[PATCH 11/89] sched/headers, delayacct: Move the 'struct task_delay_info' definition from <linux/sched.h> to <linux/delayacct.h>

[Ingo Molnar]

The 'struct task_delay_info' definition does not have to be in sched.h,
because task_struct only has a pointer to it.

So move it to <linux/delayacct.h> to reduce the size of <linux/sched.h>.

As an additional improvement make the type defined but empty in the
!CONFIG_TASK_DELAY_ACCT case - to eliminate the ugly #ifdef
around the task_struct field as well.

Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 include/linux/delayacct.h | 38 ++++++++++++++++++++++++++++++++++++--
 include/linux/sched.h     | 37 ++-----------------------------------
 2 files changed, 38 insertions(+), 37 deletions(-)

diff --git a/include/linux/delayacct.h b/include/linux/delayacct.h
index 00e60f79a9cc..a2192de5d428 100644
--- a/include/linux/delayacct.h
+++ b/include/linux/delayacct.h
@@ -18,8 +18,6 @@
 #define _LINUX_DELAYACCT_H
 
 #include <uapi/linux/taskstats.h>
-#include <linux/sched.h>
-#include <linux/slab.h>
 
 /*
  * Per-task flags relevant to delay accounting
@@ -29,8 +27,44 @@
 #define DELAYACCT_PF_SWAPIN	0x00000001	/* I am doing a swapin */
 #define DELAYACCT_PF_BLKIO	0x00000002	/* I am waiting on IO */
 
+struct task_delay_info {
 #ifdef CONFIG_TASK_DELAY_ACCT
+	spinlock_t	lock;
+	unsigned int	flags;	/* Private per-task flags */
+
+	/* For each stat XXX, add following, aligned appropriately
+	 *
+	 * struct timespec XXX_start, XXX_end;
+	 * u64 XXX_delay;
+	 * u32 XXX_count;
+	 *
+	 * Atomicity of updates to XXX_delay, XXX_count protected by
+	 * single lock above (split into XXX_lock if contention is an issue).
+	 */
+
+	/*
+	 * XXX_count is incremented on every XXX operation, the delay
+	 * associated with the operation is added to XXX_delay.
+	 * XXX_delay contains the accumulated delay time in nanoseconds.
+	 */
+	u64 blkio_start;	/* Shared by blkio, swapin */
+	u64 blkio_delay;	/* wait for sync block io completion */
+	u64 swapin_delay;	/* wait for swapin block io completion */
+	u32 blkio_count;	/* total count of the number of sync block */
+				/* io operations performed */
+	u32 swapin_count;	/* total count of the number of swapin block */
+				/* io operations performed */
+
+	u64 freepages_start;
+	u64 freepages_delay;	/* wait for memory reclaim */
+	u32 freepages_count;	/* total count of memory reclaim */
+#endif
+};
 
+#include <linux/sched.h>
+#include <linux/slab.h>
+
+#ifdef CONFIG_TASK_DELAY_ACCT
 extern int delayacct_on;	/* Delay accounting turned on/off */
 extern struct kmem_cache *delayacct_cache;
 extern void delayacct_init(void);
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 4b49d159f4d5..15971b1e3f57 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -901,39 +901,7 @@ struct sched_info {
 };
 #endif /* CONFIG_SCHED_INFO */
 
-#ifdef CONFIG_TASK_DELAY_ACCT
-struct task_delay_info {
-	spinlock_t	lock;
-	unsigned int	flags;	/* Private per-task flags */
-
-	/* For each stat XXX, add following, aligned appropriately
-	 *
-	 * struct timespec XXX_start, XXX_end;
-	 * u64 XXX_delay;
-	 * u32 XXX_count;
-	 *
-	 * Atomicity of updates to XXX_delay, XXX_count protected by
-	 * single lock above (split into XXX_lock if contention is an issue).
-	 */
-
-	/*
-	 * XXX_count is incremented on every XXX operation, the delay
-	 * associated with the operation is added to XXX_delay.
-	 * XXX_delay contains the accumulated delay time in nanoseconds.
-	 */
-	u64 blkio_start;	/* Shared by blkio, swapin */
-	u64 blkio_delay;	/* wait for sync block io completion */
-	u64 swapin_delay;	/* wait for swapin block io completion */
-	u32 blkio_count;	/* total count of the number of sync block */
-				/* io operations performed */
-	u32 swapin_count;	/* total count of the number of swapin block */
-				/* io operations performed */
-
-	u64 freepages_start;
-	u64 freepages_delay;	/* wait for memory reclaim */
-	u32 freepages_count;	/* total count of memory reclaim */
-};
-#endif	/* CONFIG_TASK_DELAY_ACCT */
+struct task_delay_info;
 
 static inline int sched_info_on(void)
 {
@@ -1615,9 +1583,8 @@ struct task_struct {
 
 	struct page_frag task_frag;
 
-#ifdef	CONFIG_TASK_DELAY_ACCT
 	struct task_delay_info *delays;
-#endif
+
 #ifdef CONFIG_FAULT_INJECTION
 	int make_it_fail;
 #endif
-- 
2.7.4