[PATCH] per-task-delay-accounting: /proc export of aggregated block I/O delays

Export I/O delays seen by a task through /proc/<tgid>/stats for use in top
etc.

Note that delays for I/O done for swapping in pages (swapin I/O) is clubbed
together with all other I/O here (this is not the case in the netlink
interface where the swapin I/O is kept distinct)

[akpm@osdl.org: printk warning fix]
Signed-off-by: Shailabh Nagar <nagar@watson.ibm.com>
Signed-off-by: Balbir Singh <balbir@in.ibm.com>
Cc: Jes Sorensen <jes@sgi.com>
Cc: Peter Chubb <peterc@gelato.unsw.edu.au>
Cc: Erich Focht <efocht@ess.nec.de>
Cc: Levent Serinol <lserinol@gmail.com>
Cc: Jay Lan <jlan@engr.sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 12 insertions, 0 deletions

diff --git a/kernel/delayacct.c b/kernel/delayacct.c
index 1be274a462ca..f05392d64267 100644
--- a/kernel/delayacct.c
+++ b/kernel/delayacct.c
@@ -164,3 +164,15 @@ done:
         spin_unlock(&tsk->delays_lock);
         return 0;
 }
+
+__u64 __delayacct_blkio_ticks(struct task_struct *tsk)
+{
+        __u64 ret;
+
+        spin_lock(&tsk->delays->lock);
+        ret = nsec_to_clock_t(tsk->delays->blkio_delay +
+                                tsk->delays->swapin_delay);
+        spin_unlock(&tsk->delays->lock);
+        return ret;
+}
+