[PATCH] per-task-delay-accounting: delay accounting usage of taskstats interface

Usage of taskstats interface by delay accounting.

Signed-off-by: Shailabh Nagar <nagar@us.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, 54 insertions, 1 deletions

diff --git a/include/linux/taskstats.h b/include/linux/taskstats.h
index 51f62759bea9..c6aeca32348e 100644
--- a/include/linux/taskstats.h
+++ b/include/linux/taskstats.h
@@ -34,7 +34,60 @@
 struct taskstats {
 
         /* Version 1 */
-        __u64   version;
+        __u16   version;
+        __u16   padding[3];     /* Userspace should not interpret the padding
+                                 * field which can be replaced by useful
+                                 * fields if struct taskstats is extended.
+                                 */
+
+        /* Delay accounting fields start
+         *
+         * All values, until comment "Delay accounting fields end" are
+         * available only if delay accounting is enabled, even though the last
+         * few fields are not delays
+         *
+         * xxx_count is the number of delay values recorded
+         * xxx_delay_total is the corresponding cumulative delay in nanoseconds
+         *
+         * xxx_delay_total wraps around to zero on overflow
+         * xxx_count incremented regardless of overflow
+         */
+
+        /* Delay waiting for cpu, while runnable
+         * count, delay_total NOT updated atomically
+         */
+        __u64   cpu_count;
+        __u64   cpu_delay_total;
+
+        /* Following four fields atomically updated using task->delays->lock */
+
+        /* Delay waiting for synchronous block I/O to complete
+         * does not account for delays in I/O submission
+         */
+        __u64   blkio_count;
+        __u64   blkio_delay_total;
+
+        /* Delay waiting for page fault I/O (swap in only) */
+        __u64   swapin_count;
+        __u64   swapin_delay_total;
+
+        /* cpu "wall-clock" running time
+         * On some architectures, value will adjust for cpu time stolen
+         * from the kernel in involuntary waits due to virtualization.
+         * Value is cumulative, in nanoseconds, without a corresponding count
+         * and wraps around to zero silently on overflow
+         */
+        __u64   cpu_run_real_total;
+
+        /* cpu "virtual" running time
+         * Uses time intervals seen by the kernel i.e. no adjustment
+         * for kernel's involuntary waits due to virtualization.
+         * Value is cumulative, in nanoseconds, without a corresponding count
+         * and wraps around to zero silently on overflow
+         */
+        __u64   cpu_run_virtual_total;
+        /* Delay accounting fields end */
+        /* version 1 ends here */
 };