commit 102301d1eae7e80c7309e80cf107f243dc989332
author Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Mon Jan 23 14:21:20 2012 -0500
committer Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Tue Mar 20 16:43:42 2012 -0400
tree ad9659462a0db0f48317a0e34576a7308262e5be
parent fd58226eed0d2becbd8cd52e6cb7ce9b1e3e9b36

xen/time: Use the pv_ops steal_time.

In the past we were using do_stolen_account() to update the
stolen time and this was done when by calling account_steal_ticks().

The do_stolen_account() was called from xen_timer_interrupt(). The
xen_timer_interrupt() would be called periodically (or frequently)
depending on what the timer decided. We would piggy-back on the
timer IRQ to update the steal time and idle time (fixed by
'remove blocked time accounting from xen "clockchip"' patch).

Instead of piggy-backing on the timer interrupt lets do it
via the provided API pv-ops time calls - the steal_clock.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

arch/x86/xen/time.c

diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c
index 5c4a7f8..59cdd1b 100644
--- a/arch/x86/xen/time.c
+++ b/arch/x86/xen/time.c
@@ -71,14 +71,14 @@
 /*
  * Runstate accounting
  */
-static void get_runstate_snapshot(struct vcpu_runstate_info *res)
+static void get_runstate_snapshot(struct vcpu_runstate_info *res, int cpu)
 {
 	u64 state_time;
 	struct vcpu_runstate_info *state;
 
 	BUG_ON(preemptible());
 
-	state = &__get_cpu_var(xen_runstate);
+	state = &per_cpu(xen_runstate, cpu);
 
 	/*
 	 * The runstate info is always updated by the hypervisor on
@@ -110,18 +110,18 @@
 		BUG();
 }
 
-static void do_stolen_accounting(void)
+static u64 xen_steal_clock(int cpu)
 {
 	struct vcpu_runstate_info state;
 	struct vcpu_runstate_info *snap;
 	s64 runnable, offline, stolen;
-	cputime_t ticks;
+	u64 ticks;
 
-	get_runstate_snapshot(&state);
+	get_runstate_snapshot(&state, cpu);
 
 	WARN_ON(state.state != RUNSTATE_running);
 
-	snap = &__get_cpu_var(xen_runstate_snapshot);
+	snap = &per_cpu(xen_runstate_snapshot, cpu);
 
 	/* work out how much time the VCPU has not been runn*ing*  */
 	runnable = state.time[RUNSTATE_runnable] - snap->time[RUNSTATE_runnable];
@@ -138,7 +138,8 @@
 
 	ticks = iter_div_u64_rem(stolen, NS_PER_TICK, &stolen);
 	__this_cpu_write(xen_residual_stolen, stolen);
-	account_steal_ticks(ticks);
+
+	return ticks;
 }
 
 /* Get the TSC speed from Xen */
@@ -377,8 +378,6 @@
 		ret = IRQ_HANDLED;
 	}
 
-	do_stolen_accounting();
-
 	return ret;
 }
 
@@ -439,6 +438,7 @@
 
 static const struct pv_time_ops xen_time_ops __initconst = {
 	.sched_clock = xen_clocksource_read,
+	.steal_clock = xen_steal_clock,
 };
 
 static void __init xen_time_init(void)
@@ -464,6 +464,9 @@
 	xen_setup_runstate_info(cpu);
 	xen_setup_timer(cpu);
 	xen_setup_cpu_clockevents();
+
+	jump_label_inc(&paravirt_steal_enabled);
+	jump_label_inc(&paravirt_steal_rq_enabled);
 }
 
 void __init xen_init_time_ops(void)