[PATCH] ifdef blktrace debugging fields

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 2712257..3696f2f 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -784,8 +784,9 @@
 	struct prio_array *array;
 
 	unsigned short ioprio;
+#ifdef CONFIG_BLK_DEV_IO_TRACE
 	unsigned int btrace_seq;
-
+#endif
 	unsigned long sleep_avg;
 	unsigned long long timestamp, last_ran;
 	unsigned long long sched_time; /* sched_clock time spent running */