Re: [PATCH 10/10] sched/fair: Implement an EEVDF like policy

[Mike Galbraith]

On Wed, 2023-03-08 at 14:36 +0100, Mike Galbraith wrote:
>
> Remember this little bugger, allegedly distilled from a real
> application control thread starvation issue?
>
> 6.3.0.g8ca09d5-master
> homer:/root # time taskset -c 3 starve      
> expecting to receive 10000000 signals
>
> real    0m24.424s
> user    0m4.468s
> sys     0m18.957s
>
> 6.3.0.g8ca09d5-eevdf
> homer:/root # time taskset -c 3 starve
> expecting to receive 10000000 signals
> zzzzzz
> ^C

Ok, seems there must be a math booboo lurking.

virgin source, 100% hog vs tbench buddy pair, all pinned.

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ P COMMAND
 5060 root      20   0    4420    680    680 R 96.01 0.004   0:41.40 3 cpuhog
 5058 root      20   0   25500   1920   1792 S 2.326 0.012   0:01.05 3 tbench
 5059 root      20   0    8796    896    768 R 1.661 0.006   0:00.78 3 tbench_srv

echo NO_PRESERVE_LAG > features

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ P COMMAND
 5060 root      20   0    4420    680    680 R 99.33 0.004   1:28.24 3 cpuhog
 5058 root      20   0   25500   1920   1792 R 0.333 0.012   0:01.75 3 tbench
 5059 root      20   0    8796    896    768 S 0.333 0.006   0:01.30 3 tbench_srv