freebsd-nq/sys/vm/vm_radix.h
Jeff Roberson 1ddda2eb24 Use SMR to provide a safe unlocked lookup for vm_radix.
The tree is kept correct for readers with store barriers and careful
ordering.  The existing object lock serializes writers.  Consumers
will be introduced in later commits.

Reviewed by:	markj, kib
Differential Revision:	https://reviews.freebsd.org/D23446
2020-02-19 19:58:31 +00:00

68 lines
2.5 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2013 EMC Corp.
* Copyright (c) 2011 Jeffrey Roberson <jeff@freebsd.org>
* Copyright (c) 2008 Mayur Shardul <mayur.shardul@gmail.com>
* All rights reserved.
*
* 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 AUTHOR 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 AUTHOR 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.
*
* $FreeBSD$
*/
#ifndef _VM_RADIX_H_
#define _VM_RADIX_H_
#include <vm/_vm_radix.h>
#ifdef _KERNEL
int vm_radix_insert(struct vm_radix *rtree, vm_page_t page);
void vm_radix_wait(void);
boolean_t vm_radix_is_singleton(struct vm_radix *rtree);
vm_page_t vm_radix_lookup(struct vm_radix *rtree, vm_pindex_t index);
vm_page_t vm_radix_lookup_ge(struct vm_radix *rtree, vm_pindex_t index);
vm_page_t vm_radix_lookup_le(struct vm_radix *rtree, vm_pindex_t index);
vm_page_t vm_radix_lookup_unlocked(struct vm_radix *rtree, vm_pindex_t index);
void vm_radix_reclaim_allnodes(struct vm_radix *rtree);
vm_page_t vm_radix_remove(struct vm_radix *rtree, vm_pindex_t index);
vm_page_t vm_radix_replace(struct vm_radix *rtree, vm_page_t newpage);
void vm_radix_zinit(void);
static __inline void
vm_radix_init(struct vm_radix *rtree)
{
rtree->rt_root = 0;
}
static __inline boolean_t
vm_radix_is_empty(struct vm_radix *rtree)
{
return (rtree->rt_root == 0);
}
#endif /* _KERNEL */
#endif /* !_VM_RADIX_H_ */