On Tue, Feb 18, 2020 at 4:35 PM Jeff Layton <jlayton@xxxxxxxxxx> wrote:
>
> On my machine (x86_64) this struct is 952 bytes, which gets rounded up
> to 1024 by kmalloc. Move this to a dedicated slabcache, so we can
> allocate them without the extra 72 bytes of overhead per.
>
> Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
> ---
> fs/ceph/mds_client.c | 5 +++--
> fs/ceph/super.c | 8 ++++++++
> include/linux/ceph/libceph.h | 1 +
> 3 files changed, 12 insertions(+), 2 deletions(-)
>
> v2: switch to kmem_cache_zalloc()
>
> diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
> index 2980e57ca7b9..fab9d6461a65 100644
> --- a/fs/ceph/mds_client.c
> +++ b/fs/ceph/mds_client.c
> @@ -736,7 +736,7 @@ void ceph_mdsc_release_request(struct kref *kref)
> put_request_session(req);
> ceph_unreserve_caps(req->r_mdsc, &req->r_caps_reservation);
> WARN_ON_ONCE(!list_empty(&req->r_wait));
> - kfree(req);
> + kmem_cache_free(ceph_mds_request_cachep, req);
> }
>
> DEFINE_RB_FUNCS(request, struct ceph_mds_request, r_tid, r_node)
> @@ -2094,8 +2094,9 @@ int ceph_alloc_readdir_reply_buffer(struct ceph_mds_request *req,
> struct ceph_mds_request *
> ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode)
> {
> - struct ceph_mds_request *req = kzalloc(sizeof(*req), GFP_NOFS);
> + struct ceph_mds_request *req;
>
> + req = kmem_cache_zalloc(ceph_mds_request_cachep, GFP_NOFS);
> if (!req)
> return ERR_PTR(-ENOMEM);
>
> diff --git a/fs/ceph/super.c b/fs/ceph/super.c
> index c7f150686a53..b1329cd5388a 100644
> --- a/fs/ceph/super.c
> +++ b/fs/ceph/super.c
> @@ -729,6 +729,7 @@ struct kmem_cache *ceph_cap_flush_cachep;
> struct kmem_cache *ceph_dentry_cachep;
> struct kmem_cache *ceph_file_cachep;
> struct kmem_cache *ceph_dir_file_cachep;
> +struct kmem_cache *ceph_mds_request_cachep;
>
> static void ceph_inode_init_once(void *foo)
> {
> @@ -769,6 +770,10 @@ static int __init init_caches(void)
> if (!ceph_dir_file_cachep)
> goto bad_dir_file;
>
> + ceph_mds_request_cachep = KMEM_CACHE(ceph_mds_request, SLAB_MEM_SPREAD);
> + if (!ceph_mds_request_cachep)
> + goto bad_mds_req;
> +
> error = ceph_fscache_register();
> if (error)
> goto bad_fscache;
> @@ -776,6 +781,8 @@ static int __init init_caches(void)
> return 0;
>
> bad_fscache:
> + kmem_cache_destroy(ceph_mds_request_cachep);
> +bad_mds_req:
> kmem_cache_destroy(ceph_dir_file_cachep);
> bad_dir_file:
> kmem_cache_destroy(ceph_file_cachep);
> @@ -804,6 +811,7 @@ static void destroy_caches(void)
> kmem_cache_destroy(ceph_dentry_cachep);
> kmem_cache_destroy(ceph_file_cachep);
> kmem_cache_destroy(ceph_dir_file_cachep);
> + kmem_cache_destroy(ceph_mds_request_cachep);
>
> ceph_fscache_unregister();
> }
> diff --git a/include/linux/ceph/libceph.h b/include/linux/ceph/libceph.h
> index ec73ebc4827d..525b7c3f1c81 100644
> --- a/include/linux/ceph/libceph.h
> +++ b/include/linux/ceph/libceph.h
> @@ -272,6 +272,7 @@ extern struct kmem_cache *ceph_cap_flush_cachep;
> extern struct kmem_cache *ceph_dentry_cachep;
> extern struct kmem_cache *ceph_file_cachep;
> extern struct kmem_cache *ceph_dir_file_cachep;
> +extern struct kmem_cache *ceph_mds_request_cachep;
>
> /* ceph_common.c */
> extern bool libceph_compatible(void *data);
Looks good, thanks for addressing my nit.
Ilya
