freebsd-dev/sys/vm/vm_phys.h
Doug Moore b8590dae50 The function vm_phys_free_contig invokes vm_phys_free_pages for every
power-of-two page block it frees, launching an unsuccessful search for
a buddy to pair up with each time.  The only possible buddy-up mergers
are across the boundaries of the freed region, so change
vm_phys_free_contig simply to enqueue the freed interior blocks, via a
new function vm_phys_enqueue_contig, and then call vm_phys_free_pages
on the bounding blocks to create as big a cross-boundary block as
possible after buddy-merging.

The only callers of vm_phys_free_contig at the moment call it in
situations where merging blocks across the boundary is clearly
impossible, so just call vm_phys_enqueue_contig in those places and
avoid trying to buddy-up at all.

One beneficiary of this change is in breaking reservations.  For the
case where memory is freed in breaking a reservation with only the
first and last pages allocated, the number of cycles consumed by the
operation drops about 11% with this change.

Suggested by: alc
Reviewed by: alc
Approved by: kib, markj (mentors)
Differential Revision: https://reviews.freebsd.org/D16901
2019-05-31 21:02:42 +00:00

129 lines
4.1 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* 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
#ifndef VM_NFREEORDER_MAX
#define VM_NFREEORDER_MAX VM_NFREEORDER
#endif
/* Domains must be dense (non-sparse) and zero-based. */
struct mem_affinity {
vm_paddr_t start;
vm_paddr_t end;
int domain;
};
#ifdef NUMA
extern struct mem_affinity *mem_affinity;
extern int *mem_locality;
#endif
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_MAX];
};
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_seg(vm_paddr_t start, vm_paddr_t end);
vm_page_t vm_phys_alloc_contig(int domain, 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 domain, int freelist, int pool,
int order);
int vm_phys_alloc_npages(int domain, int pool, int npages, vm_page_t ma[]);
vm_page_t vm_phys_alloc_pages(int domain, int pool, int order);
int vm_phys_domain_match(int prefer, vm_paddr_t low, vm_paddr_t high);
void vm_phys_enqueue_contig(vm_page_t m, u_long npages);
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);
void vm_phys_register_domains(int ndomains, struct mem_affinity *affinity,
int *locality);
vm_page_t vm_phys_scan_contig(int domain, 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);
int vm_phys_mem_affinity(int f, int t);
/*
*
* vm_phys_domain:
*
* Return the index of the domain the page belongs to.
*/
static inline int
vm_phys_domain(vm_page_t m)
{
#ifdef NUMA
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 (domn);
#else
return (0);
#endif
}
#endif /* _KERNEL */
#endif /* !_VM_PHYS_H_ */