Re: [RESEND PATCH 0/5] perf core: Support overwrite ring buffer

Ingo Molnar
2016-03-08T17:37:21Z

* Dmitry Vyukov <dvyukov@google.com> wrote:

> > fomalhaut:~/go/src/github.com/google/syzkaller> ps aux | grep -i syz
> > mingo 1374 0.0 0.0 118476 2376 pts/2 S+ 18:23 0:00 grep --color=auto -i syz
> >
> > and with no kernel messages in dmesg - and with a fully functional system.
> >
> > I'm running the 16-task load on a 120 CPU system - should I increase it to 120?
> > Does the code expect to saturate the system?
>
> No, it does not expect to saturate the system. Set "procs" to 480, or
> something like that.

Does not seem to help much:

fomalhaut:~> vmstat 10
procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu-----
r b swpd free buff cache si so bi bo in cs us sy id wa st

1 0 0 257465904 219940 4736092 0 0 0 102 16022 4396 0 1 99 0 0
2 0 0 257452144 220496 4755052 0 0 2 3649 14286 4627 0 1 99 0 0
2 0 0 257473408 221188 4770824 0 0 15 1898 17175 4474 0 1 99 0 0

Only around 1% system utilization. Should I go for 1,000 or more? :)

Peter, do you experience with running syz-kaller on larger CPU count Intel
systems?

Thanks,

Ingo