![Christoph Lameter](/assets/img/avatar_default.png)
Patch to allocate the control structures for for ide devices on the node of the device itself (for NUMA systems). The patch depends on the Slab API change patch by Manfred and me (in mm) and the pcidev_to_node patch that I posted today. Does some realignment too. Signed-off-by: Justin M. Forbes <jmforbes@linuxtx.org> Signed-off-by: Christoph Lameter <christoph@lameter.com> Signed-off-by: Pravin Shelar <pravin@calsoftinc.com> Signed-off-by: Shobhit Dayal <shobhit@calsoftinc.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
291 lines
8 KiB
C
291 lines
8 KiB
C
/*
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* linux/mm/mempool.c
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*
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* memory buffer pool support. Such pools are mostly used
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* for guaranteed, deadlock-free memory allocations during
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* extreme VM load.
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*
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* started by Ingo Molnar, Copyright (C) 2001
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*/
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#include <linux/mm.h>
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#include <linux/slab.h>
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#include <linux/module.h>
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#include <linux/mempool.h>
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#include <linux/blkdev.h>
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#include <linux/writeback.h>
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static void add_element(mempool_t *pool, void *element)
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{
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BUG_ON(pool->curr_nr >= pool->min_nr);
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pool->elements[pool->curr_nr++] = element;
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}
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static void *remove_element(mempool_t *pool)
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{
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BUG_ON(pool->curr_nr <= 0);
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return pool->elements[--pool->curr_nr];
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}
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static void free_pool(mempool_t *pool)
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{
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while (pool->curr_nr) {
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void *element = remove_element(pool);
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pool->free(element, pool->pool_data);
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}
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kfree(pool->elements);
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kfree(pool);
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}
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/**
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* mempool_create - create a memory pool
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* @min_nr: the minimum number of elements guaranteed to be
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* allocated for this pool.
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* @alloc_fn: user-defined element-allocation function.
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* @free_fn: user-defined element-freeing function.
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* @pool_data: optional private data available to the user-defined functions.
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*
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* this function creates and allocates a guaranteed size, preallocated
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* memory pool. The pool can be used from the mempool_alloc and mempool_free
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* functions. This function might sleep. Both the alloc_fn() and the free_fn()
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* functions might sleep - as long as the mempool_alloc function is not called
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* from IRQ contexts.
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*/
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mempool_t *mempool_create(int min_nr, mempool_alloc_t *alloc_fn,
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mempool_free_t *free_fn, void *pool_data)
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{
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return mempool_create_node(min_nr,alloc_fn,free_fn, pool_data,-1);
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}
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EXPORT_SYMBOL(mempool_create);
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mempool_t *mempool_create_node(int min_nr, mempool_alloc_t *alloc_fn,
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mempool_free_t *free_fn, void *pool_data, int node_id)
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{
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mempool_t *pool;
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pool = kmalloc_node(sizeof(*pool), GFP_KERNEL, node_id);
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if (!pool)
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return NULL;
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memset(pool, 0, sizeof(*pool));
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pool->elements = kmalloc_node(min_nr * sizeof(void *),
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GFP_KERNEL, node_id);
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if (!pool->elements) {
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kfree(pool);
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return NULL;
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}
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spin_lock_init(&pool->lock);
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pool->min_nr = min_nr;
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pool->pool_data = pool_data;
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init_waitqueue_head(&pool->wait);
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pool->alloc = alloc_fn;
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pool->free = free_fn;
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/*
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* First pre-allocate the guaranteed number of buffers.
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*/
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while (pool->curr_nr < pool->min_nr) {
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void *element;
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element = pool->alloc(GFP_KERNEL, pool->pool_data);
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if (unlikely(!element)) {
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free_pool(pool);
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return NULL;
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}
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add_element(pool, element);
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}
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return pool;
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}
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EXPORT_SYMBOL(mempool_create_node);
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/**
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* mempool_resize - resize an existing memory pool
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* @pool: pointer to the memory pool which was allocated via
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* mempool_create().
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* @new_min_nr: the new minimum number of elements guaranteed to be
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* allocated for this pool.
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* @gfp_mask: the usual allocation bitmask.
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*
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* This function shrinks/grows the pool. In the case of growing,
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* it cannot be guaranteed that the pool will be grown to the new
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* size immediately, but new mempool_free() calls will refill it.
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*
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* Note, the caller must guarantee that no mempool_destroy is called
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* while this function is running. mempool_alloc() & mempool_free()
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* might be called (eg. from IRQ contexts) while this function executes.
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*/
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int mempool_resize(mempool_t *pool, int new_min_nr, unsigned int __nocast gfp_mask)
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{
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void *element;
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void **new_elements;
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unsigned long flags;
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BUG_ON(new_min_nr <= 0);
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spin_lock_irqsave(&pool->lock, flags);
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if (new_min_nr <= pool->min_nr) {
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while (new_min_nr < pool->curr_nr) {
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element = remove_element(pool);
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spin_unlock_irqrestore(&pool->lock, flags);
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pool->free(element, pool->pool_data);
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spin_lock_irqsave(&pool->lock, flags);
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}
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pool->min_nr = new_min_nr;
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goto out_unlock;
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}
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spin_unlock_irqrestore(&pool->lock, flags);
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/* Grow the pool */
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new_elements = kmalloc(new_min_nr * sizeof(*new_elements), gfp_mask);
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if (!new_elements)
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return -ENOMEM;
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spin_lock_irqsave(&pool->lock, flags);
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if (unlikely(new_min_nr <= pool->min_nr)) {
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/* Raced, other resize will do our work */
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spin_unlock_irqrestore(&pool->lock, flags);
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kfree(new_elements);
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goto out;
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}
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memcpy(new_elements, pool->elements,
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pool->curr_nr * sizeof(*new_elements));
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kfree(pool->elements);
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pool->elements = new_elements;
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pool->min_nr = new_min_nr;
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while (pool->curr_nr < pool->min_nr) {
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spin_unlock_irqrestore(&pool->lock, flags);
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element = pool->alloc(gfp_mask, pool->pool_data);
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if (!element)
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goto out;
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spin_lock_irqsave(&pool->lock, flags);
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if (pool->curr_nr < pool->min_nr) {
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add_element(pool, element);
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} else {
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spin_unlock_irqrestore(&pool->lock, flags);
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pool->free(element, pool->pool_data); /* Raced */
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goto out;
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}
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}
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out_unlock:
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spin_unlock_irqrestore(&pool->lock, flags);
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out:
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return 0;
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}
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EXPORT_SYMBOL(mempool_resize);
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/**
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* mempool_destroy - deallocate a memory pool
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* @pool: pointer to the memory pool which was allocated via
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* mempool_create().
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*
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* this function only sleeps if the free_fn() function sleeps. The caller
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* has to guarantee that all elements have been returned to the pool (ie:
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* freed) prior to calling mempool_destroy().
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*/
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void mempool_destroy(mempool_t *pool)
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{
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if (pool->curr_nr != pool->min_nr)
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BUG(); /* There were outstanding elements */
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free_pool(pool);
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}
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EXPORT_SYMBOL(mempool_destroy);
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/**
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* mempool_alloc - allocate an element from a specific memory pool
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* @pool: pointer to the memory pool which was allocated via
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* mempool_create().
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* @gfp_mask: the usual allocation bitmask.
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*
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* this function only sleeps if the alloc_fn function sleeps or
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* returns NULL. Note that due to preallocation, this function
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* *never* fails when called from process contexts. (it might
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* fail if called from an IRQ context.)
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*/
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void * mempool_alloc(mempool_t *pool, unsigned int __nocast gfp_mask)
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{
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void *element;
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unsigned long flags;
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DEFINE_WAIT(wait);
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int gfp_temp;
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might_sleep_if(gfp_mask & __GFP_WAIT);
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gfp_mask |= __GFP_NOMEMALLOC; /* don't allocate emergency reserves */
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gfp_mask |= __GFP_NORETRY; /* don't loop in __alloc_pages */
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gfp_mask |= __GFP_NOWARN; /* failures are OK */
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gfp_temp = gfp_mask & ~(__GFP_WAIT|__GFP_IO);
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repeat_alloc:
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element = pool->alloc(gfp_temp, pool->pool_data);
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if (likely(element != NULL))
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return element;
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spin_lock_irqsave(&pool->lock, flags);
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if (likely(pool->curr_nr)) {
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element = remove_element(pool);
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spin_unlock_irqrestore(&pool->lock, flags);
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return element;
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}
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spin_unlock_irqrestore(&pool->lock, flags);
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/* We must not sleep in the GFP_ATOMIC case */
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if (!(gfp_mask & __GFP_WAIT))
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return NULL;
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/* Now start performing page reclaim */
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gfp_temp = gfp_mask;
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prepare_to_wait(&pool->wait, &wait, TASK_UNINTERRUPTIBLE);
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smp_mb();
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if (!pool->curr_nr)
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io_schedule();
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finish_wait(&pool->wait, &wait);
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goto repeat_alloc;
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}
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EXPORT_SYMBOL(mempool_alloc);
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/**
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* mempool_free - return an element to the pool.
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* @element: pool element pointer.
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* @pool: pointer to the memory pool which was allocated via
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* mempool_create().
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*
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* this function only sleeps if the free_fn() function sleeps.
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*/
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void mempool_free(void *element, mempool_t *pool)
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{
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unsigned long flags;
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smp_mb();
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if (pool->curr_nr < pool->min_nr) {
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spin_lock_irqsave(&pool->lock, flags);
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if (pool->curr_nr < pool->min_nr) {
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add_element(pool, element);
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spin_unlock_irqrestore(&pool->lock, flags);
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wake_up(&pool->wait);
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return;
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}
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spin_unlock_irqrestore(&pool->lock, flags);
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}
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pool->free(element, pool->pool_data);
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}
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EXPORT_SYMBOL(mempool_free);
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/*
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* A commonly used alloc and free fn.
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*/
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void *mempool_alloc_slab(unsigned int __nocast gfp_mask, void *pool_data)
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{
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kmem_cache_t *mem = (kmem_cache_t *) pool_data;
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return kmem_cache_alloc(mem, gfp_mask);
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}
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EXPORT_SYMBOL(mempool_alloc_slab);
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void mempool_free_slab(void *element, void *pool_data)
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{
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kmem_cache_t *mem = (kmem_cache_t *) pool_data;
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kmem_cache_free(mem, element);
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}
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EXPORT_SYMBOL(mempool_free_slab);
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