[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>
diff --git a/include/linux/delayacct.h b/include/linux/delayacct.h
index 0ecbf9a..d955078 100644
--- a/include/linux/delayacct.h
+++ b/include/linux/delayacct.h
@@ -18,6 +18,7 @@
#define _LINUX_DELAYACCT_H
#include <linux/sched.h>
+#include <linux/taskstats_kern.h>
/*
* Per-task flags relevant to delay accounting
@@ -35,6 +36,7 @@
extern void __delayacct_tsk_exit(struct task_struct *);
extern void __delayacct_blkio_start(void);
extern void __delayacct_blkio_end(void);
+extern int __delayacct_add_tsk(struct taskstats *, struct task_struct *);
static inline void delayacct_set_flag(int flag)
{
@@ -74,6 +76,16 @@
__delayacct_blkio_end();
}
+static inline int delayacct_add_tsk(struct taskstats *d,
+ struct task_struct *tsk)
+{
+ if (likely(!delayacct_on))
+ return -EINVAL;
+ if (!tsk->delays)
+ return 0;
+ return __delayacct_add_tsk(d, tsk);
+}
+
#else
static inline void delayacct_set_flag(int flag)
{}
@@ -89,6 +101,9 @@
{}
static inline void delayacct_blkio_end(void)
{}
+static inline int delayacct_add_tsk(struct taskstats *d,
+ struct task_struct *tsk)
+{ return 0; }
#endif /* CONFIG_TASK_DELAY_ACCT */
#endif
diff --git a/include/linux/sched.h b/include/linux/sched.h
index f751062..3c5610c 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -990,6 +990,7 @@
*/
struct pipe_inode_info *splice_pipe;
#ifdef CONFIG_TASK_DELAY_ACCT
+ spinlock_t delays_lock;
struct task_delay_info *delays;
#endif
};
diff --git a/include/linux/taskstats.h b/include/linux/taskstats.h
index 51f6275..c6aeca3 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 */
};
diff --git a/include/linux/taskstats_kern.h b/include/linux/taskstats_kern.h
index bd0ecb96..fc9da2e 100644
--- a/include/linux/taskstats_kern.h
+++ b/include/linux/taskstats_kern.h
@@ -17,6 +17,7 @@
#ifdef CONFIG_TASKSTATS
extern kmem_cache_t *taskstats_cache;
+extern struct mutex taskstats_exit_mutex;
static inline void taskstats_exit_alloc(struct taskstats **ptidstats,
struct taskstats **ptgidstats)