Use the slab cache for the structure dm_buffer, so that the size is not padded up to the next power of two.
Signed-off-by: Mikulas Patocka <[email protected]> --- drivers/md/dm-bufio.c | 27 ++++++++++++++++++--------- 1 file changed, 18 insertions(+), 9 deletions(-) Index: linux-2.6/drivers/md/dm-bufio.c =================================================================== --- linux-2.6.orig/drivers/md/dm-bufio.c 2018-03-26 15:33:50.987250000 +0200 +++ linux-2.6/drivers/md/dm-bufio.c 2018-03-26 15:34:12.907250000 +0200 @@ -100,10 +100,10 @@ struct dm_bufio_client { unsigned block_size; unsigned char sectors_per_block_bits; unsigned char pages_per_block_bits; - unsigned aux_size; void (*alloc_callback)(struct dm_buffer *); void (*write_callback)(struct dm_buffer *); + struct kmem_cache *slab_buffer; struct kmem_cache *slab_cache; struct dm_io_client *dm_io; @@ -435,8 +435,7 @@ static void free_buffer_data(struct dm_b */ static struct dm_buffer *alloc_buffer(struct dm_bufio_client *c, gfp_t gfp_mask) { - struct dm_buffer *b = kmalloc(sizeof(struct dm_buffer) + c->aux_size, - gfp_mask); + struct dm_buffer *b = kmem_cache_alloc(c->slab_buffer, gfp_mask); if (!b) return NULL; @@ -445,7 +444,7 @@ static struct dm_buffer *alloc_buffer(st b->data = alloc_buffer_data(c, gfp_mask, &b->data_mode); if (!b->data) { - kfree(b); + kmem_cache_free(c->slab_buffer, b); return NULL; } @@ -467,7 +466,7 @@ static void free_buffer(struct dm_buffer adjust_total_allocated(b->data_mode, -(long)c->block_size); free_buffer_data(c, b->data, b->data_mode); - kfree(b); + kmem_cache_free(c->slab_buffer, b); } /* @@ -1641,6 +1640,7 @@ struct dm_bufio_client *dm_bufio_client_ int r; struct dm_bufio_client *c; unsigned i; + char slab_name[27]; BUG_ON(block_size < 1 << SECTOR_SHIFT || (block_size & (block_size - 1))); @@ -1658,7 +1658,6 @@ struct dm_bufio_client *dm_bufio_client_ c->pages_per_block_bits = (__ffs(block_size) >= PAGE_SHIFT) ? __ffs(block_size) - PAGE_SHIFT : 0; - c->aux_size = aux_size; c->alloc_callback = alloc_callback; c->write_callback = write_callback; @@ -1683,14 +1682,22 @@ struct dm_bufio_client *dm_bufio_client_ } if (block_size < PAGE_SIZE) { - char name[26]; - snprintf(name, sizeof name, "dm_bufio_cache-%u", c->block_size); - c->slab_cache = kmem_cache_create(name, c->block_size, ARCH_KMALLOC_MINALIGN, SLAB_RECLAIM_ACCOUNT, NULL); + snprintf(slab_name, sizeof slab_name, "dm_bufio_cache-%u", c->block_size); + c->slab_cache = kmem_cache_create(slab_name, c->block_size, ARCH_KMALLOC_MINALIGN, SLAB_RECLAIM_ACCOUNT, NULL); if (!c->slab_cache) { r = -ENOMEM; goto bad; } } + if (aux_size) + snprintf(slab_name, sizeof slab_name, "dm_bufio_buffer-%u", aux_size); + else + snprintf(slab_name, sizeof slab_name, "dm_bufio_buffer"); + c->slab_buffer = kmem_cache_create(slab_name, sizeof(struct dm_buffer) + aux_size, 0, SLAB_RECLAIM_ACCOUNT, NULL); + if (!c->slab_buffer) { + r = -ENOMEM; + goto bad; + } while (c->need_reserved_buffers) { struct dm_buffer *b = alloc_buffer(c, GFP_KERNEL); @@ -1726,6 +1733,7 @@ bad: free_buffer(b); } kmem_cache_destroy(c->slab_cache); + kmem_cache_destroy(c->slab_buffer); dm_io_client_destroy(c->dm_io); bad_dm_io: mutex_destroy(&c->lock); @@ -1773,6 +1781,7 @@ void dm_bufio_client_destroy(struct dm_b BUG_ON(c->n_buffers[i]); kmem_cache_destroy(c->slab_cache); + kmem_cache_destroy(c->slab_buffer); dm_io_client_destroy(c->dm_io); mutex_destroy(&c->lock); kfree(c); -- dm-devel mailing list [email protected] https://www.redhat.com/mailman/listinfo/dm-devel
