sched: Provide iowait counters
For counting how long an application has been waiting for
(disk) IO, there currently is only the HZ sample driven
information available, while for all other counters in this
class, a high resolution version is available via
CONFIG_SCHEDSTATS.
In order to make an improved bootchart tool possible, we also
need a higher resolution version of the iowait time.
This patch below adds this scheduler statistic to the kernel.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4A64B813.1080506@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/sched.h b/include/linux/sched.h
index e209ae0..9c96ef2 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1111,6 +1111,8 @@
u64 wait_max;
u64 wait_count;
u64 wait_sum;
+ u64 iowait_count;
+ u64 iowait_sum;
u64 sleep_start;
u64 sleep_max;
@@ -1231,6 +1233,8 @@
unsigned did_exec:1;
unsigned in_execve:1; /* Tell the LSMs that the process is doing an
* execve */
+ unsigned in_iowait:1;
+
/* Revert to default priority/policy when forking */
unsigned sched_reset_on_fork:1;