On 09/01/2009 02:50 PM, Glauber Costa wrote:
KVM clock is great to avoid drifting in guest VMs running ontop of kvm.
However, the current mechanism will not propagate changes in wallclock value
upwards. This effectively means that in a large pool of VMs that need accurate
timing,
all of them has to run NTP, instead of just the host doing it.
Since the host updates information in the shared memory area upon msr writes,
this patch introduces a worker that writes to that msr, and calls
do_settimeofday
at fixed intervals, with second resolution. A interval of 0 determines that we
are not interested in this behaviour. A later patch will make this optional at
runtime
+
+static void kvm_sync_wall_clock(struct work_struct *work)
+{
+ struct timespec now;
+
+ kvm_get_wall_ts(&now);
What happens if we schedule here?
+
+ do_settimeofday(&now);
+ schedule_next_update();
+}
+
+static __init int init_updates(void)
+{
+ schedule_next_update();
+ return 0;
+}
+/*
+ * It has to be run after workqueues are initialized, since we call
+ * schedule_delayed_work. Other than that, we have no specific requirements
+ */
+late_initcall(init_updates);
Should this run on bare metal too?
--
error compiling committee.c: too many arguments to function
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
