# HG changeset patch
# User awilliam@xxxxxxxxxxxx
# Date 1173713999 21600
# Node ID 9ea0c5f469c871f3b6a387a61555a725cecdd1b6
# Parent 800f7904d6a4a3f5c0deaaa444289dff139ad610
[IA64] PV steal time accounting
Signed-off-by: Atsushi SAKAI <sakaia@xxxxxxxxxxxxxx>
---
linux-2.6-xen-sparse/arch/ia64/kernel/time.c | 131 +++++++++++++++++++++++++++
1 files changed, 131 insertions(+)
diff -r 800f7904d6a4 -r 9ea0c5f469c8
linux-2.6-xen-sparse/arch/ia64/kernel/time.c
--- a/linux-2.6-xen-sparse/arch/ia64/kernel/time.c Mon Mar 12 08:43:56
2007 -0600
+++ b/linux-2.6-xen-sparse/arch/ia64/kernel/time.c Mon Mar 12 09:39:59
2007 -0600
@@ -29,6 +29,13 @@
#include <asm/sections.h>
#include <asm/system.h>
+#ifdef CONFIG_XEN
+#include <linux/kernel_stat.h>
+#include <linux/posix-timers.h>
+#include <xen/interface/vcpu.h>
+#include <asm/percpu.h>
+#endif
+
extern unsigned long wall_jiffies;
volatile int time_keeper_id = 0; /* smp_processor_id() of time-keeper */
@@ -38,6 +45,13 @@ unsigned long last_cli_ip;
unsigned long last_cli_ip;
EXPORT_SYMBOL(last_cli_ip);
+#endif
+
+#ifdef CONFIG_XEN
+DEFINE_PER_CPU(struct vcpu_runstate_info, runstate);
+DEFINE_PER_CPU(unsigned long, processed_stolen_time);
+DEFINE_PER_CPU(unsigned long, processed_blocked_time);
+#define NS_PER_TICK (1000000000LL/HZ)
#endif
static struct time_interpolator itc_interpolator = {
@@ -46,10 +60,96 @@ static struct time_interpolator itc_inte
.source = TIME_SOURCE_CPU
};
+#ifdef CONFIG_XEN
+static unsigned long
+consider_steal_time(unsigned long new_itm, struct pt_regs *regs)
+{
+ unsigned long stolen, blocked, sched_time;
+ unsigned long delta_itm = 0, stolentick = 0;
+ int i, cpu = smp_processor_id();
+ struct vcpu_runstate_info *runstate;
+ struct task_struct *p = current;
+
+ runstate = &per_cpu(runstate, smp_processor_id());
+
+ do {
+ sched_time = runstate->state_entry_time;
+ mb();
+ stolen = runstate->time[RUNSTATE_runnable] +
+ runstate->time[RUNSTATE_offline] -
+ per_cpu(processed_stolen_time, cpu);
+ blocked = runstate->time[RUNSTATE_blocked] -
+ per_cpu(processed_blocked_time, cpu);
+ mb();
+ } while (sched_time != runstate->state_entry_time);
+
+ /*
+ * Check for vcpu migration effect
+ * In this case, itc value is reversed.
+ * This causes huge stolen value.
+ * This function just checks and reject this effect.
+ */
+ if (!time_after_eq(runstate->time[RUNSTATE_blocked],
+ per_cpu(processed_blocked_time, cpu)))
+ blocked = 0;
+
+ if (!time_after_eq(runstate->time[RUNSTATE_runnable] +
+ runstate->time[RUNSTATE_offline],
+ per_cpu(processed_stolen_time, cpu)))
+ stolen = 0;
+
+ if (!time_after(delta_itm + new_itm, ia64_get_itc()))
+ stolentick = ia64_get_itc() - delta_itm - new_itm;
+
+ do_div(stolentick, NS_PER_TICK);
+ stolentick++;
+
+ do_div(stolen, NS_PER_TICK);
+
+ if (stolen > stolentick)
+ stolen = stolentick;
+
+ stolentick -= stolen;
+ do_div(blocked, NS_PER_TICK);
+
+ if (blocked > stolentick)
+ blocked = stolentick;
+
+ if (stolen > 0 || blocked > 0) {
+ account_steal_time(NULL, jiffies_to_cputime(stolen));
+ account_steal_time(idle_task(cpu),
jiffies_to_cputime(blocked));
+ run_local_timers();
+
+ if (rcu_pending(cpu))
+ rcu_check_callbacks(cpu, user_mode(regs));
+
+ scheduler_tick();
+ run_posix_cpu_timers(p);
+ delta_itm += local_cpu_data->itm_delta * (stolen + blocked);
+
+ if (cpu == time_keeper_id) {
+ write_seqlock(&xtime_lock);
+ for(i = 0; i < stolen + blocked; i++)
+ do_timer(regs);
+ local_cpu_data->itm_next = delta_itm + new_itm;
+ write_sequnlock(&xtime_lock);
+ } else {
+ local_cpu_data->itm_next = delta_itm + new_itm;
+ }
+ per_cpu(processed_stolen_time,cpu) += NS_PER_TICK * stolen;
+ per_cpu(processed_blocked_time,cpu) += NS_PER_TICK * blocked;
+ }
+ return delta_itm;
+}
+#else
+#define consider_steal_time(new_itm, regs) (0)
+#endif
+
static irqreturn_t
timer_interrupt (int irq, void *dev_id, struct pt_regs *regs)
{
unsigned long new_itm;
+ unsigned long delta_itm; /* XEN */
if (unlikely(cpu_is_offline(smp_processor_id()))) {
return IRQ_HANDLED;
@@ -64,6 +164,13 @@ timer_interrupt (int irq, void *dev_id,
ia64_get_itc(), new_itm);
profile_tick(CPU_PROFILING, regs);
+
+ if (is_running_on_xen()) {
+ delta_itm = consider_steal_time(new_itm, regs);
+ new_itm += delta_itm;
+ if (time_after(new_itm, ia64_get_itc()) && delta_itm)
+ goto skip_process_time_accounting;
+ }
while (1) {
update_process_times(user_mode(regs));
@@ -87,6 +194,8 @@ timer_interrupt (int irq, void *dev_id,
if (time_after(new_itm, ia64_get_itc()))
break;
}
+
+skip_process_time_accounting: /* XEN */
do {
/*
@@ -142,6 +251,25 @@ static int __init nojitter_setup(char *s
__setup("nojitter", nojitter_setup);
+#ifdef CONFIG_XEN
+/* taken from i386/kernel/time-xen.c */
+static void init_missing_ticks_accounting(int cpu)
+{
+ struct vcpu_register_runstate_memory_area area;
+ struct vcpu_runstate_info *runstate = &per_cpu(runstate, cpu);
+
+ memset(runstate, 0, sizeof(*runstate));
+
+ area.addr.v = runstate;
+ HYPERVISOR_vcpu_op(VCPUOP_register_runstate_memory_area, cpu, &area);
+
+ per_cpu(processed_blocked_time, cpu) = runstate->time[RUNSTATE_blocked];
+ per_cpu(processed_stolen_time, cpu) = runstate->time[RUNSTATE_runnable]
+ + runstate->time[RUNSTATE_offline];
+}
+#else
+#define init_missing_ticks_accounting(cpu) do {} while (0)
+#endif
void __devinit
ia64_init_itm (void)
@@ -225,6 +353,9 @@ ia64_init_itm (void)
register_time_interpolator(&itc_interpolator);
}
+ if (is_running_on_xen())
+ init_missing_ticks_accounting(smp_processor_id());
+
/* Setup the CPU local timer tick */
ia64_cpu_local_tick();
}
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