Messages in this thread | | | Date | Tue, 28 May 2013 17:18:01 -0700 | From | John Stultz <> | Subject | Re: [PATCH 1/3] x86: increase precision of x86_platform.get/set_wallclock() |
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On 05/13/2013 10:56 AM, David Vrabel wrote: > From: David Vrabel <david.vrabel@citrix.com> > > All the virtualized platforms (KVM, lguest and Xen) have persistent > wallclocks that have more than one second of precision. > > read_persistent_wallclock() and update_persistent_wallclock() allow > for nanosecond precision but their implementation on x86 with > x86_platform.get/set_wallclock() only allows for one second precision. > This means guests may see a wallclock time that is off by up to 1 > second. > > Make set_wallclock() and get_wallclock() take a struct timespec > parameter (which allows for nanosecond precision) so KVM and Xen > guests may start with a more accurate wallclock time and a Xen dom0 > can maintain a more accurate wallclock for guests. > > Signed-off-by: David Vrabel <david.vrabel@citrix.com> > --- > arch/x86/include/asm/mc146818rtc.h | 4 ++-- > arch/x86/include/asm/x86_init.h | 6 ++++-- > arch/x86/kernel/kvmclock.c | 9 +++------ > arch/x86/kernel/rtc.c | 17 +++++++---------- > arch/x86/lguest/boot.c | 4 ++-- > arch/x86/platform/efi/efi.c | 10 ++++++---- > arch/x86/xen/time.c | 19 ++++++------------- > include/linux/efi.h | 4 ++--
Just FYI, David: You missed the vrtc code with this conversion.
I finally got around to pushing my current queue to my public tree and the kbuild robot noticed the build failure (required INTEL_MID config to trigger).
The fix I've queued is here: https://git.linaro.org/gitweb?p=people/jstultz/linux.git;a=commitdiff;h=52d8e9cc6718ae9e6c44b7723028e4717ba91c8b;hp=1dd5234774b33a17743ae62e8b46b5cd0059e1c7
Let me know if you have any objection or comments on this.
thanks -john
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