[PATCH 1/2] Add scaled time to taskstats based process accounting
Michael Neuling
mikey at neuling.org
Fri Aug 17 11:09:41 EST 2007
This adds items to the taststats struct to account for user and system
time based on scaling the CPU frequency and instruction issue rates.
Adds account_(user|system)_time_scaled callbacks which architectures
can use to account for time using this mechanism.
Signed-off-by: Michael Neuling <mikey at neuling.org>
---
Updated based on comments from Balbir
include/linux/kernel_stat.h | 2 ++
include/linux/sched.h | 2 +-
include/linux/taskstats.h | 11 +++++++++--
kernel/delayacct.c | 6 ++++++
kernel/fork.c | 2 ++
kernel/sched.c | 21 +++++++++++++++++++++
kernel/timer.c | 7 +++++--
kernel/tsacct.c | 4 ++++
8 files changed, 50 insertions(+), 5 deletions(-)
Index: linux-2.6-ozlabs/include/linux/kernel_stat.h
===================================================================
--- linux-2.6-ozlabs.orig/include/linux/kernel_stat.h
+++ linux-2.6-ozlabs/include/linux/kernel_stat.h
@@ -52,7 +52,9 @@ static inline int kstat_irqs(int irq)
}
extern void account_user_time(struct task_struct *, cputime_t);
+extern void account_user_time_scaled(struct task_struct *, cputime_t);
extern void account_system_time(struct task_struct *, int, cputime_t);
+extern void account_system_time_scaled(struct task_struct *, cputime_t);
extern void account_steal_time(struct task_struct *, cputime_t);
#endif /* _LINUX_KERNEL_STAT_H */
Index: linux-2.6-ozlabs/include/linux/sched.h
===================================================================
--- linux-2.6-ozlabs.orig/include/linux/sched.h
+++ linux-2.6-ozlabs/include/linux/sched.h
@@ -1020,7 +1020,7 @@ struct task_struct {
int __user *clear_child_tid; /* CLONE_CHILD_CLEARTID */
unsigned int rt_priority;
- cputime_t utime, stime;
+ cputime_t utime, stime, utimescaled, stimescaled;
unsigned long nvcsw, nivcsw; /* context switch counts */
struct timespec start_time; /* monotonic time */
struct timespec real_start_time; /* boot based time */
Index: linux-2.6-ozlabs/include/linux/taskstats.h
===================================================================
--- linux-2.6-ozlabs.orig/include/linux/taskstats.h
+++ linux-2.6-ozlabs/include/linux/taskstats.h
@@ -31,7 +31,7 @@
*/
-#define TASKSTATS_VERSION 5
+#define TASKSTATS_VERSION 6
#define TS_COMM_LEN 32 /* should be >= TASK_COMM_LEN
* in linux/sched.h */
@@ -85,9 +85,12 @@ struct taskstats {
* 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
+ * and wraps around to zero silently on overflow. The
+ * _scaled_ version accounts for cpus which can scale the
+ * number of instructions executed each cycle.
*/
__u64 cpu_run_real_total;
+ __u64 cpu_scaled_run_real_total;
/* cpu "virtual" running time
* Uses time intervals seen by the kernel i.e. no adjustment
@@ -142,6 +145,10 @@ struct taskstats {
__u64 write_char; /* bytes written */
__u64 read_syscalls; /* read syscalls */
__u64 write_syscalls; /* write syscalls */
+
+ /* time accounting for SMT machines */
+ __u64 ac_utimescaled; /* utime scaled on frequency etc */
+ __u64 ac_stimescaled; /* stime scaled on frequency etc */
/* Extended accounting fields end */
#define TASKSTATS_HAS_IO_ACCOUNTING
Index: linux-2.6-ozlabs/kernel/delayacct.c
===================================================================
--- linux-2.6-ozlabs.orig/kernel/delayacct.c
+++ linux-2.6-ozlabs/kernel/delayacct.c
@@ -115,6 +115,12 @@ int __delayacct_add_tsk(struct taskstats
tmp += timespec_to_ns(&ts);
d->cpu_run_real_total = (tmp < (s64)d->cpu_run_real_total) ? 0 : tmp;
+ tmp = (s64)d->cpu_scaled_run_real_total;
+ cputime_to_timespec(tsk->utimescaled + tsk->stimescaled, &ts);
+ tmp += timespec_to_ns(&ts);
+ d->cpu_scaled_run_real_total =
+ (tmp < (s64)d->cpu_scaled_run_real_total) ? 0 : tmp;
+
/*
* No locking available for sched_info (and too expensive to add one)
* Mitigate by taking snapshot of values
Index: linux-2.6-ozlabs/kernel/fork.c
===================================================================
--- linux-2.6-ozlabs.orig/kernel/fork.c
+++ linux-2.6-ozlabs/kernel/fork.c
@@ -1045,6 +1045,8 @@ static struct task_struct *copy_process(
p->utime = cputime_zero;
p->stime = cputime_zero;
+ p->utimescaled = cputime_zero;
+ p->stimescaled = cputime_zero;
#ifdef CONFIG_TASK_XACCT
p->rchar = 0; /* I/O counter: bytes read */
Index: linux-2.6-ozlabs/kernel/sched.c
===================================================================
--- linux-2.6-ozlabs.orig/kernel/sched.c
+++ linux-2.6-ozlabs/kernel/sched.c
@@ -3249,6 +3249,16 @@ void account_user_time(struct task_struc
}
/*
+ * Account scaled user cpu time to a process.
+ * @p: the process that the cpu time gets accounted to
+ * @cputime: the cpu time spent in user space since the last update
+ */
+void account_user_time_scaled(struct task_struct *p, cputime_t cputime)
+{
+ p->utimescaled = cputime_add(p->utimescaled, cputime);
+}
+
+/*
* Account system cpu time to a process.
* @p: the process that the cpu time gets accounted to
* @hardirq_offset: the offset to subtract from hardirq_count()
@@ -3280,6 +3290,17 @@ void account_system_time(struct task_str
}
/*
+ * Account scaled system cpu time to a process.
+ * @p: the process that the cpu time gets accounted to
+ * @hardirq_offset: the offset to subtract from hardirq_count()
+ * @cputime: the cpu time spent in kernel space since the last update
+ */
+void account_system_time_scaled(struct task_struct *p, cputime_t cputime)
+{
+ p->stimescaled = cputime_add(p->stimescaled, cputime);
+}
+
+/*
* Account for involuntary wait time.
* @p: the process from which the cpu time has been stolen
* @steal: the cpu time spent in involuntary wait
Index: linux-2.6-ozlabs/kernel/timer.c
===================================================================
--- linux-2.6-ozlabs.orig/kernel/timer.c
+++ linux-2.6-ozlabs/kernel/timer.c
@@ -826,10 +826,13 @@ void update_process_times(int user_tick)
int cpu = smp_processor_id();
/* Note: this timer irq context must be accounted for as well. */
- if (user_tick)
+ if (user_tick) {
account_user_time(p, jiffies_to_cputime(1));
- else
+ account_user_time_scaled(p, jiffies_to_cputime(1));
+ } else {
account_system_time(p, HARDIRQ_OFFSET, jiffies_to_cputime(1));
+ account_system_time_scaled(p, jiffies_to_cputime(1));
+ }
run_local_timers();
if (rcu_pending(cpu))
rcu_check_callbacks(cpu, user_tick);
Index: linux-2.6-ozlabs/kernel/tsacct.c
===================================================================
--- linux-2.6-ozlabs.orig/kernel/tsacct.c
+++ linux-2.6-ozlabs/kernel/tsacct.c
@@ -62,6 +62,10 @@ void bacct_add_tsk(struct taskstats *sta
rcu_read_unlock();
stats->ac_utime = cputime_to_msecs(tsk->utime) * USEC_PER_MSEC;
stats->ac_stime = cputime_to_msecs(tsk->stime) * USEC_PER_MSEC;
+ stats->ac_utimescaled =
+ cputime_to_msecs(tsk->utimescaled) * USEC_PER_MSEC;
+ stats->ac_stimescaled =
+ cputime_to_msecs(tsk->stimescaled) * USEC_PER_MSEC;
stats->ac_minflt = tsk->min_flt;
stats->ac_majflt = tsk->maj_flt;
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