This is another way to compute guest time... I remove the "account modifiers"
mechanism and call directly account_guest_time() from account_system_time().
account_system_time() computes user, system and guest times according value
accumulated in vtime (a ktime_t) in task_struct by the virtual machine.
-- 
------------- [EMAIL PROTECTED]  --------------
          "Software is hard" - Donald Knuth
Index: kvm/include/linux/sched.h
===================================================================
--- kvm.orig/include/linux/sched.h      2007-08-17 10:18:53.000000000 +0200
+++ kvm/include/linux/sched.h   2007-08-17 12:33:22.000000000 +0200
@@ -1192,6 +1192,9 @@
 #ifdef CONFIG_FAULT_INJECTION
        int make_it_fail;
 #endif
+#ifdef CONFIG_GUEST_ACCOUNTING
+       ktime_t vtime;
+#endif
 };
 
 /*
Index: kvm/kernel/sched.c
===================================================================
--- kvm.orig/kernel/sched.c     2007-08-17 10:18:53.000000000 +0200
+++ kvm/kernel/sched.c  2007-08-17 12:33:07.000000000 +0200
@@ -3233,6 +3233,37 @@
                cpustat->user = cputime64_add(cpustat->user, tmp);
 }
 
+#ifdef CONFIG_GUEST_ACCOUNTING
+/*
+ * Account guest time to a process
+ * @p: the process that the cpu time gets accounted to
+ * @cputime: the cpu time spent in kernel space since the last update
+ */
+
+static cputime_t account_guest_time(struct task_struct *p, cputime_t cputime)
+{
+       struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
+       ktime_t kmsec = ktime_set(0, NSEC_PER_MSEC);
+       cputime_t cmsec = msecs_to_cputime(1);
+
+       while ((ktime_to_ns(p->vtime) >= NSEC_PER_MSEC) &&
+               (cputime_to_msecs(cputime) >= 1)) {
+               p->vtime = ktime_sub(p->vtime, kmsec);
+               p->utime = cputime_add(p->utime, cmsec);
+               p->gtime = cputime_add(p->gtime, cmsec);
+
+               cpustat->guest = cputime64_add(cpustat->guest,
+                               cputime_to_cputime64(cmsec));
+               cpustat->user = cputime64_add(cpustat->user,
+               cputime_to_cputime64(cmsec));
+
+               cputime = cputime_sub(cputime, cmsec);
+       }
+
+       return cputime;
+}
+#endif
+
 /*
  * Account system cpu time to a process.
  * @p: the process that the cpu time gets accounted to
@@ -3246,6 +3277,10 @@
        struct rq *rq = this_rq();
        cputime64_t tmp;
 
+#ifdef CONFIG_GUEST_ACCOUNTING
+       cputime = account_guest_time(p, cputime);
+#endif
+
        p->stime = cputime_add(p->stime, cputime);
 
        /* Add system time to cpustat. */
_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linux-foundation.org/mailman/listinfo/virtualization

Reply via email to