Glommer at 18:02, 29 September 2010

2010-09-29T18:02:05Z

← Older revision		Revision as of 14:02, 29 September 2010
Line 16:		Line 16:
	* make sure successive gettimeofday calls never go backwards (testing this can take days)		* make sure successive gettimeofday calls never go backwards (testing this can take days)
	* make sure that calls to different time sources (like gettimeofday and monotonic) do not deviate too much, nor go backwards.		* make sure that calls to different time sources (like gettimeofday and monotonic) do not deviate too much, nor go backwards.

			=== Note ===

			Older Linux guests with backported versions of kvmclock may need different ways to check for kvmclock. This is due to the fact that those guests might lack total support for the clocksource subsystem

			* RHEL/CentOS 5.x: for the x86_64 version, the "current_clocksource" file exists, but will always return "jiffies", no matter what. One should search for "KVM" in dmesg \| grep time.c

Glommer at 13:42, 19 January 2010

2010-01-19T13:42:18Z

New page

= KVM PVclock =

Linux guests only.

== Testing ==

You can verify kvm-clock is enable by checking

/sys/devices/system/clocksource/clocksource0/current_clocksource

Output should say "kvm-clock"

Some basic mechanism to make sure it works:

* Try guests without kvm-clock too. Make sure they at least boot
* make sure successive gettimeofday calls never go backwards (testing this can take days)
* make sure that calls to different time sources (like gettimeofday and monotonic) do not deviate too much, nor go backwards.

KVMClock - Revision history

Glommer at 18:02, 29 September 2010

Glommer at 13:42, 19 January 2010