writeback: show writeback reason with __print_symbolic

This makes the binary trace understandable by trace-cmd.

CC: Dave Chinner <david@fromorbit.com>
CC: Curt Wohlgemuth <curtw@google.com>
CC: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>

diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index ac86f8b3e3cb1cf050753148c3f3d065b18e6cf9..517f211a3bd45c60f607e5da7d957bc739d55d47 100644 (file)
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -47,17 +47,6 @@ struct wb_writeback_work {
        struct completion *done;        /* set if the caller waits */
 };
 
-const char *wb_reason_name[] = {
-       [WB_REASON_BACKGROUND]          = "background",
-       [WB_REASON_TRY_TO_FREE_PAGES]   = "try_to_free_pages",
-       [WB_REASON_SYNC]                = "sync",
-       [WB_REASON_PERIODIC]            = "periodic",
-       [WB_REASON_LAPTOP_TIMER]        = "laptop_timer",
-       [WB_REASON_FREE_MORE_MEM]       = "free_more_memory",
-       [WB_REASON_FS_FREE_SPACE]       = "fs_free_space",
-       [WB_REASON_FORKER_THREAD]       = "forker_thread"
-};
-
 /*
  * Include the creation of the trace points after defining the
  * wb_writeback_work structure so that the definition remains local to this

diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h
index b99caa8b780c624af834caeab4130549479e3844..99d1d0decf88e41a7c0c038d463330e8351046b1 100644 (file)
--- a/include/trace/events/writeback.h
+++ b/include/trace/events/writeback.h
@@ -21,6 +21,16 @@
                {I_REFERENCED,          "I_REFERENCED"}         \
        )
 
+#define WB_WORK_REASON                                                 \
+               {WB_REASON_BACKGROUND,          "background"},          \
+               {WB_REASON_TRY_TO_FREE_PAGES,   "try_to_free_pages"},   \
+               {WB_REASON_SYNC,                "sync"},                \
+               {WB_REASON_PERIODIC,            "periodic"},            \
+               {WB_REASON_LAPTOP_TIMER,        "laptop_timer"},        \
+               {WB_REASON_FREE_MORE_MEM,       "free_more_memory"},    \
+               {WB_REASON_FS_FREE_SPACE,       "fs_free_space"},       \
+               {WB_REASON_FORKER_THREAD,       "forker_thread"}
+
 struct wb_writeback_work;
 
 DECLARE_EVENT_CLASS(writeback_work_class,
@@ -55,7 +65,7 @@ DECLARE_EVENT_CLASS(writeback_work_class,
                  __entry->for_kupdate,
                  __entry->range_cyclic,
                  __entry->for_background,
-                 wb_reason_name[__entry->reason]
+                 __print_symbolic(__entry->reason, WB_WORK_REASON)
        )
 );
 #define DEFINE_WRITEBACK_WORK_EVENT(name) \
@@ -184,7 +194,8 @@ TRACE_EVENT(writeback_queue_io,
                __entry->older, /* older_than_this in jiffies */
                __entry->age,   /* older_than_this in relative milliseconds */
                __entry->moved,
-               wb_reason_name[__entry->reason])
+               __print_symbolic(__entry->reason, WB_WORK_REASON)
+       )
 );
 
 TRACE_EVENT(global_dirty_state,