freebsd-skq/sys/vm/vm_phys.h
Mateusz Guzik 1dbf52e7d9 Reduce traffic on vm_cnt.v_free_count
The variable is modified with the highly contended page free queue lock.
It unnecessarily shares a cacheline with purely read-only fields and is
re-read after the lock is dropped in the page allocation code making the
hold time longer.

Pad the variable just like the others and store the value as found with
the lock held instead of re-reading.

Provides a modest 1%-ish speed up in concurrent page faults.

Reviewed by:	kib, markj
Differential Revision:	https://reviews.freebsd.org/D12665
2017-10-13 21:54:34 +00:00

126 lines
4.0 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_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);
void vm_phys_init_page(vm_paddr_t pa);
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);
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)
{
#ifdef VM_NUMA_ALLOC
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 u_int
vm_phys_freecnt_adj(vm_page_t m, int adj)
{
mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
vm_phys_domain(m)->vmd_free_count += adj;
return (vm_cnt.v_free_count += adj);
}
#endif /* _KERNEL */
#endif /* !_VM_PHYS_H_ */