From c9aaa8957f203bd6df83b002fb40b98390bed078 Mon Sep 17 00:00:00 2001 From: Glauber Costa Date: Mon, 11 Jul 2011 15:28:14 -0400 Subject: KVM: Steal time implementation To implement steal time, we need the hypervisor to pass the guest information about how much time was spent running other processes outside the VM, while the vcpu had meaningful work to do - halt time does not count. This information is acquired through the run_delay field of delayacct/schedstats infrastructure, that counts time spent in a runqueue but not running. Steal time is a per-cpu information, so the traditional MSR-based infrastructure is used. A new msr, KVM_MSR_STEAL_TIME, holds the memory area address containing information about steal time This patch contains the hypervisor part of the steal time infrasructure, and can be backported independently of the guest portion. [avi, yongjie: export delayacct_on, to avoid build failures in some configs] Signed-off-by: Glauber Costa Tested-by: Eric B Munson CC: Rik van Riel CC: Jeremy Fitzhardinge CC: Peter Zijlstra CC: Anthony Liguori Signed-off-by: Yongjie Ren Signed-off-by: Avi Kivity --- kernel/delayacct.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'kernel/delayacct.c') diff --git a/kernel/delayacct.c b/kernel/delayacct.c index ead9b610aa71..418b3f7053aa 100644 --- a/kernel/delayacct.c +++ b/kernel/delayacct.c @@ -19,8 +19,10 @@ #include #include #include +#include int delayacct_on __read_mostly = 1; /* Delay accounting turned on/off */ +EXPORT_SYMBOL_GPL(delayacct_on); struct kmem_cache *delayacct_cache; static int __init delayacct_setup_disable(char *str) -- cgit v1.2.3-59-g8ed1b