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/* $NetBSD: uvm_page.c,v 1.252 2023/04/09 09:00:56 riastradh Exp $ */
/*-
* Copyright (c) 2019, 2020 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Andrew Doran.
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
/*
* Copyright (c) 1997 Charles D. Cranor and Washington University.
* Copyright (c) 1991, 1993, The Regents of the University of California.
*
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* The Mach Operating System project at Carnegie-Mellon University.
*
* 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.
* 3. 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 REGENTS 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 REGENTS 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.
*
* @(#)vm_page.c 8.3 (Berkeley) 3/21/94
* from: Id: uvm_page.c,v 1.1.2.18 1998/02/06 05:24:42 chs Exp
*
*
* Copyright (c) 1987, 1990 Carnegie-Mellon University.
* All rights reserved.
*
* Permission to use, copy, modify and distribute this software and
* its documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*/
/*
* uvm_page.c: page ops.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: uvm_page.c,v 1.252 2023/04/09 09:00:56 riastradh Exp $");
#include "opt_ddb.h"
#include "opt_uvm.h"
#include "opt_uvmhist.h"
#include "opt_readahead.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sched.h>
#include <sys/kernel.h>
#include <sys/vnode.h>
#include <sys/proc.h>
#include <sys/radixtree.h>
#include <sys/atomic.h>
#include <sys/cpu.h>
#include <ddb/db_active.h>
#include <uvm/uvm.h>
#include <uvm/uvm_ddb.h>
#include <uvm/uvm_pdpolicy.h>
#include <uvm/uvm_pgflcache.h>
/*
* number of pages per-CPU to reserve for the kernel.
*/
#ifndef UVM_RESERVED_PAGES_PER_CPU
#define UVM_RESERVED_PAGES_PER_CPU 5
#endif
int vm_page_reserve_kernel = UVM_RESERVED_PAGES_PER_CPU;
/*
* physical memory size;
*/
psize_t physmem;
/*
* local variables
*/
/*
* these variables record the values returned by vm_page_bootstrap,
* for debugging purposes. The implementation of uvm_pageboot_alloc
* and pmap_startup here also uses them internally.
*/
static vaddr_t virtual_space_start;
static vaddr_t virtual_space_end;
/*
* we allocate an initial number of page colors in uvm_page_init(),
* and remember them. We may re-color pages as cache sizes are
* discovered during the autoconfiguration phase. But we can never
* free the initial set of buckets, since they are allocated using
* uvm_pageboot_alloc().
*/
static size_t recolored_pages_memsize /* = 0 */;
static char *recolored_pages_mem;
/*
* freelist locks - one per bucket.
*/
union uvm_freelist_lock uvm_freelist_locks[PGFL_MAX_BUCKETS]
__cacheline_aligned;
/*
* basic NUMA information.
*/
static struct uvm_page_numa_region {
struct uvm_page_numa_region *next;
paddr_t start;
paddr_t size;
u_int numa_id;
} *uvm_page_numa_region;
#ifdef DEBUG
kmutex_t uvm_zerochecklock __cacheline_aligned;
vaddr_t uvm_zerocheckkva;
#endif /* DEBUG */
/*
* These functions are reserved for uvm(9) internal use and are not
* exported in the header file uvm_physseg.h
*
* Thus they are redefined here.
*/
void uvm_physseg_init_seg(uvm_physseg_t, struct vm_page *);
void uvm_physseg_seg_chomp_slab(uvm_physseg_t, struct vm_page *, size_t);
/* returns a pgs array */
struct vm_page *uvm_physseg_seg_alloc_from_slab(uvm_physseg_t, size_t);
/*
* inline functions
*/
/*
* uvm_pageinsert: insert a page in the object.
*
* => caller must lock object
* => call should have already set pg's object and offset pointers
* and bumped the version counter
*/
static inline void
uvm_pageinsert_object(struct uvm_object *uobj, struct vm_page *pg)
{
KASSERT(uobj == pg->uobject);
KASSERT(rw_write_held(uobj->vmobjlock));
KASSERT((pg->flags & PG_TABLED) == 0);
if ((pg->flags & PG_STAT) != 0) {
/* Cannot use uvm_pagegetdirty(): not yet in radix tree. */
const unsigned int status = pg->flags & (PG_CLEAN | PG_DIRTY);
if ((pg->flags & PG_FILE) != 0) {
if (uobj->uo_npages == 0) {
struct vnode *vp = (struct vnode *)uobj;
mutex_enter(vp->v_interlock);
KASSERT((vp->v_iflag & VI_PAGES) == 0);
vp->v_iflag |= VI_PAGES;
vholdl(vp);
mutex_exit(vp->v_interlock);
}
if (UVM_OBJ_IS_VTEXT(uobj)) {
cpu_count(CPU_COUNT_EXECPAGES, 1);
}
cpu_count(CPU_COUNT_FILEUNKNOWN + status, 1);
} else {
cpu_count(CPU_COUNT_ANONUNKNOWN + status, 1);
}
}
pg->flags |= PG_TABLED;
uobj->uo_npages++;
}
static inline int
uvm_pageinsert_tree(struct uvm_object *uobj, struct vm_page *pg)
{
const uint64_t idx = pg->offset >> PAGE_SHIFT;
int error;
KASSERT(rw_write_held(uobj->vmobjlock));
error = radix_tree_insert_node(&uobj->uo_pages, idx, pg);
if (error != 0) {
return error;
}
if ((pg->flags & PG_CLEAN) == 0) {
uvm_obj_page_set_dirty(pg);
}
KASSERT(((pg->flags & PG_CLEAN) == 0) ==
uvm_obj_page_dirty_p(pg));
return 0;
}
/*
* uvm_page_remove: remove page from object.
*
* => caller must lock object
*/
static inline void
uvm_pageremove_object(struct uvm_object *uobj, struct vm_page *pg)
{
KASSERT(uobj == pg->uobject);
KASSERT(rw_write_held(uobj->vmobjlock));
KASSERT(pg->flags & PG_TABLED);
if ((pg->flags & PG_STAT) != 0) {
/* Cannot use uvm_pagegetdirty(): no longer in radix tree. */
const unsigned int status = pg->flags & (PG_CLEAN | PG_DIRTY);
if ((pg->flags & PG_FILE) != 0) {
if (uobj->uo_npages == 1) {
struct vnode *vp = (struct vnode *)uobj;
mutex_enter(vp->v_interlock);
KASSERT((vp->v_iflag & VI_PAGES) != 0);
vp->v_iflag &= ~VI_PAGES;
holdrelel(vp);
mutex_exit(vp->v_interlock);
}
if (UVM_OBJ_IS_VTEXT(uobj)) {
cpu_count(CPU_COUNT_EXECPAGES, -1);
}
cpu_count(CPU_COUNT_FILEUNKNOWN + status, -1);
} else {
cpu_count(CPU_COUNT_ANONUNKNOWN + status, -1);
}
}
uobj->uo_npages--;
pg->flags &= ~PG_TABLED;
pg->uobject = NULL;
}
static inline void
uvm_pageremove_tree(struct uvm_object *uobj, struct vm_page *pg)
{
struct vm_page *opg __unused;
KASSERT(rw_write_held(uobj->vmobjlock));
opg = radix_tree_remove_node(&uobj->uo_pages, pg->offset >> PAGE_SHIFT);
KASSERT(pg == opg);
}
static void
uvm_page_init_bucket(struct pgfreelist *pgfl, struct pgflbucket *pgb, int num)
{
int i;
pgb->pgb_nfree = 0;
for (i = 0; i < uvmexp.ncolors; i++) {
LIST_INIT(&pgb->pgb_colors[i]);
}
pgfl->pgfl_buckets[num] = pgb;
}
/*
* uvm_page_init: init the page system. called from uvm_init().
*
* => we return the range of kernel virtual memory in kvm_startp/kvm_endp
*/
void
uvm_page_init(vaddr_t *kvm_startp, vaddr_t *kvm_endp)
{
static struct uvm_cpu boot_cpu __cacheline_aligned;
psize_t freepages, pagecount, bucketsize, n;
struct pgflbucket *pgb;
struct vm_page *pagearray;
char *bucketarray;
uvm_physseg_t bank;
int fl, b;
KASSERT(ncpu <= 1);
/*
* init the page queues and free page queue locks, except the
* free list; we allocate that later (with the initial vm_page
* structures).
*/
curcpu()->ci_data.cpu_uvm = &boot_cpu;
uvmpdpol_init();
for (b = 0; b < __arraycount(uvm_freelist_locks); b++) {
mutex_init(&uvm_freelist_locks[b].lock, MUTEX_DEFAULT, IPL_VM);
}
/*
* allocate vm_page structures.
*/
/*
* sanity check:
* before calling this function the MD code is expected to register
* some free RAM with the uvm_page_physload() function. our job
* now is to allocate vm_page structures for this memory.
*/
if (uvm_physseg_get_last() == UVM_PHYSSEG_TYPE_INVALID)
panic("uvm_page_bootstrap: no memory pre-allocated");
/*
* first calculate the number of free pages...
*
* note that we use start/end rather than avail_start/avail_end.
* this allows us to allocate extra vm_page structures in case we
* want to return some memory to the pool after booting.
*/
freepages = 0;
for (bank = uvm_physseg_get_first();
uvm_physseg_valid_p(bank) ;
bank = uvm_physseg_get_next(bank)) {
freepages += (uvm_physseg_get_end(bank) - uvm_physseg_get_start(bank));
}
/*
* Let MD code initialize the number of colors, or default
* to 1 color if MD code doesn't care.
*/
if (uvmexp.ncolors == 0)
uvmexp.ncolors = 1;
uvmexp.colormask = uvmexp.ncolors - 1;
KASSERT((uvmexp.colormask & uvmexp.ncolors) == 0);
/* We always start with only 1 bucket. */
uvm.bucketcount = 1;
/*
* we now know we have (PAGE_SIZE * freepages) bytes of memory we can
* use. for each page of memory we use we need a vm_page structure.
* thus, the total number of pages we can use is the total size of
* the memory divided by the PAGE_SIZE plus the size of the vm_page
* structure. we add one to freepages as a fudge factor to avoid
* truncation errors (since we can only allocate in terms of whole
* pages).
*/
pagecount = ((freepages + 1) << PAGE_SHIFT) /
(PAGE_SIZE + sizeof(struct vm_page));
bucketsize = offsetof(struct pgflbucket, pgb_colors[uvmexp.ncolors]);
bucketsize = roundup2(bucketsize, coherency_unit);
bucketarray = (void *)uvm_pageboot_alloc(
bucketsize * VM_NFREELIST +
pagecount * sizeof(struct vm_page));
pagearray = (struct vm_page *)
(bucketarray + bucketsize * VM_NFREELIST);
for (fl = 0; fl < VM_NFREELIST; fl++) {
pgb = (struct pgflbucket *)(bucketarray + bucketsize * fl);
uvm_page_init_bucket(&uvm.page_free[fl], pgb, 0);
}
memset(pagearray, 0, pagecount * sizeof(struct vm_page));
/*
* init the freelist cache in the disabled state.
*/
uvm_pgflcache_init();
/*
* init the vm_page structures and put them in the correct place.
*/
/* First init the extent */
for (bank = uvm_physseg_get_first(),
uvm_physseg_seg_chomp_slab(bank, pagearray, pagecount);
uvm_physseg_valid_p(bank);
bank = uvm_physseg_get_next(bank)) {
n = uvm_physseg_get_end(bank) - uvm_physseg_get_start(bank);
uvm_physseg_seg_alloc_from_slab(bank, n);
uvm_physseg_init_seg(bank, pagearray);
/* set up page array pointers */
pagearray += n;
pagecount -= n;
}
/*
* pass up the values of virtual_space_start and
* virtual_space_end (obtained by uvm_pageboot_alloc) to the upper
* layers of the VM.
*/
*kvm_startp = round_page(virtual_space_start);
*kvm_endp = trunc_page(virtual_space_end);
/*
* init various thresholds.
*/
uvmexp.reserve_pagedaemon = 1;
uvmexp.reserve_kernel = vm_page_reserve_kernel;
/*
* done!
*/
uvm.page_init_done = true;
}
/*
* uvm_pgfl_lock: lock all freelist buckets
*/
void
uvm_pgfl_lock(void)
{
int i;
for (i = 0; i < __arraycount(uvm_freelist_locks); i++) {
mutex_spin_enter(&uvm_freelist_locks[i].lock);
}
}
/*
* uvm_pgfl_unlock: unlock all freelist buckets
*/
void
uvm_pgfl_unlock(void)
{
int i;
for (i = 0; i < __arraycount(uvm_freelist_locks); i++) {
mutex_spin_exit(&uvm_freelist_locks[i].lock);
}
}
/*
* uvm_setpagesize: set the page size
*
* => sets page_shift and page_mask from uvmexp.pagesize.
*/
void
uvm_setpagesize(void)
{
/*
* If uvmexp.pagesize is 0 at this point, we expect PAGE_SIZE
* to be a constant (indicated by being a non-zero value).
*/
if (uvmexp.pagesize == 0) {
if (PAGE_SIZE == 0)
panic("uvm_setpagesize: uvmexp.pagesize not set");
uvmexp.pagesize = PAGE_SIZE;
}
uvmexp.pagemask = uvmexp.pagesize - 1;
if ((uvmexp.pagemask & uvmexp.pagesize) != 0)
panic("uvm_setpagesize: page size %u (%#x) not a power of two",
uvmexp.pagesize, uvmexp.pagesize);
for (uvmexp.pageshift = 0; ; uvmexp.pageshift++)
if ((1 << uvmexp.pageshift) == uvmexp.pagesize)
break;
}
/*
* uvm_pageboot_alloc: steal memory from physmem for bootstrapping
*/
vaddr_t
uvm_pageboot_alloc(vsize_t size)
{
static bool initialized = false;
vaddr_t addr;
#if !defined(PMAP_STEAL_MEMORY)
vaddr_t vaddr;
paddr_t paddr;
#endif
/*
* on first call to this function, initialize ourselves.
*/
if (initialized == false) {
pmap_virtual_space(&virtual_space_start, &virtual_space_end);
/* round it the way we like it */
virtual_space_start = round_page(virtual_space_start);
virtual_space_end = trunc_page(virtual_space_end);
initialized = true;
}
/* round to page size */
size = round_page(size);
uvmexp.bootpages += atop(size);
#if defined(PMAP_STEAL_MEMORY)
/*
* defer bootstrap allocation to MD code (it may want to allocate
* from a direct-mapped segment). pmap_steal_memory should adjust
* virtual_space_start/virtual_space_end if necessary.
*/
addr = pmap_steal_memory(size, &virtual_space_start,
&virtual_space_end);
return addr;
#else /* !PMAP_STEAL_MEMORY */
/*
* allocate virtual memory for this request
*/
if (virtual_space_start == virtual_space_end ||
(virtual_space_end - virtual_space_start) < size)
panic("uvm_pageboot_alloc: out of virtual space");
addr = virtual_space_start;
#ifdef PMAP_GROWKERNEL
/*
* If the kernel pmap can't map the requested space,
* then allocate more resources for it.
*/
if (uvm_maxkaddr < (addr + size)) {
uvm_maxkaddr = pmap_growkernel(addr + size);
if (uvm_maxkaddr < (addr + size))
panic("uvm_pageboot_alloc: pmap_growkernel() failed");
}
#endif
virtual_space_start += size;
/*
* allocate and mapin physical pages to back new virtual pages
*/
for (vaddr = round_page(addr) ; vaddr < addr + size ;
vaddr += PAGE_SIZE) {
if (!uvm_page_physget(&paddr))
panic("uvm_pageboot_alloc: out of memory");
/*
* Note this memory is no longer managed, so using
* pmap_kenter is safe.
*/
pmap_kenter_pa(vaddr, paddr, VM_PROT_READ|VM_PROT_WRITE, 0);
}
pmap_update(pmap_kernel());
return addr;
#endif /* PMAP_STEAL_MEMORY */
}
#if !defined(PMAP_STEAL_MEMORY)
/*
* uvm_page_physget: "steal" one page from the vm_physmem structure.
*
* => attempt to allocate it off the end of a segment in which the "avail"
* values match the start/end values. if we can't do that, then we
* will advance both values (making them equal, and removing some
* vm_page structures from the non-avail area).
* => return false if out of memory.
*/
/* subroutine: try to allocate from memory chunks on the specified freelist */
static bool uvm_page_physget_freelist(paddr_t *, int);
static bool
uvm_page_physget_freelist(paddr_t *paddrp, int freelist)
{
uvm_physseg_t lcv;
/* pass 1: try allocating from a matching end */
#if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST)
for (lcv = uvm_physseg_get_last(); uvm_physseg_valid_p(lcv); lcv = uvm_physseg_get_prev(lcv))
#else
for (lcv = uvm_physseg_get_first(); uvm_physseg_valid_p(lcv); lcv = uvm_physseg_get_next(lcv))
#endif
{
if (uvm.page_init_done == true)
panic("uvm_page_physget: called _after_ bootstrap");
/* Try to match at front or back on unused segment */
if (uvm_page_physunload(lcv, freelist, paddrp))
return true;
}
/* pass2: forget about matching ends, just allocate something */
#if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST)
for (lcv = uvm_physseg_get_last(); uvm_physseg_valid_p(lcv); lcv = uvm_physseg_get_prev(lcv))
#else
for (lcv = uvm_physseg_get_first(); uvm_physseg_valid_p(lcv); lcv = uvm_physseg_get_next(lcv))
#endif
{
/* Try the front regardless. */
if (uvm_page_physunload_force(lcv, freelist, paddrp))
return true;
}
return false;
}
bool
uvm_page_physget(paddr_t *paddrp)
{
int i;
/* try in the order of freelist preference */
for (i = 0; i < VM_NFREELIST; i++)
if (uvm_page_physget_freelist(paddrp, i) == true)
return (true);
return (false);
}
#endif /* PMAP_STEAL_MEMORY */
/*
* PHYS_TO_VM_PAGE: find vm_page for a PA. used by MI code to get vm_pages
* back from an I/O mapping (ugh!). used in some MD code as well.
*/
struct vm_page *
uvm_phys_to_vm_page(paddr_t pa)
{
paddr_t pf = atop(pa);
paddr_t off;
uvm_physseg_t upm;
upm = uvm_physseg_find(pf, &off);
if (upm != UVM_PHYSSEG_TYPE_INVALID)
return uvm_physseg_get_pg(upm, off);
return(NULL);
}
paddr_t
uvm_vm_page_to_phys(const struct vm_page *pg)
{
return pg->phys_addr & ~(PAGE_SIZE - 1);
}
/*
* uvm_page_numa_load: load NUMA range description.
*/
void
uvm_page_numa_load(paddr_t start, paddr_t size, u_int numa_id)
{
struct uvm_page_numa_region *d;
KASSERT(numa_id < PGFL_MAX_BUCKETS);
d = kmem_alloc(sizeof(*d), KM_SLEEP);
d->start = start;
d->size = size;
d->numa_id = numa_id;
d->next = uvm_page_numa_region;
uvm_page_numa_region = d;
}
/*
* uvm_page_numa_lookup: lookup NUMA node for the given page.
*/
static u_int
uvm_page_numa_lookup(struct vm_page *pg)
{
struct uvm_page_numa_region *d;
static bool warned;
paddr_t pa;
KASSERT(uvm_page_numa_region != NULL);
pa = VM_PAGE_TO_PHYS(pg);
for (d = uvm_page_numa_region; d != NULL; d = d->next) {
if (pa >= d->start && pa < d->start + d->size) {
return d->numa_id;
}
}
if (!warned) {
printf("uvm_page_numa_lookup: failed, first pg=%p pa=%#"
PRIxPADDR "\n", pg, VM_PAGE_TO_PHYS(pg));
warned = true;
}
return 0;
}
/*
* uvm_page_redim: adjust freelist dimensions if they have changed.
*/
static void
uvm_page_redim(int newncolors, int newnbuckets)
{
struct pgfreelist npgfl;
struct pgflbucket *opgb, *npgb;
struct pgflist *ohead, *nhead;
struct vm_page *pg;
size_t bucketsize, bucketmemsize, oldbucketmemsize;
int fl, ob, oc, nb, nc, obuckets, ocolors;
char *bucketarray, *oldbucketmem, *bucketmem;
KASSERT(((newncolors - 1) & newncolors) == 0);
/* Anything to do? */
if (newncolors <= uvmexp.ncolors &&
newnbuckets == uvm.bucketcount) {
return;
}
if (uvm.page_init_done == false) {
uvmexp.ncolors = newncolors;
return;
}
bucketsize = offsetof(struct pgflbucket, pgb_colors[newncolors]);
bucketsize = roundup2(bucketsize, coherency_unit);
bucketmemsize = bucketsize * newnbuckets * VM_NFREELIST +
coherency_unit - 1;
bucketmem = kmem_zalloc(bucketmemsize, KM_SLEEP);
bucketarray = (char *)roundup2((uintptr_t)bucketmem, coherency_unit);
ocolors = uvmexp.ncolors;
obuckets = uvm.bucketcount;
/* Freelist cache musn't be enabled. */
uvm_pgflcache_pause();
/* Make sure we should still do this. */
uvm_pgfl_lock();
if (newncolors <= uvmexp.ncolors &&
newnbuckets == uvm.bucketcount) {
uvm_pgfl_unlock();
uvm_pgflcache_resume();
kmem_free(bucketmem, bucketmemsize);
return;
}
uvmexp.ncolors = newncolors;
uvmexp.colormask = uvmexp.ncolors - 1;
uvm.bucketcount = newnbuckets;
for (fl = 0; fl < VM_NFREELIST; fl++) {
/* Init new buckets in new freelist. */
memset(&npgfl, 0, sizeof(npgfl));
for (nb = 0; nb < newnbuckets; nb++) {
npgb = (struct pgflbucket *)bucketarray;
uvm_page_init_bucket(&npgfl, npgb, nb);
bucketarray += bucketsize;
}
/* Now transfer pages from the old freelist. */
for (nb = ob = 0; ob < obuckets; ob++) {
opgb = uvm.page_free[fl].pgfl_buckets[ob];
for (oc = 0; oc < ocolors; oc++) {
ohead = &opgb->pgb_colors[oc];
while ((pg = LIST_FIRST(ohead)) != NULL) {
LIST_REMOVE(pg, pageq.list);
/*
* Here we decide on the NEW color &
* bucket for the page. For NUMA
* we'll use the info that the
* hardware gave us. For non-NUMA
* assign take physical page frame
* number and cache color into
* account. We do this to try and
* avoid defeating any memory
* interleaving in the hardware.
*/
KASSERT(
uvm_page_get_bucket(pg) == ob);
KASSERT(fl ==
uvm_page_get_freelist(pg));
if (uvm_page_numa_region != NULL) {
nb = uvm_page_numa_lookup(pg);
} else {
nb = atop(VM_PAGE_TO_PHYS(pg))
/ uvmexp.ncolors / 8
% newnbuckets;
}
uvm_page_set_bucket(pg, nb);
npgb = npgfl.pgfl_buckets[nb];
npgb->pgb_nfree++;
nc = VM_PGCOLOR(pg);
nhead = &npgb->pgb_colors[nc];
LIST_INSERT_HEAD(nhead, pg, pageq.list);
}
}
}
/* Install the new freelist. */
memcpy(&uvm.page_free[fl], &npgfl, sizeof(npgfl));
}
/* Unlock and free the old memory. */
oldbucketmemsize = recolored_pages_memsize;
oldbucketmem = recolored_pages_mem;
recolored_pages_memsize = bucketmemsize;
recolored_pages_mem = bucketmem;
uvm_pgfl_unlock();
uvm_pgflcache_resume();
if (oldbucketmemsize) {
kmem_free(oldbucketmem, oldbucketmemsize);
}
/*
* this calls uvm_km_alloc() which may want to hold
* uvm_freelist_lock.
*/
uvm_pager_realloc_emerg();
}
/*
* uvm_page_recolor: Recolor the pages if the new color count is
* larger than the old one.
*/
void
uvm_page_recolor(int newncolors)
{
uvm_page_redim(newncolors, uvm.bucketcount);
}
/*
* uvm_page_rebucket: Determine a bucket structure and redim the free
* lists to match.
*/
void
uvm_page_rebucket(void)
{
u_int min_numa, max_numa, npackage, shift;
struct cpu_info *ci, *ci2, *ci3;
CPU_INFO_ITERATOR cii;
/*
* If we have more than one NUMA node, and the maximum NUMA node ID
* is less than PGFL_MAX_BUCKETS, then we'll use NUMA distribution
* for free pages.
*/
min_numa = (u_int)-1;
max_numa = 0;
for (CPU_INFO_FOREACH(cii, ci)) {
if (ci->ci_numa_id < min_numa) {
min_numa = ci->ci_numa_id;
}
if (ci->ci_numa_id > max_numa) {
max_numa = ci->ci_numa_id;
}
}
if (min_numa != max_numa && max_numa < PGFL_MAX_BUCKETS) {
aprint_debug("UVM: using NUMA allocation scheme\n");
for (CPU_INFO_FOREACH(cii, ci)) {
ci->ci_data.cpu_uvm->pgflbucket = ci->ci_numa_id;
}
uvm_page_redim(uvmexp.ncolors, max_numa + 1);
return;
}
/*
* Otherwise we'll go with a scheme to maximise L2/L3 cache locality
* and minimise lock contention. Count the total number of CPU
* packages, and then try to distribute the buckets among CPU
* packages evenly.
*/
npackage = curcpu()->ci_nsibling[CPUREL_PACKAGE1ST];
/*
* Figure out how to arrange the packages & buckets, and the total
* number of buckets we need. XXX 2 may not be the best factor.
*/
for (shift = 0; npackage > PGFL_MAX_BUCKETS; shift++) {
npackage >>= 1;
}
uvm_page_redim(uvmexp.ncolors, npackage);
/*
* Now tell each CPU which bucket to use. In the outer loop, scroll
* through all CPU packages.
*/
npackage = 0;
ci = curcpu();
ci2 = ci->ci_sibling[CPUREL_PACKAGE1ST];
do {
/*
* In the inner loop, scroll through all CPUs in the package
* and assign the same bucket ID.
*/
ci3 = ci2;
do {
ci3->ci_data.cpu_uvm->pgflbucket = npackage >> shift;
ci3 = ci3->ci_sibling[CPUREL_PACKAGE];
} while (ci3 != ci2);
npackage++;
ci2 = ci2->ci_sibling[CPUREL_PACKAGE1ST];
} while (ci2 != ci->ci_sibling[CPUREL_PACKAGE1ST]);
aprint_debug("UVM: using package allocation scheme, "
"%d package(s) per bucket\n", 1 << shift);
}
/*
* uvm_cpu_attach: initialize per-CPU data structures.
*/
void
uvm_cpu_attach(struct cpu_info *ci)
{
struct uvm_cpu *ucpu;
/* Already done in uvm_page_init(). */
if (!CPU_IS_PRIMARY(ci)) {
/* Add more reserve pages for this CPU. */
uvmexp.reserve_kernel += vm_page_reserve_kernel;
/* Allocate per-CPU data structures. */
ucpu = kmem_zalloc(sizeof(struct uvm_cpu) + coherency_unit - 1,
KM_SLEEP);
ucpu = (struct uvm_cpu *)roundup2((uintptr_t)ucpu,
coherency_unit);
ci->ci_data.cpu_uvm = ucpu;
} else {
ucpu = ci->ci_data.cpu_uvm;
}
uvmpdpol_init_cpu(ucpu);
/*
* Attach RNG source for this CPU's VM events
*/
rnd_attach_source(&ucpu->rs, ci->ci_data.cpu_name, RND_TYPE_VM,
RND_FLAG_COLLECT_TIME|RND_FLAG_COLLECT_VALUE|
RND_FLAG_ESTIMATE_VALUE);
}
/*
* uvm_availmem: fetch the total amount of free memory in pages. this can
* have a detrimental effect on performance due to false sharing; don't call
* unless needed.
*
* some users can request the amount of free memory so often that it begins
* to impact upon performance. if calling frequently and an inexact value
* is okay, call with cached = true.
*/
int
uvm_availmem(bool cached)
{
int64_t fp;
cpu_count_sync(cached);
if ((fp = cpu_count_get(CPU_COUNT_FREEPAGES)) < 0) {
/*
* XXXAD could briefly go negative because it's impossible
* to get a clean snapshot. address this for other counters
* used as running totals before NetBSD 10 although less
* important for those.
*/
fp = 0;
}
return (int)fp;
}
/*
* uvm_pagealloc_pgb: helper routine that tries to allocate any color from a
* specific freelist and specific bucket only.
*
* => must be at IPL_VM or higher to protect per-CPU data structures.
*/
static struct vm_page *
uvm_pagealloc_pgb(struct uvm_cpu *ucpu, int f, int b, int *trycolorp, int flags)
{
int c, trycolor, colormask;
struct pgflbucket *pgb;
struct vm_page *pg;
kmutex_t *lock;
bool fill;
/*
* Skip the bucket if empty, no lock needed. There could be many
* empty freelists/buckets.
*/
pgb = uvm.page_free[f].pgfl_buckets[b];
if (pgb->pgb_nfree == 0) {
return NULL;
}
/* Skip bucket if low on memory. */
lock = &uvm_freelist_locks[b].lock;
mutex_spin_enter(lock);
if (__predict_false(pgb->pgb_nfree <= uvmexp.reserve_kernel)) {
if ((flags & UVM_PGA_USERESERVE) == 0 ||
(pgb->pgb_nfree <= uvmexp.reserve_pagedaemon &&
curlwp != uvm.pagedaemon_lwp)) {
mutex_spin_exit(lock);
return NULL;
}
fill = false;
} else {
fill = true;
}
/* Try all page colors as needed. */
c = trycolor = *trycolorp;
colormask = uvmexp.colormask;
do {
pg = LIST_FIRST(&pgb->pgb_colors[c]);
if (__predict_true(pg != NULL)) {
/*
* Got a free page! PG_FREE must be cleared under
* lock because of uvm_pglistalloc().
*/
LIST_REMOVE(pg, pageq.list);
KASSERT(pg->flags == PG_FREE);
pg->flags = PG_BUSY | PG_CLEAN | PG_FAKE;
pgb->pgb_nfree--;
CPU_COUNT(CPU_COUNT_FREEPAGES, -1);
/*
* While we have the bucket locked and our data
* structures fresh in L1 cache, we have an ideal
* opportunity to grab some pages for the freelist
* cache without causing extra contention. Only do
* so if we found pages in this CPU's preferred
* bucket.
*/
if (__predict_true(b == ucpu->pgflbucket && fill)) {
uvm_pgflcache_fill(ucpu, f, b, c);
}
mutex_spin_exit(lock);
KASSERT(uvm_page_get_bucket(pg) == b);
CPU_COUNT(c == trycolor ?
CPU_COUNT_COLORHIT : CPU_COUNT_COLORMISS, 1);
CPU_COUNT(CPU_COUNT_CPUMISS, 1);
*trycolorp = c;
return pg;
}
c = (c + 1) & colormask;
} while (c != trycolor);
mutex_spin_exit(lock);
return NULL;
}
/*
* uvm_pagealloc_pgfl: helper routine for uvm_pagealloc_strat that allocates
* any color from any bucket, in a specific freelist.
*
* => must be at IPL_VM or higher to protect per-CPU data structures.
*/
static struct vm_page *
uvm_pagealloc_pgfl(struct uvm_cpu *ucpu, int f, int *trycolorp, int flags)
{
int b, trybucket, bucketcount;
struct vm_page *pg;
/* Try for the exact thing in the per-CPU cache. */
if ((pg = uvm_pgflcache_alloc(ucpu, f, *trycolorp)) != NULL) {
CPU_COUNT(CPU_COUNT_CPUHIT, 1);
CPU_COUNT(CPU_COUNT_COLORHIT, 1);
return pg;
}
/* Walk through all buckets, trying our preferred bucket first. */
trybucket = ucpu->pgflbucket;
b = trybucket;
bucketcount = uvm.bucketcount;
do {
pg = uvm_pagealloc_pgb(ucpu, f, b, trycolorp, flags);
if (pg != NULL) {
return pg;
}
b = (b + 1 == bucketcount ? 0 : b + 1);
} while (b != trybucket);
return NULL;
}
/*
* uvm_pagealloc_strat: allocate vm_page from a particular free list.
*
* => return null if no pages free
* => wake up pagedaemon if number of free pages drops below low water mark
* => if obj != NULL, obj must be locked (to put in obj's tree)
* => if anon != NULL, anon must be locked (to put in anon)
* => only one of obj or anon can be non-null
* => caller must activate/deactivate page if it is not wired.
* => free_list is ignored if strat == UVM_PGA_STRAT_NORMAL.
* => policy decision: it is more important to pull a page off of the
* appropriate priority free list than it is to get a page from the
* correct bucket or color bin. This is because we live with the
* consequences of a bad free list decision for the entire
* lifetime of the page, e.g. if the page comes from memory that
* is slower to access.
*/
struct vm_page *
uvm_pagealloc_strat(struct uvm_object *obj, voff_t off, struct vm_anon *anon,
int flags, int strat, int free_list)
{
int color, lcv, error, s;
struct uvm_cpu *ucpu;
struct vm_page *pg;
lwp_t *l;
KASSERT(obj == NULL || anon == NULL);
KASSERT(anon == NULL || (flags & UVM_FLAG_COLORMATCH) || off == 0);
KASSERT(off == trunc_page(off));
KASSERT(obj == NULL || rw_write_held(obj->vmobjlock));
KASSERT(anon == NULL || anon->an_lock == NULL ||
rw_write_held(anon->an_lock));
/*
* This implements a global round-robin page coloring
* algorithm.
*/
s = splvm();
ucpu = curcpu()->ci_data.cpu_uvm;
if (flags & UVM_FLAG_COLORMATCH) {
color = atop(off) & uvmexp.colormask;
} else {
color = ucpu->pgflcolor;
}
/*
* fail if any of these conditions is true:
* [1] there really are no free pages, or
* [2] only kernel "reserved" pages remain and
* reserved pages have not been requested.
* [3] only pagedaemon "reserved" pages remain and
* the requestor isn't the pagedaemon.
* we make kernel reserve pages available if called by a
* kernel thread.
*/
l = curlwp;
if (__predict_true(l != NULL) && (l->l_flag & LW_SYSTEM) != 0) {
flags |= UVM_PGA_USERESERVE;
}
again:
switch (strat) {
case UVM_PGA_STRAT_NORMAL:
/* Check freelists: descending priority (ascending id) order. */
for (lcv = 0; lcv < VM_NFREELIST; lcv++) {
pg = uvm_pagealloc_pgfl(ucpu, lcv, &color, flags);
if (pg != NULL) {
goto gotit;
}
}
/* No pages free! Have pagedaemon free some memory. */
splx(s);
uvm_kick_pdaemon();
return NULL;
case UVM_PGA_STRAT_ONLY:
case UVM_PGA_STRAT_FALLBACK:
/* Attempt to allocate from the specified free list. */
KASSERT(free_list >= 0);
KASSERT(free_list < VM_NFREELIST);
pg = uvm_pagealloc_pgfl(ucpu, free_list, &color, flags);
if (pg != NULL) {
goto gotit;
}
/* Fall back, if possible. */
if (strat == UVM_PGA_STRAT_FALLBACK) {
strat = UVM_PGA_STRAT_NORMAL;
goto again;
}
/* No pages free! Have pagedaemon free some memory. */
splx(s);
uvm_kick_pdaemon();
return NULL;
case UVM_PGA_STRAT_NUMA:
/*
* NUMA strategy (experimental): allocating from the correct
* bucket is more important than observing freelist
* priority. Look only to the current NUMA node; if that
* fails, we need to look to other NUMA nodes, so retry with
* the normal strategy.
*/
for (lcv = 0; lcv < VM_NFREELIST; lcv++) {
pg = uvm_pgflcache_alloc(ucpu, lcv, color);
if (pg != NULL) {
CPU_COUNT(CPU_COUNT_CPUHIT, 1);
CPU_COUNT(CPU_COUNT_COLORHIT, 1);
goto gotit;
}
pg = uvm_pagealloc_pgb(ucpu, lcv,
ucpu->pgflbucket, &color, flags);
if (pg != NULL) {
goto gotit;
}
}
strat = UVM_PGA_STRAT_NORMAL;
goto again;
default:
panic("uvm_pagealloc_strat: bad strat %d", strat);
/* NOTREACHED */
}
gotit:
/*
* We now know which color we actually allocated from; set
* the next color accordingly.
*/
ucpu->pgflcolor = (color + 1) & uvmexp.colormask;
/*
* while still at IPL_VM, update allocation statistics.
*/
if (anon) {
CPU_COUNT(CPU_COUNT_ANONCLEAN, 1);
}
splx(s);
KASSERT(pg->flags == (PG_BUSY|PG_CLEAN|PG_FAKE));
/*
* assign the page to the object. as the page was free, we know
* that pg->uobject and pg->uanon are NULL. we only need to take
* the page's interlock if we are changing the values.
*/
if (anon != NULL || obj != NULL) {
mutex_enter(&pg->interlock);
}
pg->offset = off;
pg->uobject = obj;
pg->uanon = anon;
KASSERT(uvm_page_owner_locked_p(pg, true));
if (anon) {
anon->an_page = pg;
pg->flags |= PG_ANON;
mutex_exit(&pg->interlock);
} else if (obj) {
/*
* set PG_FILE|PG_AOBJ before the first uvm_pageinsert.
*/
if (UVM_OBJ_IS_VNODE(obj)) {
pg->flags |= PG_FILE;
} else if (UVM_OBJ_IS_AOBJ(obj)) {
pg->flags |= PG_AOBJ;
}
uvm_pageinsert_object(obj, pg);
mutex_exit(&pg->interlock);
error = uvm_pageinsert_tree(obj, pg);
if (error != 0) {
mutex_enter(&pg->interlock);
uvm_pageremove_object(obj, pg);
mutex_exit(&pg->interlock);
uvm_pagefree(pg);
return NULL;
}
}
#if defined(UVM_PAGE_TRKOWN)
pg->owner_tag = NULL;
#endif
UVM_PAGE_OWN(pg, "new alloc");
if (flags & UVM_PGA_ZERO) {
/* A zero'd page is not clean. */
if (obj != NULL || anon != NULL) {
uvm_pagemarkdirty(pg, UVM_PAGE_STATUS_DIRTY);
}
pmap_zero_page(VM_PAGE_TO_PHYS(pg));
}
return(pg);
}
/*
* uvm_pagereplace: replace a page with another
*
* => object must be locked
* => page interlocks must be held
*/
void
uvm_pagereplace(struct vm_page *oldpg, struct vm_page *newpg)
{
struct uvm_object *uobj = oldpg->uobject;
struct vm_page *pg __diagused;
uint64_t idx;
KASSERT((oldpg->flags & PG_TABLED) != 0);
KASSERT(uobj != NULL);
KASSERT((newpg->flags & PG_TABLED) == 0);
KASSERT(newpg->uobject == NULL);
KASSERT(rw_write_held(uobj->vmobjlock));
KASSERT(mutex_owned(&oldpg->interlock));
KASSERT(mutex_owned(&newpg->interlock));
newpg->uobject = uobj;
newpg->offset = oldpg->offset;
idx = newpg->offset >> PAGE_SHIFT;
pg = radix_tree_replace_node(&uobj->uo_pages, idx, newpg);
KASSERT(pg == oldpg);
if (((oldpg->flags ^ newpg->flags) & PG_CLEAN) != 0) {
if ((newpg->flags & PG_CLEAN) != 0) {
uvm_obj_page_clear_dirty(newpg);
} else {
uvm_obj_page_set_dirty(newpg);
}
}
/*
* oldpg's PG_STAT is stable. newpg is not reachable by others yet.
*/
newpg->flags |=
(newpg->flags & ~PG_STAT) | (oldpg->flags & PG_STAT);
uvm_pageinsert_object(uobj, newpg);
uvm_pageremove_object(uobj, oldpg);
}
/*
* uvm_pagerealloc: reallocate a page from one object to another
*
* => both objects must be locked
*/
int
uvm_pagerealloc(struct vm_page *pg, struct uvm_object *newobj, voff_t newoff)
{
int error = 0;
/*
* remove it from the old object
*/
if (pg->uobject) {
uvm_pageremove_tree(pg->uobject, pg);
uvm_pageremove_object(pg->uobject, pg);
}
/*
* put it in the new object
*/
if (newobj) {
mutex_enter(&pg->interlock);
pg->uobject = newobj;
pg->offset = newoff;
if (UVM_OBJ_IS_VNODE(newobj)) {
pg->flags |= PG_FILE;
} else if (UVM_OBJ_IS_AOBJ(newobj)) {
pg->flags |= PG_AOBJ;
}
uvm_pageinsert_object(newobj, pg);
mutex_exit(&pg->interlock);
error = uvm_pageinsert_tree(newobj, pg);
if (error != 0) {
mutex_enter(&pg->interlock);
uvm_pageremove_object(newobj, pg);
mutex_exit(&pg->interlock);
}
}
return error;
}
/*
* uvm_pagefree: free page
*
* => erase page's identity (i.e. remove from object)
* => put page on free list
* => caller must lock owning object (either anon or uvm_object)
* => assumes all valid mappings of pg are gone
*/
void
uvm_pagefree(struct vm_page *pg)
{
struct pgfreelist *pgfl;
struct pgflbucket *pgb;
struct uvm_cpu *ucpu;
kmutex_t *lock;
int bucket, s;
bool locked;
#ifdef DEBUG
if (pg->uobject == (void *)0xdeadbeef &&
pg->uanon == (void *)0xdeadbeef) {
panic("uvm_pagefree: freeing free page %p", pg);
}
#endif /* DEBUG */
KASSERT((pg->flags & PG_PAGEOUT) == 0);
KASSERT(!(pg->flags & PG_FREE));
KASSERT(pg->uobject == NULL || rw_write_held(pg->uobject->vmobjlock));
KASSERT(pg->uobject != NULL || pg->uanon == NULL ||
rw_write_held(pg->uanon->an_lock));
/*
* remove the page from the object's tree before acquiring any page
* interlocks: this can acquire locks to free radixtree nodes.
*/
if (pg->uobject != NULL) {
uvm_pageremove_tree(pg->uobject, pg);
}
/*
* if the page is loaned, resolve the loan instead of freeing.
*/
if (pg->loan_count) {
KASSERT(pg->wire_count == 0);
/*
* if the page is owned by an anon then we just want to
* drop anon ownership. the kernel will free the page when
* it is done with it. if the page is owned by an object,
* remove it from the object and mark it dirty for the benefit
* of possible anon owners.
*
* regardless of previous ownership, wakeup any waiters,
* unbusy the page, and we're done.
*/
uvm_pagelock(pg);
locked = true;
if (pg->uobject != NULL) {
uvm_pageremove_object(pg->uobject, pg);
pg->flags &= ~(PG_FILE|PG_AOBJ);
} else if (pg->uanon != NULL) {
if ((pg->flags & PG_ANON) == 0) {
pg->loan_count--;
} else {
const unsigned status = uvm_pagegetdirty(pg);
pg->flags &= ~PG_ANON;
cpu_count(CPU_COUNT_ANONUNKNOWN + status, -1);
}
pg->uanon->an_page = NULL;
pg->uanon = NULL;
}
if (pg->pqflags & PQ_WANTED) {
wakeup(pg);
}
pg->pqflags &= ~PQ_WANTED;
pg->flags &= ~(PG_BUSY|PG_RELEASED|PG_PAGER1);
#ifdef UVM_PAGE_TRKOWN
pg->owner_tag = NULL;
#endif
KASSERT((pg->flags & PG_STAT) == 0);
if (pg->loan_count) {
KASSERT(pg->uobject == NULL);
if (pg->uanon == NULL) {
uvm_pagedequeue(pg);
}
uvm_pageunlock(pg);
return;
}
} else if (pg->uobject != NULL || pg->uanon != NULL ||
pg->wire_count != 0) {
uvm_pagelock(pg);
locked = true;
} else {
locked = false;
}
/*
* remove page from its object or anon.
*/
if (pg->uobject != NULL) {
uvm_pageremove_object(pg->uobject, pg);
} else if (pg->uanon != NULL) {
const unsigned int status = uvm_pagegetdirty(pg);
pg->uanon->an_page = NULL;
pg->uanon = NULL;
cpu_count(CPU_COUNT_ANONUNKNOWN + status, -1);
}
/*
* if the page was wired, unwire it now.
*/
if (pg->wire_count) {
pg->wire_count = 0;
atomic_dec_uint(&uvmexp.wired);
}
if (locked) {
/*
* wake anyone waiting on the page.
*/
if ((pg->pqflags & PQ_WANTED) != 0) {
pg->pqflags &= ~PQ_WANTED;
wakeup(pg);
}
/*
* now remove the page from the queues.
*/
uvm_pagedequeue(pg);
uvm_pageunlock(pg);
} else {
KASSERT(!uvmpdpol_pageisqueued_p(pg));
}
/*
* and put on free queue
*/
#ifdef DEBUG
pg->uobject = (void *)0xdeadbeef;
pg->uanon = (void *)0xdeadbeef;
#endif /* DEBUG */
/* Try to send the page to the per-CPU cache. */
s = splvm();
ucpu = curcpu()->ci_data.cpu_uvm;
bucket = uvm_page_get_bucket(pg);
if (bucket == ucpu->pgflbucket && uvm_pgflcache_free(ucpu, pg)) {
splx(s);
return;
}
/* Didn't work. Never mind, send it to a global bucket. */
pgfl = &uvm.page_free[uvm_page_get_freelist(pg)];
pgb = pgfl->pgfl_buckets[bucket];
lock = &uvm_freelist_locks[bucket].lock;
mutex_spin_enter(lock);
/* PG_FREE must be set under lock because of uvm_pglistalloc(). */
pg->flags = PG_FREE;
LIST_INSERT_HEAD(&pgb->pgb_colors[VM_PGCOLOR(pg)], pg, pageq.list);
pgb->pgb_nfree++;
CPU_COUNT(CPU_COUNT_FREEPAGES, 1);
mutex_spin_exit(lock);
splx(s);
}
/*
* uvm_page_unbusy: unbusy an array of pages.
*
* => pages must either all belong to the same object, or all belong to anons.
* => if pages are object-owned, object must be locked.
* => if pages are anon-owned, anons must be locked.
* => caller must make sure that anon-owned pages are not PG_RELEASED.
*/
void
uvm_page_unbusy(struct vm_page **pgs, int npgs)
{
struct vm_page *pg;
int i, pageout_done;
UVMHIST_FUNC(__func__); UVMHIST_CALLED(ubchist);
pageout_done = 0;
for (i = 0; i < npgs; i++) {
pg = pgs[i];
if (pg == NULL || pg == PGO_DONTCARE) {
continue;
}
KASSERT(uvm_page_owner_locked_p(pg, true));
KASSERT(pg->flags & PG_BUSY);
if (pg->flags & PG_PAGEOUT) {
pg->flags &= ~PG_PAGEOUT;
pg->flags |= PG_RELEASED;
pageout_done++;
atomic_inc_uint(&uvmexp.pdfreed);
}
if (pg->flags & PG_RELEASED) {
UVMHIST_LOG(ubchist, "releasing pg %#jx",
(uintptr_t)pg, 0, 0, 0);
KASSERT(pg->uobject != NULL ||
(pg->uanon != NULL && pg->uanon->an_ref > 0));
pg->flags &= ~PG_RELEASED;
uvm_pagefree(pg);
} else {
UVMHIST_LOG(ubchist, "unbusying pg %#jx",
(uintptr_t)pg, 0, 0, 0);
KASSERT((pg->flags & PG_FAKE) == 0);
pg->flags &= ~PG_BUSY;
uvm_pagelock(pg);
uvm_pagewakeup(pg);
uvm_pageunlock(pg);
UVM_PAGE_OWN(pg, NULL);
}
}
if (pageout_done != 0) {
uvm_pageout_done(pageout_done);
}
}
/*
* uvm_pagewait: wait for a busy page
*
* => page must be known PG_BUSY
* => object must be read or write locked
* => object will be unlocked on return
*/
void
uvm_pagewait(struct vm_page *pg, krwlock_t *lock, const char *wmesg)
{
KASSERT(rw_lock_held(lock));
KASSERT((pg->flags & PG_BUSY) != 0);
KASSERT(uvm_page_owner_locked_p(pg, false));
mutex_enter(&pg->interlock);
pg->pqflags |= PQ_WANTED;
rw_exit(lock);
UVM_UNLOCK_AND_WAIT(pg, &pg->interlock, false, wmesg, 0);
}
/*
* uvm_pagewakeup: wake anyone waiting on a page
*
* => page interlock must be held
*/
void
uvm_pagewakeup(struct vm_page *pg)
{
UVMHIST_FUNC(__func__); UVMHIST_CALLED(ubchist);
KASSERT(mutex_owned(&pg->interlock));
UVMHIST_LOG(ubchist, "waking pg %#jx", (uintptr_t)pg, 0, 0, 0);
if ((pg->pqflags & PQ_WANTED) != 0) {
wakeup(pg);
pg->pqflags &= ~PQ_WANTED;
}
}
/*
* uvm_pagewanted_p: return true if someone is waiting on the page
*
* => object must be write locked (lock out all concurrent access)
*/
bool
uvm_pagewanted_p(struct vm_page *pg)
{
KASSERT(uvm_page_owner_locked_p(pg, true));
return (atomic_load_relaxed(&pg->pqflags) & PQ_WANTED) != 0;
}
#if defined(UVM_PAGE_TRKOWN)
/*
* uvm_page_own: set or release page ownership
*
* => this is a debugging function that keeps track of who sets PG_BUSY
* and where they do it. it can be used to track down problems
* such a process setting "PG_BUSY" and never releasing it.
* => page's object [if any] must be locked
* => if "tag" is NULL then we are releasing page ownership
*/
void
uvm_page_own(struct vm_page *pg, const char *tag)
{
KASSERT((pg->flags & (PG_PAGEOUT|PG_RELEASED)) == 0);
KASSERT(uvm_page_owner_locked_p(pg, true));
/* gain ownership? */
if (tag) {
KASSERT((pg->flags & PG_BUSY) != 0);
if (pg->owner_tag) {
printf("uvm_page_own: page %p already owned "
"by proc %d.%d [%s]\n", pg,
pg->owner, pg->lowner, pg->owner_tag);
panic("uvm_page_own");
}
pg->owner = curproc->p_pid;
pg->lowner = curlwp->l_lid;
pg->owner_tag = tag;
return;
}
/* drop ownership */
KASSERT((pg->flags & PG_BUSY) == 0);
if (pg->owner_tag == NULL) {
printf("uvm_page_own: dropping ownership of an non-owned "
"page (%p)\n", pg);
panic("uvm_page_own");
}
pg->owner_tag = NULL;
}
#endif
/*
* uvm_pagelookup: look up a page
*
* => caller should lock object to keep someone from pulling the page
* out from under it
*/
struct vm_page *
uvm_pagelookup(struct uvm_object *obj, voff_t off)
{
struct vm_page *pg;
KASSERT(db_active || rw_lock_held(obj->vmobjlock));
pg = radix_tree_lookup_node(&obj->uo_pages, off >> PAGE_SHIFT);
KASSERT(pg == NULL || obj->uo_npages != 0);
KASSERT(pg == NULL || (pg->flags & (PG_RELEASED|PG_PAGEOUT)) == 0 ||
(pg->flags & PG_BUSY) != 0);
return pg;
}
/*
* uvm_pagewire: wire the page, thus removing it from the daemon's grasp
*
* => caller must lock objects
* => caller must hold pg->interlock
*/
void
uvm_pagewire(struct vm_page *pg)
{
KASSERT(uvm_page_owner_locked_p(pg, true));
KASSERT(mutex_owned(&pg->interlock));
#if defined(READAHEAD_STATS)
if ((pg->flags & PG_READAHEAD) != 0) {
uvm_ra_hit.ev_count++;
pg->flags &= ~PG_READAHEAD;
}
#endif /* defined(READAHEAD_STATS) */
if (pg->wire_count == 0) {
uvm_pagedequeue(pg);
atomic_inc_uint(&uvmexp.wired);
}
pg->wire_count++;
KASSERT(pg->wire_count > 0); /* detect wraparound */
}
/*
* uvm_pageunwire: unwire the page.
*
* => activate if wire count goes to zero.
* => caller must lock objects
* => caller must hold pg->interlock
*/
void
uvm_pageunwire(struct vm_page *pg)
{
KASSERT(uvm_page_owner_locked_p(pg, true));
KASSERT(pg->wire_count != 0);
KASSERT(!uvmpdpol_pageisqueued_p(pg));
KASSERT(mutex_owned(&pg->interlock));
pg->wire_count--;
if (pg->wire_count == 0) {
uvm_pageactivate(pg);
KASSERT(uvmexp.wired != 0);
atomic_dec_uint(&uvmexp.wired);
}
}
/*
* uvm_pagedeactivate: deactivate page
*
* => caller must lock objects
* => caller must check to make sure page is not wired
* => object that page belongs to must be locked (so we can adjust pg->flags)
* => caller must clear the reference on the page before calling
* => caller must hold pg->interlock
*/
void
uvm_pagedeactivate(struct vm_page *pg)
{
KASSERT(uvm_page_owner_locked_p(pg, false));
KASSERT(mutex_owned(&pg->interlock));
if (pg->wire_count == 0) {
KASSERT(uvmpdpol_pageisqueued_p(pg));
uvmpdpol_pagedeactivate(pg);
}
}
/*
* uvm_pageactivate: activate page
*
* => caller must lock objects
* => caller must hold pg->interlock
*/
void
uvm_pageactivate(struct vm_page *pg)
{
KASSERT(uvm_page_owner_locked_p(pg, false));
KASSERT(mutex_owned(&pg->interlock));
#if defined(READAHEAD_STATS)
if ((pg->flags & PG_READAHEAD) != 0) {
uvm_ra_hit.ev_count++;
pg->flags &= ~PG_READAHEAD;
}
#endif /* defined(READAHEAD_STATS) */
if (pg->wire_count == 0) {
uvmpdpol_pageactivate(pg);
}
}
/*
* uvm_pagedequeue: remove a page from any paging queue
*
* => caller must lock objects
* => caller must hold pg->interlock
*/
void
uvm_pagedequeue(struct vm_page *pg)
{
KASSERT(uvm_page_owner_locked_p(pg, true));
KASSERT(mutex_owned(&pg->interlock));
if (uvmpdpol_pageisqueued_p(pg)) {
uvmpdpol_pagedequeue(pg);
}
}
/*
* uvm_pageenqueue: add a page to a paging queue without activating.
* used where a page is not really demanded (yet). eg. read-ahead
*
* => caller must lock objects
* => caller must hold pg->interlock
*/
void
uvm_pageenqueue(struct vm_page *pg)
{
KASSERT(uvm_page_owner_locked_p(pg, false));
KASSERT(mutex_owned(&pg->interlock));
if (pg->wire_count == 0 && !uvmpdpol_pageisqueued_p(pg)) {
uvmpdpol_pageenqueue(pg);
}
}
/*
* uvm_pagelock: acquire page interlock
*/
void
uvm_pagelock(struct vm_page *pg)
{
mutex_enter(&pg->interlock);
}
/*
* uvm_pagelock2: acquire two page interlocks
*/
void
uvm_pagelock2(struct vm_page *pg1, struct vm_page *pg2)
{
if (pg1 < pg2) {
mutex_enter(&pg1->interlock);
mutex_enter(&pg2->interlock);
} else {
mutex_enter(&pg2->interlock);
mutex_enter(&pg1->interlock);
}
}
/*
* uvm_pageunlock: release page interlock, and if a page replacement intent
* is set on the page, pass it to uvmpdpol to make real.
*
* => caller must hold pg->interlock
*/
void
uvm_pageunlock(struct vm_page *pg)
{
if ((pg->pqflags & PQ_INTENT_SET) == 0 ||
(pg->pqflags & PQ_INTENT_QUEUED) != 0) {
mutex_exit(&pg->interlock);
return;
}
pg->pqflags |= PQ_INTENT_QUEUED;
mutex_exit(&pg->interlock);
uvmpdpol_pagerealize(pg);
}
/*
* uvm_pageunlock2: release two page interlocks, and for both pages if a
* page replacement intent is set on the page, pass it to uvmpdpol to make
* real.
*
* => caller must hold pg->interlock
*/
void
uvm_pageunlock2(struct vm_page *pg1, struct vm_page *pg2)
{
if ((pg1->pqflags & PQ_INTENT_SET) == 0 ||
(pg1->pqflags & PQ_INTENT_QUEUED) != 0) {
mutex_exit(&pg1->interlock);
pg1 = NULL;
} else {
pg1->pqflags |= PQ_INTENT_QUEUED;
mutex_exit(&pg1->interlock);
}
if ((pg2->pqflags & PQ_INTENT_SET) == 0 ||
(pg2->pqflags & PQ_INTENT_QUEUED) != 0) {
mutex_exit(&pg2->interlock);
pg2 = NULL;
} else {
pg2->pqflags |= PQ_INTENT_QUEUED;
mutex_exit(&pg2->interlock);
}
if (pg1 != NULL) {
uvmpdpol_pagerealize(pg1);
}
if (pg2 != NULL) {
uvmpdpol_pagerealize(pg2);
}
}
/*
* uvm_pagezero: zero fill a page
*
* => if page is part of an object then the object should be locked
* to protect pg->flags.
*/
void
uvm_pagezero(struct vm_page *pg)
{
uvm_pagemarkdirty(pg, UVM_PAGE_STATUS_DIRTY);
pmap_zero_page(VM_PAGE_TO_PHYS(pg));
}
/*
* uvm_pagecopy: copy a page
*
* => if page is part of an object then the object should be locked
* to protect pg->flags.
*/
void
uvm_pagecopy(struct vm_page *src, struct vm_page *dst)
{
uvm_pagemarkdirty(dst, UVM_PAGE_STATUS_DIRTY);
pmap_copy_page(VM_PAGE_TO_PHYS(src), VM_PAGE_TO_PHYS(dst));
}
/*
* uvm_pageismanaged: test it see that a page (specified by PA) is managed.
*/
bool
uvm_pageismanaged(paddr_t pa)
{
return (uvm_physseg_find(atop(pa), NULL) != UVM_PHYSSEG_TYPE_INVALID);
}
/*
* uvm_page_lookup_freelist: look up the free list for the specified page
*/
int
uvm_page_lookup_freelist(struct vm_page *pg)
{
uvm_physseg_t upm;
upm = uvm_physseg_find(atop(VM_PAGE_TO_PHYS(pg)), NULL);
KASSERT(upm != UVM_PHYSSEG_TYPE_INVALID);
return uvm_physseg_get_free_list(upm);
}
/*
* uvm_page_owner_locked_p: return true if object associated with page is
* locked. this is a weak check for runtime assertions only.
*/
bool
uvm_page_owner_locked_p(struct vm_page *pg, bool exclusive)
{
if (pg->uobject != NULL) {
return exclusive
? rw_write_held(pg->uobject->vmobjlock)
: rw_lock_held(pg->uobject->vmobjlock);
}
if (pg->uanon != NULL) {
return exclusive
? rw_write_held(pg->uanon->an_lock)
: rw_lock_held(pg->uanon->an_lock);
}
return true;
}
/*
* uvm_pagereadonly_p: return if the page should be mapped read-only
*/
bool
uvm_pagereadonly_p(struct vm_page *pg)
{
struct uvm_object * const uobj = pg->uobject;
KASSERT(uobj == NULL || rw_lock_held(uobj->vmobjlock));
KASSERT(uobj != NULL || rw_lock_held(pg->uanon->an_lock));
if ((pg->flags & PG_RDONLY) != 0) {
return true;
}
if (uvm_pagegetdirty(pg) == UVM_PAGE_STATUS_CLEAN) {
return true;
}
if (uobj == NULL) {
return false;
}
return UVM_OBJ_NEEDS_WRITEFAULT(uobj);
}
#ifdef PMAP_DIRECT
/*
* Call pmap to translate physical address into a virtual and to run a callback
* for it. Used to avoid actually mapping the pages, pmap most likely uses direct map
* or equivalent.
*/
int
uvm_direct_process(struct vm_page **pgs, u_int npages, voff_t off, vsize_t len,
int (*process)(void *, size_t, void *), void *arg)
{
int error = 0;
paddr_t pa;
size_t todo;
voff_t pgoff = (off & PAGE_MASK);
struct vm_page *pg;
KASSERT(npages > 0);
KASSERT(len > 0);
for (int i = 0; i < npages; i++) {
pg = pgs[i];
KASSERT(len > 0);
/*
* Caller is responsible for ensuring all the pages are
* available.
*/
KASSERT(pg != NULL);
KASSERT(pg != PGO_DONTCARE);
pa = VM_PAGE_TO_PHYS(pg);
todo = MIN(len, PAGE_SIZE - pgoff);
error = pmap_direct_process(pa, pgoff, todo, process, arg);
if (error)
break;
pgoff = 0;
len -= todo;
}
KASSERTMSG(error != 0 || len == 0, "len %lu != 0 for non-error", len);
return error;
}
#endif /* PMAP_DIRECT */
#if defined(DDB) || defined(DEBUGPRINT)
/*
* uvm_page_printit: actually print the page
*/
static const char page_flagbits[] = UVM_PGFLAGBITS;
static const char page_pqflagbits[] = UVM_PQFLAGBITS;
void
uvm_page_printit(struct vm_page *pg, bool full,
void (*pr)(const char *, ...))
{
struct vm_page *tpg;
struct uvm_object *uobj;
struct pgflbucket *pgb;
struct pgflist *pgl;
char pgbuf[128];
(*pr)("PAGE %p:\n", pg);
snprintb(pgbuf, sizeof(pgbuf), page_flagbits, pg->flags);
(*pr)(" flags=%s\n", pgbuf);
snprintb(pgbuf, sizeof(pgbuf), page_pqflagbits, pg->pqflags);
(*pr)(" pqflags=%s\n", pgbuf);
(*pr)(" uobject=%p, uanon=%p, offset=0x%llx\n",
pg->uobject, pg->uanon, (long long)pg->offset);
(*pr)(" loan_count=%d wire_count=%d bucket=%d freelist=%d\n",
pg->loan_count, pg->wire_count, uvm_page_get_bucket(pg),
uvm_page_get_freelist(pg));
(*pr)(" pa=0x%lx\n", (long)VM_PAGE_TO_PHYS(pg));
#if defined(UVM_PAGE_TRKOWN)
if (pg->flags & PG_BUSY)
(*pr)(" owning process = %d.%d, tag=%s\n",
pg->owner, pg->lowner, pg->owner_tag);
else
(*pr)(" page not busy, no owner\n");
#else
(*pr)(" [page ownership tracking disabled]\n");
#endif
if (!full)
return;
/* cross-verify object/anon */
if ((pg->flags & PG_FREE) == 0) {
if (pg->flags & PG_ANON) {
if (pg->uanon == NULL || pg->uanon->an_page != pg)
(*pr)(" >>> ANON DOES NOT POINT HERE <<< (%p)\n",
(pg->uanon) ? pg->uanon->an_page : NULL);
else
(*pr)(" anon backpointer is OK\n");
} else {
uobj = pg->uobject;
if (uobj) {
(*pr)(" checking object list\n");
tpg = uvm_pagelookup(uobj, pg->offset);
if (tpg)
(*pr)(" page found on object list\n");
else
(*pr)(" >>> PAGE NOT FOUND ON OBJECT LIST! <<<\n");
}
}
}
/* cross-verify page queue */
if (pg->flags & PG_FREE) {
int fl = uvm_page_get_freelist(pg);
int b = uvm_page_get_bucket(pg);
pgb = uvm.page_free[fl].pgfl_buckets[b];
pgl = &pgb->pgb_colors[VM_PGCOLOR(pg)];
(*pr)(" checking pageq list\n");
LIST_FOREACH(tpg, pgl, pageq.list) {
if (tpg == pg) {
break;
}
}
if (tpg)
(*pr)(" page found on pageq list\n");
else
(*pr)(" >>> PAGE NOT FOUND ON PAGEQ LIST! <<<\n");
}
}
/*
* uvm_page_printall - print a summary of all managed pages
*/
void
uvm_page_printall(void (*pr)(const char *, ...))
{
uvm_physseg_t i;
paddr_t pfn;
struct vm_page *pg;
(*pr)("%18s %4s %4s %18s %18s"
#ifdef UVM_PAGE_TRKOWN
" OWNER"
#endif
"\n", "PAGE", "FLAG", "PQ", "UOBJECT", "UANON");
for (i = uvm_physseg_get_first();
uvm_physseg_valid_p(i);
i = uvm_physseg_get_next(i)) {
for (pfn = uvm_physseg_get_start(i);
pfn < uvm_physseg_get_end(i);
pfn++) {
pg = PHYS_TO_VM_PAGE(ptoa(pfn));
(*pr)("%18p %04x %08x %18p %18p",
pg, pg->flags, pg->pqflags, pg->uobject,
pg->uanon);
#ifdef UVM_PAGE_TRKOWN
if (pg->flags & PG_BUSY)
(*pr)(" %d [%s]", pg->owner, pg->owner_tag);
#endif
(*pr)("\n");
}
}
}
/*
* uvm_page_print_freelists - print a summary freelists
*/
void
uvm_page_print_freelists(void (*pr)(const char *, ...))
{
struct pgfreelist *pgfl;
struct pgflbucket *pgb;
int fl, b, c;
(*pr)("There are %d freelists with %d buckets of %d colors.\n\n",
VM_NFREELIST, uvm.bucketcount, uvmexp.ncolors);
for (fl = 0; fl < VM_NFREELIST; fl++) {
pgfl = &uvm.page_free[fl];
(*pr)("freelist(%d) @ %p\n", fl, pgfl);
for (b = 0; b < uvm.bucketcount; b++) {
pgb = uvm.page_free[fl].pgfl_buckets[b];
(*pr)(" bucket(%d) @ %p, nfree = %d, lock @ %p:\n",
b, pgb, pgb->pgb_nfree,
&uvm_freelist_locks[b].lock);
for (c = 0; c < uvmexp.ncolors; c++) {
(*pr)(" color(%d) @ %p, ", c,
&pgb->pgb_colors[c]);
(*pr)("first page = %p\n",
LIST_FIRST(&pgb->pgb_colors[c]));
}
}
}
}
#endif /* DDB || DEBUGPRINT */
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