diff options
author | Kent Overstreet <kent.overstreet@linux.dev> | 2024-01-16 17:00:02 -0500 |
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committer | Kent Overstreet <kent.overstreet@linux.dev> | 2024-01-16 17:17:23 -0500 |
commit | b5fd066153c40a70a29caa1ea7987723ab687763 (patch) | |
tree | 6d43a8b0a90d549a54c65565ac96c92b3e84b594 /c_src/linux/mempool.c | |
parent | 06ff8b55b70fda44d91b31b5511fafd1680a8934 (diff) |
Move c_src dirs back to toplevel
We just wanted c sourcefiles out of the top level, not c source
directories.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Diffstat (limited to 'c_src/linux/mempool.c')
-rw-r--r-- | c_src/linux/mempool.c | 541 |
1 files changed, 0 insertions, 541 deletions
diff --git a/c_src/linux/mempool.c b/c_src/linux/mempool.c deleted file mode 100644 index 74d4fbb3..00000000 --- a/c_src/linux/mempool.c +++ /dev/null @@ -1,541 +0,0 @@ -// 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/slab.h> -//#include <linux/kasan.h> -//#include <linux/kmemleak.h> -#include <linux/export.h> -#include <linux/jiffies.h> -#include <linux/mempool.h> -#include <linux/mempool.h> -#include <linux/sched.h> - -#if defined(CONFIG_DEBUG_SLAB) || defined(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) -{ - /* Mempools backed by slab allocator */ - if (pool->free == mempool_free_slab || pool->free == mempool_kfree) { - __check_element(pool, element, ksize(element)); - } else if (pool->free == mempool_free_pages) { - /* Mempools backed by page allocator */ - int order = (int)(long)pool->pool_data; - void *addr = kmap_atomic((struct page *)element); - - __check_element(pool, addr, 1UL << (PAGE_SHIFT + order)); - kunmap_atomic(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) -{ - /* Mempools backed by slab allocator */ - if (pool->alloc == mempool_alloc_slab || pool->alloc == mempool_kmalloc) { - __poison_element(element, ksize(element)); - } else if (pool->alloc == mempool_alloc_pages) { - /* Mempools backed by page allocator */ - int order = (int)(long)pool->pool_data; - void *addr = kmap_atomic((struct page *)element); - - __poison_element(addr, 1UL << (PAGE_SHIFT + order)); - kunmap_atomic(addr); - } -} -#else /* CONFIG_DEBUG_SLAB || 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_DEBUG_SLAB || CONFIG_SLUB_DEBUG_ON */ - -static __always_inline void kasan_poison_element(mempool_t *pool, void *element) -{ -#if 0 - if (pool->alloc == mempool_alloc_slab || pool->alloc == mempool_kmalloc) - kasan_poison_kfree(element, _RET_IP_); - else if (pool->alloc == mempool_alloc_pages) - kasan_free_pages(element, (unsigned long)pool->pool_data); -#endif -} - -static void kasan_unpoison_element(mempool_t *pool, void *element) -{ -#if 0 - if (pool->alloc == mempool_alloc_slab || pool->alloc == mempool_kmalloc) - kasan_unpoison_slab(element); - else if (pool->alloc == mempool_alloc_pages) - kasan_alloc_pages(element, (unsigned long)pool->pool_data); -#endif -} - -static __always_inline void add_element(mempool_t *pool, void *element) -{ - BUG_ON(pool->curr_nr >= pool->min_nr); - poison_element(pool, element); - 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(min_nr, sizeof(void *), gfp_mask); - 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(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, 0); - -} -EXPORT_SYMBOL(mempool_init); - -/** - * mempool_create - 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. - * - * 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(int min_nr, mempool_alloc_t *alloc_fn, - mempool_free_t *free_fn, void *pool_data) -{ - return mempool_create_node(min_nr,alloc_fn,free_fn, pool_data, - GFP_KERNEL, 0); -} -EXPORT_SYMBOL(mempool_create); - -mempool_t *mempool_create_node(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 = kzalloc(sizeof(*pool), gfp_mask); - 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); - -/** - * 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(mempool_t *pool, gfp_t gfp_mask) -{ - void *element; - unsigned long flags; - DEFINE_WAIT(wait); - gfp_t gfp_temp; - - WARN_ON_ONCE(gfp_mask & __GFP_ZERO); - - gfp_mask |= __GFP_NORETRY; /* don't loop in __alloc_pages */ - gfp_mask |= __GFP_NOWARN; /* failures are OK */ - - gfp_temp = gfp_mask & ~(__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(); - 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; - } - - /* Let's wait for someone else to return an element to @pool */ - 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); - -/** - * 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; - return kmem_cache_alloc(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(size, gfp_mask); -} -EXPORT_SYMBOL(mempool_kmalloc); - -void mempool_kfree(void *element, void *pool_data) -{ - kfree(element); -} -EXPORT_SYMBOL(mempool_kfree); - -/* - * 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(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); |