libceph: allocate ceph message data with a slab allocator

Create a slab cache to manage ceph_msg_data structure allocation.

This is part of:
    http://tracker.ceph.com/issues/3926

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

1 files changed, 23 insertions, 3 deletions

diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index bc1ba4c2605d..eb0a46a49bd4 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -155,6 +155,7 @@ static bool con_flag_test_and_set(struct ceph_connection *con,
 /* Slab caches for frequently-allocated structures */
 
 static struct kmem_cache        *ceph_msg_cache;
+static struct kmem_cache        *ceph_msg_data_cache;
 
 /* static tag bytes (protocol control messages) */
 static char tag_msg = CEPH_MSGR_TAG_MSG;
@@ -236,11 +237,30 @@ static int ceph_msgr_slab_init(void)
         ceph_msg_cache = kmem_cache_create("ceph_msg",
                                         sizeof (struct ceph_msg),
                                         __alignof__(struct ceph_msg), 0, NULL);
-        return ceph_msg_cache ? 0 : -ENOMEM;
+
+        if (!ceph_msg_cache)
+                return -ENOMEM;
+
+        BUG_ON(ceph_msg_data_cache);
+        ceph_msg_data_cache = kmem_cache_create("ceph_msg_data",
+                                        sizeof (struct ceph_msg_data),
+                                        __alignof__(struct ceph_msg_data),
+                                        0, NULL);
+        if (ceph_msg_data_cache)
+                return 0;
+
+        kmem_cache_destroy(ceph_msg_cache);
+        ceph_msg_cache = NULL;
+
+        return -ENOMEM;
 }
 
 static void ceph_msgr_slab_exit(void)
 {
+        BUG_ON(!ceph_msg_data_cache);
+        kmem_cache_destroy(ceph_msg_data_cache);
+        ceph_msg_data_cache = NULL;
+
         BUG_ON(!ceph_msg_cache);
         kmem_cache_destroy(ceph_msg_cache);
         ceph_msg_cache = NULL;
@@ -3008,7 +3028,7 @@ static struct ceph_msg_data *ceph_msg_data_create(enum ceph_msg_data_type type)
         if (WARN_ON(!ceph_msg_data_type_valid(type)))
                 return NULL;
 
-        data = kzalloc(sizeof (*data), GFP_NOFS);
+        data = kmem_cache_zalloc(ceph_msg_data_cache, GFP_NOFS);
         if (data)
                 data->type = type;
         INIT_LIST_HEAD(&data->links);
@@ -3026,7 +3046,7 @@ static void ceph_msg_data_destroy(struct ceph_msg_data *data)
                 ceph_pagelist_release(data->pagelist);
                 kfree(data->pagelist);
         }
-        kfree(data);
+        kmem_cache_free(ceph_msg_data_cache, data);
 }
 
 void ceph_msg_data_add_pages(struct ceph_msg *msg, struct page **pages,