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freebsd-nq/sys/kern/subr_vmem.c
Konstantin Belousov cb596eea82 vmem: trivial warning and style fixes. 
Add __unused to some args.
Change type of the iterator variables to match loop control.
Remove excessive {}.

Reviewed by:	markj
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D27220
2020-11-17 02:18:34 +00:00

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/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c)2006,2007,2008,2009 YAMAMOTO Takashi,
* Copyright (c) 2013 EMC Corp.
* 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.
*/
/*
* From:
* $NetBSD: vmem_impl.h,v 1.2 2013/01/29 21:26:24 para Exp $
* $NetBSD: subr_vmem.c,v 1.83 2013/03/06 11:20:10 yamt Exp $
*/
/*
* reference:
* - Magazines and Vmem: Extending the Slab Allocator
* to Many CPUs and Arbitrary Resources
* http://www.usenix.org/event/usenix01/bonwick.html
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_ddb.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/queue.h>
#include <sys/callout.h>
#include <sys/hash.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/smp.h>
#include <sys/condvar.h>
#include <sys/sysctl.h>
#include <sys/taskqueue.h>
#include <sys/vmem.h>
#include <sys/vmmeter.h>
#include "opt_vm.h"
#include <vm/uma.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_object.h>
#include <vm/vm_kern.h>
#include <vm/vm_extern.h>
#include <vm/vm_param.h>
#include <vm/vm_page.h>
#include <vm/vm_pageout.h>
#include <vm/vm_phys.h>
#include <vm/vm_pagequeue.h>
#include <vm/uma_int.h>
#define VMEM_OPTORDER 5
#define VMEM_OPTVALUE (1 << VMEM_OPTORDER)
#define VMEM_MAXORDER \
(VMEM_OPTVALUE - 1 + sizeof(vmem_size_t) * NBBY - VMEM_OPTORDER)
#define VMEM_HASHSIZE_MIN 16
#define VMEM_HASHSIZE_MAX 131072
#define VMEM_QCACHE_IDX_MAX 16
#define VMEM_FITMASK (M_BESTFIT | M_FIRSTFIT | M_NEXTFIT)
#define VMEM_FLAGS (M_NOWAIT | M_WAITOK | M_USE_RESERVE | M_NOVM | \
M_BESTFIT | M_FIRSTFIT | M_NEXTFIT)
#define BT_FLAGS (M_NOWAIT | M_WAITOK | M_USE_RESERVE | M_NOVM)
#define QC_NAME_MAX 16
/*
* Data structures private to vmem.
*/
MALLOC_DEFINE(M_VMEM, "vmem", "vmem internal structures");
typedef struct vmem_btag bt_t;
TAILQ_HEAD(vmem_seglist, vmem_btag);
LIST_HEAD(vmem_freelist, vmem_btag);
LIST_HEAD(vmem_hashlist, vmem_btag);
struct qcache {
uma_zone_t qc_cache;
vmem_t *qc_vmem;
vmem_size_t qc_size;
char qc_name[QC_NAME_MAX];
};
typedef struct qcache qcache_t;
#define QC_POOL_TO_QCACHE(pool) ((qcache_t *)(pool->pr_qcache))
#define VMEM_NAME_MAX 16
/* boundary tag */
struct vmem_btag {
TAILQ_ENTRY(vmem_btag) bt_seglist;
union {
LIST_ENTRY(vmem_btag) u_freelist; /* BT_TYPE_FREE */
LIST_ENTRY(vmem_btag) u_hashlist; /* BT_TYPE_BUSY */
} bt_u;
#define bt_hashlist bt_u.u_hashlist
#define bt_freelist bt_u.u_freelist
vmem_addr_t bt_start;
vmem_size_t bt_size;
int bt_type;
};
/* vmem arena */
struct vmem {
struct mtx_padalign vm_lock;
struct cv vm_cv;
char vm_name[VMEM_NAME_MAX+1];
LIST_ENTRY(vmem) vm_alllist;
struct vmem_hashlist vm_hash0[VMEM_HASHSIZE_MIN];
struct vmem_freelist vm_freelist[VMEM_MAXORDER];
struct vmem_seglist vm_seglist;
struct vmem_hashlist *vm_hashlist;
vmem_size_t vm_hashsize;
/* Constant after init */
vmem_size_t vm_qcache_max;
vmem_size_t vm_quantum_mask;
vmem_size_t vm_import_quantum;
int vm_quantum_shift;
/* Written on alloc/free */
LIST_HEAD(, vmem_btag) vm_freetags;
int vm_nfreetags;
int vm_nbusytag;
vmem_size_t vm_inuse;
vmem_size_t vm_size;
vmem_size_t vm_limit;
struct vmem_btag vm_cursor;
/* Used on import. */
vmem_import_t *vm_importfn;
vmem_release_t *vm_releasefn;
void *vm_arg;
/* Space exhaustion callback. */
vmem_reclaim_t *vm_reclaimfn;
/* quantum cache */
qcache_t vm_qcache[VMEM_QCACHE_IDX_MAX];
};
#define BT_TYPE_SPAN 1 /* Allocated from importfn */
#define BT_TYPE_SPAN_STATIC 2 /* vmem_add() or create. */
#define BT_TYPE_FREE 3 /* Available space. */
#define BT_TYPE_BUSY 4 /* Used space. */
#define BT_TYPE_CURSOR 5 /* Cursor for nextfit allocations. */
#define BT_ISSPAN_P(bt) ((bt)->bt_type <= BT_TYPE_SPAN_STATIC)
#define BT_END(bt) ((bt)->bt_start + (bt)->bt_size - 1)
#if defined(DIAGNOSTIC)
static int enable_vmem_check = 1;
SYSCTL_INT(_debug, OID_AUTO, vmem_check, CTLFLAG_RWTUN,
&enable_vmem_check, 0, "Enable vmem check");
static void vmem_check(vmem_t *);
#endif
static struct callout vmem_periodic_ch;
static int vmem_periodic_interval;
static struct task vmem_periodic_wk;
static struct mtx_padalign __exclusive_cache_line vmem_list_lock;
static LIST_HEAD(, vmem) vmem_list = LIST_HEAD_INITIALIZER(vmem_list);
static uma_zone_t vmem_zone;
/* ---- misc */
#define VMEM_CONDVAR_INIT(vm, wchan) cv_init(&vm->vm_cv, wchan)
#define VMEM_CONDVAR_DESTROY(vm) cv_destroy(&vm->vm_cv)
#define VMEM_CONDVAR_WAIT(vm) cv_wait(&vm->vm_cv, &vm->vm_lock)
#define VMEM_CONDVAR_BROADCAST(vm) cv_broadcast(&vm->vm_cv)
#define VMEM_LOCK(vm) mtx_lock(&vm->vm_lock)
#define VMEM_TRYLOCK(vm) mtx_trylock(&vm->vm_lock)
#define VMEM_UNLOCK(vm) mtx_unlock(&vm->vm_lock)
#define VMEM_LOCK_INIT(vm, name) mtx_init(&vm->vm_lock, (name), NULL, MTX_DEF)
#define VMEM_LOCK_DESTROY(vm) mtx_destroy(&vm->vm_lock)
#define VMEM_ASSERT_LOCKED(vm) mtx_assert(&vm->vm_lock, MA_OWNED);
#define VMEM_ALIGNUP(addr, align) (-(-(addr) & -(align)))
#define VMEM_CROSS_P(addr1, addr2, boundary) \
((((addr1) ^ (addr2)) & -(boundary)) != 0)
#define ORDER2SIZE(order) ((order) < VMEM_OPTVALUE ? ((order) + 1) : \
(vmem_size_t)1 << ((order) - (VMEM_OPTVALUE - VMEM_OPTORDER - 1)))
#define SIZE2ORDER(size) ((size) <= VMEM_OPTVALUE ? ((size) - 1) : \
(flsl(size) + (VMEM_OPTVALUE - VMEM_OPTORDER - 2)))
/*
* Maximum number of boundary tags that may be required to satisfy an
* allocation. Two may be required to import. Another two may be
* required to clip edges.
*/
#define BT_MAXALLOC 4
/*
* Max free limits the number of locally cached boundary tags. We
* just want to avoid hitting the zone allocator for every call.
*/
#define BT_MAXFREE (BT_MAXALLOC * 8)
/* Allocator for boundary tags. */
static uma_zone_t vmem_bt_zone;
/* boot time arena storage. */
static struct vmem kernel_arena_storage;
static struct vmem buffer_arena_storage;
static struct vmem transient_arena_storage;
/* kernel and kmem arenas are aliased for backwards KPI compat. */
vmem_t *kernel_arena = &kernel_arena_storage;
vmem_t *kmem_arena = &kernel_arena_storage;
vmem_t *buffer_arena = &buffer_arena_storage;
vmem_t *transient_arena = &transient_arena_storage;
#ifdef DEBUG_MEMGUARD
static struct vmem memguard_arena_storage;
vmem_t *memguard_arena = &memguard_arena_storage;
#endif
static bool
bt_isbusy(bt_t *bt)
{
return (bt->bt_type == BT_TYPE_BUSY);
}
static bool
bt_isfree(bt_t *bt)
{
return (bt->bt_type == BT_TYPE_FREE);
}
/*
* Fill the vmem's boundary tag cache. We guarantee that boundary tag
* allocation will not fail once bt_fill() passes. To do so we cache
* at least the maximum possible tag allocations in the arena.
*/
static __noinline int
_bt_fill(vmem_t *vm, int flags)
{
bt_t *bt;
VMEM_ASSERT_LOCKED(vm);
/*
* Only allow the kernel arena and arenas derived from kernel arena to
* dip into reserve tags. They are where new tags come from.
*/
flags &= BT_FLAGS;
if (vm != kernel_arena && vm->vm_arg != kernel_arena)
flags &= ~M_USE_RESERVE;
/*
* Loop until we meet the reserve. To minimize the lock shuffle
* and prevent simultaneous fills we first try a NOWAIT regardless
* of the caller's flags. Specify M_NOVM so we don't recurse while
* holding a vmem lock.
*/
while (vm->vm_nfreetags < BT_MAXALLOC) {
bt = uma_zalloc(vmem_bt_zone,
(flags & M_USE_RESERVE) | M_NOWAIT | M_NOVM);
if (bt == NULL) {
VMEM_UNLOCK(vm);
bt = uma_zalloc(vmem_bt_zone, flags);
VMEM_LOCK(vm);
if (bt == NULL)
break;
}
LIST_INSERT_HEAD(&vm->vm_freetags, bt, bt_freelist);
vm->vm_nfreetags++;
}
if (vm->vm_nfreetags < BT_MAXALLOC)
return ENOMEM;
return 0;
}
static inline int
bt_fill(vmem_t *vm, int flags)
{
if (vm->vm_nfreetags >= BT_MAXALLOC)
return (0);
return (_bt_fill(vm, flags));
}
/*
* Pop a tag off of the freetag stack.
*/
static bt_t *
bt_alloc(vmem_t *vm)
{
bt_t *bt;
VMEM_ASSERT_LOCKED(vm);
bt = LIST_FIRST(&vm->vm_freetags);
MPASS(bt != NULL);
LIST_REMOVE(bt, bt_freelist);
vm->vm_nfreetags--;
return bt;
}
/*
* Trim the per-vmem free list. Returns with the lock released to
* avoid allocator recursions.
*/
static void
bt_freetrim(vmem_t *vm, int freelimit)
{
LIST_HEAD(, vmem_btag) freetags;
bt_t *bt;
LIST_INIT(&freetags);
VMEM_ASSERT_LOCKED(vm);
while (vm->vm_nfreetags > freelimit) {
bt = LIST_FIRST(&vm->vm_freetags);
LIST_REMOVE(bt, bt_freelist);
vm->vm_nfreetags--;
LIST_INSERT_HEAD(&freetags, bt, bt_freelist);
}
VMEM_UNLOCK(vm);
while ((bt = LIST_FIRST(&freetags)) != NULL) {
LIST_REMOVE(bt, bt_freelist);
uma_zfree(vmem_bt_zone, bt);
}
}
static inline void
bt_free(vmem_t *vm, bt_t *bt)
{
VMEM_ASSERT_LOCKED(vm);
MPASS(LIST_FIRST(&vm->vm_freetags) != bt);
LIST_INSERT_HEAD(&vm->vm_freetags, bt, bt_freelist);
vm->vm_nfreetags++;
}
/*
* Hide MAXALLOC tags before dropping the arena lock to ensure that a
* concurrent allocation attempt does not grab them.
*/
static void
bt_save(vmem_t *vm)
{
KASSERT(vm->vm_nfreetags >= BT_MAXALLOC,
("%s: insufficient free tags %d", __func__, vm->vm_nfreetags));
vm->vm_nfreetags -= BT_MAXALLOC;
}
static void
bt_restore(vmem_t *vm)
{
vm->vm_nfreetags += BT_MAXALLOC;
}
/*
* freelist[0] ... [1, 1]
* freelist[1] ... [2, 2]
* :
* freelist[29] ... [30, 30]
* freelist[30] ... [31, 31]
* freelist[31] ... [32, 63]
* freelist[33] ... [64, 127]
* :
* freelist[n] ... [(1 << (n - 26)), (1 << (n - 25)) - 1]
* :
*/
static struct vmem_freelist *
bt_freehead_tofree(vmem_t *vm, vmem_size_t size)
{
const vmem_size_t qsize = size >> vm->vm_quantum_shift;
const int idx = SIZE2ORDER(qsize);
MPASS(size != 0 && qsize != 0);
MPASS((size & vm->vm_quantum_mask) == 0);
MPASS(idx >= 0);
MPASS(idx < VMEM_MAXORDER);
return &vm->vm_freelist[idx];
}
/*
* bt_freehead_toalloc: return the freelist for the given size and allocation
* strategy.
*
* For M_FIRSTFIT, return the list in which any blocks are large enough
* for the requested size. otherwise, return the list which can have blocks
* large enough for the requested size.
*/
static struct vmem_freelist *
bt_freehead_toalloc(vmem_t *vm, vmem_size_t size, int strat)
{
const vmem_size_t qsize = size >> vm->vm_quantum_shift;
int idx = SIZE2ORDER(qsize);
MPASS(size != 0 && qsize != 0);
MPASS((size & vm->vm_quantum_mask) == 0);
if (strat == M_FIRSTFIT && ORDER2SIZE(idx) != qsize) {
idx++;
/* check too large request? */
}
MPASS(idx >= 0);
MPASS(idx < VMEM_MAXORDER);
return &vm->vm_freelist[idx];
}
/* ---- boundary tag hash */
static struct vmem_hashlist *
bt_hashhead(vmem_t *vm, vmem_addr_t addr)
{
struct vmem_hashlist *list;
unsigned int hash;
hash = hash32_buf(&addr, sizeof(addr), 0);
list = &vm->vm_hashlist[hash % vm->vm_hashsize];
return list;
}
static bt_t *
bt_lookupbusy(vmem_t *vm, vmem_addr_t addr)
{
struct vmem_hashlist *list;
bt_t *bt;
VMEM_ASSERT_LOCKED(vm);
list = bt_hashhead(vm, addr);
LIST_FOREACH(bt, list, bt_hashlist) {
if (bt->bt_start == addr) {
break;
}
}
return bt;
}
static void
bt_rembusy(vmem_t *vm, bt_t *bt)
{
VMEM_ASSERT_LOCKED(vm);
MPASS(vm->vm_nbusytag > 0);
vm->vm_inuse -= bt->bt_size;
vm->vm_nbusytag--;
LIST_REMOVE(bt, bt_hashlist);
}
static void
bt_insbusy(vmem_t *vm, bt_t *bt)
{
struct vmem_hashlist *list;
VMEM_ASSERT_LOCKED(vm);
MPASS(bt->bt_type == BT_TYPE_BUSY);
list = bt_hashhead(vm, bt->bt_start);
LIST_INSERT_HEAD(list, bt, bt_hashlist);
vm->vm_nbusytag++;
vm->vm_inuse += bt->bt_size;
}
/* ---- boundary tag list */
static void
bt_remseg(vmem_t *vm, bt_t *bt)
{
MPASS(bt->bt_type != BT_TYPE_CURSOR);
TAILQ_REMOVE(&vm->vm_seglist, bt, bt_seglist);
bt_free(vm, bt);
}
static void
bt_insseg(vmem_t *vm, bt_t *bt, bt_t *prev)
{
TAILQ_INSERT_AFTER(&vm->vm_seglist, prev, bt, bt_seglist);
}
static void
bt_insseg_tail(vmem_t *vm, bt_t *bt)
{
TAILQ_INSERT_TAIL(&vm->vm_seglist, bt, bt_seglist);
}
static void
bt_remfree(vmem_t *vm __unused, bt_t *bt)
{
MPASS(bt->bt_type == BT_TYPE_FREE);
LIST_REMOVE(bt, bt_freelist);
}
static void
bt_insfree(vmem_t *vm, bt_t *bt)
{
struct vmem_freelist *list;
list = bt_freehead_tofree(vm, bt->bt_size);
LIST_INSERT_HEAD(list, bt, bt_freelist);
}
/* ---- vmem internal functions */
/*
* Import from the arena into the quantum cache in UMA.
*
* We use VMEM_ADDR_QCACHE_MIN instead of 0: uma_zalloc() returns 0 to indicate
* failure, so UMA can't be used to cache a resource with value 0.
*/
static int
qc_import(void *arg, void **store, int cnt, int domain, int flags)
{
qcache_t *qc;
vmem_addr_t addr;
int i;
KASSERT((flags & M_WAITOK) == 0, ("blocking allocation"));
qc = arg;
for (i = 0; i < cnt; i++) {
if (vmem_xalloc(qc->qc_vmem, qc->qc_size, 0, 0, 0,
VMEM_ADDR_QCACHE_MIN, VMEM_ADDR_MAX, flags, &addr) != 0)
break;
store[i] = (void *)addr;
}
return (i);
}
/*
* Release memory from the UMA cache to the arena.
*/
static void
qc_release(void *arg, void **store, int cnt)
{
qcache_t *qc;
int i;
qc = arg;
for (i = 0; i < cnt; i++)
vmem_xfree(qc->qc_vmem, (vmem_addr_t)store[i], qc->qc_size);
}
static void
qc_init(vmem_t *vm, vmem_size_t qcache_max)
{
qcache_t *qc;
vmem_size_t size;
int qcache_idx_max;
int i;
MPASS((qcache_max & vm->vm_quantum_mask) == 0);
qcache_idx_max = MIN(qcache_max >> vm->vm_quantum_shift,
VMEM_QCACHE_IDX_MAX);
vm->vm_qcache_max = qcache_idx_max << vm->vm_quantum_shift;
for (i = 0; i < qcache_idx_max; i++) {
qc = &vm->vm_qcache[i];
size = (i + 1) << vm->vm_quantum_shift;
snprintf(qc->qc_name, sizeof(qc->qc_name), "%s-%zu",
vm->vm_name, size);
qc->qc_vmem = vm;
qc->qc_size = size;
qc->qc_cache = uma_zcache_create(qc->qc_name, size,
NULL, NULL, NULL, NULL, qc_import, qc_release, qc, 0);
MPASS(qc->qc_cache);
}
}
static void
qc_destroy(vmem_t *vm)
{
int qcache_idx_max;
int i;
qcache_idx_max = vm->vm_qcache_max >> vm->vm_quantum_shift;
for (i = 0; i < qcache_idx_max; i++)
uma_zdestroy(vm->vm_qcache[i].qc_cache);
}
static void
qc_drain(vmem_t *vm)
{
int qcache_idx_max;
int i;
qcache_idx_max = vm->vm_qcache_max >> vm->vm_quantum_shift;
for (i = 0; i < qcache_idx_max; i++)
uma_zone_reclaim(vm->vm_qcache[i].qc_cache, UMA_RECLAIM_DRAIN);
}
#ifndef UMA_MD_SMALL_ALLOC
static struct mtx_padalign __exclusive_cache_line vmem_bt_lock;
/*
* vmem_bt_alloc: Allocate a new page of boundary tags.
*
* On architectures with uma_small_alloc there is no recursion; no address
* space need be allocated to allocate boundary tags. For the others, we
* must handle recursion. Boundary tags are necessary to allocate new
* boundary tags.
*
* UMA guarantees that enough tags are held in reserve to allocate a new
* page of kva. We dip into this reserve by specifying M_USE_RESERVE only
* when allocating the page to hold new boundary tags. In this way the
* reserve is automatically filled by the allocation that uses the reserve.
*
* We still have to guarantee that the new tags are allocated atomically since
* many threads may try concurrently. The bt_lock provides this guarantee.
* We convert WAITOK allocations to NOWAIT and then handle the blocking here
* on failure. It's ok to return NULL for a WAITOK allocation as UMA will
* loop again after checking to see if we lost the race to allocate.
*
* There is a small race between vmem_bt_alloc() returning the page and the
* zone lock being acquired to add the page to the zone. For WAITOK
* allocations we just pause briefly. NOWAIT may experience a transient
* failure. To alleviate this we permit a small number of simultaneous
* fills to proceed concurrently so NOWAIT is less likely to fail unless
* we are really out of KVA.
*/
static void *
vmem_bt_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
int wait)
{
vmem_addr_t addr;
*pflag = UMA_SLAB_KERNEL;
/*
* Single thread boundary tag allocation so that the address space
* and memory are added in one atomic operation.
*/
mtx_lock(&vmem_bt_lock);
if (vmem_xalloc(vm_dom[domain].vmd_kernel_arena, bytes, 0, 0, 0,
VMEM_ADDR_MIN, VMEM_ADDR_MAX,
M_NOWAIT | M_NOVM | M_USE_RESERVE | M_BESTFIT, &addr) == 0) {
if (kmem_back_domain(domain, kernel_object, addr, bytes,
M_NOWAIT | M_USE_RESERVE) == 0) {
mtx_unlock(&vmem_bt_lock);
return ((void *)addr);
}
vmem_xfree(vm_dom[domain].vmd_kernel_arena, addr, bytes);
mtx_unlock(&vmem_bt_lock);
/*
* Out of memory, not address space. This may not even be
* possible due to M_USE_RESERVE page allocation.
*/
if (wait & M_WAITOK)
vm_wait_domain(domain);
return (NULL);
}
mtx_unlock(&vmem_bt_lock);
/*
* We're either out of address space or lost a fill race.
*/
if (wait & M_WAITOK)
pause("btalloc", 1);
return (NULL);
}
#endif
void
vmem_startup(void)
{
mtx_init(&vmem_list_lock, "vmem list lock", NULL, MTX_DEF);
vmem_zone = uma_zcreate("vmem",
sizeof(struct vmem), NULL, NULL, NULL, NULL,
UMA_ALIGN_PTR, 0);
#ifdef UMA_MD_SMALL_ALLOC
vmem_bt_zone = uma_zcreate("vmem btag",
sizeof(struct vmem_btag), NULL, NULL, NULL, NULL,
UMA_ALIGN_PTR, UMA_ZONE_VM);
#else
vmem_bt_zone = uma_zcreate("vmem btag",
sizeof(struct vmem_btag), NULL, NULL, NULL, NULL,
UMA_ALIGN_PTR, UMA_ZONE_VM | UMA_ZONE_NOFREE);
mtx_init(&vmem_bt_lock, "btag lock", NULL, MTX_DEF);
uma_prealloc(vmem_bt_zone, BT_MAXALLOC);
/*
* Reserve enough tags to allocate new tags. We allow multiple
* CPUs to attempt to allocate new tags concurrently to limit
* false restarts in UMA. vmem_bt_alloc() allocates from a per-domain
* arena, which may involve importing a range from the kernel arena,
* so we need to keep at least 2 * BT_MAXALLOC tags reserved.
*/
uma_zone_reserve(vmem_bt_zone, 2 * BT_MAXALLOC * mp_ncpus);
uma_zone_set_allocf(vmem_bt_zone, vmem_bt_alloc);
#endif
}
/* ---- rehash */
static int
vmem_rehash(vmem_t *vm, vmem_size_t newhashsize)
{
bt_t *bt;
struct vmem_hashlist *newhashlist;
struct vmem_hashlist *oldhashlist;
vmem_size_t i, oldhashsize;
MPASS(newhashsize > 0);
newhashlist = malloc(sizeof(struct vmem_hashlist) * newhashsize,
M_VMEM, M_NOWAIT);
if (newhashlist == NULL)
return ENOMEM;
for (i = 0; i < newhashsize; i++) {
LIST_INIT(&newhashlist[i]);
}
VMEM_LOCK(vm);
oldhashlist = vm->vm_hashlist;
oldhashsize = vm->vm_hashsize;
vm->vm_hashlist = newhashlist;
vm->vm_hashsize = newhashsize;
if (oldhashlist == NULL) {
VMEM_UNLOCK(vm);
return 0;
}
for (i = 0; i < oldhashsize; i++) {
while ((bt = LIST_FIRST(&oldhashlist[i])) != NULL) {
bt_rembusy(vm, bt);
bt_insbusy(vm, bt);
}
}
VMEM_UNLOCK(vm);
if (oldhashlist != vm->vm_hash0)
free(oldhashlist, M_VMEM);
return 0;
}
static void
vmem_periodic_kick(void *dummy)
{
taskqueue_enqueue(taskqueue_thread, &vmem_periodic_wk);
}
static void
vmem_periodic(void *unused, int pending)
{
vmem_t *vm;
vmem_size_t desired;
vmem_size_t current;
mtx_lock(&vmem_list_lock);
LIST_FOREACH(vm, &vmem_list, vm_alllist) {
#ifdef DIAGNOSTIC
/* Convenient time to verify vmem state. */
if (enable_vmem_check == 1) {
VMEM_LOCK(vm);
vmem_check(vm);
VMEM_UNLOCK(vm);
}
#endif
desired = 1 << flsl(vm->vm_nbusytag);
desired = MIN(MAX(desired, VMEM_HASHSIZE_MIN),
VMEM_HASHSIZE_MAX);
current = vm->vm_hashsize;
/* Grow in powers of two. Shrink less aggressively. */
if (desired >= current * 2 || desired * 4 <= current)
vmem_rehash(vm, desired);
/*
* Periodically wake up threads waiting for resources,
* so they could ask for reclamation again.
*/
VMEM_CONDVAR_BROADCAST(vm);
}
mtx_unlock(&vmem_list_lock);
callout_reset(&vmem_periodic_ch, vmem_periodic_interval,
vmem_periodic_kick, NULL);
}
static void
vmem_start_callout(void *unused)
{
TASK_INIT(&vmem_periodic_wk, 0, vmem_periodic, NULL);
vmem_periodic_interval = hz * 10;
callout_init(&vmem_periodic_ch, 1);
callout_reset(&vmem_periodic_ch, vmem_periodic_interval,
vmem_periodic_kick, NULL);
}
SYSINIT(vfs, SI_SUB_CONFIGURE, SI_ORDER_ANY, vmem_start_callout, NULL);
static void
vmem_add1(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, int type)
{
bt_t *btfree, *btprev, *btspan;
VMEM_ASSERT_LOCKED(vm);
MPASS(type == BT_TYPE_SPAN || type == BT_TYPE_SPAN_STATIC);
MPASS((size & vm->vm_quantum_mask) == 0);
if (vm->vm_releasefn == NULL) {
/*
* The new segment will never be released, so see if it is
* contiguous with respect to an existing segment. In this case
* a span tag is not needed, and it may be possible now or in
* the future to coalesce the new segment with an existing free
* segment.
*/
btprev = TAILQ_LAST(&vm->vm_seglist, vmem_seglist);
if ((!bt_isbusy(btprev) && !bt_isfree(btprev)) ||
btprev->bt_start + btprev->bt_size != addr)
btprev = NULL;
} else {
btprev = NULL;
}
if (btprev == NULL || bt_isbusy(btprev)) {
if (btprev == NULL) {
btspan = bt_alloc(vm);
btspan->bt_type = type;
btspan->bt_start = addr;
btspan->bt_size = size;
bt_insseg_tail(vm, btspan);
}
btfree = bt_alloc(vm);
btfree->bt_type = BT_TYPE_FREE;
btfree->bt_start = addr;
btfree->bt_size = size;
bt_insseg_tail(vm, btfree);
bt_insfree(vm, btfree);
} else {
bt_remfree(vm, btprev);
btprev->bt_size += size;
bt_insfree(vm, btprev);
}
vm->vm_size += size;
}
static void
vmem_destroy1(vmem_t *vm)
{
bt_t *bt;
/*
* Drain per-cpu quantum caches.
*/
qc_destroy(vm);
/*
* The vmem should now only contain empty segments.
*/
VMEM_LOCK(vm);
MPASS(vm->vm_nbusytag == 0);
TAILQ_REMOVE(&vm->vm_seglist, &vm->vm_cursor, bt_seglist);
while ((bt = TAILQ_FIRST(&vm->vm_seglist)) != NULL)
bt_remseg(vm, bt);
if (vm->vm_hashlist != NULL && vm->vm_hashlist != vm->vm_hash0)
free(vm->vm_hashlist, M_VMEM);
bt_freetrim(vm, 0);
VMEM_CONDVAR_DESTROY(vm);
VMEM_LOCK_DESTROY(vm);
uma_zfree(vmem_zone, vm);
}
static int
vmem_import(vmem_t *vm, vmem_size_t size, vmem_size_t align, int flags)
{
vmem_addr_t addr;
int error;
if (vm->vm_importfn == NULL)
return (EINVAL);
/*
* To make sure we get a span that meets the alignment we double it
* and add the size to the tail. This slightly overestimates.
*/
if (align != vm->vm_quantum_mask + 1)
size = (align * 2) + size;
size = roundup(size, vm->vm_import_quantum);
if (vm->vm_limit != 0 && vm->vm_limit < vm->vm_size + size)
return (ENOMEM);
bt_save(vm);
VMEM_UNLOCK(vm);
error = (vm->vm_importfn)(vm->vm_arg, size, flags, &addr);
VMEM_LOCK(vm);
bt_restore(vm);
if (error)
return (ENOMEM);
vmem_add1(vm, addr, size, BT_TYPE_SPAN);
return 0;
}
/*
* vmem_fit: check if a bt can satisfy the given restrictions.
*
* it's a caller's responsibility to ensure the region is big enough
* before calling us.
*/
static int
vmem_fit(const bt_t *bt, vmem_size_t size, vmem_size_t align,
vmem_size_t phase, vmem_size_t nocross, vmem_addr_t minaddr,
vmem_addr_t maxaddr, vmem_addr_t *addrp)
{
vmem_addr_t start;
vmem_addr_t end;
MPASS(size > 0);
MPASS(bt->bt_size >= size); /* caller's responsibility */
/*
* XXX assumption: vmem_addr_t and vmem_size_t are
* unsigned integer of the same size.
*/
start = bt->bt_start;
if (start < minaddr) {
start = minaddr;
}
end = BT_END(bt);
if (end > maxaddr)
end = maxaddr;
if (start > end)
return (ENOMEM);
start = VMEM_ALIGNUP(start - phase, align) + phase;
if (start < bt->bt_start)
start += align;
if (VMEM_CROSS_P(start, start + size - 1, nocross)) {
MPASS(align < nocross);
start = VMEM_ALIGNUP(start - phase, nocross) + phase;
}
if (start <= end && end - start >= size - 1) {
MPASS((start & (align - 1)) == phase);
MPASS(!VMEM_CROSS_P(start, start + size - 1, nocross));
MPASS(minaddr <= start);
MPASS(maxaddr == 0 || start + size - 1 <= maxaddr);
MPASS(bt->bt_start <= start);
MPASS(BT_END(bt) - start >= size - 1);
*addrp = start;
return (0);
}
return (ENOMEM);
}
/*
* vmem_clip: Trim the boundary tag edges to the requested start and size.
*/
static void
vmem_clip(vmem_t *vm, bt_t *bt, vmem_addr_t start, vmem_size_t size)
{
bt_t *btnew;
bt_t *btprev;
VMEM_ASSERT_LOCKED(vm);
MPASS(bt->bt_type == BT_TYPE_FREE);
MPASS(bt->bt_size >= size);
bt_remfree(vm, bt);
if (bt->bt_start != start) {
btprev = bt_alloc(vm);
btprev->bt_type = BT_TYPE_FREE;
btprev->bt_start = bt->bt_start;
btprev->bt_size = start - bt->bt_start;
bt->bt_start = start;
bt->bt_size -= btprev->bt_size;
bt_insfree(vm, btprev);
bt_insseg(vm, btprev,
TAILQ_PREV(bt, vmem_seglist, bt_seglist));
}
MPASS(bt->bt_start == start);
if (bt->bt_size != size && bt->bt_size - size > vm->vm_quantum_mask) {
/* split */
btnew = bt_alloc(vm);
btnew->bt_type = BT_TYPE_BUSY;
btnew->bt_start = bt->bt_start;
btnew->bt_size = size;
bt->bt_start = bt->bt_start + size;
bt->bt_size -= size;
bt_insfree(vm, bt);
bt_insseg(vm, btnew,
TAILQ_PREV(bt, vmem_seglist, bt_seglist));
bt_insbusy(vm, btnew);
bt = btnew;
} else {
bt->bt_type = BT_TYPE_BUSY;
bt_insbusy(vm, bt);
}
MPASS(bt->bt_size >= size);
}
static int
vmem_try_fetch(vmem_t *vm, const vmem_size_t size, vmem_size_t align, int flags)
{
vmem_size_t avail;
VMEM_ASSERT_LOCKED(vm);
/*
* XXX it is possible to fail to meet xalloc constraints with the
* imported region. It is up to the user to specify the
* import quantum such that it can satisfy any allocation.
*/
if (vmem_import(vm, size, align, flags) == 0)
return (1);
/*
* Try to free some space from the quantum cache or reclaim
* functions if available.
*/
if (vm->vm_qcache_max != 0 || vm->vm_reclaimfn != NULL) {
avail = vm->vm_size - vm->vm_inuse;
bt_save(vm);
VMEM_UNLOCK(vm);
if (vm->vm_qcache_max != 0)
qc_drain(vm);
if (vm->vm_reclaimfn != NULL)
vm->vm_reclaimfn(vm, flags);
VMEM_LOCK(vm);
bt_restore(vm);
/* If we were successful retry even NOWAIT. */
if (vm->vm_size - vm->vm_inuse > avail)
return (1);
}
if ((flags & M_NOWAIT) != 0)
return (0);
bt_save(vm);
VMEM_CONDVAR_WAIT(vm);
bt_restore(vm);
return (1);
}
static int
vmem_try_release(vmem_t *vm, struct vmem_btag *bt, const bool remfree)
{
struct vmem_btag *prev;
MPASS(bt->bt_type == BT_TYPE_FREE);
if (vm->vm_releasefn == NULL)
return (0);
prev = TAILQ_PREV(bt, vmem_seglist, bt_seglist);
MPASS(prev != NULL);
MPASS(prev->bt_type != BT_TYPE_FREE);
if (prev->bt_type == BT_TYPE_SPAN && prev->bt_size == bt->bt_size) {
vmem_addr_t spanaddr;
vmem_size_t spansize;
MPASS(prev->bt_start == bt->bt_start);
spanaddr = prev->bt_start;
spansize = prev->bt_size;
if (remfree)
bt_remfree(vm, bt);
bt_remseg(vm, bt);
bt_remseg(vm, prev);
vm->vm_size -= spansize;
VMEM_CONDVAR_BROADCAST(vm);
bt_freetrim(vm, BT_MAXFREE);
vm->vm_releasefn(vm->vm_arg, spanaddr, spansize);
return (1);
}
return (0);
}
static int
vmem_xalloc_nextfit(vmem_t *vm, const vmem_size_t size, vmem_size_t align,
const vmem_size_t phase, const vmem_size_t nocross, int flags,
vmem_addr_t *addrp)
{
struct vmem_btag *bt, *cursor, *next, *prev;
int error;
error = ENOMEM;
VMEM_LOCK(vm);
/*
* Make sure we have enough tags to complete the operation.
*/
if (bt_fill(vm, flags) != 0)
goto out;
retry:
/*
* Find the next free tag meeting our constraints. If one is found,
* perform the allocation.
*/
for (cursor = &vm->vm_cursor, bt = TAILQ_NEXT(cursor, bt_seglist);
bt != cursor; bt = TAILQ_NEXT(bt, bt_seglist)) {
if (bt == NULL)
bt = TAILQ_FIRST(&vm->vm_seglist);
if (bt->bt_type == BT_TYPE_FREE && bt->bt_size >= size &&
(error = vmem_fit(bt, size, align, phase, nocross,
VMEM_ADDR_MIN, VMEM_ADDR_MAX, addrp)) == 0) {
vmem_clip(vm, bt, *addrp, size);
break;
}
}
/*
* Try to coalesce free segments around the cursor. If we succeed, and
* have not yet satisfied the allocation request, try again with the
* newly coalesced segment.
*/
if ((next = TAILQ_NEXT(cursor, bt_seglist)) != NULL &&
(prev = TAILQ_PREV(cursor, vmem_seglist, bt_seglist)) != NULL &&
next->bt_type == BT_TYPE_FREE && prev->bt_type == BT_TYPE_FREE &&
prev->bt_start + prev->bt_size == next->bt_start) {
prev->bt_size += next->bt_size;
bt_remfree(vm, next);
bt_remseg(vm, next);
/*
* The coalesced segment might be able to satisfy our request.
* If not, we might need to release it from the arena.
*/
if (error == ENOMEM && prev->bt_size >= size &&
(error = vmem_fit(prev, size, align, phase, nocross,
VMEM_ADDR_MIN, VMEM_ADDR_MAX, addrp)) == 0) {
vmem_clip(vm, prev, *addrp, size);
bt = prev;
} else
(void)vmem_try_release(vm, prev, true);
}
/*
* If the allocation was successful, advance the cursor.
*/
if (error == 0) {
TAILQ_REMOVE(&vm->vm_seglist, cursor, bt_seglist);
for (; bt != NULL && bt->bt_start < *addrp + size;
bt = TAILQ_NEXT(bt, bt_seglist))
;
if (bt != NULL)
TAILQ_INSERT_BEFORE(bt, cursor, bt_seglist);
else
TAILQ_INSERT_HEAD(&vm->vm_seglist, cursor, bt_seglist);
}
/*
* Attempt to bring additional resources into the arena. If that fails
* and M_WAITOK is specified, sleep waiting for resources to be freed.
*/
if (error == ENOMEM && vmem_try_fetch(vm, size, align, flags))
goto retry;
out:
VMEM_UNLOCK(vm);
return (error);
}
/* ---- vmem API */
void
vmem_set_import(vmem_t *vm, vmem_import_t *importfn,
vmem_release_t *releasefn, void *arg, vmem_size_t import_quantum)
{
VMEM_LOCK(vm);
KASSERT(vm->vm_size == 0, ("%s: arena is non-empty", __func__));
vm->vm_importfn = importfn;
vm->vm_releasefn = releasefn;
vm->vm_arg = arg;
vm->vm_import_quantum = import_quantum;
VMEM_UNLOCK(vm);
}
void
vmem_set_limit(vmem_t *vm, vmem_size_t limit)
{
VMEM_LOCK(vm);
vm->vm_limit = limit;
VMEM_UNLOCK(vm);
}
void
vmem_set_reclaim(vmem_t *vm, vmem_reclaim_t *reclaimfn)
{
VMEM_LOCK(vm);
vm->vm_reclaimfn = reclaimfn;
VMEM_UNLOCK(vm);
}
/*
* vmem_init: Initializes vmem arena.
*/
vmem_t *
vmem_init(vmem_t *vm, const char *name, vmem_addr_t base, vmem_size_t size,
vmem_size_t quantum, vmem_size_t qcache_max, int flags)
{
vmem_size_t i;
MPASS(quantum > 0);
MPASS((quantum & (quantum - 1)) == 0);
bzero(vm, sizeof(*vm));
VMEM_CONDVAR_INIT(vm, name);
VMEM_LOCK_INIT(vm, name);
vm->vm_nfreetags = 0;
LIST_INIT(&vm->vm_freetags);
strlcpy(vm->vm_name, name, sizeof(vm->vm_name));
vm->vm_quantum_mask = quantum - 1;
vm->vm_quantum_shift = flsl(quantum) - 1;
vm->vm_nbusytag = 0;
vm->vm_size = 0;
vm->vm_limit = 0;
vm->vm_inuse = 0;
qc_init(vm, qcache_max);
TAILQ_INIT(&vm->vm_seglist);
vm->vm_cursor.bt_start = vm->vm_cursor.bt_size = 0;
vm->vm_cursor.bt_type = BT_TYPE_CURSOR;
TAILQ_INSERT_TAIL(&vm->vm_seglist, &vm->vm_cursor, bt_seglist);
for (i = 0; i < VMEM_MAXORDER; i++)
LIST_INIT(&vm->vm_freelist[i]);
memset(&vm->vm_hash0, 0, sizeof(vm->vm_hash0));
vm->vm_hashsize = VMEM_HASHSIZE_MIN;
vm->vm_hashlist = vm->vm_hash0;
if (size != 0) {
if (vmem_add(vm, base, size, flags) != 0) {
vmem_destroy1(vm);
return NULL;
}
}
mtx_lock(&vmem_list_lock);
LIST_INSERT_HEAD(&vmem_list, vm, vm_alllist);
mtx_unlock(&vmem_list_lock);
return vm;
}
/*
* vmem_create: create an arena.
*/
vmem_t *
vmem_create(const char *name, vmem_addr_t base, vmem_size_t size,
vmem_size_t quantum, vmem_size_t qcache_max, int flags)
{
vmem_t *vm;
vm = uma_zalloc(vmem_zone, flags & (M_WAITOK|M_NOWAIT));
if (vm == NULL)
return (NULL);
if (vmem_init(vm, name, base, size, quantum, qcache_max,
flags) == NULL)
return (NULL);
return (vm);
}
void
vmem_destroy(vmem_t *vm)
{
mtx_lock(&vmem_list_lock);
LIST_REMOVE(vm, vm_alllist);
mtx_unlock(&vmem_list_lock);
vmem_destroy1(vm);
}
vmem_size_t
vmem_roundup_size(vmem_t *vm, vmem_size_t size)
{
return (size + vm->vm_quantum_mask) & ~vm->vm_quantum_mask;
}
/*
* vmem_alloc: allocate resource from the arena.
*/
int
vmem_alloc(vmem_t *vm, vmem_size_t size, int flags, vmem_addr_t *addrp)
{
const int strat __unused = flags & VMEM_FITMASK;
qcache_t *qc;
flags &= VMEM_FLAGS;
MPASS(size > 0);
MPASS(strat == M_BESTFIT || strat == M_FIRSTFIT || strat == M_NEXTFIT);
if ((flags & M_NOWAIT) == 0)
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "vmem_alloc");
if (size <= vm->vm_qcache_max) {
/*
* Resource 0 cannot be cached, so avoid a blocking allocation
* in qc_import() and give the vmem_xalloc() call below a chance
* to return 0.
*/
qc = &vm->vm_qcache[(size - 1) >> vm->vm_quantum_shift];
*addrp = (vmem_addr_t)uma_zalloc(qc->qc_cache,
(flags & ~M_WAITOK) | M_NOWAIT);
if (__predict_true(*addrp != 0))
return (0);
}
return (vmem_xalloc(vm, size, 0, 0, 0, VMEM_ADDR_MIN, VMEM_ADDR_MAX,
flags, addrp));
}
int
vmem_xalloc(vmem_t *vm, const vmem_size_t size0, vmem_size_t align,
const vmem_size_t phase, const vmem_size_t nocross,
const vmem_addr_t minaddr, const vmem_addr_t maxaddr, int flags,
vmem_addr_t *addrp)
{
const vmem_size_t size = vmem_roundup_size(vm, size0);
struct vmem_freelist *list;
struct vmem_freelist *first;
struct vmem_freelist *end;
bt_t *bt;
int error;
int strat;
flags &= VMEM_FLAGS;
strat = flags & VMEM_FITMASK;
MPASS(size0 > 0);
MPASS(size > 0);
MPASS(strat == M_BESTFIT || strat == M_FIRSTFIT || strat == M_NEXTFIT);
MPASS((flags & (M_NOWAIT|M_WAITOK)) != (M_NOWAIT|M_WAITOK));
if ((flags & M_NOWAIT) == 0)
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "vmem_xalloc");
MPASS((align & vm->vm_quantum_mask) == 0);
MPASS((align & (align - 1)) == 0);
MPASS((phase & vm->vm_quantum_mask) == 0);
MPASS((nocross & vm->vm_quantum_mask) == 0);
MPASS((nocross & (nocross - 1)) == 0);
MPASS((align == 0 && phase == 0) || phase < align);
MPASS(nocross == 0 || nocross >= size);
MPASS(minaddr <= maxaddr);
MPASS(!VMEM_CROSS_P(phase, phase + size - 1, nocross));
if (strat == M_NEXTFIT)
MPASS(minaddr == VMEM_ADDR_MIN && maxaddr == VMEM_ADDR_MAX);
if (align == 0)
align = vm->vm_quantum_mask + 1;
*addrp = 0;
/*
* Next-fit allocations don't use the freelists.
*/
if (strat == M_NEXTFIT)
return (vmem_xalloc_nextfit(vm, size0, align, phase, nocross,
flags, addrp));
end = &vm->vm_freelist[VMEM_MAXORDER];
/*
* choose a free block from which we allocate.
*/
first = bt_freehead_toalloc(vm, size, strat);
VMEM_LOCK(vm);
/*
* Make sure we have enough tags to complete the operation.
*/
error = bt_fill(vm, flags);
if (error != 0)
goto out;
for (;;) {
/*
* Scan freelists looking for a tag that satisfies the
* allocation. If we're doing BESTFIT we may encounter
* sizes below the request. If we're doing FIRSTFIT we
* inspect only the first element from each list.
*/
for (list = first; list < end; list++) {
LIST_FOREACH(bt, list, bt_freelist) {
if (bt->bt_size >= size) {
error = vmem_fit(bt, size, align, phase,
nocross, minaddr, maxaddr, addrp);
if (error == 0) {
vmem_clip(vm, bt, *addrp, size);
goto out;
}
}
/* FIRST skips to the next list. */
if (strat == M_FIRSTFIT)
break;
}
}
/*
* Retry if the fast algorithm failed.
*/
if (strat == M_FIRSTFIT) {
strat = M_BESTFIT;
first = bt_freehead_toalloc(vm, size, strat);
continue;
}
/*
* Try a few measures to bring additional resources into the
* arena. If all else fails, we will sleep waiting for
* resources to be freed.
*/
if (!vmem_try_fetch(vm, size, align, flags)) {
error = ENOMEM;
break;
}
}
out:
VMEM_UNLOCK(vm);
if (error != 0 && (flags & M_NOWAIT) == 0)
panic("failed to allocate waiting allocation\n");
return (error);
}
/*
* vmem_free: free the resource to the arena.
*/
void
vmem_free(vmem_t *vm, vmem_addr_t addr, vmem_size_t size)
{
qcache_t *qc;
MPASS(size > 0);
if (size <= vm->vm_qcache_max &&
__predict_true(addr >= VMEM_ADDR_QCACHE_MIN)) {
qc = &vm->vm_qcache[(size - 1) >> vm->vm_quantum_shift];
uma_zfree(qc->qc_cache, (void *)addr);
} else
vmem_xfree(vm, addr, size);
}
void
vmem_xfree(vmem_t *vm, vmem_addr_t addr, vmem_size_t size __unused)
{
bt_t *bt;
bt_t *t;
MPASS(size > 0);
VMEM_LOCK(vm);
bt = bt_lookupbusy(vm, addr);
MPASS(bt != NULL);
MPASS(bt->bt_start == addr);
MPASS(bt->bt_size == vmem_roundup_size(vm, size) ||
bt->bt_size - vmem_roundup_size(vm, size) <= vm->vm_quantum_mask);
MPASS(bt->bt_type == BT_TYPE_BUSY);
bt_rembusy(vm, bt);
bt->bt_type = BT_TYPE_FREE;
/* coalesce */
t = TAILQ_NEXT(bt, bt_seglist);
if (t != NULL && t->bt_type == BT_TYPE_FREE) {
MPASS(BT_END(bt) < t->bt_start); /* YYY */
bt->bt_size += t->bt_size;
bt_remfree(vm, t);
bt_remseg(vm, t);
}
t = TAILQ_PREV(bt, vmem_seglist, bt_seglist);
if (t != NULL && t->bt_type == BT_TYPE_FREE) {
MPASS(BT_END(t) < bt->bt_start); /* YYY */
bt->bt_size += t->bt_size;
bt->bt_start = t->bt_start;
bt_remfree(vm, t);
bt_remseg(vm, t);
}
if (!vmem_try_release(vm, bt, false)) {
bt_insfree(vm, bt);
VMEM_CONDVAR_BROADCAST(vm);
bt_freetrim(vm, BT_MAXFREE);
}
}
/*
* vmem_add:
*
*/
int
vmem_add(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, int flags)
{
int error;
flags &= VMEM_FLAGS;
VMEM_LOCK(vm);
error = bt_fill(vm, flags);
if (error == 0)
vmem_add1(vm, addr, size, BT_TYPE_SPAN_STATIC);
VMEM_UNLOCK(vm);
return (error);
}
/*
* vmem_size: information about arenas size
*/
vmem_size_t
vmem_size(vmem_t *vm, int typemask)
{
int i;
switch (typemask) {
case VMEM_ALLOC:
return vm->vm_inuse;
case VMEM_FREE:
return vm->vm_size - vm->vm_inuse;
case VMEM_FREE|VMEM_ALLOC:
return vm->vm_size;
case VMEM_MAXFREE:
VMEM_LOCK(vm);
for (i = VMEM_MAXORDER - 1; i >= 0; i--) {
if (LIST_EMPTY(&vm->vm_freelist[i]))
continue;
VMEM_UNLOCK(vm);
return ((vmem_size_t)ORDER2SIZE(i) <<
vm->vm_quantum_shift);
}
VMEM_UNLOCK(vm);
return (0);
default:
panic("vmem_size");
}
}
/* ---- debug */
#if defined(DDB) || defined(DIAGNOSTIC)
static void bt_dump(const bt_t *, int (*)(const char *, ...)
__printflike(1, 2));
static const char *
bt_type_string(int type)
{
switch (type) {
case BT_TYPE_BUSY:
return "busy";
case BT_TYPE_FREE:
return "free";
case BT_TYPE_SPAN:
return "span";
case BT_TYPE_SPAN_STATIC:
return "static span";
case BT_TYPE_CURSOR:
return "cursor";
default:
break;
}
return "BOGUS";
}
static void
bt_dump(const bt_t *bt, int (*pr)(const char *, ...))
{
(*pr)("\t%p: %jx %jx, %d(%s)\n",
bt, (intmax_t)bt->bt_start, (intmax_t)bt->bt_size,
bt->bt_type, bt_type_string(bt->bt_type));
}
static void
vmem_dump(const vmem_t *vm , int (*pr)(const char *, ...) __printflike(1, 2))
{
const bt_t *bt;
int i;
(*pr)("vmem %p '%s'\n", vm, vm->vm_name);
TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
bt_dump(bt, pr);
}
for (i = 0; i < VMEM_MAXORDER; i++) {
const struct vmem_freelist *fl = &vm->vm_freelist[i];
if (LIST_EMPTY(fl)) {
continue;
}
(*pr)("freelist[%d]\n", i);
LIST_FOREACH(bt, fl, bt_freelist) {
bt_dump(bt, pr);
}
}
}
#endif /* defined(DDB) || defined(DIAGNOSTIC) */
#if defined(DDB)
#include <ddb/ddb.h>
static bt_t *
vmem_whatis_lookup(vmem_t *vm, vmem_addr_t addr)
{
bt_t *bt;
TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
if (BT_ISSPAN_P(bt)) {
continue;
}
if (bt->bt_start <= addr && addr <= BT_END(bt)) {
return bt;
}
}
return NULL;
}
void
vmem_whatis(vmem_addr_t addr, int (*pr)(const char *, ...))
{
vmem_t *vm;
LIST_FOREACH(vm, &vmem_list, vm_alllist) {
bt_t *bt;
bt = vmem_whatis_lookup(vm, addr);
if (bt == NULL) {
continue;
}
(*pr)("%p is %p+%zu in VMEM '%s' (%s)\n",
(void *)addr, (void *)bt->bt_start,
(vmem_size_t)(addr - bt->bt_start), vm->vm_name,
(bt->bt_type == BT_TYPE_BUSY) ? "allocated" : "free");
}
}
void
vmem_printall(const char *modif, int (*pr)(const char *, ...))
{
const vmem_t *vm;
LIST_FOREACH(vm, &vmem_list, vm_alllist) {
vmem_dump(vm, pr);
}
}
void
vmem_print(vmem_addr_t addr, const char *modif, int (*pr)(const char *, ...))
{
const vmem_t *vm = (const void *)addr;
vmem_dump(vm, pr);
}
DB_SHOW_COMMAND(vmemdump, vmemdump)
{
if (!have_addr) {
db_printf("usage: show vmemdump <addr>\n");
return;
}
vmem_dump((const vmem_t *)addr, db_printf);
}
DB_SHOW_ALL_COMMAND(vmemdump, vmemdumpall)
{
const vmem_t *vm;
LIST_FOREACH(vm, &vmem_list, vm_alllist)
vmem_dump(vm, db_printf);
}
DB_SHOW_COMMAND(vmem, vmem_summ)
{
const vmem_t *vm = (const void *)addr;
const bt_t *bt;
size_t ft[VMEM_MAXORDER], ut[VMEM_MAXORDER];
size_t fs[VMEM_MAXORDER], us[VMEM_MAXORDER];
int ord;
if (!have_addr) {
db_printf("usage: show vmem <addr>\n");
return;
}
db_printf("vmem %p '%s'\n", vm, vm->vm_name);
db_printf("\tquantum:\t%zu\n", vm->vm_quantum_mask + 1);
db_printf("\tsize:\t%zu\n", vm->vm_size);
db_printf("\tinuse:\t%zu\n", vm->vm_inuse);
db_printf("\tfree:\t%zu\n", vm->vm_size - vm->vm_inuse);
db_printf("\tbusy tags:\t%d\n", vm->vm_nbusytag);
db_printf("\tfree tags:\t%d\n", vm->vm_nfreetags);
memset(&ft, 0, sizeof(ft));
memset(&ut, 0, sizeof(ut));
memset(&fs, 0, sizeof(fs));
memset(&us, 0, sizeof(us));
TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
ord = SIZE2ORDER(bt->bt_size >> vm->vm_quantum_shift);
if (bt->bt_type == BT_TYPE_BUSY) {
ut[ord]++;
us[ord] += bt->bt_size;
} else if (bt->bt_type == BT_TYPE_FREE) {
ft[ord]++;
fs[ord] += bt->bt_size;
}
}
db_printf("\t\t\tinuse\tsize\t\tfree\tsize\n");
for (ord = 0; ord < VMEM_MAXORDER; ord++) {
if (ut[ord] == 0 && ft[ord] == 0)
continue;
db_printf("\t%-15zu %zu\t%-15zu %zu\t%-16zu\n",
ORDER2SIZE(ord) << vm->vm_quantum_shift,
ut[ord], us[ord], ft[ord], fs[ord]);
}
}
DB_SHOW_ALL_COMMAND(vmem, vmem_summall)
{
const vmem_t *vm;
LIST_FOREACH(vm, &vmem_list, vm_alllist)
vmem_summ((db_expr_t)vm, TRUE, count, modif);
}
#endif /* defined(DDB) */
#define vmem_printf printf
#if defined(DIAGNOSTIC)
static bool
vmem_check_sanity(vmem_t *vm)
{
const bt_t *bt, *bt2;
MPASS(vm != NULL);
TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
if (bt->bt_start > BT_END(bt)) {
printf("corrupted tag\n");
bt_dump(bt, vmem_printf);
return false;
}
}
TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) {
if (bt->bt_type == BT_TYPE_CURSOR) {
if (bt->bt_start != 0 || bt->bt_size != 0) {
printf("corrupted cursor\n");
return false;
}
continue;
}
TAILQ_FOREACH(bt2, &vm->vm_seglist, bt_seglist) {
if (bt == bt2) {
continue;
}
if (bt2->bt_type == BT_TYPE_CURSOR) {
continue;
}
if (BT_ISSPAN_P(bt) != BT_ISSPAN_P(bt2)) {
continue;
}
if (bt->bt_start <= BT_END(bt2) &&
bt2->bt_start <= BT_END(bt)) {
printf("overwrapped tags\n");
bt_dump(bt, vmem_printf);
bt_dump(bt2, vmem_printf);
return false;
}
}
}
return true;
}
static void
vmem_check(vmem_t *vm)
{
if (!vmem_check_sanity(vm)) {
panic("insanity vmem %p", vm);
}
}
#endif /* defined(DIAGNOSTIC) */
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