On Wed, 2006-07-26 at 06:04 +1000, Dave Airlie wrote:
> I'm wondering why x86 doesn't have gettimeofday vDSO (does x86 have
> proper vDSO support at all apart from sysenter?),
I know, I'm late to the party here. :)
Anyway, i386 doesn't have vDSO gettimeofday because its always been too
messy to do. Now that the clocksource bits are in, we can start to
really work on it.
I just uploaded my C4 release of the timekeeping code here:
http://sr71.net/~jstultz/tod/broken-out/
If you grab the following patches:
linux-2.6.18-rc3_timeofday-vsyscall-support_C4.patch
linux-2.6.18-rc3_timeofday-i386-vsyscall_C4.patch
They should apply to the current -git tree and then you can use the
following test to see an LD_PRELOAD demo (as real support needs glibc
changes).
http://sr71.net/~jstultz/tod/vsyscall-gtod_test_C4.tar.bz2
Only lightly tested, so beware, and I've only added support so far for
the TSC (so don't be surprised if you don't see a performance
improvement if you using a different clocksource).
thanks
-john
john stultz wrote:
>
> Only lightly tested, so beware, and I've only added support so far for
> the TSC (so don't be surprised if you don't see a performance
> improvement if you using a different clocksource).
>
We should be able to use HPET in userspace, too.
-hpa
On Tue, 2006-08-01 at 21:26 -0700, H. Peter Anvin wrote:
> john stultz wrote:
> >
> > Only lightly tested, so beware, and I've only added support so far for
> > the TSC (so don't be surprised if you don't see a performance
> > improvement if you using a different clocksource).
> >
>
> We should be able to use HPET in userspace, too.
Oh yes, HPET and Cyclone as well. It just requires mapping their mmio
page as user readable. I just haven't gotten to it yet. :)
-john