per-task-delay-accounting: update taskstats for memory reclaim delay

Add members for memory reclaim delay to taskstats, and accumulate them in
__delayacct_add_tsk() .

Signed-off-by: Keika Kobayashi <[e-mail]>
Cc: Hiroshi Shimamoto <[e-mail]>
Cc: Balbir Singh <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

Documentation/accounting/taskstats-struct.txt

···
 
 5) Time accounting for SMT machines
 
+6) Extended delay accounting fields for memory reclaim
+
 Future extension should add fields to the end of the taskstats struct, and
 should not change the relative position of each field within the struct.
 
···
 	__u64	ac_utimescaled;		/* utime scaled on frequency etc */
 	__u64	ac_stimescaled;		/* stime scaled on frequency etc */
 	__u64	cpu_scaled_run_real_total; /* scaled cpu_run_real_total */
+
+6) Extended delay accounting fields for memory reclaim
+	/* Delay waiting for memory reclaim */
+	__u64	freepages_count;
+	__u64	freepages_delay_total;
 }

include/linux/taskstats.h

···
  */
 
 
-#define TASKSTATS_VERSION	6
+#define TASKSTATS_VERSION	7
 #define TS_COMM_LEN		32	/* should be >= TASK_COMM_LEN
 					 * in linux/sched.h */
 
···
 	__u64	ac_utimescaled;		/* utime scaled on frequency etc */
 	__u64	ac_stimescaled;		/* stime scaled on frequency etc */
 	__u64	cpu_scaled_run_real_total; /* scaled cpu_run_real_total */
+
+	/* Delay waiting for memory reclaim */
+	__u64	freepages_count;
+	__u64	freepages_delay_total;
 };
 
 

kernel/delayacct.c

···
 	d->blkio_delay_total = (tmp < d->blkio_delay_total) ? 0 : tmp;
 	tmp = d->swapin_delay_total + tsk->delays->swapin_delay;
 	d->swapin_delay_total = (tmp < d->swapin_delay_total) ? 0 : tmp;
+	tmp = d->freepages_delay_total + tsk->delays->freepages_delay;
+	d->freepages_delay_total = (tmp < d->freepages_delay_total) ? 0 : tmp;
 	d->blkio_count += tsk->delays->blkio_count;
 	d->swapin_count += tsk->delays->swapin_count;
+	d->freepages_count += tsk->delays->freepages_count;
 	spin_unlock_irqrestore(&tsk->delays->lock, flags);
 
 done: