freebsd-dev/sys/kern/kern_malloc.c
Matt Macy 06bf2a6aef Add simple preempt safe epoch API
Read locking is over used in the kernel to guarantee liveness. This API makes
it easy to provide livenes guarantees without atomics.

Includes epoch_test kernel module to stress test the API.

Documentation will follow initial use case.

Test case and improvements to preemption handling in response to discussion
with mjg@

Reviewed by:	imp@, shurd@
Approved by:	sbruno@
2018-05-10 17:55:24 +00:00

1277 lines
32 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1987, 1991, 1993
* The Regents of the University of California.
* Copyright (c) 2005-2009 Robert N. M. Watson
* Copyright (c) 2008 Otto Moerbeek <otto@drijf.net> (mallocarray)
* 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.
* 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.
*
* @(#)kern_malloc.c 8.3 (Berkeley) 1/4/94
*/
/*
* Kernel malloc(9) implementation -- general purpose kernel memory allocator
* based on memory types. Back end is implemented using the UMA(9) zone
* allocator. A set of fixed-size buckets are used for smaller allocations,
* and a special UMA allocation interface is used for larger allocations.
* Callers declare memory types, and statistics are maintained independently
* for each memory type. Statistics are maintained per-CPU for performance
* reasons. See malloc(9) and comments in malloc.h for a detailed
* description.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_ddb.h"
#include "opt_vm.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kdb.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/vmmeter.h>
#include <sys/proc.h>
#include <sys/sbuf.h>
#include <sys/sysctl.h>
#include <sys/time.h>
#include <sys/vmem.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_pageout.h>
#include <vm/vm_param.h>
#include <vm/vm_kern.h>
#include <vm/vm_extern.h>
#include <vm/vm_map.h>
#include <vm/vm_page.h>
#include <vm/uma.h>
#include <vm/uma_int.h>
#include <vm/uma_dbg.h>
#ifdef DEBUG_MEMGUARD
#include <vm/memguard.h>
#endif
#ifdef DEBUG_REDZONE
#include <vm/redzone.h>
#endif
#if defined(INVARIANTS) && defined(__i386__)
#include <machine/cpu.h>
#endif
#include <ddb/ddb.h>
#ifdef KDTRACE_HOOKS
#include <sys/dtrace_bsd.h>
bool __read_frequently dtrace_malloc_enabled;
dtrace_malloc_probe_func_t __read_mostly dtrace_malloc_probe;
#endif
#if defined(INVARIANTS) || defined(MALLOC_MAKE_FAILURES) || \
defined(DEBUG_MEMGUARD) || defined(DEBUG_REDZONE)
#define MALLOC_DEBUG 1
#endif
/*
* When realloc() is called, if the new size is sufficiently smaller than
* the old size, realloc() will allocate a new, smaller block to avoid
* wasting memory. 'Sufficiently smaller' is defined as: newsize <=
* oldsize / 2^n, where REALLOC_FRACTION defines the value of 'n'.
*/
#ifndef REALLOC_FRACTION
#define REALLOC_FRACTION 1 /* new block if <= half the size */
#endif
/*
* Centrally define some common malloc types.
*/
MALLOC_DEFINE(M_CACHE, "cache", "Various Dynamically allocated caches");
MALLOC_DEFINE(M_DEVBUF, "devbuf", "device driver memory");
MALLOC_DEFINE(M_TEMP, "temp", "misc temporary data buffers");
static struct malloc_type *kmemstatistics;
static int kmemcount;
#define KMEM_ZSHIFT 4
#define KMEM_ZBASE 16
#define KMEM_ZMASK (KMEM_ZBASE - 1)
#define KMEM_ZMAX 65536
#define KMEM_ZSIZE (KMEM_ZMAX >> KMEM_ZSHIFT)
static uint8_t kmemsize[KMEM_ZSIZE + 1];
#ifndef MALLOC_DEBUG_MAXZONES
#define MALLOC_DEBUG_MAXZONES 1
#endif
static int numzones = MALLOC_DEBUG_MAXZONES;
/*
* Small malloc(9) memory allocations are allocated from a set of UMA buckets
* of various sizes.
*
* XXX: The comment here used to read "These won't be powers of two for
* long." It's possible that a significant amount of wasted memory could be
* recovered by tuning the sizes of these buckets.
*/
struct {
int kz_size;
char *kz_name;
uma_zone_t kz_zone[MALLOC_DEBUG_MAXZONES];
} kmemzones[] = {
{16, "16", },
{32, "32", },
{64, "64", },
{128, "128", },
{256, "256", },
{512, "512", },
{1024, "1024", },
{2048, "2048", },
{4096, "4096", },
{8192, "8192", },
{16384, "16384", },
{32768, "32768", },
{65536, "65536", },
{0, NULL},
};
/*
* Zone to allocate malloc type descriptions from. For ABI reasons, memory
* types are described by a data structure passed by the declaring code, but
* the malloc(9) implementation has its own data structure describing the
* type and statistics. This permits the malloc(9)-internal data structures
* to be modified without breaking binary-compiled kernel modules that
* declare malloc types.
*/
static uma_zone_t mt_zone;
u_long vm_kmem_size;
SYSCTL_ULONG(_vm, OID_AUTO, kmem_size, CTLFLAG_RDTUN, &vm_kmem_size, 0,
"Size of kernel memory");
static u_long kmem_zmax = KMEM_ZMAX;
SYSCTL_ULONG(_vm, OID_AUTO, kmem_zmax, CTLFLAG_RDTUN, &kmem_zmax, 0,
"Maximum allocation size that malloc(9) would use UMA as backend");
static u_long vm_kmem_size_min;
SYSCTL_ULONG(_vm, OID_AUTO, kmem_size_min, CTLFLAG_RDTUN, &vm_kmem_size_min, 0,
"Minimum size of kernel memory");
static u_long vm_kmem_size_max;
SYSCTL_ULONG(_vm, OID_AUTO, kmem_size_max, CTLFLAG_RDTUN, &vm_kmem_size_max, 0,
"Maximum size of kernel memory");
static u_int vm_kmem_size_scale;
SYSCTL_UINT(_vm, OID_AUTO, kmem_size_scale, CTLFLAG_RDTUN, &vm_kmem_size_scale, 0,
"Scale factor for kernel memory size");
static int sysctl_kmem_map_size(SYSCTL_HANDLER_ARGS);
SYSCTL_PROC(_vm, OID_AUTO, kmem_map_size,
CTLFLAG_RD | CTLTYPE_ULONG | CTLFLAG_MPSAFE, NULL, 0,
sysctl_kmem_map_size, "LU", "Current kmem allocation size");
static int sysctl_kmem_map_free(SYSCTL_HANDLER_ARGS);
SYSCTL_PROC(_vm, OID_AUTO, kmem_map_free,
CTLFLAG_RD | CTLTYPE_ULONG | CTLFLAG_MPSAFE, NULL, 0,
sysctl_kmem_map_free, "LU", "Free space in kmem");
/*
* The malloc_mtx protects the kmemstatistics linked list.
*/
struct mtx malloc_mtx;
#ifdef MALLOC_PROFILE
uint64_t krequests[KMEM_ZSIZE + 1];
static int sysctl_kern_mprof(SYSCTL_HANDLER_ARGS);
#endif
static int sysctl_kern_malloc_stats(SYSCTL_HANDLER_ARGS);
/*
* time_uptime of the last malloc(9) failure (induced or real).
*/
static time_t t_malloc_fail;
#if defined(MALLOC_MAKE_FAILURES) || (MALLOC_DEBUG_MAXZONES > 1)
static SYSCTL_NODE(_debug, OID_AUTO, malloc, CTLFLAG_RD, 0,
"Kernel malloc debugging options");
#endif
/*
* malloc(9) fault injection -- cause malloc failures every (n) mallocs when
* the caller specifies M_NOWAIT. If set to 0, no failures are caused.
*/
#ifdef MALLOC_MAKE_FAILURES
static int malloc_failure_rate;
static int malloc_nowait_count;
static int malloc_failure_count;
SYSCTL_INT(_debug_malloc, OID_AUTO, failure_rate, CTLFLAG_RWTUN,
&malloc_failure_rate, 0, "Every (n) mallocs with M_NOWAIT will fail");
SYSCTL_INT(_debug_malloc, OID_AUTO, failure_count, CTLFLAG_RD,
&malloc_failure_count, 0, "Number of imposed M_NOWAIT malloc failures");
#endif
static int
sysctl_kmem_map_size(SYSCTL_HANDLER_ARGS)
{
u_long size;
size = uma_size();
return (sysctl_handle_long(oidp, &size, 0, req));
}
static int
sysctl_kmem_map_free(SYSCTL_HANDLER_ARGS)
{
u_long size, limit;
/* The sysctl is unsigned, implement as a saturation value. */
size = uma_size();
limit = uma_limit();
if (size > limit)
size = 0;
else
size = limit - size;
return (sysctl_handle_long(oidp, &size, 0, req));
}
/*
* malloc(9) uma zone separation -- sub-page buffer overruns in one
* malloc type will affect only a subset of other malloc types.
*/
#if MALLOC_DEBUG_MAXZONES > 1
static void
tunable_set_numzones(void)
{
TUNABLE_INT_FETCH("debug.malloc.numzones",
&numzones);
/* Sanity check the number of malloc uma zones. */
if (numzones <= 0)
numzones = 1;
if (numzones > MALLOC_DEBUG_MAXZONES)
numzones = MALLOC_DEBUG_MAXZONES;
}
SYSINIT(numzones, SI_SUB_TUNABLES, SI_ORDER_ANY, tunable_set_numzones, NULL);
SYSCTL_INT(_debug_malloc, OID_AUTO, numzones, CTLFLAG_RDTUN | CTLFLAG_NOFETCH,
&numzones, 0, "Number of malloc uma subzones");
/*
* Any number that changes regularly is an okay choice for the
* offset. Build numbers are pretty good of you have them.
*/
static u_int zone_offset = __FreeBSD_version;
TUNABLE_INT("debug.malloc.zone_offset", &zone_offset);
SYSCTL_UINT(_debug_malloc, OID_AUTO, zone_offset, CTLFLAG_RDTUN,
&zone_offset, 0, "Separate malloc types by examining the "
"Nth character in the malloc type short description.");
static void
mtp_set_subzone(struct malloc_type *mtp)
{
struct malloc_type_internal *mtip;
const char *desc;
size_t len;
u_int val;
mtip = mtp->ks_handle;
desc = mtp->ks_shortdesc;
if (desc == NULL || (len = strlen(desc)) == 0)
val = 0;
else
val = desc[zone_offset % len];
mtip->mti_zone = (val % numzones);
}
static inline u_int
mtp_get_subzone(struct malloc_type *mtp)
{
struct malloc_type_internal *mtip;
mtip = mtp->ks_handle;
KASSERT(mtip->mti_zone < numzones,
("mti_zone %u out of range %d",
mtip->mti_zone, numzones));
return (mtip->mti_zone);
}
#elif MALLOC_DEBUG_MAXZONES == 0
#error "MALLOC_DEBUG_MAXZONES must be positive."
#else
static void
mtp_set_subzone(struct malloc_type *mtp)
{
struct malloc_type_internal *mtip;
mtip = mtp->ks_handle;
mtip->mti_zone = 0;
}
static inline u_int
mtp_get_subzone(struct malloc_type *mtp)
{
return (0);
}
#endif /* MALLOC_DEBUG_MAXZONES > 1 */
int
malloc_last_fail(void)
{
return (time_uptime - t_malloc_fail);
}
/*
* An allocation has succeeded -- update malloc type statistics for the
* amount of bucket size. Occurs within a critical section so that the
* thread isn't preempted and doesn't migrate while updating per-PCU
* statistics.
*/
static void
malloc_type_zone_allocated(struct malloc_type *mtp, unsigned long size,
int zindx)
{
struct malloc_type_internal *mtip;
struct malloc_type_stats *mtsp;
critical_enter();
mtip = mtp->ks_handle;
mtsp = &mtip->mti_stats[curcpu];
if (size > 0) {
mtsp->mts_memalloced += size;
mtsp->mts_numallocs++;
}
if (zindx != -1)
mtsp->mts_size |= 1 << zindx;
#ifdef KDTRACE_HOOKS
if (__predict_false(dtrace_malloc_enabled)) {
uint32_t probe_id = mtip->mti_probes[DTMALLOC_PROBE_MALLOC];
if (probe_id != 0)
(dtrace_malloc_probe)(probe_id,
(uintptr_t) mtp, (uintptr_t) mtip,
(uintptr_t) mtsp, size, zindx);
}
#endif
critical_exit();
}
void
malloc_type_allocated(struct malloc_type *mtp, unsigned long size)
{
if (size > 0)
malloc_type_zone_allocated(mtp, size, -1);
}
/*
* A free operation has occurred -- update malloc type statistics for the
* amount of the bucket size. Occurs within a critical section so that the
* thread isn't preempted and doesn't migrate while updating per-CPU
* statistics.
*/
void
malloc_type_freed(struct malloc_type *mtp, unsigned long size)
{
struct malloc_type_internal *mtip;
struct malloc_type_stats *mtsp;
critical_enter();
mtip = mtp->ks_handle;
mtsp = &mtip->mti_stats[curcpu];
mtsp->mts_memfreed += size;
mtsp->mts_numfrees++;
#ifdef KDTRACE_HOOKS
if (__predict_false(dtrace_malloc_enabled)) {
uint32_t probe_id = mtip->mti_probes[DTMALLOC_PROBE_FREE];
if (probe_id != 0)
(dtrace_malloc_probe)(probe_id,
(uintptr_t) mtp, (uintptr_t) mtip,
(uintptr_t) mtsp, size, 0);
}
#endif
critical_exit();
}
/*
* contigmalloc:
*
* Allocate a block of physically contiguous memory.
*
* If M_NOWAIT is set, this routine will not block and return NULL if
* the allocation fails.
*/
void *
contigmalloc(unsigned long size, struct malloc_type *type, int flags,
vm_paddr_t low, vm_paddr_t high, unsigned long alignment,
vm_paddr_t boundary)
{
void *ret;
ret = (void *)kmem_alloc_contig(kernel_arena, size, flags, low, high,
alignment, boundary, VM_MEMATTR_DEFAULT);
if (ret != NULL)
malloc_type_allocated(type, round_page(size));
return (ret);
}
void *
contigmalloc_domain(unsigned long size, struct malloc_type *type,
int domain, int flags, vm_paddr_t low, vm_paddr_t high,
unsigned long alignment, vm_paddr_t boundary)
{
void *ret;
ret = (void *)kmem_alloc_contig_domain(domain, size, flags, low, high,
alignment, boundary, VM_MEMATTR_DEFAULT);
if (ret != NULL)
malloc_type_allocated(type, round_page(size));
return (ret);
}
/*
* contigfree:
*
* Free a block of memory allocated by contigmalloc.
*
* This routine may not block.
*/
void
contigfree(void *addr, unsigned long size, struct malloc_type *type)
{
kmem_free(kernel_arena, (vm_offset_t)addr, size);
malloc_type_freed(type, round_page(size));
}
#ifdef MALLOC_DEBUG
static int
malloc_dbg(caddr_t *vap, size_t *sizep, struct malloc_type *mtp,
int flags)
{
#ifdef INVARIANTS
int indx;
KASSERT(mtp->ks_magic == M_MAGIC, ("malloc: bad malloc type magic"));
/*
* Check that exactly one of M_WAITOK or M_NOWAIT is specified.
*/
indx = flags & (M_WAITOK | M_NOWAIT);
if (indx != M_NOWAIT && indx != M_WAITOK) {
static struct timeval lasterr;
static int curerr, once;
if (once == 0 && ppsratecheck(&lasterr, &curerr, 1)) {
printf("Bad malloc flags: %x\n", indx);
kdb_backtrace();
flags |= M_WAITOK;
once++;
}
}
#endif
#ifdef MALLOC_MAKE_FAILURES
if ((flags & M_NOWAIT) && (malloc_failure_rate != 0)) {
atomic_add_int(&malloc_nowait_count, 1);
if ((malloc_nowait_count % malloc_failure_rate) == 0) {
atomic_add_int(&malloc_failure_count, 1);
t_malloc_fail = time_uptime;
*vap = NULL;
return (EJUSTRETURN);
}
}
#endif
if (flags & M_WAITOK) {
KASSERT(curthread->td_intr_nesting_level == 0,
("malloc(M_WAITOK) in interrupt context"));
KASSERT(curthread->td_epochnest == 0,
("malloc(M_WAITOK) in epoch context"));
}
KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
("malloc: called with spinlock or critical section held"));
#ifdef DEBUG_MEMGUARD
if (memguard_cmp_mtp(mtp, *sizep)) {
*vap = memguard_alloc(*sizep, flags);
if (*vap != NULL)
return (EJUSTRETURN);
/* This is unfortunate but should not be fatal. */
}
#endif
#ifdef DEBUG_REDZONE
*sizep = redzone_size_ntor(*sizep);
#endif
return (0);
}
#endif
/*
* malloc:
*
* Allocate a block of memory.
*
* If M_NOWAIT is set, this routine will not block and return NULL if
* the allocation fails.
*/
void *
malloc(size_t size, struct malloc_type *mtp, int flags)
{
int indx;
caddr_t va;
uma_zone_t zone;
#if defined(DEBUG_REDZONE)
unsigned long osize = size;
#endif
#ifdef MALLOC_DEBUG
if (malloc_dbg(&va, &size, mtp, flags) != 0)
return (va);
#endif
if (size <= kmem_zmax) {
if (size & KMEM_ZMASK)
size = (size & ~KMEM_ZMASK) + KMEM_ZBASE;
indx = kmemsize[size >> KMEM_ZSHIFT];
zone = kmemzones[indx].kz_zone[mtp_get_subzone(mtp)];
#ifdef MALLOC_PROFILE
krequests[size >> KMEM_ZSHIFT]++;
#endif
va = uma_zalloc(zone, flags);
if (va != NULL)
size = zone->uz_size;
malloc_type_zone_allocated(mtp, va == NULL ? 0 : size, indx);
} else {
size = roundup(size, PAGE_SIZE);
zone = NULL;
va = uma_large_malloc(size, flags);
malloc_type_allocated(mtp, va == NULL ? 0 : size);
}
if (flags & M_WAITOK)
KASSERT(va != NULL, ("malloc(M_WAITOK) returned NULL"));
else if (va == NULL)
t_malloc_fail = time_uptime;
#ifdef DEBUG_REDZONE
if (va != NULL)
va = redzone_setup(va, osize);
#endif
return ((void *) va);
}
void *
malloc_domain(size_t size, struct malloc_type *mtp, int domain,
int flags)
{
int indx;
caddr_t va;
uma_zone_t zone;
#if defined(DEBUG_REDZONE)
unsigned long osize = size;
#endif
#ifdef MALLOC_DEBUG
if (malloc_dbg(&va, &size, mtp, flags) != 0)
return (va);
#endif
if (size <= kmem_zmax) {
if (size & KMEM_ZMASK)
size = (size & ~KMEM_ZMASK) + KMEM_ZBASE;
indx = kmemsize[size >> KMEM_ZSHIFT];
zone = kmemzones[indx].kz_zone[mtp_get_subzone(mtp)];
#ifdef MALLOC_PROFILE
krequests[size >> KMEM_ZSHIFT]++;
#endif
va = uma_zalloc_domain(zone, NULL, domain, flags);
if (va != NULL)
size = zone->uz_size;
malloc_type_zone_allocated(mtp, va == NULL ? 0 : size, indx);
} else {
size = roundup(size, PAGE_SIZE);
zone = NULL;
va = uma_large_malloc_domain(size, domain, flags);
malloc_type_allocated(mtp, va == NULL ? 0 : size);
}
if (flags & M_WAITOK)
KASSERT(va != NULL, ("malloc(M_WAITOK) returned NULL"));
else if (va == NULL)
t_malloc_fail = time_uptime;
#ifdef DEBUG_REDZONE
if (va != NULL)
va = redzone_setup(va, osize);
#endif
return ((void *) va);
}
void *
mallocarray(size_t nmemb, size_t size, struct malloc_type *type, int flags)
{
if (WOULD_OVERFLOW(nmemb, size))
panic("mallocarray: %zu * %zu overflowed", nmemb, size);
return (malloc(size * nmemb, type, flags));
}
#ifdef INVARIANTS
static void
free_save_type(void *addr, struct malloc_type *mtp, u_long size)
{
struct malloc_type **mtpp = addr;
/*
* Cache a pointer to the malloc_type that most recently freed
* this memory here. This way we know who is most likely to
* have stepped on it later.
*
* This code assumes that size is a multiple of 8 bytes for
* 64 bit machines
*/
mtpp = (struct malloc_type **) ((unsigned long)mtpp & ~UMA_ALIGN_PTR);
mtpp += (size - sizeof(struct malloc_type *)) /
sizeof(struct malloc_type *);
*mtpp = mtp;
}
#endif
#ifdef MALLOC_DEBUG
static int
free_dbg(void **addrp, struct malloc_type *mtp)
{
void *addr;
addr = *addrp;
KASSERT(mtp->ks_magic == M_MAGIC, ("free: bad malloc type magic"));
KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
("free: called with spinlock or critical section held"));
/* free(NULL, ...) does nothing */
if (addr == NULL)
return (EJUSTRETURN);
#ifdef DEBUG_MEMGUARD
if (is_memguard_addr(addr)) {
memguard_free(addr);
return (EJUSTRETURN);
}
#endif
#ifdef DEBUG_REDZONE
redzone_check(addr);
*addrp = redzone_addr_ntor(addr);
#endif
return (0);
}
#endif
/*
* free:
*
* Free a block of memory allocated by malloc.
*
* This routine may not block.
*/
void
free(void *addr, struct malloc_type *mtp)
{
uma_slab_t slab;
u_long size;
#ifdef MALLOC_DEBUG
if (free_dbg(&addr, mtp) != 0)
return;
#endif
/* free(NULL, ...) does nothing */
if (addr == NULL)
return;
slab = vtoslab((vm_offset_t)addr & (~UMA_SLAB_MASK));
if (slab == NULL)
panic("free: address %p(%p) has not been allocated.\n",
addr, (void *)((u_long)addr & (~UMA_SLAB_MASK)));
if (!(slab->us_flags & UMA_SLAB_MALLOC)) {
size = slab->us_keg->uk_size;
#ifdef INVARIANTS
free_save_type(addr, mtp, size);
#endif
uma_zfree_arg(LIST_FIRST(&slab->us_keg->uk_zones), addr, slab);
} else {
size = slab->us_size;
uma_large_free(slab);
}
malloc_type_freed(mtp, size);
}
void
free_domain(void *addr, struct malloc_type *mtp)
{
uma_slab_t slab;
u_long size;
#ifdef MALLOC_DEBUG
if (free_dbg(&addr, mtp) != 0)
return;
#endif
/* free(NULL, ...) does nothing */
if (addr == NULL)
return;
slab = vtoslab((vm_offset_t)addr & (~UMA_SLAB_MASK));
if (slab == NULL)
panic("free_domain: address %p(%p) has not been allocated.\n",
addr, (void *)((u_long)addr & (~UMA_SLAB_MASK)));
if (!(slab->us_flags & UMA_SLAB_MALLOC)) {
size = slab->us_keg->uk_size;
#ifdef INVARIANTS
free_save_type(addr, mtp, size);
#endif
uma_zfree_domain(LIST_FIRST(&slab->us_keg->uk_zones),
addr, slab);
} else {
size = slab->us_size;
uma_large_free(slab);
}
malloc_type_freed(mtp, size);
}
/*
* realloc: change the size of a memory block
*/
void *
realloc(void *addr, size_t size, struct malloc_type *mtp, int flags)
{
uma_slab_t slab;
unsigned long alloc;
void *newaddr;
KASSERT(mtp->ks_magic == M_MAGIC,
("realloc: bad malloc type magic"));
KASSERT(curthread->td_critnest == 0 || SCHEDULER_STOPPED(),
("realloc: called with spinlock or critical section held"));
/* realloc(NULL, ...) is equivalent to malloc(...) */
if (addr == NULL)
return (malloc(size, mtp, flags));
/*
* XXX: Should report free of old memory and alloc of new memory to
* per-CPU stats.
*/
#ifdef DEBUG_MEMGUARD
if (is_memguard_addr(addr))
return (memguard_realloc(addr, size, mtp, flags));
#endif
#ifdef DEBUG_REDZONE
slab = NULL;
alloc = redzone_get_size(addr);
#else
slab = vtoslab((vm_offset_t)addr & ~(UMA_SLAB_MASK));
/* Sanity check */
KASSERT(slab != NULL,
("realloc: address %p out of range", (void *)addr));
/* Get the size of the original block */
if (!(slab->us_flags & UMA_SLAB_MALLOC))
alloc = slab->us_keg->uk_size;
else
alloc = slab->us_size;
/* Reuse the original block if appropriate */
if (size <= alloc
&& (size > (alloc >> REALLOC_FRACTION) || alloc == MINALLOCSIZE))
return (addr);
#endif /* !DEBUG_REDZONE */
/* Allocate a new, bigger (or smaller) block */
if ((newaddr = malloc(size, mtp, flags)) == NULL)
return (NULL);
/* Copy over original contents */
bcopy(addr, newaddr, min(size, alloc));
free(addr, mtp);
return (newaddr);
}
/*
* reallocf: same as realloc() but free memory on failure.
*/
void *
reallocf(void *addr, size_t size, struct malloc_type *mtp, int flags)
{
void *mem;
if ((mem = realloc(addr, size, mtp, flags)) == NULL)
free(addr, mtp);
return (mem);
}
#ifndef __sparc64__
CTASSERT(VM_KMEM_SIZE_SCALE >= 1);
#endif
/*
* Initialize the kernel memory (kmem) arena.
*/
void
kmeminit(void)
{
u_long mem_size;
u_long tmp;
#ifdef VM_KMEM_SIZE
if (vm_kmem_size == 0)
vm_kmem_size = VM_KMEM_SIZE;
#endif
#ifdef VM_KMEM_SIZE_MIN
if (vm_kmem_size_min == 0)
vm_kmem_size_min = VM_KMEM_SIZE_MIN;
#endif
#ifdef VM_KMEM_SIZE_MAX
if (vm_kmem_size_max == 0)
vm_kmem_size_max = VM_KMEM_SIZE_MAX;
#endif
/*
* Calculate the amount of kernel virtual address (KVA) space that is
* preallocated to the kmem arena. In order to support a wide range
* of machines, it is a function of the physical memory size,
* specifically,
*
* min(max(physical memory size / VM_KMEM_SIZE_SCALE,
* VM_KMEM_SIZE_MIN), VM_KMEM_SIZE_MAX)
*
* Every architecture must define an integral value for
* VM_KMEM_SIZE_SCALE. However, the definitions of VM_KMEM_SIZE_MIN
* and VM_KMEM_SIZE_MAX, which represent respectively the floor and
* ceiling on this preallocation, are optional. Typically,
* VM_KMEM_SIZE_MAX is itself a function of the available KVA space on
* a given architecture.
*/
mem_size = vm_cnt.v_page_count;
if (mem_size <= 32768) /* delphij XXX 128MB */
kmem_zmax = PAGE_SIZE;
if (vm_kmem_size_scale < 1)
vm_kmem_size_scale = VM_KMEM_SIZE_SCALE;
/*
* Check if we should use defaults for the "vm_kmem_size"
* variable:
*/
if (vm_kmem_size == 0) {
vm_kmem_size = (mem_size / vm_kmem_size_scale) * PAGE_SIZE;
if (vm_kmem_size_min > 0 && vm_kmem_size < vm_kmem_size_min)
vm_kmem_size = vm_kmem_size_min;
if (vm_kmem_size_max > 0 && vm_kmem_size >= vm_kmem_size_max)
vm_kmem_size = vm_kmem_size_max;
}
/*
* The amount of KVA space that is preallocated to the
* kmem arena can be set statically at compile-time or manually
* through the kernel environment. However, it is still limited to
* twice the physical memory size, which has been sufficient to handle
* the most severe cases of external fragmentation in the kmem arena.
*/
if (vm_kmem_size / 2 / PAGE_SIZE > mem_size)
vm_kmem_size = 2 * mem_size * PAGE_SIZE;
vm_kmem_size = round_page(vm_kmem_size);
#ifdef DEBUG_MEMGUARD
tmp = memguard_fudge(vm_kmem_size, kernel_map);
#else
tmp = vm_kmem_size;
#endif
uma_set_limit(tmp);
#ifdef DEBUG_MEMGUARD
/*
* Initialize MemGuard if support compiled in. MemGuard is a
* replacement allocator used for detecting tamper-after-free
* scenarios as they occur. It is only used for debugging.
*/
memguard_init(kernel_arena);
#endif
}
/*
* Initialize the kernel memory allocator
*/
/* ARGSUSED*/
static void
mallocinit(void *dummy)
{
int i;
uint8_t indx;
mtx_init(&malloc_mtx, "malloc", NULL, MTX_DEF);
kmeminit();
if (kmem_zmax < PAGE_SIZE || kmem_zmax > KMEM_ZMAX)
kmem_zmax = KMEM_ZMAX;
mt_zone = uma_zcreate("mt_zone", sizeof(struct malloc_type_internal),
#ifdef INVARIANTS
mtrash_ctor, mtrash_dtor, mtrash_init, mtrash_fini,
#else
NULL, NULL, NULL, NULL,
#endif
UMA_ALIGN_PTR, UMA_ZONE_MALLOC);
for (i = 0, indx = 0; kmemzones[indx].kz_size != 0; indx++) {
int size = kmemzones[indx].kz_size;
char *name = kmemzones[indx].kz_name;
int subzone;
for (subzone = 0; subzone < numzones; subzone++) {
kmemzones[indx].kz_zone[subzone] =
uma_zcreate(name, size,
#ifdef INVARIANTS
mtrash_ctor, mtrash_dtor, mtrash_init, mtrash_fini,
#else
NULL, NULL, NULL, NULL,
#endif
UMA_ALIGN_PTR, UMA_ZONE_MALLOC);
}
for (;i <= size; i+= KMEM_ZBASE)
kmemsize[i >> KMEM_ZSHIFT] = indx;
}
}
SYSINIT(kmem, SI_SUB_KMEM, SI_ORDER_SECOND, mallocinit, NULL);
void
malloc_init(void *data)
{
struct malloc_type_internal *mtip;
struct malloc_type *mtp;
KASSERT(vm_cnt.v_page_count != 0, ("malloc_register before vm_init"));
mtp = data;
if (mtp->ks_magic != M_MAGIC)
panic("malloc_init: bad malloc type magic");
mtip = uma_zalloc(mt_zone, M_WAITOK | M_ZERO);
mtp->ks_handle = mtip;
mtp_set_subzone(mtp);
mtx_lock(&malloc_mtx);
mtp->ks_next = kmemstatistics;
kmemstatistics = mtp;
kmemcount++;
mtx_unlock(&malloc_mtx);
}
void
malloc_uninit(void *data)
{
struct malloc_type_internal *mtip;
struct malloc_type_stats *mtsp;
struct malloc_type *mtp, *temp;
uma_slab_t slab;
long temp_allocs, temp_bytes;
int i;
mtp = data;
KASSERT(mtp->ks_magic == M_MAGIC,
("malloc_uninit: bad malloc type magic"));
KASSERT(mtp->ks_handle != NULL, ("malloc_deregister: cookie NULL"));
mtx_lock(&malloc_mtx);
mtip = mtp->ks_handle;
mtp->ks_handle = NULL;
if (mtp != kmemstatistics) {
for (temp = kmemstatistics; temp != NULL;
temp = temp->ks_next) {
if (temp->ks_next == mtp) {
temp->ks_next = mtp->ks_next;
break;
}
}
KASSERT(temp,
("malloc_uninit: type '%s' not found", mtp->ks_shortdesc));
} else
kmemstatistics = mtp->ks_next;
kmemcount--;
mtx_unlock(&malloc_mtx);
/*
* Look for memory leaks.
*/
temp_allocs = temp_bytes = 0;
for (i = 0; i < MAXCPU; i++) {
mtsp = &mtip->mti_stats[i];
temp_allocs += mtsp->mts_numallocs;
temp_allocs -= mtsp->mts_numfrees;
temp_bytes += mtsp->mts_memalloced;
temp_bytes -= mtsp->mts_memfreed;
}
if (temp_allocs > 0 || temp_bytes > 0) {
printf("Warning: memory type %s leaked memory on destroy "
"(%ld allocations, %ld bytes leaked).\n", mtp->ks_shortdesc,
temp_allocs, temp_bytes);
}
slab = vtoslab((vm_offset_t) mtip & (~UMA_SLAB_MASK));
uma_zfree_arg(mt_zone, mtip, slab);
}
struct malloc_type *
malloc_desc2type(const char *desc)
{
struct malloc_type *mtp;
mtx_assert(&malloc_mtx, MA_OWNED);
for (mtp = kmemstatistics; mtp != NULL; mtp = mtp->ks_next) {
if (strcmp(mtp->ks_shortdesc, desc) == 0)
return (mtp);
}
return (NULL);
}
static int
sysctl_kern_malloc_stats(SYSCTL_HANDLER_ARGS)
{
struct malloc_type_stream_header mtsh;
struct malloc_type_internal *mtip;
struct malloc_type_header mth;
struct malloc_type *mtp;
int error, i;
struct sbuf sbuf;
error = sysctl_wire_old_buffer(req, 0);
if (error != 0)
return (error);
sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
sbuf_clear_flags(&sbuf, SBUF_INCLUDENUL);
mtx_lock(&malloc_mtx);
/*
* Insert stream header.
*/
bzero(&mtsh, sizeof(mtsh));
mtsh.mtsh_version = MALLOC_TYPE_STREAM_VERSION;
mtsh.mtsh_maxcpus = MAXCPU;
mtsh.mtsh_count = kmemcount;
(void)sbuf_bcat(&sbuf, &mtsh, sizeof(mtsh));
/*
* Insert alternating sequence of type headers and type statistics.
*/
for (mtp = kmemstatistics; mtp != NULL; mtp = mtp->ks_next) {
mtip = (struct malloc_type_internal *)mtp->ks_handle;
/*
* Insert type header.
*/
bzero(&mth, sizeof(mth));
strlcpy(mth.mth_name, mtp->ks_shortdesc, MALLOC_MAX_NAME);
(void)sbuf_bcat(&sbuf, &mth, sizeof(mth));
/*
* Insert type statistics for each CPU.
*/
for (i = 0; i < MAXCPU; i++) {
(void)sbuf_bcat(&sbuf, &mtip->mti_stats[i],
sizeof(mtip->mti_stats[i]));
}
}
mtx_unlock(&malloc_mtx);
error = sbuf_finish(&sbuf);
sbuf_delete(&sbuf);
return (error);
}
SYSCTL_PROC(_kern, OID_AUTO, malloc_stats, CTLFLAG_RD|CTLTYPE_STRUCT,
0, 0, sysctl_kern_malloc_stats, "s,malloc_type_ustats",
"Return malloc types");
SYSCTL_INT(_kern, OID_AUTO, malloc_count, CTLFLAG_RD, &kmemcount, 0,
"Count of kernel malloc types");
void
malloc_type_list(malloc_type_list_func_t *func, void *arg)
{
struct malloc_type *mtp, **bufmtp;
int count, i;
size_t buflen;
mtx_lock(&malloc_mtx);
restart:
mtx_assert(&malloc_mtx, MA_OWNED);
count = kmemcount;
mtx_unlock(&malloc_mtx);
buflen = sizeof(struct malloc_type *) * count;
bufmtp = malloc(buflen, M_TEMP, M_WAITOK);
mtx_lock(&malloc_mtx);
if (count < kmemcount) {
free(bufmtp, M_TEMP);
goto restart;
}
for (mtp = kmemstatistics, i = 0; mtp != NULL; mtp = mtp->ks_next, i++)
bufmtp[i] = mtp;
mtx_unlock(&malloc_mtx);
for (i = 0; i < count; i++)
(func)(bufmtp[i], arg);
free(bufmtp, M_TEMP);
}
#ifdef DDB
DB_SHOW_COMMAND(malloc, db_show_malloc)
{
struct malloc_type_internal *mtip;
struct malloc_type *mtp;
uint64_t allocs, frees;
uint64_t alloced, freed;
int i;
db_printf("%18s %12s %12s %12s\n", "Type", "InUse", "MemUse",
"Requests");
for (mtp = kmemstatistics; mtp != NULL; mtp = mtp->ks_next) {
mtip = (struct malloc_type_internal *)mtp->ks_handle;
allocs = 0;
frees = 0;
alloced = 0;
freed = 0;
for (i = 0; i < MAXCPU; i++) {
allocs += mtip->mti_stats[i].mts_numallocs;
frees += mtip->mti_stats[i].mts_numfrees;
alloced += mtip->mti_stats[i].mts_memalloced;
freed += mtip->mti_stats[i].mts_memfreed;
}
db_printf("%18s %12ju %12juK %12ju\n",
mtp->ks_shortdesc, allocs - frees,
(alloced - freed + 1023) / 1024, allocs);
if (db_pager_quit)
break;
}
}
#if MALLOC_DEBUG_MAXZONES > 1
DB_SHOW_COMMAND(multizone_matches, db_show_multizone_matches)
{
struct malloc_type_internal *mtip;
struct malloc_type *mtp;
u_int subzone;
if (!have_addr) {
db_printf("Usage: show multizone_matches <malloc type/addr>\n");
return;
}
mtp = (void *)addr;
if (mtp->ks_magic != M_MAGIC) {
db_printf("Magic %lx does not match expected %x\n",
mtp->ks_magic, M_MAGIC);
return;
}
mtip = mtp->ks_handle;
subzone = mtip->mti_zone;
for (mtp = kmemstatistics; mtp != NULL; mtp = mtp->ks_next) {
mtip = mtp->ks_handle;
if (mtip->mti_zone != subzone)
continue;
db_printf("%s\n", mtp->ks_shortdesc);
if (db_pager_quit)
break;
}
}
#endif /* MALLOC_DEBUG_MAXZONES > 1 */
#endif /* DDB */
#ifdef MALLOC_PROFILE
static int
sysctl_kern_mprof(SYSCTL_HANDLER_ARGS)
{
struct sbuf sbuf;
uint64_t count;
uint64_t waste;
uint64_t mem;
int error;
int rsize;
int size;
int i;
waste = 0;
mem = 0;
error = sysctl_wire_old_buffer(req, 0);
if (error != 0)
return (error);
sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
sbuf_printf(&sbuf,
"\n Size Requests Real Size\n");
for (i = 0; i < KMEM_ZSIZE; i++) {
size = i << KMEM_ZSHIFT;
rsize = kmemzones[kmemsize[i]].kz_size;
count = (long long unsigned)krequests[i];
sbuf_printf(&sbuf, "%6d%28llu%11d\n", size,
(unsigned long long)count, rsize);
if ((rsize * count) > (size * count))
waste += (rsize * count) - (size * count);
mem += (rsize * count);
}
sbuf_printf(&sbuf,
"\nTotal memory used:\t%30llu\nTotal Memory wasted:\t%30llu\n",
(unsigned long long)mem, (unsigned long long)waste);
error = sbuf_finish(&sbuf);
sbuf_delete(&sbuf);
return (error);
}
SYSCTL_OID(_kern, OID_AUTO, mprof, CTLTYPE_STRING|CTLFLAG_RD,
NULL, 0, sysctl_kern_mprof, "A", "Malloc Profiling");
#endif /* MALLOC_PROFILE */