nfsd: create a dedicated slabcache for DRC entries

Currently we use kmalloc() which wastes a little bit of memory on each
allocation since it's a power of 2 allocator. Since we're allocating a
1024 of these now, and may need even more later, let's create a new
slabcache for them.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c
index 972c14a..4aad9e4 100644 (file)
--- a/fs/nfsd/nfscache.c
+++ b/fs/nfsd/nfscache.c
@@ -26,6 +26,7 @@
 static struct hlist_head *     cache_hash;
 static struct list_head        lru_head;
 static int                     cache_disabled = 1;
+static struct kmem_cache       *drc_slab;
 
 /*
  * Calculate the hash index from an XID.
@@ -51,10 +52,15 @@ int nfsd_reply_cache_init(void)
        struct svc_cacherep     *rp;
        int                     i;
 
+       drc_slab = kmem_cache_create("nfsd_drc", sizeof(struct svc_cacherep),
+                                       0, 0, NULL);
+       if (!drc_slab)
+               goto out_nomem;
+
        INIT_LIST_HEAD(&lru_head);
        i = CACHESIZE;
        while (i) {
-               rp = kmalloc(sizeof(*rp), GFP_KERNEL);
+               rp = kmem_cache_alloc(drc_slab, GFP_KERNEL);
                if (!rp)
                        goto out_nomem;
                list_add(&rp->c_lru, &lru_head);
@@ -85,13 +91,18 @@ void nfsd_reply_cache_shutdown(void)
                if (rp->c_state == RC_DONE && rp->c_type == RC_REPLBUFF)
                        kfree(rp->c_replvec.iov_base);
                list_del(&rp->c_lru);
-               kfree(rp);
+               kmem_cache_free(drc_slab, rp);
        }
 
        cache_disabled = 1;
 
        kfree (cache_hash);
        cache_hash = NULL;
+
+       if (drc_slab) {
+               kmem_cache_destroy(drc_slab);
+               drc_slab = NULL;
+       }
 }
 
 /*