freebsd-dev/sys/vm/vm_reserv.h
Alan Cox c869e67208 Introduce a new mechanism for relocating virtual pages to a new physical
address and use this mechanism when:

1. kmem_alloc_{attr,contig}() can't find suitable free pages in the physical
   memory allocator's free page lists.  This replaces the long-standing
   approach of scanning the inactive and inactive queues, converting clean
   pages into PG_CACHED pages and laundering dirty pages.  In contrast, the
   new mechanism does not use PG_CACHED pages nor does it trigger a large
   number of I/O operations.

2. on 32-bit MIPS processors, uma_small_alloc() and the pmap can't find
   free pages in the physical memory allocator's free page lists that are
   covered by the direct map.  Tested by: adrian

3. ttm_bo_global_init() and ttm_vm_page_alloc_dma32() can't find suitable
   free pages in the physical memory allocator's free page lists.

In the coming months, I expect that this new mechanism will be applied in
other places.  For example, balloon drivers should use relocation to
minimize fragmentation of the guest physical address space.

Make vm_phys_alloc_contig() a little smarter (and more efficient in some
cases).  Specifically, use vm_phys_segs[] earlier to avoid scanning free
page lists that can't possibly contain suitable pages.

Reviewed by:	kib, markj
Glanced at:	jhb
Discussed with:	jeff
Sponsored by:	EMC / Isilon Storage Division
Differential Revision:	https://reviews.freebsd.org/D4444
2015-12-19 18:42:50 +00:00

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2.8 KiB
C

/*-
* Copyright (c) 2002-2006 Rice University
* Copyright (c) 2007-2008 Alan L. Cox <alc@cs.rice.edu>
* All rights reserved.
*
* This software was developed for the FreeBSD Project by Alan L. Cox,
* Olivier Crameri, Peter Druschel, Sitaram Iyer, and Juan Navarro.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
* HOLDERS 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.
*
* $FreeBSD$
*/
/*
* Superpage reservation management definitions
*/
#ifndef _VM_RESERV_H_
#define _VM_RESERV_H_
#ifdef _KERNEL
#if VM_NRESERVLEVEL > 0
/*
* The following functions are only to be used by the virtual memory system.
*/
vm_page_t vm_reserv_alloc_contig(vm_object_t object, vm_pindex_t pindex,
u_long npages, vm_paddr_t low, vm_paddr_t high,
u_long alignment, vm_paddr_t boundary);
vm_page_t vm_reserv_alloc_page(vm_object_t object, vm_pindex_t pindex,
vm_page_t mpred);
void vm_reserv_break_all(vm_object_t object);
boolean_t vm_reserv_free_page(vm_page_t m);
void vm_reserv_init(void);
bool vm_reserv_is_page_free(vm_page_t m);
int vm_reserv_level(vm_page_t m);
int vm_reserv_level_iffullpop(vm_page_t m);
boolean_t vm_reserv_reactivate_page(vm_page_t m);
boolean_t vm_reserv_reclaim_contig(u_long npages, vm_paddr_t low,
vm_paddr_t high, u_long alignment, vm_paddr_t boundary);
boolean_t vm_reserv_reclaim_inactive(void);
void vm_reserv_rename(vm_page_t m, vm_object_t new_object,
vm_object_t old_object, vm_pindex_t old_object_offset);
int vm_reserv_size(int level);
vm_paddr_t vm_reserv_startup(vm_offset_t *vaddr, vm_paddr_t end,
vm_paddr_t high_water);
#endif /* VM_NRESERVLEVEL > 0 */
#endif /* _KERNEL */
#endif /* !_VM_RESERV_H_ */