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c7aebda8a1
freebsd-dev/sys/vm/vm_phys.c
Attilio Rao c7aebda8a1 The soft and hard busy mechanism rely on the vm object lock to work. 
Unify the 2 concept into a real, minimal, sxlock where the shared
acquisition represent the soft busy and the exclusive acquisition
represent the hard busy.
The old VPO_WANTED mechanism becames the hard-path for this new lock
and it becomes per-page rather than per-object.
The vm_object lock becames an interlock for this functionality:
it can be held in both read or write mode.
However, if the vm_object lock is held in read mode while acquiring
or releasing the busy state, the thread owner cannot make any
assumption on the busy state unless it is also busying it.

Also:
- Add a new flag to directly shared busy pages while vm_page_alloc
  and vm_page_grab are being executed.  This will be very helpful
  once these functions happen under a read object lock.
- Move the swapping sleep into its own per-object flag

The KPI is heavilly changed this is why the version is bumped.
It is very likely that some VM ports users will need to change
their own code.

Sponsored by:	EMC / Isilon storage division
Discussed with:	alc
Reviewed by:	jeff, kib
Tested by:	gavin, bapt (older version)
Tested by:	pho, scottl
2013-08-09 11:11:11 +00:00

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/*-
* 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.
*/
/*
* Physical memory system implementation
*
* Any external functions defined by this module are only to be used by the
* virtual memory system.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_ddb.h"
#include "opt_vm.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#if MAXMEMDOM > 1
#include <sys/proc.h>
#endif
#include <sys/queue.h>
#include <sys/sbuf.h>
#include <sys/sysctl.h>
#include <sys/vmmeter.h>
#include <ddb/ddb.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_phys.h>
_Static_assert(sizeof(long) * NBBY >= VM_PHYSSEG_MAX,
"Too many physsegs.");
struct mem_affinity *mem_affinity;
int vm_ndomains = 1;
struct vm_phys_seg vm_phys_segs[VM_PHYSSEG_MAX];
int vm_phys_nsegs;
#define VM_PHYS_FICTITIOUS_NSEGS 8
static struct vm_phys_fictitious_seg {
vm_paddr_t start;
vm_paddr_t end;
vm_page_t first_page;
} vm_phys_fictitious_segs[VM_PHYS_FICTITIOUS_NSEGS];
static struct mtx vm_phys_fictitious_reg_mtx;
MALLOC_DEFINE(M_FICT_PAGES, "vm_fictitious", "Fictitious VM pages");
static struct vm_freelist
vm_phys_free_queues[MAXMEMDOM][VM_NFREELIST][VM_NFREEPOOL][VM_NFREEORDER];
static int vm_nfreelists = VM_FREELIST_DEFAULT + 1;
static int cnt_prezero;
SYSCTL_INT(_vm_stats_misc, OID_AUTO, cnt_prezero, CTLFLAG_RD,
&cnt_prezero, 0, "The number of physical pages prezeroed at idle time");
static int sysctl_vm_phys_free(SYSCTL_HANDLER_ARGS);
SYSCTL_OID(_vm, OID_AUTO, phys_free, CTLTYPE_STRING | CTLFLAG_RD,
NULL, 0, sysctl_vm_phys_free, "A", "Phys Free Info");
static int sysctl_vm_phys_segs(SYSCTL_HANDLER_ARGS);
SYSCTL_OID(_vm, OID_AUTO, phys_segs, CTLTYPE_STRING | CTLFLAG_RD,
NULL, 0, sysctl_vm_phys_segs, "A", "Phys Seg Info");
SYSCTL_INT(_vm, OID_AUTO, ndomains, CTLFLAG_RD,
&vm_ndomains, 0, "Number of physical memory domains available.");
static vm_page_t vm_phys_alloc_domain_pages(int domain, int flind, int pool,
int order);
static void _vm_phys_create_seg(vm_paddr_t start, vm_paddr_t end, int flind,
int domain);
static void vm_phys_create_seg(vm_paddr_t start, vm_paddr_t end, int flind);
static int vm_phys_paddr_to_segind(vm_paddr_t pa);
static void vm_phys_split_pages(vm_page_t m, int oind, struct vm_freelist *fl,
int order);
static __inline int
vm_rr_selectdomain(void)
{
#if MAXMEMDOM > 1
struct thread *td;
td = curthread;
td->td_dom_rr_idx++;
td->td_dom_rr_idx %= vm_ndomains;
return (td->td_dom_rr_idx);
#else
return (0);
#endif
}
boolean_t
vm_phys_domain_intersects(long mask, vm_paddr_t low, vm_paddr_t high)
{
struct vm_phys_seg *s;
int idx;
while ((idx = ffsl(mask)) != 0) {
idx--; /* ffsl counts from 1 */
mask &= ~(1UL << idx);
s = &vm_phys_segs[idx];
if (low < s->end && high > s->start)
return (TRUE);
}
return (FALSE);
}
/*
* Outputs the state of the physical memory allocator, specifically,
* the amount of physical memory in each free list.
*/
static int
sysctl_vm_phys_free(SYSCTL_HANDLER_ARGS)
{
struct sbuf sbuf;
struct vm_freelist *fl;
int dom, error, flind, oind, pind;
error = sysctl_wire_old_buffer(req, 0);
if (error != 0)
return (error);
sbuf_new_for_sysctl(&sbuf, NULL, 128 * vm_ndomains, req);
for (dom = 0; dom < vm_ndomains; dom++) {
sbuf_printf(&sbuf,"DOMAIN: %d\n", dom);
for (flind = 0; flind < vm_nfreelists; flind++) {
sbuf_printf(&sbuf, "FREE LIST %d:\n"
"\n ORDER (SIZE) | NUMBER"
"\n ", flind);
for (pind = 0; pind < VM_NFREEPOOL; pind++)
sbuf_printf(&sbuf, " | POOL %d", pind);
sbuf_printf(&sbuf, "\n-- ");
for (pind = 0; pind < VM_NFREEPOOL; pind++)
sbuf_printf(&sbuf, "-- -- ");
sbuf_printf(&sbuf, "--\n");
for (oind = VM_NFREEORDER - 1; oind >= 0; oind--) {
sbuf_printf(&sbuf, " %2d (%6dK)", oind,
1 << (PAGE_SHIFT - 10 + oind));
for (pind = 0; pind < VM_NFREEPOOL; pind++) {
fl = vm_phys_free_queues[dom][flind][pind];
sbuf_printf(&sbuf, " | %6.6d",
fl[oind].lcnt);
}
sbuf_printf(&sbuf, "\n");
}
sbuf_printf(&sbuf, "\n");
}
sbuf_printf(&sbuf, "\n");
}
error = sbuf_finish(&sbuf);
sbuf_delete(&sbuf);
return (error);
}
/*
* Outputs the set of physical memory segments.
*/
static int
sysctl_vm_phys_segs(SYSCTL_HANDLER_ARGS)
{
struct sbuf sbuf;
struct vm_phys_seg *seg;
int error, segind;
error = sysctl_wire_old_buffer(req, 0);
if (error != 0)
return (error);
sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
for (segind = 0; segind < vm_phys_nsegs; segind++) {
sbuf_printf(&sbuf, "\nSEGMENT %d:\n\n", segind);
seg = &vm_phys_segs[segind];
sbuf_printf(&sbuf, "start: %#jx\n",
(uintmax_t)seg->start);
sbuf_printf(&sbuf, "end: %#jx\n",
(uintmax_t)seg->end);
sbuf_printf(&sbuf, "domain: %d\n", seg->domain);
sbuf_printf(&sbuf, "free list: %p\n", seg->free_queues);
}
error = sbuf_finish(&sbuf);
sbuf_delete(&sbuf);
return (error);
}
static void
vm_freelist_add(struct vm_freelist *fl, vm_page_t m, int order, int tail)
{
m->order = order;
if (tail)
TAILQ_INSERT_TAIL(&fl[order].pl, m, pageq);
else
TAILQ_INSERT_HEAD(&fl[order].pl, m, pageq);
fl[order].lcnt++;
}
static void
vm_freelist_rem(struct vm_freelist *fl, vm_page_t m, int order)
{
TAILQ_REMOVE(&fl[order].pl, m, pageq);
fl[order].lcnt--;
m->order = VM_NFREEORDER;
}
/*
* Create a physical memory segment.
*/
static void
_vm_phys_create_seg(vm_paddr_t start, vm_paddr_t end, int flind, int domain)
{
struct vm_phys_seg *seg;
#ifdef VM_PHYSSEG_SPARSE
long pages;
int segind;
pages = 0;
for (segind = 0; segind < vm_phys_nsegs; segind++) {
seg = &vm_phys_segs[segind];
pages += atop(seg->end - seg->start);
}
#endif
KASSERT(vm_phys_nsegs < VM_PHYSSEG_MAX,
("vm_phys_create_seg: increase VM_PHYSSEG_MAX"));
KASSERT(domain < vm_ndomains,
("vm_phys_create_seg: invalid domain provided"));
seg = &vm_phys_segs[vm_phys_nsegs++];
seg->start = start;
seg->end = end;
seg->domain = domain;
#ifdef VM_PHYSSEG_SPARSE
seg->first_page = &vm_page_array[pages];
#else
seg->first_page = PHYS_TO_VM_PAGE(start);
#endif
seg->free_queues = &vm_phys_free_queues[domain][flind];
}
static void
vm_phys_create_seg(vm_paddr_t start, vm_paddr_t end, int flind)
{
int i;
if (mem_affinity == NULL) {
_vm_phys_create_seg(start, end, flind, 0);
return;
}
for (i = 0;; i++) {
if (mem_affinity[i].end == 0)
panic("Reached end of affinity info");
if (mem_affinity[i].end <= start)
continue;
if (mem_affinity[i].start > start)
panic("No affinity info for start %jx",
(uintmax_t)start);
if (mem_affinity[i].end >= end) {
_vm_phys_create_seg(start, end, flind,
mem_affinity[i].domain);
break;
}
_vm_phys_create_seg(start, mem_affinity[i].end, flind,
mem_affinity[i].domain);
start = mem_affinity[i].end;
}
}
/*
* Initialize the physical memory allocator.
*/
void
vm_phys_init(void)
{
struct vm_freelist *fl;
int dom, flind, i, oind, pind;
for (i = 0; phys_avail[i + 1] != 0; i += 2) {
#ifdef VM_FREELIST_ISADMA
if (phys_avail[i] < 16777216) {
if (phys_avail[i + 1] > 16777216) {
vm_phys_create_seg(phys_avail[i], 16777216,
VM_FREELIST_ISADMA);
vm_phys_create_seg(16777216, phys_avail[i + 1],
VM_FREELIST_DEFAULT);
} else {
vm_phys_create_seg(phys_avail[i],
phys_avail[i + 1], VM_FREELIST_ISADMA);
}
if (VM_FREELIST_ISADMA >= vm_nfreelists)
vm_nfreelists = VM_FREELIST_ISADMA + 1;
} else
#endif
#ifdef VM_FREELIST_HIGHMEM
if (phys_avail[i + 1] > VM_HIGHMEM_ADDRESS) {
if (phys_avail[i] < VM_HIGHMEM_ADDRESS) {
vm_phys_create_seg(phys_avail[i],
VM_HIGHMEM_ADDRESS, VM_FREELIST_DEFAULT);
vm_phys_create_seg(VM_HIGHMEM_ADDRESS,
phys_avail[i + 1], VM_FREELIST_HIGHMEM);
} else {
vm_phys_create_seg(phys_avail[i],
phys_avail[i + 1], VM_FREELIST_HIGHMEM);
}
if (VM_FREELIST_HIGHMEM >= vm_nfreelists)
vm_nfreelists = VM_FREELIST_HIGHMEM + 1;
} else
#endif
vm_phys_create_seg(phys_avail[i], phys_avail[i + 1],
VM_FREELIST_DEFAULT);
}
for (dom = 0; dom < vm_ndomains; dom++) {
for (flind = 0; flind < vm_nfreelists; flind++) {
for (pind = 0; pind < VM_NFREEPOOL; pind++) {
fl = vm_phys_free_queues[dom][flind][pind];
for (oind = 0; oind < VM_NFREEORDER; oind++)
TAILQ_INIT(&fl[oind].pl);
}
}
}
mtx_init(&vm_phys_fictitious_reg_mtx, "vmfctr", NULL, MTX_DEF);
}
/*
* Split a contiguous, power of two-sized set of physical pages.
*/
static __inline void
vm_phys_split_pages(vm_page_t m, int oind, struct vm_freelist *fl, int order)
{
vm_page_t m_buddy;
while (oind > order) {
oind--;
m_buddy = &m[1 << oind];
KASSERT(m_buddy->order == VM_NFREEORDER,
("vm_phys_split_pages: page %p has unexpected order %d",
m_buddy, m_buddy->order));
vm_freelist_add(fl, m_buddy, oind, 0);
}
}
/*
* Initialize a physical page and add it to the free lists.
*/
void
vm_phys_add_page(vm_paddr_t pa)
{
vm_page_t m;
struct vm_domain *vmd;
cnt.v_page_count++;
m = vm_phys_paddr_to_vm_page(pa);
m->phys_addr = pa;
m->queue = PQ_NONE;
m->segind = vm_phys_paddr_to_segind(pa);
vmd = vm_phys_domain(m);
vmd->vmd_page_count++;
vmd->vmd_segs |= 1UL << m->segind;
m->flags = PG_FREE;
KASSERT(m->order == VM_NFREEORDER,
("vm_phys_add_page: page %p has unexpected order %d",
m, m->order));
m->pool = VM_FREEPOOL_DEFAULT;
pmap_page_init(m);
mtx_lock(&vm_page_queue_free_mtx);
vm_phys_freecnt_adj(m, 1);
vm_phys_free_pages(m, 0);
mtx_unlock(&vm_page_queue_free_mtx);
}
/*
* Allocate a contiguous, power of two-sized set of physical pages
* from the free lists.
*
* The free page queues must be locked.
*/
vm_page_t
vm_phys_alloc_pages(int pool, int order)
{
vm_page_t m;
int dom, domain, flind;
KASSERT(pool < VM_NFREEPOOL,
("vm_phys_alloc_pages: pool %d is out of range", pool));
KASSERT(order < VM_NFREEORDER,
("vm_phys_alloc_pages: order %d is out of range", order));
for (dom = 0; dom < vm_ndomains; dom++) {
domain = vm_rr_selectdomain();
for (flind = 0; flind < vm_nfreelists; flind++) {
m = vm_phys_alloc_domain_pages(domain, flind, pool,
order);
if (m != NULL)
return (m);
}
}
return (NULL);
}
/*
* Find and dequeue a free page on the given free list, with the
* specified pool and order
*/
vm_page_t
vm_phys_alloc_freelist_pages(int flind, int pool, int order)
{
vm_page_t m;
int dom, domain;
KASSERT(flind < VM_NFREELIST,
("vm_phys_alloc_freelist_pages: freelist %d is out of range", flind));
KASSERT(pool < VM_NFREEPOOL,
("vm_phys_alloc_freelist_pages: pool %d is out of range", pool));
KASSERT(order < VM_NFREEORDER,
("vm_phys_alloc_freelist_pages: order %d is out of range", order));
for (dom = 0; dom < vm_ndomains; dom++) {
domain = vm_rr_selectdomain();
m = vm_phys_alloc_domain_pages(domain, flind, pool, order);
if (m != NULL)
return (m);
}
return (NULL);
}
static vm_page_t
vm_phys_alloc_domain_pages(int domain, int flind, int pool, int order)
{
struct vm_freelist *fl;
struct vm_freelist *alt;
int oind, pind;
vm_page_t m;
mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
fl = &vm_phys_free_queues[domain][flind][pool][0];
for (oind = order; oind < VM_NFREEORDER; oind++) {
m = TAILQ_FIRST(&fl[oind].pl);
if (m != NULL) {
vm_freelist_rem(fl, m, oind);
vm_phys_split_pages(m, oind, fl, order);
return (m);
}
}
/*
* The given pool was empty. Find the largest
* contiguous, power-of-two-sized set of pages in any
* pool. Transfer these pages to the given pool, and
* use them to satisfy the allocation.
*/
for (oind = VM_NFREEORDER - 1; oind >= order; oind--) {
for (pind = 0; pind < VM_NFREEPOOL; pind++) {
alt = &vm_phys_free_queues[domain][flind][pind][0];
m = TAILQ_FIRST(&alt[oind].pl);
if (m != NULL) {
vm_freelist_rem(alt, m, oind);
vm_phys_set_pool(pool, m, oind);
vm_phys_split_pages(m, oind, fl, order);
return (m);
}
}
}
return (NULL);
}
/*
* Find the vm_page corresponding to the given physical address.
*/
vm_page_t
vm_phys_paddr_to_vm_page(vm_paddr_t pa)
{
struct vm_phys_seg *seg;
int segind;
for (segind = 0; segind < vm_phys_nsegs; segind++) {
seg = &vm_phys_segs[segind];
if (pa >= seg->start && pa < seg->end)
return (&seg->first_page[atop(pa - seg->start)]);
}
return (NULL);
}
vm_page_t
vm_phys_fictitious_to_vm_page(vm_paddr_t pa)
{
struct vm_phys_fictitious_seg *seg;
vm_page_t m;
int segind;
m = NULL;
for (segind = 0; segind < VM_PHYS_FICTITIOUS_NSEGS; segind++) {
seg = &vm_phys_fictitious_segs[segind];
if (pa >= seg->start && pa < seg->end) {
m = &seg->first_page[atop(pa - seg->start)];
KASSERT((m->flags & PG_FICTITIOUS) != 0,
("%p not fictitious", m));
break;
}
}
return (m);
}
int
vm_phys_fictitious_reg_range(vm_paddr_t start, vm_paddr_t end,
vm_memattr_t memattr)
{
struct vm_phys_fictitious_seg *seg;
vm_page_t fp;
long i, page_count;
int segind;
#ifdef VM_PHYSSEG_DENSE
long pi;
boolean_t malloced;
#endif
page_count = (end - start) / PAGE_SIZE;
#ifdef VM_PHYSSEG_DENSE
pi = atop(start);
if (pi >= first_page && atop(end) < vm_page_array_size) {
fp = &vm_page_array[pi - first_page];
malloced = FALSE;
} else
#endif
{
fp = malloc(page_count * sizeof(struct vm_page), M_FICT_PAGES,
M_WAITOK | M_ZERO);
#ifdef VM_PHYSSEG_DENSE
malloced = TRUE;
#endif
}
for (i = 0; i < page_count; i++) {
vm_page_initfake(&fp[i], start + PAGE_SIZE * i, memattr);
fp[i].oflags &= ~VPO_UNMANAGED;
fp[i].busy_lock = VPB_UNBUSIED;
}
mtx_lock(&vm_phys_fictitious_reg_mtx);
for (segind = 0; segind < VM_PHYS_FICTITIOUS_NSEGS; segind++) {
seg = &vm_phys_fictitious_segs[segind];
if (seg->start == 0 && seg->end == 0) {
seg->start = start;
seg->end = end;
seg->first_page = fp;
mtx_unlock(&vm_phys_fictitious_reg_mtx);
return (0);
}
}
mtx_unlock(&vm_phys_fictitious_reg_mtx);
#ifdef VM_PHYSSEG_DENSE
if (malloced)
#endif
free(fp, M_FICT_PAGES);
return (EBUSY);
}
void
vm_phys_fictitious_unreg_range(vm_paddr_t start, vm_paddr_t end)
{
struct vm_phys_fictitious_seg *seg;
vm_page_t fp;
int segind;
#ifdef VM_PHYSSEG_DENSE
long pi;
#endif
#ifdef VM_PHYSSEG_DENSE
pi = atop(start);
#endif
mtx_lock(&vm_phys_fictitious_reg_mtx);
for (segind = 0; segind < VM_PHYS_FICTITIOUS_NSEGS; segind++) {
seg = &vm_phys_fictitious_segs[segind];
if (seg->start == start && seg->end == end) {
seg->start = seg->end = 0;
fp = seg->first_page;
seg->first_page = NULL;
mtx_unlock(&vm_phys_fictitious_reg_mtx);
#ifdef VM_PHYSSEG_DENSE
if (pi < first_page || atop(end) >= vm_page_array_size)
#endif
free(fp, M_FICT_PAGES);
return;
}
}
mtx_unlock(&vm_phys_fictitious_reg_mtx);
KASSERT(0, ("Unregistering not registered fictitious range"));
}
/*
* Find the segment containing the given physical address.
*/
static int
vm_phys_paddr_to_segind(vm_paddr_t pa)
{
struct vm_phys_seg *seg;
int segind;
for (segind = 0; segind < vm_phys_nsegs; segind++) {
seg = &vm_phys_segs[segind];
if (pa >= seg->start && pa < seg->end)
return (segind);
}
panic("vm_phys_paddr_to_segind: paddr %#jx is not in any segment" ,
(uintmax_t)pa);
}
/*
* Free a contiguous, power of two-sized set of physical pages.
*
* The free page queues must be locked.
*/
void
vm_phys_free_pages(vm_page_t m, int order)
{
struct vm_freelist *fl;
struct vm_phys_seg *seg;
vm_paddr_t pa;
vm_page_t m_buddy;
KASSERT(m->order == VM_NFREEORDER,
("vm_phys_free_pages: page %p has unexpected order %d",
m, m->order));
KASSERT(m->pool < VM_NFREEPOOL,
("vm_phys_free_pages: page %p has unexpected pool %d",
m, m->pool));
KASSERT(order < VM_NFREEORDER,
("vm_phys_free_pages: order %d is out of range", order));
mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
seg = &vm_phys_segs[m->segind];
if (order < VM_NFREEORDER - 1) {
pa = VM_PAGE_TO_PHYS(m);
do {
pa ^= ((vm_paddr_t)1 << (PAGE_SHIFT + order));
if (pa < seg->start || pa >= seg->end)
break;
m_buddy = &seg->first_page[atop(pa - seg->start)];
if (m_buddy->order != order)
break;
fl = (*seg->free_queues)[m_buddy->pool];
vm_freelist_rem(fl, m_buddy, order);
if (m_buddy->pool != m->pool)
vm_phys_set_pool(m->pool, m_buddy, order);
order++;
pa &= ~(((vm_paddr_t)1 << (PAGE_SHIFT + order)) - 1);
m = &seg->first_page[atop(pa - seg->start)];
} while (order < VM_NFREEORDER - 1);
}
fl = (*seg->free_queues)[m->pool];
vm_freelist_add(fl, m, order, 1);
}
/*
* Free a contiguous, arbitrarily sized set of physical pages.
*
* The free page queues must be locked.
*/
void
vm_phys_free_contig(vm_page_t m, u_long npages)
{
u_int n;
int order;
/*
* Avoid unnecessary coalescing by freeing the pages in the largest
* possible power-of-two-sized subsets.
*/
mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
for (;; npages -= n) {
/*
* Unsigned "min" is used here so that "order" is assigned
* "VM_NFREEORDER - 1" when "m"'s physical address is zero
* or the low-order bits of its physical address are zero
* because the size of a physical address exceeds the size of
* a long.
*/
order = min(ffsl(VM_PAGE_TO_PHYS(m) >> PAGE_SHIFT) - 1,
VM_NFREEORDER - 1);
n = 1 << order;
if (npages < n)
break;
vm_phys_free_pages(m, order);
m += n;
}
/* The residual "npages" is less than "1 << (VM_NFREEORDER - 1)". */
for (; npages > 0; npages -= n) {
order = flsl(npages) - 1;
n = 1 << order;
vm_phys_free_pages(m, order);
m += n;
}
}
/*
* Set the pool for a contiguous, power of two-sized set of physical pages.
*/
void
vm_phys_set_pool(int pool, vm_page_t m, int order)
{
vm_page_t m_tmp;
for (m_tmp = m; m_tmp < &m[1 << order]; m_tmp++)
m_tmp->pool = pool;
}
/*
* Search for the given physical page "m" in the free lists. If the search
* succeeds, remove "m" from the free lists and return TRUE. Otherwise, return
* FALSE, indicating that "m" is not in the free lists.
*
* The free page queues must be locked.
*/
boolean_t
vm_phys_unfree_page(vm_page_t m)
{
struct vm_freelist *fl;
struct vm_phys_seg *seg;
vm_paddr_t pa, pa_half;
vm_page_t m_set, m_tmp;
int order;
mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
/*
* First, find the contiguous, power of two-sized set of free
* physical pages containing the given physical page "m" and
* assign it to "m_set".
*/
seg = &vm_phys_segs[m->segind];
for (m_set = m, order = 0; m_set->order == VM_NFREEORDER &&
order < VM_NFREEORDER - 1; ) {
order++;
pa = m->phys_addr & (~(vm_paddr_t)0 << (PAGE_SHIFT + order));
if (pa >= seg->start)
m_set = &seg->first_page[atop(pa - seg->start)];
else
return (FALSE);
}
if (m_set->order < order)
return (FALSE);
if (m_set->order == VM_NFREEORDER)
return (FALSE);
KASSERT(m_set->order < VM_NFREEORDER,
("vm_phys_unfree_page: page %p has unexpected order %d",
m_set, m_set->order));
/*
* Next, remove "m_set" from the free lists. Finally, extract
* "m" from "m_set" using an iterative algorithm: While "m_set"
* is larger than a page, shrink "m_set" by returning the half
* of "m_set" that does not contain "m" to the free lists.
*/
fl = (*seg->free_queues)[m_set->pool];
order = m_set->order;
vm_freelist_rem(fl, m_set, order);
while (order > 0) {
order--;
pa_half = m_set->phys_addr ^ (1 << (PAGE_SHIFT + order));
if (m->phys_addr < pa_half)
m_tmp = &seg->first_page[atop(pa_half - seg->start)];
else {
m_tmp = m_set;
m_set = &seg->first_page[atop(pa_half - seg->start)];
}
vm_freelist_add(fl, m_tmp, order, 0);
}
KASSERT(m_set == m, ("vm_phys_unfree_page: fatal inconsistency"));
return (TRUE);
}
/*
* Try to zero one physical page. Used by an idle priority thread.
*/
boolean_t
vm_phys_zero_pages_idle(void)
{
static struct vm_freelist *fl;
static int flind, oind, pind;
vm_page_t m, m_tmp;
int domain;
domain = vm_rr_selectdomain();
fl = vm_phys_free_queues[domain][0][0];
mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
for (;;) {
TAILQ_FOREACH_REVERSE(m, &fl[oind].pl, pglist, pageq) {
for (m_tmp = m; m_tmp < &m[1 << oind]; m_tmp++) {
if ((m_tmp->flags & (PG_CACHED | PG_ZERO)) == 0) {
vm_phys_unfree_page(m_tmp);
vm_phys_freecnt_adj(m, -1);
mtx_unlock(&vm_page_queue_free_mtx);
pmap_zero_page_idle(m_tmp);
m_tmp->flags |= PG_ZERO;
mtx_lock(&vm_page_queue_free_mtx);
vm_phys_freecnt_adj(m, 1);
vm_phys_free_pages(m_tmp, 0);
vm_page_zero_count++;
cnt_prezero++;
return (TRUE);
}
}
}
oind++;
if (oind == VM_NFREEORDER) {
oind = 0;
pind++;
if (pind == VM_NFREEPOOL) {
pind = 0;
flind++;
if (flind == vm_nfreelists)
flind = 0;
}
fl = vm_phys_free_queues[domain][flind][pind];
}
}
}
/*
* Allocate a contiguous set of physical pages of the given size
* "npages" from the free lists. All of the physical pages must be at
* or above the given physical address "low" and below the given
* physical address "high". The given value "alignment" determines the
* alignment of the first physical page in the set. If the given value
* "boundary" is non-zero, then the set of physical pages cannot cross
* any physical address boundary that is a multiple of that value. Both
* "alignment" and "boundary" must be a power of two.
*/
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)
{
struct vm_freelist *fl;
struct vm_phys_seg *seg;
vm_paddr_t pa, pa_last, size;
vm_page_t m, m_ret;
u_long npages_end;
int dom, domain, flind, oind, order, pind;
mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
size = npages << PAGE_SHIFT;
KASSERT(size != 0,
("vm_phys_alloc_contig: size must not be 0"));
KASSERT((alignment & (alignment - 1)) == 0,
("vm_phys_alloc_contig: alignment must be a power of 2"));
KASSERT((boundary & (boundary - 1)) == 0,
("vm_phys_alloc_contig: boundary must be a power of 2"));
/* Compute the queue that is the best fit for npages. */
for (order = 0; (1 << order) < npages; order++);
dom = 0;
restartdom:
domain = vm_rr_selectdomain();
for (flind = 0; flind < vm_nfreelists; flind++) {
for (oind = min(order, VM_NFREEORDER - 1); oind < VM_NFREEORDER; oind++) {
for (pind = 0; pind < VM_NFREEPOOL; pind++) {
fl = &vm_phys_free_queues[domain][flind][pind][0];
TAILQ_FOREACH(m_ret, &fl[oind].pl, pageq) {
/*
* A free list may contain physical pages
* from one or more segments.
*/
seg = &vm_phys_segs[m_ret->segind];
if (seg->start > high ||
low >= seg->end)
continue;
/*
* Is the size of this allocation request
* larger than the largest block size?
*/
if (order >= VM_NFREEORDER) {
/*
* Determine if a sufficient number
* of subsequent blocks to satisfy
* the allocation request are free.
*/
pa = VM_PAGE_TO_PHYS(m_ret);
pa_last = pa + size;
for (;;) {
pa += 1 << (PAGE_SHIFT + VM_NFREEORDER - 1);
if (pa >= pa_last)
break;
if (pa < seg->start ||
pa >= seg->end)
break;
m = &seg->first_page[atop(pa - seg->start)];
if (m->order != VM_NFREEORDER - 1)
break;
}
/* If not, continue to the next block. */
if (pa < pa_last)
continue;
}
/*
* Determine if the blocks are within the given range,
* satisfy the given alignment, and do not cross the
* given boundary.
*/
pa = VM_PAGE_TO_PHYS(m_ret);
if (pa >= low &&
pa + size <= high &&
(pa & (alignment - 1)) == 0 &&
((pa ^ (pa + size - 1)) & ~(boundary - 1)) == 0)
goto done;
}
}
}
}
if (++dom < vm_ndomains)
goto restartdom;
return (NULL);
done:
for (m = m_ret; m < &m_ret[npages]; m = &m[1 << oind]) {
fl = (*seg->free_queues)[m->pool];
vm_freelist_rem(fl, m, m->order);
}
if (m_ret->pool != VM_FREEPOOL_DEFAULT)
vm_phys_set_pool(VM_FREEPOOL_DEFAULT, m_ret, oind);
fl = (*seg->free_queues)[m_ret->pool];
vm_phys_split_pages(m_ret, oind, fl, order);
/* Return excess pages to the free lists. */
npages_end = roundup2(npages, 1 << imin(oind, order));
if (npages < npages_end)
vm_phys_free_contig(&m_ret[npages], npages_end - npages);
return (m_ret);
}
#ifdef DDB
/*
* Show the number of physical pages in each of the free lists.
*/
DB_SHOW_COMMAND(freepages, db_show_freepages)
{
struct vm_freelist *fl;
int flind, oind, pind, dom;
for (dom = 0; dom < vm_ndomains; dom++) {
db_printf("DOMAIN: %d\n", dom);
for (flind = 0; flind < vm_nfreelists; flind++) {
db_printf("FREE LIST %d:\n"
"\n ORDER (SIZE) | NUMBER"
"\n ", flind);
for (pind = 0; pind < VM_NFREEPOOL; pind++)
db_printf(" | POOL %d", pind);
db_printf("\n-- ");
for (pind = 0; pind < VM_NFREEPOOL; pind++)
db_printf("-- -- ");
db_printf("--\n");
for (oind = VM_NFREEORDER - 1; oind >= 0; oind--) {
db_printf(" %2.2d (%6.6dK)", oind,
1 << (PAGE_SHIFT - 10 + oind));
for (pind = 0; pind < VM_NFREEPOOL; pind++) {
fl = vm_phys_free_queues[dom][flind][pind];
db_printf(" | %6.6d", fl[oind].lcnt);
}
db_printf("\n");
}
db_printf("\n");
}
db_printf("\n");
}
}
#endif
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