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

Peter Zijlstra
2016-03-08T16:31:13Z

On Tue, Mar 08, 2016 at 05:27:03PM +0100, Ingo Molnar wrote:
> > > triton:~/go/src/github.com/google/syzkaller> cat perf.cfg
> > > {
> > > "http": "localhost:50000",
> > > "workdir": "/home/mingo/go/src/github.com/google/syzkaller/workdir",
> > > "syzkaller": "/home/mingo/go/src/github.com/google/syzkaller",
> > > "vmlinux": "-",
> > > "type": "local",
> > > "count": 1,
> > > "procs": 16,
> > > "nocover": true,

this^^^

> I now get periodic output of:
>
> fomalhaut:~/go/src/github.com/google/syzkaller> bin/syz-manager -config src/github.com/google/syzkaller/perf.cfg
> 2016/03/08 17:24:07 failed to read config file: open src/github.com/google/syzkaller/perf.cfg: no such file or directory
> fomalhaut:~/go/src/github.com/google/syzkaller> bin/syz-manager -config perf.cfg
> 2016/03/08 17:24:19 loading corpus...
> 2016/03/08 17:24:19 loaded 0 programs
> 2016/03/08 17:24:19 serving http on http://localhost:50000
> 2016/03/08 17:24:19 serving rpc on tcp://127.0.0.1:37006
> 2016/03/08 17:24:34 local-0: saving crash 'BUG: /sys/kernel/debug/kcov is missing (permission denied). Enable CONFIG_KCOV and mount debugfs.' to crash-local-0-1457454274467286949
> 2016/03/08 17:24:34 local-0: lost connection: exit status 1

> is CONFIG_KCOV=y a must-have feature? There's no KCOV support upstream that I can
> see.

Should have disabled that.