freebsd-dev/sys/vm/vm_phys.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

127 lines
4.1 KiB
C

/*-
* Copyright (c) 2002-2006 Rice University
* Copyright (c) 2007 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.
*
* $FreeBSD$
*/
/*
* Physical memory system definitions
*/
#ifndef _VM_PHYS_H_
#define _VM_PHYS_H_
#ifdef _KERNEL
/* Domains must be dense (non-sparse) and zero-based. */
struct mem_affinity {
vm_paddr_t start;
vm_paddr_t end;
int domain;
};
struct vm_freelist {
struct pglist pl;
int lcnt;
};
struct vm_phys_seg {
vm_paddr_t start;
vm_paddr_t end;
vm_page_t first_page;
int domain;
struct vm_freelist (*free_queues)[VM_NFREEPOOL][VM_NFREEORDER];
};
extern struct mem_affinity *mem_affinity;
extern int *mem_locality;
extern int vm_ndomains;
extern struct vm_phys_seg vm_phys_segs[];
extern int vm_phys_nsegs;
/*
* The following functions are only to be used by the virtual memory system.
*/
void vm_phys_add_page(vm_paddr_t pa);
void vm_phys_add_seg(vm_paddr_t start, vm_paddr_t end);
vm_page_t vm_phys_alloc_contig(u_long npages, vm_paddr_t low, vm_paddr_t high,
u_long alignment, vm_paddr_t boundary);
vm_page_t vm_phys_alloc_freelist_pages(int freelist, int pool, int order);
vm_page_t vm_phys_alloc_pages(int pool, int order);
boolean_t vm_phys_domain_intersects(long mask, vm_paddr_t low, vm_paddr_t high);
int vm_phys_fictitious_reg_range(vm_paddr_t start, vm_paddr_t end,
vm_memattr_t memattr);
void vm_phys_fictitious_unreg_range(vm_paddr_t start, vm_paddr_t end);
vm_page_t vm_phys_fictitious_to_vm_page(vm_paddr_t pa);
void vm_phys_free_contig(vm_page_t m, u_long npages);
void vm_phys_free_pages(vm_page_t m, int order);
void vm_phys_init(void);
vm_page_t vm_phys_paddr_to_vm_page(vm_paddr_t pa);
vm_page_t vm_phys_scan_contig(u_long npages, vm_paddr_t low, vm_paddr_t high,
u_long alignment, vm_paddr_t boundary, int options);
void vm_phys_set_pool(int pool, vm_page_t m, int order);
boolean_t vm_phys_unfree_page(vm_page_t m);
boolean_t vm_phys_zero_pages_idle(void);
int vm_phys_mem_affinity(int f, int t);
/*
* vm_phys_domain:
*
* Return the memory domain the page belongs to.
*/
static inline struct vm_domain *
vm_phys_domain(vm_page_t m)
{
#if MAXMEMDOM > 1
int domn, segind;
/* XXXKIB try to assert that the page is managed */
segind = m->segind;
KASSERT(segind < vm_phys_nsegs, ("segind %d m %p", segind, m));
domn = vm_phys_segs[segind].domain;
KASSERT(domn < vm_ndomains, ("domain %d m %p", domn, m));
return (&vm_dom[domn]);
#else
return (&vm_dom[0]);
#endif
}
static inline void
vm_phys_freecnt_adj(vm_page_t m, int adj)
{
mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
vm_cnt.v_free_count += adj;
vm_phys_domain(m)->vmd_free_count += adj;
}
#endif /* _KERNEL */
#endif /* !_VM_PHYS_H_ */