Update clock() syscall to keep track of effective cpu time

davxy · Dec 15, 2018 · bdd9b2a · bdd9b2a
1 parent 07764cd
commit bdd9b2a
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Showing 8 changed files with 24 additions and 13 deletions.
diff --git a/kernel/src/proc/scheduler.c b/kernel/src/proc/scheduler.c
@@ -84,10 +84,12 @@ int do_signal(void)
     return 0;
 }
 
+
 void scheduler(void)
 {
     struct task *curr;
     struct task *next;
+    static clock_t prev_clock;
 
     curr = current;
     next = list_container(current->tasks.next,
@@ -102,6 +104,10 @@ void scheduler(void)
         next = &ktask;
     }
 
+    /* Update CPU usage statistics */
+    current->usage += (timer_ticks - prev_clock);
+    prev_clock = timer_ticks;
+
     current = next;
     current->counter = msecs_to_ticks(SCHED_TIMESLICE);
 

diff --git a/kernel/src/proc/task.c b/kernel/src/proc/task.c
@@ -77,6 +77,7 @@ int task_init(struct task *tsk, task_entry_t entry)
     tsk->brk = current->brk;
 
     /* sheduler */
+    tsk->usage = 0;
     tsk->state = TASK_RUNNING;
     tsk->counter = msecs_to_ticks(SCHED_TIMESLICE);
     tsk->exit_code = 0;

diff --git a/kernel/src/proc/task.h b/kernel/src/proc/task.h
@@ -66,6 +66,7 @@ struct task {
     struct timer_event  alarm;          /**< Alarm timer event (pre-allocated) */
     struct list_link    condw;          /**< Conditional wait */
     dev_t               tty;            /**< Controlling terminal */
+    clock_t             usage;          /**< CPU time in clock ticks */
 };
 
 

diff --git a/kernel/src/sys/sys_clock.c b/kernel/src/sys/sys_clock.c
@@ -18,9 +18,9 @@
  */
 
 #include "sys.h"
-#include "timer.h"
+#include "proc.h"
 
 unsigned int sys_clock(void)
 {
-    return (unsigned int)timer_ticks;
+    return (unsigned int)current->usage;
 }
diff --git a/kernel/src/timer.c b/kernel/src/timer.c
@@ -20,7 +20,7 @@
 #include "timer.h"
 #include "proc.h"
 
-unsigned long timer_ticks = 0;
+clock_t timer_ticks = 0;
 
 /* Timer events queue. */
 static struct list_link timer_events;

diff --git a/kernel/src/timer.h b/kernel/src/timer.h
@@ -26,12 +26,11 @@
 
 
 /* Clock ticks since system startup. */
-extern unsigned long timer_ticks;
+extern clock_t timer_ticks;
 
 /** Converts milliseconds to clock ticks. */
 #define msecs_to_ticks(msecs) \
-        (((unsigned long)(msecs) + \
-                (1000L / CLOCKS_PER_SEC) - 1) / (1000L / CLOCKS_PER_SEC))
+        (((unsigned long)(msecs) + (1000L / CLOCKS_PER_SEC) - 1) / (1000L / CLOCKS_PER_SEC))
 
 #define ticks_to_msecs(ticks) \
         ((1000L / CLOCKS_PER_SEC) * (unsigned long)(ticks))

diff --git a/libc/include/time.h b/libc/include/time.h
@@ -28,11 +28,6 @@ struct timespec {
     long    tv_nsec;    /**> Nanoseconds */
 };
 
-/*
- * The macro `CLOCKS_PER_SEC' is an expression with type `clock_t' that is
- * the number per second of the value returned by the `clock' function.
- * The value of CLOCKS_PER_SEC is required to be 1 million on all XSI systems.
- */
 #define CLOCKS_PER_SEC ((clock_t) 100)
 
 clock_t clock(void);

diff --git a/user/src/test/sleep.c b/user/src/test/sleep.c
@@ -23,9 +23,18 @@
 
 int main(void)
 {
+    clock_t prev;
+
+    prev = clock();
     while (1) {
-        printf("Hello from %d (%u)\n", getpid(), clock());
-        sleep(1);
+        if ((clock() - prev)/CLOCKS_PER_SEC >= 3) {
+            printf("\n");
+            printf("Going to sleep...(cpu time: ~%u)\n",
+                    clock()/ CLOCKS_PER_SEC);
+            prev = clock();
+            sleep(3);
+        }
+        printf(".");
     }
     return 0;
 }