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mars/brick_mem.c

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// (c) 2011 Thomas Schoebel-Theuer / 1&1 Internet AG
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <asm/atomic.h>
#include "brick_mem.h"
#include "brick_say.h"
#include "brick_locks.h"
#define BRICK_DEBUG_MEM 10000
//#define LIMIT_MEM
#define USE_KERNEL_PAGES // currently mandatory (vmalloc does not work)
//#define BUMP_LIMITS // try to avoid this
#define ALLOW_DYNAMIC_RAISE 512
#ifndef CONFIG_DEBUG_KERNEL
#undef BRICK_DEBUG_MEM
#endif
#define MAGIC_BLOCK (int)0x8B395D7B
#define MAGIC_BEND (int)0x8B395D7C
#define MAGIC_MEM (int)0x8B395D7D
#define MAGIC_END (int)0x8B395D7E
#define MAGIC_STR (int)0x8B395D7F
#define INT_ACCESS(ptr,offset) (*(int*)(((char*)(ptr)) + (offset)))
#define _BRICK_FMT(_fmt) __BASE_FILE__ " %d %s(): " _fmt, __LINE__, __FUNCTION__
#define _BRICK_MSG(_dump, PREFIX, _fmt, _args...) do { say(PREFIX _BRICK_FMT(_fmt), ##_args); if (_dump) dump_stack(); } while (0)
#define BRICK_ERROR "MEM_ERROR "
#define BRICK_WARNING "MEM_WARN "
#define BRICK_INFO "MEM_INFO "
#define BRICK_ERR(_fmt, _args...) _BRICK_MSG(true, BRICK_ERROR, _fmt, ##_args)
#define BRICK_WRN(_fmt, _args...) _BRICK_MSG(false, BRICK_WARNING, _fmt, ##_args)
#define BRICK_INF(_fmt, _args...) _BRICK_MSG(false, BRICK_INFO, _fmt, ##_args)
/////////////////////////////////////////////////////////////////////////
// limit handling
#ifdef LIMIT_MEM
#include <linux/swap.h>
#include <linux/mm.h>
#endif
long long brick_global_memlimit = 0;
EXPORT_SYMBOL_GPL(brick_global_memlimit);
/////////////////////////////////////////////////////////////////////////
// small memory allocation (use this only for len < PAGE_SIZE)
#ifdef BRICK_DEBUG_MEM
static atomic_t mem_count[BRICK_DEBUG_MEM] = {};
static atomic_t mem_free[BRICK_DEBUG_MEM] = {};
static int mem_len[BRICK_DEBUG_MEM] = {};
#define PLUS_SIZE (2 * sizeof(int))
#else
#define PLUS_SIZE 0
#endif
void *_brick_mem_alloc(int len, int line)
{
void *res;
#ifdef CONFIG_DEBUG_KERNEL
might_sleep();
#endif
res = kmalloc(len + PLUS_SIZE + sizeof(int), GFP_BRICK);
#ifdef BRICK_DEBUG_MEM
if (likely(res)) {
if (unlikely(line < 0))
line = 0;
else if (unlikely(line >= BRICK_DEBUG_MEM))
line = BRICK_DEBUG_MEM - 1;
INT_ACCESS(res, 0) = MAGIC_MEM;
INT_ACCESS(res, sizeof(int)) = line;
res += PLUS_SIZE;
INT_ACCESS(res, len) = MAGIC_END;
atomic_inc(&mem_count[line]);
mem_len[line] = len;
}
#endif
return res;
}
EXPORT_SYMBOL_GPL(_brick_mem_alloc);
void _brick_mem_free(void *data, int cline)
{
if (data) {
#ifdef BRICK_DEBUG_MEM
void *test = data - PLUS_SIZE;
int magic = INT_ACCESS(test, 0);
int line = INT_ACCESS(test, sizeof(int));
if (unlikely(magic != MAGIC_MEM)) {
BRICK_ERR("line %d memory corruption: magix %08x != %08x\n", cline, magic, MAGIC_STR);
return;
}
if (unlikely(line < 0 || line >= BRICK_DEBUG_MEM)) {
BRICK_ERR("line %d memory corruption: alloc line = %d\n", cline, line);
return;
}
INT_ACCESS(test, 0) = 0xffffffff;
atomic_dec(&mem_count[line]);
atomic_inc(&mem_free[line]);
data = test;
#endif
kfree(data);
}
}
EXPORT_SYMBOL_GPL(_brick_mem_free);
/////////////////////////////////////////////////////////////////////////
// string memory allocation
#ifdef BRICK_DEBUG_MEM
static atomic_t string_count[BRICK_DEBUG_MEM] = {};
static atomic_t string_free[BRICK_DEBUG_MEM] = {};
#endif
char *_brick_string_alloc(int len, int line)
{
char *res;
#ifdef CONFIG_DEBUG_KERNEL
might_sleep();
#endif
if (len <= 0) {
len = BRICK_STRING_LEN;
}
#ifdef BRICK_DEBUG_MEM
len += sizeof(int) * 4;
#endif
#ifdef CONFIG_DEBUG_KERNEL
res = kzalloc(len + 1024, GFP_BRICK);
#else
res = kzalloc(len, GFP_BRICK);
#endif
#ifdef BRICK_DEBUG_MEM
if (likely(res)) {
if (unlikely(line < 0))
line = 0;
else if (unlikely(line >= BRICK_DEBUG_MEM))
line = BRICK_DEBUG_MEM - 1;
INT_ACCESS(res, 0) = MAGIC_STR;
INT_ACCESS(res, sizeof(int)) = len;
INT_ACCESS(res, sizeof(int) * 2) = line;
INT_ACCESS(res, len - sizeof(int)) = MAGIC_END;
atomic_inc(&string_count[line]);
res += sizeof(int) * 3;
}
#endif
return res;
}
EXPORT_SYMBOL_GPL(_brick_string_alloc);
void _brick_string_free(const char *data, int cline)
{
if (data) {
#ifdef BRICK_DEBUG_MEM
int magic;
int len;
int line;
data -= sizeof(int) * 3;
magic = INT_ACCESS(data, 0);
if (unlikely(magic != MAGIC_STR)) {
BRICK_ERR("cline %d stringmem corruption: magix %08x != %08x\n", cline, magic, MAGIC_STR);
return;
}
len = INT_ACCESS(data, sizeof(int));
line = INT_ACCESS(data, sizeof(int) * 2);
if (unlikely(line < 0 || line >= BRICK_DEBUG_MEM)) {
BRICK_ERR("cline %d stringmem corruption: line = %d (len = %d)\n", cline, line, len);
return;
}
magic = INT_ACCESS(data, len - sizeof(int));
if (unlikely(magic != MAGIC_END)) {
BRICK_ERR("cline %d stringmem corruption: end_magix %08x != %08x, line = %d len = %d\n", cline, magic, MAGIC_END, len, line);
return;
}
INT_ACCESS(data, len - sizeof(int)) = 0xffffffff;
atomic_dec(&string_count[line]);
atomic_inc(&string_free[line]);
#endif
kfree(data);
}
}
EXPORT_SYMBOL_GPL(_brick_string_free);
/////////////////////////////////////////////////////////////////////////
// block memory allocation
static
int len2order(int len)
{
int order = 0;
while ((PAGE_SIZE << order) < len)
order++;
if (unlikely(order > BRICK_MAX_ORDER || len <= 0)) {
BRICK_ERR("trying to allocate %d bytes (max = %d)\n", len, (int)(PAGE_SIZE << order));
return -1;
}
return order;
}
#ifdef BRICK_DEBUG_MEM
// indexed by line
static atomic_t block_count[BRICK_DEBUG_MEM] = {};
static atomic_t block_free[BRICK_DEBUG_MEM] = {};
static int block_len[BRICK_DEBUG_MEM] = {};
// indexed by order
static atomic_t op_count[BRICK_MAX_ORDER+1] = {};
static atomic_t raw_count[BRICK_MAX_ORDER+1] = {};
static atomic_t alloc_count[BRICK_MAX_ORDER+1] = {};
static int alloc_max[BRICK_MAX_ORDER+1] = {};
#endif
static inline
void *__brick_block_alloc(int order)
{
#ifdef BRICK_DEBUG_MEM
atomic_inc(&raw_count[order]);
#endif
#ifdef USE_KERNEL_PAGES
return (void*)__get_free_pages(GFP_BRICK, order);
#else
return __vmalloc(PAGE_SIZE << order, GFP_BRICK, PAGE_KERNEL_IO);
#endif
}
static inline
void __brick_block_free(void *data, int order)
{
#ifdef USE_KERNEL_PAGES
__free_pages(virt_to_page((unsigned long)data), order);
#else
vfree(data);
#endif
#ifdef BRICK_DEBUG_MEM
atomic_dec(&raw_count[order]);
#endif
}
bool brick_allow_freelist = true;
EXPORT_SYMBOL_GPL(brick_allow_freelist);
#ifdef CONFIG_MARS_MEM_PREALLOC
/* Note: we have no separate lists per CPU.
* This should not hurt because the freelists are only used
* for higher-order pages which should be rather low-frequency.
*/
static spinlock_t freelist_lock[BRICK_MAX_ORDER+1];
static void *brick_freelist[BRICK_MAX_ORDER+1] = {};
static atomic_t freelist_count[BRICK_MAX_ORDER+1] = {};
static int freelist_max[BRICK_MAX_ORDER+1] = {};
static
void *_get_free(int order)
{
void *data;
unsigned long flags;
traced_lock(&freelist_lock[order], flags);
data = brick_freelist[order];
if (likely(data)) {
void *next = *(void**)data;
#ifdef BRICK_DEBUG_MEM // check for corruptions
void *copy = *(((void**)data)+1);
if (unlikely(next != copy)) { // found a corruption
// prevent further trouble by leaving a memleak
brick_freelist[order] = NULL;
traced_unlock(&freelist_lock[order], flags);
BRICK_ERR("freelist corruption at %p (next %p != %p, murdered = %d), order = %d\n", data, next, copy, atomic_read(&freelist_count[order]), order);
return NULL;
}
#endif
brick_freelist[order] = next;
atomic_dec(&freelist_count[order]);
}
traced_unlock(&freelist_lock[order], flags);
return data;
}
static
void _put_free(void *data, int order)
{
void *next;
unsigned long flags;
traced_lock(&freelist_lock[order], flags);
next = brick_freelist[order];
*(void**)data = next;
#ifdef BRICK_DEBUG_MEM // insert redundant copy for checking
*(((void**)data)+1) = next;
#endif
brick_freelist[order] = data;
traced_unlock(&freelist_lock[order], flags);
atomic_inc(&freelist_count[order]);
}
static
void _free_all(void)
{
int order;
for (order = BRICK_MAX_ORDER; order >= 0; order--) {
for (;;) {
void *data = _get_free(order);
if (!data)
break;
__brick_block_free(data, order);
}
}
}
int brick_mem_reserve(struct mem_reservation *r)
{
int order;
int status = 0;
for (order = BRICK_MAX_ORDER; order >= 0; order--) {
int max = r->amount[order];
int i;
freelist_max[order] += max;
BRICK_INF("preallocating %d at order %d (new maxlevel = %d)\n", max, order, freelist_max[order]);
max = freelist_max[order] - atomic_read(&freelist_count[order]);
if (max >= 0) {
for (i = 0; i < max; i++) {
void *data = __brick_block_alloc(order);
if (likely(data)) {
_put_free(data, order);
} else {
status = -ENOMEM;
}
}
} else {
for (i = 0; i < -max; i++) {
void *data = _get_free(order);
if (likely(data)) {
__brick_block_free(data, order);
}
}
}
}
return status;
}
#else
int brick_mem_reserve(struct mem_reservation *r)
{
BRICK_INF("preallocation is not compiled in\n");
return 0;
}
#endif
EXPORT_SYMBOL_GPL(brick_mem_reserve);
void *_brick_block_alloc(loff_t pos, int len, int line)
{
void *data;
#ifdef BRICK_DEBUG_MEM
int count;
const int plus = len <= PAGE_SIZE ? 0 : PAGE_SIZE * 2;
#else
const int plus = 0;
#endif
int order = len2order(len + plus);
if (unlikely(order < 0)) {
BRICK_ERR("trying to allocate %d bytes (max = %d)\n", len, (int)(PAGE_SIZE << order));
return NULL;
}
#ifdef CONFIG_DEBUG_KERNEL
might_sleep();
#endif
#ifdef BRICK_DEBUG_MEM
atomic_inc(&op_count[order]);
atomic_inc(&alloc_count[order]);
count = atomic_read(&alloc_count[order]);
// statistics
if (count > alloc_max[order])
alloc_max[order] = count;
/* Dynamic increase of limits, in order to reduce
* fragmentation on higher-order pages.
* This comes on cost of higher memory usage.
*/
#if defined(ALLOW_DYNAMIC_RAISE) && defined(CONFIG_MARS_MEM_PREALLOC)
if (order > 0 && count > freelist_max[order] && count <= ALLOW_DYNAMIC_RAISE)
freelist_max[order] = count;
#endif
#endif
#ifdef CONFIG_MARS_MEM_PREALLOC
data = _get_free(order);
if (!data)
#endif
data = __brick_block_alloc(order);
#ifdef BRICK_DEBUG_MEM
if (likely(data) && order > 0) {
if (unlikely(line < 0))
line = 0;
else if (unlikely(line >= BRICK_DEBUG_MEM))
line = BRICK_DEBUG_MEM - 1;
atomic_inc(&block_count[line]);
block_len[line] = len;
INT_ACCESS(data, 0) = MAGIC_BLOCK;
INT_ACCESS(data, sizeof(int)) = line;
INT_ACCESS(data, sizeof(int) * 2) = len;
data += PAGE_SIZE;
INT_ACCESS(data, len) = MAGIC_BEND;
}
#endif
return data;
}
EXPORT_SYMBOL_GPL(_brick_block_alloc);
void _brick_block_free(void *data, int len, int cline)
{
int order;
#ifdef BRICK_DEBUG_MEM
const int plus = len <= PAGE_SIZE ? 0 : PAGE_SIZE * 2;
#else
const int plus = 0;
#endif
if (!data) {
return;
}
order = len2order(len + plus);
#ifdef BRICK_DEBUG_MEM
if (order > 0) {
void *test = data - PAGE_SIZE;
int magic = INT_ACCESS(test, 0);
int line = INT_ACCESS(test, sizeof(int));
int oldlen = INT_ACCESS(test, sizeof(int)*2);
int magic2;
if (unlikely(magic != MAGIC_BLOCK)) {
BRICK_ERR("line %d memory corruption: magix %08x != %08x\n", cline, magic, MAGIC_BLOCK);
return;
}
if (unlikely(line < 0 || line >= BRICK_DEBUG_MEM)) {
BRICK_ERR("line %d memory corruption: alloc line = %d\n", cline, line);
return;
}
if (unlikely(oldlen != len)) {
BRICK_ERR("line %d memory corruption: len != oldlen (%d != %d)\n", cline, len, oldlen);
return;
}
magic2 = INT_ACCESS(data, len);
if (unlikely(magic2 != MAGIC_BEND)) {
BRICK_ERR("line %d memory corruption: magix %08x != %08x\n", cline, magic, MAGIC_BEND);
return;
}
INT_ACCESS(test, 0) = 0xffffffff;
INT_ACCESS(data, len) = 0xffffffff;
atomic_dec(&block_count[line]);
atomic_inc(&block_free[line]);
data = test;
}
#endif
#ifdef CONFIG_MARS_MEM_PREALLOC
if (order > 0 && brick_allow_freelist && atomic_read(&freelist_count[order]) <= freelist_max[order]) {
_put_free(data, order);
} else
#endif
__brick_block_free(data, order);
#ifdef BRICK_DEBUG_MEM
atomic_dec(&alloc_count[order]);
#endif
}
EXPORT_SYMBOL_GPL(_brick_block_free);
struct page *brick_iomap(void *data, int *offset, int *len)
{
int _offset = ((unsigned long)data) & (PAGE_SIZE-1);
struct page *page;
*offset = _offset;
if (*len > PAGE_SIZE - _offset) {
*len = PAGE_SIZE - _offset;
}
if (is_vmalloc_addr(data)) {
page = vmalloc_to_page(data);
} else {
page = virt_to_page(data);
}
return page;
}
EXPORT_SYMBOL_GPL(brick_iomap);
/////////////////////////////////////////////////////////////////////////
// module
void brick_mem_statistics(void)
{
#ifdef BRICK_DEBUG_MEM
int i;
int count = 0;
int places = 0;
BRICK_INF("======== page allocation:\n");
#ifdef CONFIG_MARS_MEM_PREALLOC
for (i = 0; i <= BRICK_MAX_ORDER; i++) {
BRICK_INF("pages order = %d operations = %9d freelist_count = %4d / %3d raw_count = %5d alloc_count = %5d max_count = %5d\n", i, atomic_read(&op_count[i]), atomic_read(&freelist_count[i]), freelist_max[i], atomic_read(&raw_count[i]), atomic_read(&alloc_count[i]), alloc_max[i]);
}
#endif
for (i = 0; i < BRICK_DEBUG_MEM; i++) {
int val = atomic_read(&block_count[i]);
if (val) {
count += val;
places++;
BRICK_INF("line %4d: %6d allocated (last size = %4d, freed = %6d)\n", i, val, block_len[i], atomic_read(&block_free[i]));
}
}
BRICK_INF("======== %d block allocations in %d places\n", count, places);
count = places = 0;
for (i = 0; i < BRICK_DEBUG_MEM; i++) {
int val = atomic_read(&mem_count[i]);
if (val) {
count += val;
places++;
BRICK_INF("line %4d: %6d allocated (last size = %4d, freed = %6d)\n", i, val, mem_len[i], atomic_read(&mem_free[i]));
}
}
BRICK_INF("======== %d memory allocations in %d places\n", count, places);
count = places = 0;
for (i = 0; i < BRICK_DEBUG_MEM; i++) {
int val = atomic_read(&string_count[i]);
if (val) {
count += val;
places++;
BRICK_INF("line %4d: %6d allocated (freed = %6d)\n", i, val, atomic_read(&string_free[i]));
}
}
BRICK_INF("======== %d string allocations in %d places\n", count, places);
#endif
}
EXPORT_SYMBOL_GPL(brick_mem_statistics);
// module init stuff
#ifdef BUMP_LIMITS // quirk: bump the memory reserve limits.
extern int min_free_kbytes;
static int old_free_kbytes = 0;
#endif
int __init init_brick_mem(void)
{
#ifdef CONFIG_MARS_MEM_PREALLOC
int i;
for (i = BRICK_MAX_ORDER; i >= 0; i--) {
spin_lock_init(&freelist_lock[i]);
}
#endif
#ifdef LIMIT_MEM // provisionary
brick_global_memlimit = total_swapcache_pages * (PAGE_SIZE / 4);
BRICK_INF("brick_global_memlimit = %lld\n", brick_global_memlimit);
#endif
#ifdef BUMP_LIMITS // quirk: bump the memory reserve limits. TODO: determine right values.
old_free_kbytes = min_free_kbytes;
min_free_kbytes *= 4;
setup_per_zone_wmarks();
#endif
return 0;
}
void __exit exit_brick_mem(void)
{
#ifdef CONFIG_MARS_MEM_PREALLOC
_free_all();
#endif
#ifdef BUMP_LIMITS // quirk: bump the memory reserve limits.
min_free_kbytes = old_free_kbytes;
setup_per_zone_wmarks();
#endif
brick_mem_statistics();
}
#ifndef CONFIG_MARS_HAVE_BIGMODULE
MODULE_DESCRIPTION("generic brick infrastructure");
MODULE_AUTHOR("Thomas Schoebel-Theuer <tst@1und1.de>");
MODULE_LICENSE("GPL");
module_init(init_brick_mem);
module_exit(exit_brick_mem);
#endif
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