1 files changed, 13 insertions, 0 deletions

diff --git a/include/linux/delayacct.h b/include/linux/delayacct.h
index 55d1ca5e60f5..ab94bc083558 100644
--- a/include/linux/delayacct.h
+++ b/include/linux/delayacct.h
@@ -26,6 +26,7 @@
  * Used to set current->delays->flags
  */
 #define DELAYACCT_PF_SWAPIN     0x00000001      /* I am doing a swapin */
+#define DELAYACCT_PF_BLKIO      0x00000002      /* I am waiting on IO */
 
 #ifdef CONFIG_TASK_DELAY_ACCT
 
@@ -39,6 +40,14 @@ extern void __delayacct_blkio_end(void);
 extern int __delayacct_add_tsk(struct taskstats *, struct task_struct *);
 extern __u64 __delayacct_blkio_ticks(struct task_struct *);
 
+static inline int delayacct_is_task_waiting_on_io(struct task_struct *p)
+{
+        if (p->delays)
+                return (p->delays->flags & DELAYACCT_PF_BLKIO);
+        else
+                return 0;
+}
+
 static inline void delayacct_set_flag(int flag)
 {
         if (current->delays)
@@ -71,6 +80,7 @@ static inline void delayacct_tsk_free(struct task_struct *tsk)
 
 static inline void delayacct_blkio_start(void)
 {
+        delayacct_set_flag(DELAYACCT_PF_BLKIO);
         if (current->delays)
                 __delayacct_blkio_start();
 }
@@ -79,6 +89,7 @@ static inline void delayacct_blkio_end(void)
 {
         if (current->delays)
                 __delayacct_blkio_end();
+        delayacct_clear_flag(DELAYACCT_PF_BLKIO);
 }
 
 static inline int delayacct_add_tsk(struct taskstats *d,
@@ -116,6 +127,8 @@ static inline int delayacct_add_tsk(struct taskstats *d,
 { return 0; }
 static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk)
 { return 0; }
+static inline int delayacct_is_task_waiting_on_io(struct task_struct *p)
+{ return 0; }
 #endif /* CONFIG_TASK_DELAY_ACCT */
 
 #endif