I wrote something to collect the standard queueing statistics a while
back but am not sure what I did with it. I think Rick Lindsley might
still have a copy around.
Actually, better than that -- it's in the mjb tree. But I'll repost it
here for those who might find it generally useful. I've regenerated the
patch below for 2.6.0-test1, but while it applies and compiles cleanly,
I haven't really exercised it to any extent yet in 2.6.
The code adds extra fields to the stat field for each process and
each cpu.
Note that per-process info is only available while that process is
alive. Once a process exits, the specific information about it is lost.
The extra fields for the cpu info in /proc decay over time instead of
accumulating, so they are more of a "wait average" (similar to a load
average) rather than a sum of wait times.
Rick
diff -rup linux-2.6.0-test1/fs/proc/array.c linux-2.6.0-qs/fs/proc/array.c
--- linux-2.6.0-test1/fs/proc/array.c Sun Jul 13 20:35:12 2003
+++ linux-2.6.0-qs/fs/proc/array.c Fri Jul 18 15:51:33 2003
@@ -336,7 +336,7 @@ int proc_pid_stat(struct task_struct *ta
read_unlock(&tasklist_lock);
res = sprintf(buffer,"%d (%s) %c %d %d %d %d %d %lu %lu \
%lu %lu %lu %lu %lu %ld %ld %ld %ld %ld %ld %llu %lu %ld %lu %lu %lu %lu %lu \
-%lu %lu %lu %lu %lu %lu %lu %lu %d %d %lu %lu\n",
+%lu %lu %lu %lu %lu %lu %lu %lu %d %d %lu %lu %lu %lu %lu\n",
task->pid,
task->comm,
state,
@@ -382,7 +382,10 @@ int proc_pid_stat(struct task_struct *ta
task->exit_signal,
task_cpu(task),
task->rt_priority,
- task->policy);
+ task->policy,
+ jiffies_to_clock_t(task->sched_info.inter_arrival_time),
+ jiffies_to_clock_t(task->sched_info.service_time),
+ jiffies_to_clock_t(task->sched_info.response_time));
if(mm)
mmput(mm);
return res;
diff -rup linux-2.6.0-test1/fs/proc/proc_misc.c linux-2.6.0-qs/fs/proc/proc_misc.c
--- linux-2.6.0-test1/fs/proc/proc_misc.c Sun Jul 13 20:30:43 2003
+++ linux-2.6.0-qs/fs/proc/proc_misc.c Fri Jul 18 15:51:33 2003
@@ -401,14 +401,20 @@ static int kstat_read_proc(char *page, c
jiffies_to_clock_t(idle),
jiffies_to_clock_t(iowait));
for (i = 0 ; i < NR_CPUS; i++){
- if (!cpu_online(i)) continue;
- len += sprintf(page + len, "cpu%d %u %u %u %u %u\n",
+ struct sched_info info;
+ if (!cpu_online(i))
+ continue;
+ cpu_sched_info(&info, i);
+ len += sprintf(page + len, "cpu%d %u %u %u %u %u %u %u %u\n",
i,
jiffies_to_clock_t(kstat_cpu(i).cpustat.user),
jiffies_to_clock_t(kstat_cpu(i).cpustat.nice),
jiffies_to_clock_t(kstat_cpu(i).cpustat.system),
jiffies_to_clock_t(kstat_cpu(i).cpustat.idle),
- jiffies_to_clock_t(kstat_cpu(i).cpustat.iowait));
+ jiffies_to_clock_t(kstat_cpu(i).cpustat.iowait),
+ (uint) jiffies_to_clock_t(info.inter_arrival_time),
+ (uint) jiffies_to_clock_t(info.service_time),
+ (uint) jiffies_to_clock_t(info.response_time));
}
len += sprintf(page + len, "intr %u", sum);
diff -rup linux-2.6.0-test1/include/linux/sched.h linux-2.6.0-qs/include/linux/sched.h
--- linux-2.6.0-test1/include/linux/sched.h Sun Jul 13 20:30:40 2003
+++ linux-2.6.0-qs/include/linux/sched.h Fri Jul 18 15:51:33 2003
@@ -94,6 +94,9 @@ extern unsigned long nr_running(void);
extern unsigned long nr_uninterruptible(void);
extern unsigned long nr_iowait(void);
+struct sched_info;
+extern void cpu_sched_info(struct sched_info *, int);
+
#include <linux/time.h>
#include <linux/param.h>
#include <linux/resource.h>
@@ -320,6 +323,13 @@ struct k_itimer {
struct sigqueue *sigq; /* signal queue entry. */
};
+struct sched_info {
+ /* running averages */
+ unsigned long response_time, inter_arrival_time, service_time;
+
+ /* timestamps */
+ unsigned long last_arrival, began_service;
+};
struct io_context; /* See blkdev.h */
void exit_io_context(void);
@@ -344,6 +354,8 @@ struct task_struct {
unsigned long cpus_allowed;
unsigned int time_slice, first_time_slice;
+ struct sched_info sched_info;
+
struct list_head tasks;
struct list_head ptrace_children;
struct list_head ptrace_list;
diff -rup linux-2.6.0-test1/kernel/sched.c linux-2.6.0-qs/kernel/sched.c
--- linux-2.6.0-test1/kernel/sched.c Sun Jul 13 20:37:14 2003
+++ linux-2.6.0-qs/kernel/sched.c Fri Jul 18 15:52:26 2003
@@ -59,6 +59,11 @@
#define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio)
#define MAX_USER_PRIO (USER_PRIO(MAX_PRIO))
+/* the FIXED_1 gunk is so running averages don't vanish prematurely */
+#define RAVG_WEIGHT 128
+#define RAVG_FACTOR (RAVG_WEIGHT*FIXED_1)
+#define RUNNING_AVG(x,y) (((RAVG_WEIGHT-1)*(x)+RAVG_FACTOR*(y))/RAVG_WEIGHT)
+
/*
* These are the 'tuning knobs' of the scheduler:
*
@@ -171,6 +176,8 @@ struct runqueue {
struct list_head migration_queue;
atomic_t nr_iowait;
+
+ struct sched_info info;
};
static DEFINE_PER_CPU(struct runqueue, runqueues);
@@ -279,6 +286,74 @@ static inline void rq_unlock(runqueue_t
spin_unlock_irq(&rq->lock);
}
+static inline void sched_info_arrive(task_t *t)
+{
+ unsigned long now = jiffies;
+ unsigned long diff = now - t->sched_info.last_arrival;
+ struct runqueue *rq = task_rq(t);
+
+ t->sched_info.inter_arrival_time =
+ RUNNING_AVG(t->sched_info.inter_arrival_time, diff);
+ t->sched_info.last_arrival = now;
+
+ if (!rq)
+ return;
+ diff = now - rq->info.last_arrival;
+ rq->info.inter_arrival_time =
+ RUNNING_AVG(rq->info.inter_arrival_time, diff);
+ rq->info.last_arrival = now;
+}
+
+/* is this ever used? */
+static inline void sched_info_depart(task_t *t)
+{
+ struct runqueue *rq = task_rq(t);
+ unsigned long diff, now = jiffies;
+
+ diff = now - t->sched_info.began_service;
+ t->sched_info.service_time =
+ RUNNING_AVG(t->sched_info.service_time, diff);
+
+ if (!rq)
+ return;
+ diff = now - rq->info.began_service;
+ rq->info.service_time =
+ RUNNING_AVG(rq->info.service_time, diff);
+}
+
+static inline void sched_info_switch(task_t *prev, task_t *next)
+{
+ struct runqueue *rq = task_rq(prev);
+ unsigned long diff, now = jiffies;
+
+ /* prev now departs the cpu */
+ sched_info_depart(prev);
+
+ /* only for involuntary context switches */
+ if (prev->state == TASK_RUNNING)
+ sched_info_arrive(prev);
+
+ diff = now - next->sched_info.last_arrival;
+ next->sched_info.response_time =
+ RUNNING_AVG(next->sched_info.response_time, diff);
+ next->sched_info.began_service = now;
+
+ if (!rq)
+ return;
+ /* yes, reusing next's service time is valid */
+ rq->info.response_time =
+ RUNNING_AVG(rq->info.response_time, diff);
+ rq->info.began_service = now;
+
+ if (prev->state != TASK_RUNNING)
+ return;
+ /* if prev arrived subtract rq's last arrival from its arrival */
+ diff = now - rq->info.last_arrival;
+ rq->info.inter_arrival_time =
+ RUNNING_AVG(rq->info.inter_arrival_time, diff);
+ rq->info.last_arrival = now;
+}
+
/*
* Adding/removing a task to/from a priority array:
*/
@@ -492,15 +567,18 @@ repeat_lock_task:
(p->cpus_allowed & (1UL << smp_processor_id())))) {
set_task_cpu(p, smp_processor_id());
+ sched_info_arrive(p);
task_rq_unlock(rq, &flags);
goto repeat_lock_task;
}
if (old_state == TASK_UNINTERRUPTIBLE)
rq->nr_uninterruptible--;
- if (sync)
+ if (sync) {
+ sched_info_arrive(p);
__activate_task(p, rq);
- else {
+ } else {
activate_task(p, rq);
+ sched_info_arrive(p);
if (p->prio < rq->curr->prio)
resched_task(rq->curr);
}
@@ -554,6 +632,7 @@ void wake_up_forked_process(task_t * p)
p->sleep_avg = p->sleep_avg * CHILD_PENALTY / 100;
p->prio = effective_prio(p);
set_task_cpu(p, smp_processor_id());
+ sched_info_arrive(p);
if (unlikely(!current->array))
__activate_task(p, rq);
@@ -715,6 +794,11 @@ unsigned long nr_iowait(void)
return sum;
}
+void cpu_sched_info(struct sched_info *info, int cpu)
+{
+ memcpy(info, &cpu_rq(cpu)->info, sizeof(struct sched_info));
+}
+
/*
* double_rq_lock - safely lock two runqueues
*
@@ -1337,6 +1421,7 @@ switch_tasks:
if (likely(prev != next)) {
rq->nr_switches++;
+ sched_info_switch(prev, next);
rq->curr = next;
prepare_arch_switch(rq, next);
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Wed Jul 23 2003 - 22:00:35 EST