Re: [PATCH] do_gettimeofday() fails to compensate for lost ticks

Jesse Barnes
2003-09-24T18:21:51Z

On Wed, Sep 24, 2003 at 12:17:41PM -0600, Khalid Aziz wrote:
> > This explanation doesn't sound right. See the "lost" variable in
> > gettimeoffset(). It's supposed to account for lost ticks.
> >
> > --david
>
> David,
>
> So it would seem. What would then explain clock going backwards? Here is
> what I see when the test fails:
>
> tpget\x1037128357,995121000, tpset\x1037128358,0
>
> where tpget is what was returned by gettimeofday() and tpset is what was
> set by settimeofday(). Clock seems to have moved back by 4.879 msec.

Just FYI, Martin Hicks noticed recently that 2.6 on a machine with itc
drift also has this problem. I think John Hawkes has some ideas on how
to fix it, but I haven't had time to look at it yet.

Thanks,
Jesse