[Xen-devel] [PATCH] Initialize state_entry_time to zero for all idle vcpus

["Tian, Kevin" <kevin.tian@xxxxxxxxx>]

Initialize state_entry_time to zero for all idle vcpus

NOW() is not usable since xen time sub-system hasn't
been initialized yet. On my box, it gives a initial 
stamp ~60s due to local tsc stamp as zero and TSC
count is started from power on. Then a negative value
is added to runstate of that idle vcpu at schedule
point. The net effect is for some tool like xenpm 
to show a big idle time gap between BSP and other APs.

Signed-off-by Kevin Tian <kevin.tian@xxxxxxxxx>

diff -r bf41be7bddea xen/common/domain.c
--- a/xen/common/domain.c       Mon Dec 01 14:46:11 2008 -0500
+++ b/xen/common/domain.c       Tue Dec 09 20:56:23 2008 -0500
@@ -135,7 +135,8 @@
     v->vcpu_id = vcpu_id;
 
     v->runstate.state = is_idle_vcpu(v) ? RUNSTATE_running : RUNSTATE_offline;
-    v->runstate.state_entry_time = NOW();
+    /* Don't use NOW() before xen time sub-system is intialized */
+    v->runstate.state_entry_time = is_idle_vcpu(v) ? 0 : NOW();
 
     spin_lock_init(&v->virq_lock);

Attachment: idle_runstate.patch
Description: idle_runstate.patch

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