Re: [PATCH 4/4] sched/core: split iowait state into two states

[Rafael J. Wysocki]

On Wednesday, April 24, 2024 12:01:27 PM CEST Peter Zijlstra wrote:
> On Tue, Apr 16, 2024 at 06:11:21AM -0600, Jens Axboe wrote:
> > iowait is a bogus metric, but it's helpful in the sense that it allows
> > short waits to not enter sleep states that have a higher exit latency
> > than would've otherwise have been picked for iowait'ing tasks. However,
> > it's harmless in that lots of applications and monitoring assumes that
> > iowait is busy time, or otherwise use it as a health metric.
> > Particularly for async IO it's entirely nonsensical.
> 
> Let me get this straight, all of this is about working around
> cpuidle menu governor insaity?
> 
> Rafael, how far along are we with fully deprecating that thing? Yes it
> still exists, but should people really be using it still?

Well, they appear to be used to it ...