From: Keir Fraser <keir.fraser@citrix.com>
Date: Wed, 1 Apr 2009 14:39:20 +0000 (+0100)
Subject: Only set scheduler quantum timer for non-idle VCPUs
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~13989^2~16
X-Git-Url: https://dgit.raspbian.org/%22http:/www.example.com/cgi/%22https:/%22bookmarks://%22/%22http:/www.example.com/cgi/%22https:/%22bookmarks:/%22?a=commitdiff_plain;h=ea78378d2cb685b6fa3897a91435c36235b75446;p=xen.git

Only set scheduler quantum timer for non-idle VCPUs

This removes the last idle periodic timer in xen, and enhances the
idle average C state residency from two-digits ms  to three-digit ms.

Signed-off-by: Yu Ke <ke.yu@intel.com>
Signed-off-by: Tian Kevin <kevin.tian@intel.com>
---

diff --git a/xen/common/schedule.c b/xen/common/schedule.c
index f1121938da..23807ea330 100644
--- a/xen/common/schedule.c
+++ b/xen/common/schedule.c
@@ -818,8 +818,9 @@ static void schedule(void)
     next = next_slice.task;
 
     sd->curr = next;
-    
-    set_timer(&sd->s_timer, now + r_time);
+
+    if ( !is_idle_vcpu(next) )
+        set_timer(&sd->s_timer, now + r_time);
 
     if ( unlikely(prev == next) )
     {