Module Name: src
Committed By: bouyer
Date: Sat Oct 22 19:26:16 UTC 2011
Modified Files:
src/sys/arch/xen/xen [cherry-xenmp]: clock.c
Log Message:
Various clock fixes:
- xen_get_timecount() is CPU specific, so get the time from this
virtual CPU and not VCPU0. Also keep xen_clock_bias per-cpu.
- The periodic timer looks buggy, we stop receiving events after a (short)
while. Linux is using the one-shoot timer so use it too (and disable
the periodic timer), but rearm it from the event handler, not idle_block()
as the later may not be called if the CPU is busy, resulting it clock
event loss.
- use HYPERVISOR_block() in idle_block() again, now that interrupts are
working properly.
To generate a diff of this commit:
cvs rdiff -u -r1.54.6.4 -r1.54.6.5 src/sys/arch/xen/xen/clock.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/xen/xen/clock.c
diff -u src/sys/arch/xen/xen/clock.c:1.54.6.4 src/sys/arch/xen/xen/clock.c:1.54.6.5
--- src/sys/arch/xen/xen/clock.c:1.54.6.4 Sun Sep 18 18:54:32 2011
+++ src/sys/arch/xen/xen/clock.c Sat Oct 22 19:26:16 2011
@@ -1,4 +1,4 @@
-/* $NetBSD: clock.c,v 1.54.6.4 2011/09/18 18:54:32 cherry Exp $ */
+/* $NetBSD: clock.c,v 1.54.6.5 2011/10/22 19:26:16 bouyer Exp $ */
/*
*
@@ -29,7 +29,7 @@
#include "opt_xen.h"
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: clock.c,v 1.54.6.4 2011/09/18 18:54:32 cherry Exp $");
+__KERNEL_RCSID(0, "$NetBSD: clock.c,v 1.54.6.5 2011/10/22 19:26:16 bouyer Exp $");
#include <sys/param.h>
#include <sys/cpu.h>
@@ -94,7 +94,7 @@ static volatile uint64_t vcpu_system_tim
* back to maintain the illusion that hardclock(9) was called when it
* was supposed to be, not when Xen got around to scheduling us.
*/
-static volatile uint64_t xen_clock_bias;
+static volatile uint64_t xen_clock_bias[MAXCPUS];
#ifdef DOM0OPS
/* If we're dom0, send our time to Xen every minute or so. */
@@ -416,9 +416,10 @@ u_int
xen_get_timecount(struct timecounter *tc)
{
uint64_t ns;
+ struct cpu_info *ci = curcpu();
mutex_enter(&tmutex);
- ns = get_system_time() - xen_clock_bias;
+ ns = get_vcpu_time(ci) - xen_clock_bias[ci->ci_cpuid];
mutex_exit(&tmutex);
return (u_int)ns;
@@ -439,12 +440,10 @@ xen_initclocks(void)
int err, evtch;
static bool tcdone = false;
- struct vcpu_set_periodic_timer hardclock_period = { NS_PER_TICK };
-
struct cpu_info *ci = curcpu();
volatile struct shadow *shadow = &ci_shadow[ci->ci_cpuid];
- xen_clock_bias = 0;
+ xen_clock_bias[ci->ci_cpuid] = 0;
evcnt_attach_dynamic(&hardclock_called[ci->ci_cpuid],
EVCNT_TYPE_INTR,
@@ -468,12 +467,19 @@ xen_initclocks(void)
}
/* The splhigh requirements start here. */
- /* Set hardclock() frequency */
- err = HYPERVISOR_vcpu_op(VCPUOP_set_periodic_timer,
+ /*
+ * The periodic timer looks buggy, we stop receiving events
+ * after a while. Use the one-shot timer every NS_PER_TICK
+ * and rearm it from the event handler.
+ */
+ err = HYPERVISOR_vcpu_op(VCPUOP_stop_periodic_timer,
ci->ci_cpuid,
- &hardclock_period);
+ NULL);
KASSERT(err == 0);
+ err = HYPERVISOR_set_timer_op(
+ vcpu_system_time[ci->ci_cpuid] + NS_PER_TICK);
+ KASSERT(err == 0);
event_set_handler(evtch, (int (*)(void *))xen_timer_handler,
ci, IPL_CLOCK, "clock");
@@ -504,25 +510,34 @@ xen_timer_handler(void *arg, struct intr
int64_t delta;
struct cpu_info *ci = curcpu();
KASSERT(arg == ci);
+ int err;
+again:
mutex_enter(&tmutex);
-
delta = (int64_t)(get_vcpu_time(ci) - vcpu_system_time[ci->ci_cpuid]);
-
mutex_exit(&tmutex);
/* Several ticks may have passed without our being run; catch up. */
while (delta >= (int64_t)NS_PER_TICK) {
mutex_enter(&tmutex);
vcpu_system_time[ci->ci_cpuid] += NS_PER_TICK;
- xen_clock_bias = (delta -= NS_PER_TICK);
+ xen_clock_bias[ci->ci_cpuid] = (delta -= NS_PER_TICK);
mutex_exit(&tmutex);
hardclock((struct clockframe *)regs);
hardclock_called[ci->ci_cpuid].ev_count++;
}
+
+ /*
+ * rearm the timer. If it fails it's probably because the date
+ * is in the past, update our local time and try again.
+ */
+ err = HYPERVISOR_set_timer_op(
+ vcpu_system_time[ci->ci_cpuid] + NS_PER_TICK);
+ if (err)
+ goto again;
- if (xen_clock_bias) {
+ if (xen_clock_bias[ci->ci_cpuid]) {
mutex_enter(&tmutex);
- xen_clock_bias = 0;
+ xen_clock_bias[ci->ci_cpuid] = 0;
mutex_exit(&tmutex);
}
@@ -537,6 +552,18 @@ setstatclockrate(int arg)
void
idle_block(void)
{
+#ifdef MULTIPROCESSOR
HYPERVISOR_yield();
__sti();
+#else
+ struct cpu_info *ci = curcpu();
+ int r;
+
+ r = HYPERVISOR_set_timer_op(
+ vcpu_system_time[ci->ci_cpuid] + NS_PER_TICK);
+ if (r == 0)
+ HYPERVISOR_block();
+ else
+ __sti();
+#endif
}
