On Tue, Feb 18, 2020 at 3:11 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 | 6 +++---
> fs/ceph/super.c | 8 ++++++++
> include/linux/ceph/libceph.h | 1 +
> 3 files changed, 12 insertions(+), 3 deletions(-)
>
> diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
> index 2980e57ca7b9..76655047fca5 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 +2094,8 @@ 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 = kmem_cache_alloc(ceph_mds_request_cachep,
> + GFP_NOFS | __GFP_ZERO);
This can be kmem_cache_zalloc(), less verbose. Also, I would separate
declaration and assignment here.
Thanks,
Ilya
