Re: [PATCH RFC] tick/nohz: fix data races in get_cpu_idle_time_us()

[Peter Zijlstra]

On Tue, Jan 31, 2023 at 09:35:39PM +0300, Alexey Dobriyan wrote:

> > Seriously this procfs accuracy is the least of the problems and if this
> > would be the only issue then we could trivially fix it by declaring that
> > the procfs output might go backwards.
> 
> Declarations on l-k are meaningless.

Not really, we often do the -EWONTFIX thing.

> > If there would be a real reason to ensure monotonicity there then we could
> > easily do that in the readout code.
> 
> People expect it to be monotonic. I wrote this test fully expecting
> that /proc/uptime is monotonic. It didn't ever occured to me that
> idletime can go backwards (nor uptime, but uptime is not buggy).

People want ponies too -- people will just have to cope with not having
ponies.