages backing preloaded data (e.g., kernel modules) to the
  *	system.  Currently only supported on platforms that create a
  *	vm_phys segment for preloaded data.
  */
 void
 kmem_bootstrap_free(vm_offset_t start, vm_size_t size)
 {
 #if defined(__i386__) || defined(__amd64__)
 	struct vm_domain *vmd;
 	vm_offset_t end, va;
 	vm_paddr_t pa;
 	vm_page_t m;
 
 	end = trunc_page(start + size);
 	start = round_page(start);
 
 #ifdef __amd64__
 	/*
 	 * Preloaded files do not have execute permissions by default on amd64.
 	 * Restore the default permissions to ensure that the direct map alias
 	 * is updated.
 	 */
 	pmap_change_prot(start, end - start, VM_PROT_RW);
 #endif
 	for (va = start; va < end; va += PAGE_SIZE) {
 		pa = pmap_kextract(va);
 		m = PHYS_TO_VM_PAGE(pa);
 
 		vmd = vm_pagequeue_domain(m);
 		vm_domain_free_lock(vmd);
 		vm_phys_free_pages(m, 0);
 		vm_domain_free_unlock(vmd);
 
 		vm_domain_freecnt_inc(vmd, 1);
 		vm_cnt.v_page_count++;
 	}
 	pmap_remove(kernel_pmap, start, end);
 	(void)vmem_add(kernel_arena, start, end - start, M_WAITOK);
 #endif
 }
 
 /*
  * Allow userspace to directly trigger the VM drain routine for testing
  * purposes.
  */
 static int
 debug_vm_lowmem(SYSCTL_HANDLER_ARGS)
 {
 	int error, i;
 
 	i = 0;
 	error = sysctl_handle_int(oidp, &i, 0, req);
 	if (error)
 		return (error);
 	if ((i & ~(VM_LOW_KMEM | VM_LOW_PAGES)) != 0)
 		return (EINVAL);
 	if (i != 0)
 		EVENTHANDLER_INVOKE(vm_lowmem, i);
 	return (0);
 }
 
 SYSCTL_PROC(_debug, OID_AUTO, vm_lowmem, CTLTYPE_INT | CTLFLAG_MPSAFE | CTLFLAG_RW, 0, 0,
     debug_vm_lowmem, "I", "set to trigger vm_lowmem event with given flags");