Re: iowait v.s. idle accounting is "inconsistent" - iowait is too low

2019-07-05 Thread Alan Jenkins
On 05/07/2019 12:38, Peter Zijlstra wrote: On Fri, Jul 05, 2019 at 12:25:46PM +0100, Alan Jenkins wrote: Hi, scheduler experts! My cpu "iowait" time appears to be reported incorrectly.  Do you know why this could happen? Because iowait is a magic random number that has no sane meaning. Persona

Re: iowait v.s. idle accounting is "inconsistent" - iowait is too low

2019-07-05 Thread Peter Zijlstra
On Fri, Jul 05, 2019 at 12:25:46PM +0100, Alan Jenkins wrote: > Hi, scheduler experts! > > My cpu "iowait" time appears to be reported incorrectly.  Do you know why > this could happen? Because iowait is a magic random number that has no sane meaning. Personally I'd prefer to just delete the whol

Re: iowait v.s. idle accounting is "inconsistent" - iowait is too low

2019-07-05 Thread Alan Jenkins
Hi, scheduler experts! My cpu "iowait" time appears to be reported incorrectly.  Do you know why this could happen? Doug helped me - it was he who noticed different behaviour on v4.15 vs v4.16 vs v4.17+.  So I have some confirmation of this.  I don't think Doug mentioned what hardware he ran