freebsd-nq/sys/vm/vm_pageq.c
Alan Cox 2446e4f02c Enable the new physical memory allocator.
This allocator uses a binary buddy system with a twist.  First and
foremost, this allocator is required to support the implementation of
superpages.  As a side effect, it enables a more robust implementation
of contigmalloc(9).  Moreover, this reimplementation of
contigmalloc(9) eliminates the acquisition of Giant by
contigmalloc(..., M_NOWAIT, ...).

The twist is that this allocator tries to reduce the number of TLB
misses incurred by accesses through a direct map to small, UMA-managed
objects and page table pages.  Roughly speaking, the physical pages
that are allocated for such purposes are clustered together in the
physical address space.  The performance benefits vary.  In the most
extreme case, a uniprocessor kernel running on an Opteron, I measured
an 18% reduction in system time during a buildworld.

This allocator does not implement page coloring.  The reason is that
superpages have much the same effect.  The contiguous physical memory
allocation necessary for a superpage is inherently colored.

Finally, the one caveat is that this allocator does not effectively
support prezeroed pages.  I hope this is temporary.  On i386, this is
a slight pessimization.  However, on amd64, the beneficial effects of
the direct-map optimization outweigh the ill effects.  I speculate
that this is true in general of machines with a direct map.

Approved by:	re
2007-06-16 04:57:06 +00:00

143 lines
3.7 KiB
C

/*-
* Copyright (c) 1998 Matthew Dillon. 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.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/linker_set.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/sysctl.h>
#include <sys/proc.h>
#include <sys/vmmeter.h>
#include <sys/vnode.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_kern.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_pageout.h>
#include <vm/vm_pager.h>
#include <vm/vm_phys.h>
#include <vm/vm_extern.h>
struct vpgqueues vm_page_queues[PQ_MAXCOUNT];
void
vm_pageq_init(void)
{
int i;
vm_page_queues[PQ_CACHE].cnt = &cnt.v_cache_count;
vm_page_queues[PQ_INACTIVE].cnt = &cnt.v_inactive_count;
vm_page_queues[PQ_ACTIVE].cnt = &cnt.v_active_count;
vm_page_queues[PQ_HOLD].cnt = &cnt.v_active_count;
for (i = 0; i < PQ_COUNT; i++) {
TAILQ_INIT(&vm_page_queues[i].pl);
}
}
void
vm_pageq_requeue(vm_page_t m)
{
int queue = VM_PAGE_GETQUEUE(m);
struct vpgqueues *vpq;
if (queue != PQ_NONE) {
vpq = &vm_page_queues[queue];
TAILQ_REMOVE(&vpq->pl, m, pageq);
TAILQ_INSERT_TAIL(&vpq->pl, m, pageq);
}
}
/*
* vm_pageq_enqueue:
*/
void
vm_pageq_enqueue(int queue, vm_page_t m)
{
struct vpgqueues *vpq;
vpq = &vm_page_queues[queue];
VM_PAGE_SETQUEUE2(m, queue);
TAILQ_INSERT_TAIL(&vpq->pl, m, pageq);
++*vpq->cnt;
}
/*
* vm_pageq_remove_nowakeup:
*
* vm_page_unqueue() without any wakeup
*
* The queue containing the given page must be locked.
* This routine may not block.
*/
void
vm_pageq_remove_nowakeup(vm_page_t m)
{
int queue = VM_PAGE_GETQUEUE(m);
struct vpgqueues *pq;
if (queue != PQ_NONE) {
pq = &vm_page_queues[queue];
VM_PAGE_SETQUEUE2(m, PQ_NONE);
TAILQ_REMOVE(&pq->pl, m, pageq);
(*pq->cnt)--;
}
}
/*
* vm_pageq_remove:
*
* Remove a page from its queue.
*
* The queue containing the given page must be locked.
* This routine may not block.
*/
void
vm_pageq_remove(vm_page_t m)
{
int queue = VM_PAGE_GETQUEUE(m);
struct vpgqueues *pq;
if (queue != PQ_NONE) {
VM_PAGE_SETQUEUE2(m, PQ_NONE);
pq = &vm_page_queues[queue];
TAILQ_REMOVE(&pq->pl, m, pageq);
(*pq->cnt)--;
if (VM_PAGE_RESOLVEQUEUE(m, queue) == PQ_CACHE) {
if (vm_paging_needed())
pagedaemon_wakeup();
}
}
}