WorkStruct: Separate delayable and non-delayable events.

Separate delayable work items from non-delayable work items be splitting them
into a separate structure (delayed_work), which incorporates a work_struct and
the timer_list removed from work_struct.

The work_struct struct is huge, and this limits it's usefulness.  On a 64-bit
architecture it's nearly 100 bytes in size.  This reduces that by half for the
non-delayable type of event.

Signed-Off-By: David Howells <dhowells@redhat.com>
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index 00cb388..d5725cb 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -285,7 +285,7 @@
 static struct file_operations cache_flush_operations;
 
 static void do_cache_clean(void *data);
-static DECLARE_WORK(cache_cleaner, do_cache_clean, NULL);
+static DECLARE_DELAYED_WORK(cache_cleaner, do_cache_clean, NULL);
 
 void cache_register(struct cache_detail *cd)
 {
@@ -337,7 +337,7 @@
 	spin_unlock(&cache_list_lock);
 
 	/* start the cleaning process */
-	schedule_work(&cache_cleaner);
+	schedule_delayed_work(&cache_cleaner, 0);
 }
 
 int cache_unregister(struct cache_detail *cd)