From 78c2a44aae2950ecf0279590572b861288714946 Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Wed, 1 May 2013 12:43:04 -0500 Subject: [PATCH] rbd: allocate image object names with a slab allocator The names of objects used for image object requests are always fixed size. So create a slab cache to manage them. Define a new function rbd_segment_name_free() to match rbd_segment_name() (which is what supplies the dynamically-allocated name buffer). This is part of: http://tracker.ceph.com/issues/3926 Signed-off-by: Alex Elder Reviewed-by: Josh Durgin --- drivers/block/rbd.c | 32 +++++++++++++++++++++++++++++--- 1 file changed, 29 insertions(+), 3 deletions(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index a72842aa3b53..390946a078be 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -345,8 +345,11 @@ static DEFINE_SPINLOCK(rbd_dev_list_lock); static LIST_HEAD(rbd_client_list); /* clients */ static DEFINE_SPINLOCK(rbd_client_list_lock); +/* Slab caches for frequently-allocated structures */ + static struct kmem_cache *rbd_img_request_cache; static struct kmem_cache *rbd_obj_request_cache; +static struct kmem_cache *rbd_segment_name_cache; static int rbd_img_request_submit(struct rbd_img_request *img_request); @@ -985,7 +988,7 @@ static const char *rbd_segment_name(struct rbd_device *rbd_dev, u64 offset) u64 segment; int ret; - name = kmalloc(MAX_OBJ_NAME_SIZE + 1, GFP_NOIO); + name = kmem_cache_alloc(rbd_segment_name_cache, GFP_NOIO); if (!name) return NULL; segment = offset >> rbd_dev->header.obj_order; @@ -1001,6 +1004,13 @@ static const char *rbd_segment_name(struct rbd_device *rbd_dev, u64 offset) return name; } +static void rbd_segment_name_free(const char *name) +{ + /* The explicit cast here is needed to drop the const qualifier */ + + kmem_cache_free(rbd_segment_name_cache, (void *)name); +} + static u64 rbd_segment_offset(struct rbd_device *rbd_dev, u64 offset) { u64 segment_size = (u64) 1 << rbd_dev->header.obj_order; @@ -2033,7 +2043,8 @@ static int rbd_img_request_fill(struct rbd_img_request *img_request, length = rbd_segment_length(rbd_dev, img_offset, resid); obj_request = rbd_obj_request_create(object_name, offset, length, type); - kfree(object_name); /* object request has its own copy */ + /* object request has its own copy of the object name */ + rbd_segment_name_free(object_name); if (!obj_request) goto out_unwind; @@ -5018,8 +5029,19 @@ static int rbd_slab_init(void) sizeof (struct rbd_obj_request), __alignof__(struct rbd_obj_request), 0, NULL); - if (rbd_obj_request_cache) + if (!rbd_obj_request_cache) + goto out_err; + + rbd_assert(!rbd_segment_name_cache); + rbd_segment_name_cache = kmem_cache_create("rbd_segment_name", + MAX_OBJ_NAME_SIZE + 1, 1, 0, NULL); + if (rbd_segment_name_cache) return 0; +out_err: + if (rbd_obj_request_cache) { + kmem_cache_destroy(rbd_obj_request_cache); + rbd_obj_request_cache = NULL; + } kmem_cache_destroy(rbd_img_request_cache); rbd_img_request_cache = NULL; @@ -5029,6 +5051,10 @@ static int rbd_slab_init(void) static void rbd_slab_exit(void) { + rbd_assert(rbd_segment_name_cache); + kmem_cache_destroy(rbd_segment_name_cache); + rbd_segment_name_cache = NULL; + rbd_assert(rbd_obj_request_cache); kmem_cache_destroy(rbd_obj_request_cache); rbd_obj_request_cache = NULL;