Avi, the below fixes it for me..

---
Subject: sched_clock: fix NOHZ interaction
From: Peter Zijlstra <[EMAIL PROTECTED]>
Date: Mon Sep 01 16:44:23 CEST 2008

If HLT stops the TSC, we'll fail to account idle time, thereby inflating the
actual process times. Fix this by re-calibrating the clock against GTOD when 
leaving nohz mode.

Signed-off-by: Peter Zijlstra <[EMAIL PROTECTED]>
---
 kernel/time/tick-sched.c |    3 +++
 1 file changed, 3 insertions(+)

Index: linux-2.6/kernel/time/tick-sched.c
===================================================================
--- linux-2.6.orig/kernel/time/tick-sched.c
+++ linux-2.6/kernel/time/tick-sched.c
@@ -162,6 +162,8 @@ void tick_nohz_stop_idle(int cpu)
                ts->idle_lastupdate = now;
                ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta);
                ts->idle_active = 0;
+
+               sched_clock_idle_wakeup_event(0);
        }
 }
 
@@ -177,6 +179,7 @@ static ktime_t tick_nohz_start_idle(stru
        }
        ts->idle_entrytime = now;
        ts->idle_active = 1;
+       sched_clock_idle_sleep_event();
        return now;
 }
 


--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to