Re: Unified tracing buffer

[Martin Bligh]

>> I think the tolerance is about 500 cycles. If that's not sufficient, I guess
>> we'll have to either live with some slight misordering (which people have
>> pointed out is kind of inevitable anyway) on these broken machines?
>> It was sufficient for what we were using it for, but maybe not for everyone.
>
> Well, I dont care about the trace reordering at all. I care about user
> space visible time going backwards issues observed via the
> gettimeofday vsyscall. 500 cycles should be fine, I doubt that we can
> migrate in less than that :)

Right, that's what we were interested in.

> I guess you try this only for machines where the TSC runs with
> constant frequency, right ?

We don't do DVFS on the 'broken' TSC machines, just halt.
But yes, it's selective
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/