The minimal number of mempool elements passed to mempool_create()/mempool_resize() could be large enough to trigger high order allocation in kmalloc_node(). High order allocations are costly and/or may fail if memory is fragmented. Since we don't need the array of element pointers to be physically contiguous, use kvmalloc_node() to allocate it.
https://jira.sw.ru/browse/HCI-132 https://pmc.acronis.com/browse/VSTOR-14758 Signed-off-by: Andrey Ryabinin <aryabi...@virtuozzo.com> --- mm/mempool.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/mm/mempool.c b/mm/mempool.c index 864b0779adb7..d2535b6e25a9 100644 --- a/mm/mempool.c +++ b/mm/mempool.c @@ -153,7 +153,7 @@ void mempool_destroy(mempool_t *pool) void *element = remove_element(pool, GFP_KERNEL); pool->free(element, pool->pool_data); } - kfree(pool->elements); + kvfree(pool->elements); kfree(pool); } EXPORT_SYMBOL(mempool_destroy); @@ -188,8 +188,8 @@ mempool_t *mempool_create_node(int min_nr, mempool_alloc_t *alloc_fn, pool = kmalloc_node(sizeof(*pool), gfp_mask | __GFP_ZERO, node_id); if (!pool) return NULL; - pool->elements = kmalloc_node(min_nr * sizeof(void *), - gfp_mask, node_id); + pool->elements = kvmalloc_node(min_nr * sizeof(void *), + gfp_mask, node_id); if (!pool->elements) { kfree(pool); return NULL; @@ -239,6 +239,7 @@ int mempool_resize(mempool_t *pool, int new_min_nr, gfp_t gfp_mask) void *element; void **new_elements; unsigned long flags; + void *old_elements = NULL; BUG_ON(new_min_nr <= 0); @@ -256,7 +257,7 @@ int mempool_resize(mempool_t *pool, int new_min_nr, gfp_t gfp_mask) spin_unlock_irqrestore(&pool->lock, flags); /* Grow the pool */ - new_elements = kmalloc(new_min_nr * sizeof(*new_elements), gfp_mask); + new_elements = kvmalloc(new_min_nr * sizeof(*new_elements), gfp_mask); if (!new_elements) return -ENOMEM; @@ -264,12 +265,12 @@ int mempool_resize(mempool_t *pool, int new_min_nr, gfp_t gfp_mask) if (unlikely(new_min_nr <= pool->min_nr)) { /* Raced, other resize will do our work */ spin_unlock_irqrestore(&pool->lock, flags); - kfree(new_elements); + kvfree(new_elements); goto out; } memcpy(new_elements, pool->elements, pool->curr_nr * sizeof(*new_elements)); - kfree(pool->elements); + old_elements = pool->elements; pool->elements = new_elements; pool->min_nr = new_min_nr; @@ -290,6 +291,7 @@ int mempool_resize(mempool_t *pool, int new_min_nr, gfp_t gfp_mask) out_unlock: spin_unlock_irqrestore(&pool->lock, flags); out: + kvfree(old_elements); return 0; } EXPORT_SYMBOL(mempool_resize); -- 2.16.4 _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel
