Contributors: 40
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Linus Torvalds |
710 |
30.79% |
4 |
5.63% |
| David Rientjes |
531 |
23.03% |
3 |
4.23% |
| Andrew Morton |
185 |
8.02% |
6 |
8.45% |
| Alasdair G. Kergon |
140 |
6.07% |
1 |
1.41% |
| Kent Overstreet |
132 |
5.72% |
3 |
4.23% |
| Matthew Dobson |
129 |
5.59% |
2 |
2.82% |
| Andrey Ryabinin |
66 |
2.86% |
3 |
4.23% |
| Tejun Heo |
55 |
2.39% |
4 |
5.63% |
| Alan Cox |
53 |
2.30% |
1 |
1.41% |
| Kees Cook |
52 |
2.25% |
1 |
1.41% |
| Andrey Konovalov |
44 |
1.91% |
5 |
7.04% |
| Prasanna Meda |
28 |
1.21% |
1 |
1.41% |
| Christoph Lameter |
27 |
1.17% |
1 |
1.41% |
| Linus Torvalds (pre-git) |
21 |
0.91% |
8 |
11.27% |
| Nicholas Piggin |
20 |
0.87% |
2 |
2.82% |
| Catalin Marinas |
15 |
0.65% |
1 |
1.41% |
| Miaohe Lin |
12 |
0.52% |
1 |
1.41% |
| Rusty Russell |
10 |
0.43% |
1 |
1.41% |
| Mikulas Patocka |
8 |
0.35% |
1 |
1.41% |
| Benjamin LaHaise |
7 |
0.30% |
1 |
1.41% |
| Sebastian Ott |
7 |
0.30% |
1 |
1.41% |
| Pavel Mironchik |
6 |
0.26% |
1 |
1.41% |
| Al Viro |
5 |
0.22% |
2 |
2.82% |
| Michal Hocko |
5 |
0.22% |
1 |
1.41% |
| Fabio De Francesco |
4 |
0.17% |
1 |
1.41% |
| Pekka J Enberg |
4 |
0.17% |
1 |
1.41% |
| Mel Gorman |
4 |
0.17% |
1 |
1.41% |
| Vlastimil Babka |
4 |
0.17% |
1 |
1.41% |
| Qian Cai |
3 |
0.13% |
1 |
1.41% |
| Suren Baghdasaryan |
3 |
0.13% |
1 |
1.41% |
| Mike Rapoport |
3 |
0.13% |
1 |
1.41% |
| Matthew Dawson |
2 |
0.09% |
1 |
1.41% |
| Johannes Thumshirn |
2 |
0.09% |
1 |
1.41% |
| Dmitriy Vyukov |
2 |
0.09% |
1 |
1.41% |
| Christoph Hellwig |
2 |
0.09% |
1 |
1.41% |
| Simon Arlott |
1 |
0.04% |
1 |
1.41% |
| Ingo Molnar |
1 |
0.04% |
1 |
1.41% |
| Greg Kroah-Hartman |
1 |
0.04% |
1 |
1.41% |
| Paul Gortmaker |
1 |
0.04% |
1 |
1.41% |
| Daniel Vetter |
1 |
0.04% |
1 |
1.41% |
| Total |
2306 |
|
71 |
|
// SPDX-License-Identifier: GPL-2.0
/*
* linux/mm/mempool.c
*
* memory buffer pool support. Such pools are mostly used
* for guaranteed, deadlock-free memory allocations during
* extreme VM load.
*
* started by Ingo Molnar, Copyright (C) 2001
* debugging by David Rientjes, Copyright (C) 2015
*/
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/highmem.h>
#include <linux/kasan.h>
#include <linux/kmemleak.h>
#include <linux/export.h>
#include <linux/mempool.h>
#include <linux/writeback.h>
#include "slab.h"
#ifdef CONFIG_SLUB_DEBUG_ON
static void poison_error(mempool_t *pool, void *element, size_t size,
size_t byte)
{
const int nr = pool->curr_nr;
const int start = max_t(int, byte - (BITS_PER_LONG / 8), 0);
const int end = min_t(int, byte + (BITS_PER_LONG / 8), size);
int i;
pr_err("BUG: mempool element poison mismatch\n");
pr_err("Mempool %p size %zu\n", pool, size);
pr_err(" nr=%d @ %p: %s0x", nr, element, start > 0 ? "... " : "");
for (i = start; i < end; i++)
pr_cont("%x ", *(u8 *)(element + i));
pr_cont("%s\n", end < size ? "..." : "");
dump_stack();
}
static void __check_element(mempool_t *pool, void *element, size_t size)
{
u8 *obj = element;
size_t i;
for (i = 0; i < size; i++) {
u8 exp = (i < size - 1) ? POISON_FREE : POISON_END;
if (obj[i] != exp) {
poison_error(pool, element, size, i);
return;
}
}
memset(obj, POISON_INUSE, size);
}
static void check_element(mempool_t *pool, void *element)
{
/* Skip checking: KASAN might save its metadata in the element. */
if (kasan_enabled())
return;
/* Mempools backed by slab allocator */
if (pool->free == mempool_kfree) {
__check_element(pool, element, (size_t)pool->pool_data);
} else if (pool->free == mempool_free_slab) {
__check_element(pool, element, kmem_cache_size(pool->pool_data));
} else if (pool->free == mempool_free_pages) {
/* Mempools backed by page allocator */
int order = (int)(long)pool->pool_data;
void *addr = kmap_local_page((struct page *)element);
__check_element(pool, addr, 1UL << (PAGE_SHIFT + order));
kunmap_local(addr);
}
}
static void __poison_element(void *element, size_t size)
{
u8 *obj = element;
memset(obj, POISON_FREE, size - 1);
obj[size - 1] = POISON_END;
}
static void poison_element(mempool_t *pool, void *element)
{
/* Skip poisoning: KASAN might save its metadata in the element. */
if (kasan_enabled())
return;
/* Mempools backed by slab allocator */
if (pool->alloc == mempool_kmalloc) {
__poison_element(element, (size_t)pool->pool_data);
} else if (pool->alloc == mempool_alloc_slab) {
__poison_element(element, kmem_cache_size(pool->pool_data));
} else if (pool->alloc == mempool_alloc_pages) {
/* Mempools backed by page allocator */
int order = (int)(long)pool->pool_data;
void *addr = kmap_local_page((struct page *)element);
__poison_element(addr, 1UL << (PAGE_SHIFT + order));
kunmap_local(addr);
}
}
#else /* CONFIG_SLUB_DEBUG_ON */
static inline void check_element(mempool_t *pool, void *element)
{
}
static inline void poison_element(mempool_t *pool, void *element)
{
}
#endif /* CONFIG_SLUB_DEBUG_ON */
static __always_inline bool kasan_poison_element(mempool_t *pool, void *element)
{
if (pool->alloc == mempool_alloc_slab || pool->alloc == mempool_kmalloc)
return kasan_mempool_poison_object(element);
else if (pool->alloc == mempool_alloc_pages)
return kasan_mempool_poison_pages(element,
(unsigned long)pool->pool_data);
return true;
}
static void kasan_unpoison_element(mempool_t *pool, void *element)
{
if (pool->alloc == mempool_kmalloc)
kasan_mempool_unpoison_object(element, (size_t)pool->pool_data);
else if (pool->alloc == mempool_alloc_slab)
kasan_mempool_unpoison_object(element,
kmem_cache_size(pool->pool_data));
else if (pool->alloc == mempool_alloc_pages)
kasan_mempool_unpoison_pages(element,
(unsigned long)pool->pool_data);
}
static __always_inline void add_element(mempool_t *pool, void *element)
{
BUG_ON(pool->curr_nr >= pool->min_nr);
poison_element(pool, element);
if (kasan_poison_element(pool, element))
pool->elements[pool->curr_nr++] = element;
}
static void *remove_element(mempool_t *pool)
{
void *element = pool->elements[--pool->curr_nr];
BUG_ON(pool->curr_nr < 0);
kasan_unpoison_element(pool, element);
check_element(pool, element);
return element;
}
/**
* mempool_exit - exit a mempool initialized with mempool_init()
* @pool: pointer to the memory pool which was initialized with
* mempool_init().
*
* Free all reserved elements in @pool and @pool itself. This function
* only sleeps if the free_fn() function sleeps.
*
* May be called on a zeroed but uninitialized mempool (i.e. allocated with
* kzalloc()).
*/
void mempool_exit(mempool_t *pool)
{
while (pool->curr_nr) {
void *element = remove_element(pool);
pool->free(element, pool->pool_data);
}
kfree(pool->elements);
pool->elements = NULL;
}
EXPORT_SYMBOL(mempool_exit);
/**
* mempool_destroy - deallocate a memory pool
* @pool: pointer to the memory pool which was allocated via
* mempool_create().
*
* Free all reserved elements in @pool and @pool itself. This function
* only sleeps if the free_fn() function sleeps.
*/
void mempool_destroy(mempool_t *pool)
{
if (unlikely(!pool))
return;
mempool_exit(pool);
kfree(pool);
}
EXPORT_SYMBOL(mempool_destroy);
int mempool_init_node(mempool_t *pool, int min_nr, mempool_alloc_t *alloc_fn,
mempool_free_t *free_fn, void *pool_data,
gfp_t gfp_mask, int node_id)
{
spin_lock_init(&pool->lock);
pool->min_nr = min_nr;
pool->pool_data = pool_data;
pool->alloc = alloc_fn;
pool->free = free_fn;
init_waitqueue_head(&pool->wait);
pool->elements = kmalloc_array_node(min_nr, sizeof(void *),
gfp_mask, node_id);
if (!pool->elements)
return -ENOMEM;
/*
* First pre-allocate the guaranteed number of buffers.
*/
while (pool->curr_nr < pool->min_nr) {
void *element;
element = pool->alloc(gfp_mask, pool->pool_data);
if (unlikely(!element)) {
mempool_exit(pool);
return -ENOMEM;
}
add_element(pool, element);
}
return 0;
}
EXPORT_SYMBOL(mempool_init_node);
/**
* mempool_init - initialize a memory pool
* @pool: pointer to the memory pool that should be initialized
* @min_nr: the minimum number of elements guaranteed to be
* allocated for this pool.
* @alloc_fn: user-defined element-allocation function.
* @free_fn: user-defined element-freeing function.
* @pool_data: optional private data available to the user-defined functions.
*
* Like mempool_create(), but initializes the pool in (i.e. embedded in another
* structure).
*
* Return: %0 on success, negative error code otherwise.
*/
int mempool_init_noprof(mempool_t *pool, int min_nr, mempool_alloc_t *alloc_fn,
mempool_free_t *free_fn, void *pool_data)
{
return mempool_init_node(pool, min_nr, alloc_fn, free_fn,
pool_data, GFP_KERNEL, NUMA_NO_NODE);
}
EXPORT_SYMBOL(mempool_init_noprof);
/**
* mempool_create_node - create a memory pool
* @min_nr: the minimum number of elements guaranteed to be
* allocated for this pool.
* @alloc_fn: user-defined element-allocation function.
* @free_fn: user-defined element-freeing function.
* @pool_data: optional private data available to the user-defined functions.
* @gfp_mask: memory allocation flags
* @node_id: numa node to allocate on
*
* this function creates and allocates a guaranteed size, preallocated
* memory pool. The pool can be used from the mempool_alloc() and mempool_free()
* functions. This function might sleep. Both the alloc_fn() and the free_fn()
* functions might sleep - as long as the mempool_alloc() function is not called
* from IRQ contexts.
*
* Return: pointer to the created memory pool object or %NULL on error.
*/
mempool_t *mempool_create_node_noprof(int min_nr, mempool_alloc_t *alloc_fn,
mempool_free_t *free_fn, void *pool_data,
gfp_t gfp_mask, int node_id)
{
mempool_t *pool;
pool = kmalloc_node_noprof(sizeof(*pool), gfp_mask | __GFP_ZERO, node_id);
if (!pool)
return NULL;
if (mempool_init_node(pool, min_nr, alloc_fn, free_fn, pool_data,
gfp_mask, node_id)) {
kfree(pool);
return NULL;
}
return pool;
}
EXPORT_SYMBOL(mempool_create_node_noprof);
/**
* mempool_resize - resize an existing memory pool
* @pool: pointer to the memory pool which was allocated via
* mempool_create().
* @new_min_nr: the new minimum number of elements guaranteed to be
* allocated for this pool.
*
* This function shrinks/grows the pool. In the case of growing,
* it cannot be guaranteed that the pool will be grown to the new
* size immediately, but new mempool_free() calls will refill it.
* This function may sleep.
*
* Note, the caller must guarantee that no mempool_destroy is called
* while this function is running. mempool_alloc() & mempool_free()
* might be called (eg. from IRQ contexts) while this function executes.
*
* Return: %0 on success, negative error code otherwise.
*/
int mempool_resize(mempool_t *pool, int new_min_nr)
{
void *element;
void **new_elements;
unsigned long flags;
BUG_ON(new_min_nr <= 0);
might_sleep();
spin_lock_irqsave(&pool->lock, flags);
if (new_min_nr <= pool->min_nr) {
while (new_min_nr < pool->curr_nr) {
element = remove_element(pool);
spin_unlock_irqrestore(&pool->lock, flags);
pool->free(element, pool->pool_data);
spin_lock_irqsave(&pool->lock, flags);
}
pool->min_nr = new_min_nr;
goto out_unlock;
}
spin_unlock_irqrestore(&pool->lock, flags);
/* Grow the pool */
new_elements = kmalloc_array(new_min_nr, sizeof(*new_elements),
GFP_KERNEL);
if (!new_elements)
return -ENOMEM;
spin_lock_irqsave(&pool->lock, flags);
if (unlikely(new_min_nr <= pool->min_nr)) {
/* Raced, other resize will do our work */
spin_unlock_irqrestore(&pool->lock, flags);
kfree(new_elements);
goto out;
}
memcpy(new_elements, pool->elements,
pool->curr_nr * sizeof(*new_elements));
kfree(pool->elements);
pool->elements = new_elements;
pool->min_nr = new_min_nr;
while (pool->curr_nr < pool->min_nr) {
spin_unlock_irqrestore(&pool->lock, flags);
element = pool->alloc(GFP_KERNEL, pool->pool_data);
if (!element)
goto out;
spin_lock_irqsave(&pool->lock, flags);
if (pool->curr_nr < pool->min_nr) {
add_element(pool, element);
} else {
spin_unlock_irqrestore(&pool->lock, flags);
pool->free(element, pool->pool_data); /* Raced */
goto out;
}
}
out_unlock:
spin_unlock_irqrestore(&pool->lock, flags);
out:
return 0;
}
EXPORT_SYMBOL(mempool_resize);
/**
* mempool_alloc - allocate an element from a specific memory pool
* @pool: pointer to the memory pool which was allocated via
* mempool_create().
* @gfp_mask: the usual allocation bitmask.
*
* this function only sleeps if the alloc_fn() function sleeps or
* returns NULL. Note that due to preallocation, this function
* *never* fails when called from process contexts. (it might
* fail if called from an IRQ context.)
* Note: using __GFP_ZERO is not supported.
*
* Return: pointer to the allocated element or %NULL on error.
*/
void *mempool_alloc_noprof(mempool_t *pool, gfp_t gfp_mask)
{
void *element;
unsigned long flags;
wait_queue_entry_t wait;
gfp_t gfp_temp;
VM_WARN_ON_ONCE(gfp_mask & __GFP_ZERO);
might_alloc(gfp_mask);
gfp_mask |= __GFP_NOMEMALLOC; /* don't allocate emergency reserves */
gfp_mask |= __GFP_NORETRY; /* don't loop in __alloc_pages */
gfp_mask |= __GFP_NOWARN; /* failures are OK */
gfp_temp = gfp_mask & ~(__GFP_DIRECT_RECLAIM|__GFP_IO);
repeat_alloc:
element = pool->alloc(gfp_temp, pool->pool_data);
if (likely(element != NULL))
return element;
spin_lock_irqsave(&pool->lock, flags);
if (likely(pool->curr_nr)) {
element = remove_element(pool);
spin_unlock_irqrestore(&pool->lock, flags);
/* paired with rmb in mempool_free(), read comment there */
smp_wmb();
/*
* Update the allocation stack trace as this is more useful
* for debugging.
*/
kmemleak_update_trace(element);
return element;
}
/*
* We use gfp mask w/o direct reclaim or IO for the first round. If
* alloc failed with that and @pool was empty, retry immediately.
*/
if (gfp_temp != gfp_mask) {
spin_unlock_irqrestore(&pool->lock, flags);
gfp_temp = gfp_mask;
goto repeat_alloc;
}
/* We must not sleep if !__GFP_DIRECT_RECLAIM */
if (!(gfp_mask & __GFP_DIRECT_RECLAIM)) {
spin_unlock_irqrestore(&pool->lock, flags);
return NULL;
}
/* Let's wait for someone else to return an element to @pool */
init_wait(&wait);
prepare_to_wait(&pool->wait, &wait, TASK_UNINTERRUPTIBLE);
spin_unlock_irqrestore(&pool->lock, flags);
/*
* FIXME: this should be io_schedule(). The timeout is there as a
* workaround for some DM problems in 2.6.18.
*/
io_schedule_timeout(5*HZ);
finish_wait(&pool->wait, &wait);
goto repeat_alloc;
}
EXPORT_SYMBOL(mempool_alloc_noprof);
/**
* mempool_alloc_preallocated - allocate an element from preallocated elements
* belonging to a specific memory pool
* @pool: pointer to the memory pool which was allocated via
* mempool_create().
*
* This function is similar to mempool_alloc, but it only attempts allocating
* an element from the preallocated elements. It does not sleep and immediately
* returns if no preallocated elements are available.
*
* Return: pointer to the allocated element or %NULL if no elements are
* available.
*/
void *mempool_alloc_preallocated(mempool_t *pool)
{
void *element;
unsigned long flags;
spin_lock_irqsave(&pool->lock, flags);
if (likely(pool->curr_nr)) {
element = remove_element(pool);
spin_unlock_irqrestore(&pool->lock, flags);
/* paired with rmb in mempool_free(), read comment there */
smp_wmb();
/*
* Update the allocation stack trace as this is more useful
* for debugging.
*/
kmemleak_update_trace(element);
return element;
}
spin_unlock_irqrestore(&pool->lock, flags);
return NULL;
}
EXPORT_SYMBOL(mempool_alloc_preallocated);
/**
* mempool_free - return an element to the pool.
* @element: pool element pointer.
* @pool: pointer to the memory pool which was allocated via
* mempool_create().
*
* this function only sleeps if the free_fn() function sleeps.
*/
void mempool_free(void *element, mempool_t *pool)
{
unsigned long flags;
if (unlikely(element == NULL))
return;
/*
* Paired with the wmb in mempool_alloc(). The preceding read is
* for @element and the following @pool->curr_nr. This ensures
* that the visible value of @pool->curr_nr is from after the
* allocation of @element. This is necessary for fringe cases
* where @element was passed to this task without going through
* barriers.
*
* For example, assume @p is %NULL at the beginning and one task
* performs "p = mempool_alloc(...);" while another task is doing
* "while (!p) cpu_relax(); mempool_free(p, ...);". This function
* may end up using curr_nr value which is from before allocation
* of @p without the following rmb.
*/
smp_rmb();
/*
* For correctness, we need a test which is guaranteed to trigger
* if curr_nr + #allocated == min_nr. Testing curr_nr < min_nr
* without locking achieves that and refilling as soon as possible
* is desirable.
*
* Because curr_nr visible here is always a value after the
* allocation of @element, any task which decremented curr_nr below
* min_nr is guaranteed to see curr_nr < min_nr unless curr_nr gets
* incremented to min_nr afterwards. If curr_nr gets incremented
* to min_nr after the allocation of @element, the elements
* allocated after that are subject to the same guarantee.
*
* Waiters happen iff curr_nr is 0 and the above guarantee also
* ensures that there will be frees which return elements to the
* pool waking up the waiters.
*/
if (unlikely(READ_ONCE(pool->curr_nr) < pool->min_nr)) {
spin_lock_irqsave(&pool->lock, flags);
if (likely(pool->curr_nr < pool->min_nr)) {
add_element(pool, element);
spin_unlock_irqrestore(&pool->lock, flags);
wake_up(&pool->wait);
return;
}
spin_unlock_irqrestore(&pool->lock, flags);
}
pool->free(element, pool->pool_data);
}
EXPORT_SYMBOL(mempool_free);
/*
* A commonly used alloc and free fn.
*/
void *mempool_alloc_slab(gfp_t gfp_mask, void *pool_data)
{
struct kmem_cache *mem = pool_data;
VM_BUG_ON(mem->ctor);
return kmem_cache_alloc_noprof(mem, gfp_mask);
}
EXPORT_SYMBOL(mempool_alloc_slab);
void mempool_free_slab(void *element, void *pool_data)
{
struct kmem_cache *mem = pool_data;
kmem_cache_free(mem, element);
}
EXPORT_SYMBOL(mempool_free_slab);
/*
* A commonly used alloc and free fn that kmalloc/kfrees the amount of memory
* specified by pool_data
*/
void *mempool_kmalloc(gfp_t gfp_mask, void *pool_data)
{
size_t size = (size_t)pool_data;
return kmalloc_noprof(size, gfp_mask);
}
EXPORT_SYMBOL(mempool_kmalloc);
void mempool_kfree(void *element, void *pool_data)
{
kfree(element);
}
EXPORT_SYMBOL(mempool_kfree);
void *mempool_kvmalloc(gfp_t gfp_mask, void *pool_data)
{
size_t size = (size_t)pool_data;
return kvmalloc(size, gfp_mask);
}
EXPORT_SYMBOL(mempool_kvmalloc);
void mempool_kvfree(void *element, void *pool_data)
{
kvfree(element);
}
EXPORT_SYMBOL(mempool_kvfree);
/*
* A simple mempool-backed page allocator that allocates pages
* of the order specified by pool_data.
*/
void *mempool_alloc_pages(gfp_t gfp_mask, void *pool_data)
{
int order = (int)(long)pool_data;
return alloc_pages_noprof(gfp_mask, order);
}
EXPORT_SYMBOL(mempool_alloc_pages);
void mempool_free_pages(void *element, void *pool_data)
{
int order = (int)(long)pool_data;
__free_pages(element, order);
}
EXPORT_SYMBOL(mempool_free_pages);