Messages in this thread | | | Date | Mon, 29 Nov 2021 23:22:43 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH v0.9.1 3/6] sched/umcg: implement UMCG syscalls |
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On Mon, Nov 29, 2021 at 11:07:07PM +0100, Thomas Gleixner wrote: > On Fri, Nov 26 2021 at 22:52, Peter Zijlstra wrote:
> The size is the same, i.e. 1 bit per nanosecond :)
:-)
> > The only time that's relevant though is when you're going to mix these > > timestamps with CLOCK_THREAD_CPUTIME_ID, which might just be > > interesting. > > Uuurg. If you want to go towards CLOCK_THREAD_CPUTIME_ID, that's going > to be really nasty. Actually you can sleep on that clock, but that's a > completely different universe. If anything like that is desired then we > need to rewrite that posix CPU timer muck completely with all the bells > and whistels and race conditions attached to it. *Shudder*
Oh, I wasn't thinking anything as terrible as that. Sleeping on that clock is fundamentally daft since it doesn't run when thats is sleeping, consider trying to sleep on your own runtime :-)
I was only considering combining THREAD_CPUTIME timestamps with the UMCG timestamps to compute how much unmanaged time there was, or other such things.
Anyway, lets forget I bought this up and assume that for practical purposes all [ns] are of equal length.
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