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/*
* Memory management functions.
*
* Copyright 2000-2007 Willy Tarreau <w@1wt.eu>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
*/
#include <errno.h>
#include <haproxy/activity-t.h>
#include <haproxy/api.h>
#include <haproxy/applet-t.h>
#include <haproxy/cfgparse.h>
#include <haproxy/channel.h>
#include <haproxy/cli.h>
#include <haproxy/errors.h>
#include <haproxy/global.h>
#include <haproxy/list.h>
#include <haproxy/pool.h>
#include <haproxy/stats-t.h>
#include <haproxy/stream_interface.h>
#include <haproxy/thread.h>
#include <haproxy/tools.h>
#ifdef CONFIG_HAP_POOLS
/* These ones are initialized per-thread on startup by init_pools() */
THREAD_LOCAL size_t pool_cache_bytes = 0; /* total cache size */
THREAD_LOCAL size_t pool_cache_count = 0; /* #cache objects */
#endif
static struct list pools = LIST_HEAD_INIT(pools);
int mem_poison_byte = -1;
#ifdef DEBUG_FAIL_ALLOC
static int mem_fail_rate = 0;
#endif
/* Try to find an existing shared pool with the same characteristics and
* returns it, otherwise creates this one. NULL is returned if no memory
* is available for a new creation. Two flags are supported :
* - MEM_F_SHARED to indicate that the pool may be shared with other users
* - MEM_F_EXACT to indicate that the size must not be rounded up
*/
struct pool_head *create_pool(char *name, unsigned int size, unsigned int flags)
{
struct pool_head *pool;
struct pool_head *entry;
struct list *start;
unsigned int align;
int thr __maybe_unused;
/* We need to store a (void *) at the end of the chunks. Since we know
* that the malloc() function will never return such a small size,
* let's round the size up to something slightly bigger, in order to
* ease merging of entries. Note that the rounding is a power of two.
* This extra (void *) is not accounted for in the size computation
* so that the visible parts outside are not affected.
*
* Note: for the LRU cache, we need to store 2 doubly-linked lists.
*/
if (!(flags & MEM_F_EXACT)) {
align = 4 * sizeof(void *); // 2 lists = 4 pointers min
size = ((size + POOL_EXTRA + align - 1) & -align) - POOL_EXTRA;
}
/* TODO: thread: we do not lock pool list for now because all pools are
* created during HAProxy startup (so before threads creation) */
start = &pools;
pool = NULL;
list_for_each_entry(entry, &pools, list) {
if (entry->size == size) {
/* either we can share this place and we take it, or
* we look for a shareable one or for the next position
* before which we will insert a new one.
*/
if ((flags & entry->flags & MEM_F_SHARED)
#ifdef DEBUG_DONT_SHARE_POOLS
&& strcmp(name, entry->name) == 0
#endif
) {
/* we can share this one */
pool = entry;
DPRINTF(stderr, "Sharing %s with %s\n", name, pool->name);
break;
}
}
else if (entry->size > size) {
/* insert before this one */
start = &entry->list;
break;
}
}
if (!pool) {
if (!pool)
pool = calloc(1, sizeof(*pool));
if (!pool)
return NULL;
if (name)
strlcpy2(pool->name, name, sizeof(pool->name));
pool->size = size;
pool->flags = flags;
LIST_APPEND(start, &pool->list);
#ifdef CONFIG_HAP_POOLS
/* update per-thread pool cache if necessary */
for (thr = 0; thr < MAX_THREADS; thr++) {
LIST_INIT(&pool->cache[thr].list);
}
#endif
HA_SPIN_INIT(&pool->lock);
}
pool->users++;
return pool;
}
/* Tries to allocate an object for the pool <pool> using the system's allocator
* and directly returns it. The pool's allocated counter is checked and updated,
* but no other checks are performed. The pool's lock is not used and is not a
* problem either.
*/
void *pool_get_from_os(struct pool_head *pool)
{
if (!pool->limit || pool->allocated < pool->limit) {
void *ptr = pool_alloc_area(pool->size + POOL_EXTRA);
if (ptr) {
_HA_ATOMIC_INC(&pool->allocated);
return ptr;
}
_HA_ATOMIC_INC(&pool->failed);
}
activity[tid].pool_fail++;
return NULL;
}
/* Releases a pool item back to the operating system and atomically updates
* the allocation counter.
*/
void pool_put_to_os(struct pool_head *pool, void *ptr)
{
#ifdef DEBUG_UAF
/* This object will be released for real in order to detect a use after
* free. We also force a write to the area to ensure we crash on double
* free or free of a const area.
*/
*(uint32_t *)ptr = 0xDEADADD4;
#endif /* DEBUG_UAF */
pool_free_area(ptr, pool->size + POOL_EXTRA);
_HA_ATOMIC_DEC(&pool->allocated);
}
/* Tries to allocate an object for the pool <pool> using the system's allocator
* and directly returns it. The pool's counters are updated but the object is
* never cached, so this is usable with and without local or shared caches.
* This may be called with or without the pool lock held, so it must not use
* the pool's lock.
*/
void *pool_alloc_nocache(struct pool_head *pool)
{
void *ptr = NULL;
ptr = pool_get_from_os(pool);
if (!ptr)
return NULL;
swrate_add_scaled(&pool->needed_avg, POOL_AVG_SAMPLES, pool->used, POOL_AVG_SAMPLES/4);
_HA_ATOMIC_INC(&pool->used);
#ifdef DEBUG_MEMORY_POOLS
/* keep track of where the element was allocated from */
*POOL_LINK(pool, ptr) = (void *)pool;
#endif
return ptr;
}
/* Release a pool item back to the OS and keeps the pool's counters up to date.
* This is always defined even when pools are not enabled (their usage stats
* are maintained).
*/
void pool_free_nocache(struct pool_head *pool, void *ptr)
{
_HA_ATOMIC_DEC(&pool->used);
swrate_add(&pool->needed_avg, POOL_AVG_SAMPLES, pool->used);
pool_put_to_os(pool, ptr);
}
#ifdef CONFIG_HAP_POOLS
/* Evicts some of the oldest objects from one local cache, until its number of
* objects is no more than 16+1/8 of the total number of locally cached objects
* or the total size of the local cache is no more than 75% of its maximum (i.e.
* we don't want a single cache to use all the cache for itself). For this, the
* list is scanned in reverse.
*/
void pool_evict_from_local_cache(struct pool_head *pool)
{
struct pool_cache_head *ph = &pool->cache[tid];
struct pool_cache_item *item;
while (ph->count >= 16 + pool_cache_count / 8 &&
pool_cache_bytes > CONFIG_HAP_POOL_CACHE_SIZE * 3 / 4) {
item = LIST_NEXT(&ph->list, typeof(item), by_pool);
ph->count--;
pool_cache_bytes -= pool->size;
pool_cache_count--;
LIST_DELETE(&item->by_pool);
LIST_DELETE(&item->by_lru);
pool_put_to_shared_cache(pool, item);
}
}
/* Evicts some of the oldest objects from the local cache, pushing them to the
* global pool.
*/
void pool_evict_from_local_caches()
{
struct pool_cache_item *item;
struct pool_cache_head *ph;
struct pool_head *pool;
do {
item = LIST_PREV(&ti->pool_lru_head, struct pool_cache_item *, by_lru);
/* note: by definition we remove oldest objects so they also are the
* oldest in their own pools, thus their next is the pool's head.
*/
ph = LIST_NEXT(&item->by_pool, struct pool_cache_head *, list);
pool = container_of(ph - tid, struct pool_head, cache);
LIST_DELETE(&item->by_pool);
LIST_DELETE(&item->by_lru);
ph->count--;
pool_cache_count--;
pool_cache_bytes -= pool->size;
pool_put_to_shared_cache(pool, item);
} while (pool_cache_bytes > CONFIG_HAP_POOL_CACHE_SIZE * 7 / 8);
}
/* Frees an object to the local cache, possibly pushing oldest objects to the
* shared cache, which itself may decide to release some of them to the OS.
* While it is unspecified what the object becomes past this point, it is
* guaranteed to be released from the users' perpective.
*/
void pool_put_to_cache(struct pool_head *pool, void *ptr)
{
struct pool_cache_item *item = (struct pool_cache_item *)ptr;
struct pool_cache_head *ph = &pool->cache[tid];
LIST_INSERT(&ph->list, &item->by_pool);
LIST_INSERT(&ti->pool_lru_head, &item->by_lru);
ph->count++;
pool_cache_count++;
pool_cache_bytes += pool->size;
if (unlikely(pool_cache_bytes > CONFIG_HAP_POOL_CACHE_SIZE * 3 / 4)) {
if (ph->count >= 16 + pool_cache_count / 8)
pool_evict_from_local_cache(pool);
if (pool_cache_bytes > CONFIG_HAP_POOL_CACHE_SIZE)
pool_evict_from_local_caches();
}
}
#if defined(CONFIG_HAP_NO_GLOBAL_POOLS)
/* legacy stuff */
void pool_flush(struct pool_head *pool)
{
}
/* This function might ask the malloc library to trim its buffers. */
void pool_gc(struct pool_head *pool_ctx)
{
#if defined(HA_HAVE_MALLOC_TRIM)
malloc_trim(0);
#endif
}
#else /* CONFIG_HAP_NO_GLOBAL_POOLS */
#if defined(CONFIG_HAP_LOCKLESS_POOLS)
/*
* This function frees whatever can be freed in pool <pool>.
*/
void pool_flush(struct pool_head *pool)
{
void *next, *temp;
if (!pool)
return;
/* The loop below atomically detaches the head of the free list and
* replaces it with a NULL. Then the list can be released.
*/
next = pool->free_list;
do {
while (unlikely(next == POOL_BUSY)) {
__ha_cpu_relax();
next = _HA_ATOMIC_LOAD(&pool->free_list);
}
if (next == NULL)
return;
} while (unlikely((next = _HA_ATOMIC_XCHG(&pool->free_list, POOL_BUSY)) == POOL_BUSY));
_HA_ATOMIC_STORE(&pool->free_list, NULL);
__ha_barrier_atomic_store();
while (next) {
temp = next;
next = *POOL_LINK(pool, temp);
pool_put_to_os(pool, temp);
}
/* here, we should have pool->allocated == pool->used */
}
#else /* CONFIG_HAP_LOCKLESS_POOLS */
/*
* This function frees whatever can be freed in pool <pool>.
*/
void pool_flush(struct pool_head *pool)
{
void *temp, **next;
if (!pool)
return;
HA_SPIN_LOCK(POOL_LOCK, &pool->lock);
next = pool->free_list;
pool->free_list = NULL;
HA_SPIN_UNLOCK(POOL_LOCK, &pool->lock);
while (next) {
temp = next;
next = *POOL_LINK(pool, temp);
pool_put_to_os(pool, temp);
}
/* here, we should have pool->allocated == pool->used */
}
#endif /* CONFIG_HAP_LOCKLESS_POOLS */
/*
* This function frees whatever can be freed in all pools, but respecting
* the minimum thresholds imposed by owners. It makes sure to be alone to
* run by using thread_isolate(). <pool_ctx> is unused.
*/
void pool_gc(struct pool_head *pool_ctx)
{
struct pool_head *entry;
int isolated = thread_isolated();
if (!isolated)
thread_isolate();
list_for_each_entry(entry, &pools, list) {
void *temp;
//qfprintf(stderr, "Flushing pool %s\n", entry->name);
while (entry->free_list &&
(int)(entry->allocated - entry->used) > (int)entry->minavail) {
temp = entry->free_list;
entry->free_list = *POOL_LINK(entry, temp);
pool_put_to_os(entry, temp);
}
}
#if defined(HA_HAVE_MALLOC_TRIM)
malloc_trim(0);
#endif
if (!isolated)
thread_release();
}
#endif /* CONFIG_HAP_NO_GLOBAL_POOLS */
#else /* CONFIG_HAP_POOLS */
/* legacy stuff */
void pool_flush(struct pool_head *pool)
{
}
/* This function might ask the malloc library to trim its buffers. */
void pool_gc(struct pool_head *pool_ctx)
{
#if defined(HA_HAVE_MALLOC_TRIM)
malloc_trim(0);
#endif
}
#endif /* CONFIG_HAP_POOLS */
/*
* This function destroys a pool by freeing it completely, unless it's still
* in use. This should be called only under extreme circumstances. It always
* returns NULL if the resulting pool is empty, easing the clearing of the old
* pointer, otherwise it returns the pool.
* .
*/
void *pool_destroy(struct pool_head *pool)
{
if (pool) {
pool_flush(pool);
if (pool->used)
return pool;
pool->users--;
if (!pool->users) {
LIST_DELETE(&pool->list);
#ifndef CONFIG_HAP_LOCKLESS_POOLS
HA_SPIN_DESTROY(&pool->lock);
#endif
/* note that if used == 0, the cache is empty */
free(pool);
}
}
return NULL;
}
/* This destroys all pools on exit. It is *not* thread safe. */
void pool_destroy_all()
{
struct pool_head *entry, *back;
list_for_each_entry_safe(entry, back, &pools, list)
pool_destroy(entry);
}
/* This function dumps memory usage information into the trash buffer. */
void dump_pools_to_trash()
{
struct pool_head *entry;
unsigned long allocated, used;
int nbpools;
allocated = used = nbpools = 0;
chunk_printf(&trash, "Dumping pools usage. Use SIGQUIT to flush them.\n");
list_for_each_entry(entry, &pools, list) {
#ifndef CONFIG_HAP_LOCKLESS_POOLS
HA_SPIN_LOCK(POOL_LOCK, &entry->lock);
#endif
chunk_appendf(&trash, " - Pool %s (%u bytes) : %u allocated (%u bytes), %u used, needed_avg %u, %u failures, %u users, @%p%s\n",
entry->name, entry->size, entry->allocated,
entry->size * entry->allocated, entry->used,
swrate_avg(entry->needed_avg, POOL_AVG_SAMPLES), entry->failed,
entry->users, entry,
(entry->flags & MEM_F_SHARED) ? " [SHARED]" : "");
allocated += entry->allocated * entry->size;
used += entry->used * entry->size;
nbpools++;
#ifndef CONFIG_HAP_LOCKLESS_POOLS
HA_SPIN_UNLOCK(POOL_LOCK, &entry->lock);
#endif
}
chunk_appendf(&trash, "Total: %d pools, %lu bytes allocated, %lu used.\n",
nbpools, allocated, used);
}
/* Dump statistics on pools usage. */
void dump_pools(void)
{
dump_pools_to_trash();
qfprintf(stderr, "%s", trash.area);
}
/* This function returns the total number of failed pool allocations */
int pool_total_failures()
{
struct pool_head *entry;
int failed = 0;
list_for_each_entry(entry, &pools, list)
failed += entry->failed;
return failed;
}
/* This function returns the total amount of memory allocated in pools (in bytes) */
unsigned long pool_total_allocated()
{
struct pool_head *entry;
unsigned long allocated = 0;
list_for_each_entry(entry, &pools, list)
allocated += entry->allocated * entry->size;
return allocated;
}
/* This function returns the total amount of memory used in pools (in bytes) */
unsigned long pool_total_used()
{
struct pool_head *entry;
unsigned long used = 0;
list_for_each_entry(entry, &pools, list)
used += entry->used * entry->size;
return used;
}
/* This function dumps memory usage information onto the stream interface's
* read buffer. It returns 0 as long as it does not complete, non-zero upon
* completion. No state is used.
*/
static int cli_io_handler_dump_pools(struct appctx *appctx)
{
struct stream_interface *si = appctx->owner;
dump_pools_to_trash();
if (ci_putchk(si_ic(si), &trash) == -1) {
si_rx_room_blk(si);
return 0;
}
return 1;
}
/* callback used to create early pool <name> of size <size> and store the
* resulting pointer into <ptr>. If the allocation fails, it quits with after
* emitting an error message.
*/
void create_pool_callback(struct pool_head **ptr, char *name, unsigned int size)
{
*ptr = create_pool(name, size, MEM_F_SHARED);
if (!*ptr) {
ha_alert("Failed to allocate pool '%s' of size %u : %s. Aborting.\n",
name, size, strerror(errno));
exit(1);
}
}
/* Initializes all per-thread arrays on startup */
static void init_pools()
{
#ifdef CONFIG_HAP_POOLS
int thr;
for (thr = 0; thr < MAX_THREADS; thr++) {
LIST_INIT(&ha_thread_info[thr].pool_lru_head);
}
#endif
}
INITCALL0(STG_PREPARE, init_pools);
/* register cli keywords */
static struct cli_kw_list cli_kws = {{ },{
{ { "show", "pools", NULL }, "show pools : report information about the memory pools usage", NULL, cli_io_handler_dump_pools },
{{},}
}};
INITCALL1(STG_REGISTER, cli_register_kw, &cli_kws);
#ifdef DEBUG_FAIL_ALLOC
int mem_should_fail(const struct pool_head *pool)
{
int ret = 0;
if (mem_fail_rate > 0 && !(global.mode & MODE_STARTING)) {
if (mem_fail_rate > statistical_prng_range(100))
ret = 1;
else
ret = 0;
}
return ret;
}
/* config parser for global "tune.fail-alloc" */
static int mem_parse_global_fail_alloc(char **args, int section_type, struct proxy *curpx,
const struct proxy *defpx, const char *file, int line,
char **err)
{
if (too_many_args(1, args, err, NULL))
return -1;
mem_fail_rate = atoi(args[1]);
if (mem_fail_rate < 0 || mem_fail_rate > 100) {
memprintf(err, "'%s' expects a numeric value between 0 and 100.", args[0]);
return -1;
}
return 0;
}
#endif
/* register global config keywords */
static struct cfg_kw_list mem_cfg_kws = {ILH, {
#ifdef DEBUG_FAIL_ALLOC
{ CFG_GLOBAL, "tune.fail-alloc", mem_parse_global_fail_alloc },
#endif
{ 0, NULL, NULL }
}};
INITCALL1(STG_REGISTER, cfg_register_keywords, &mem_cfg_kws);
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/