On Sat, 25 Feb 2017, Peter Zijlstra wrote:
> On Sat, Feb 25, 2017 at 04:10:37PM +0800, Tan Xiaojun wrote:
>
> > 2)If it is, where we will fix it more appropriate, perf_fuzzer(not set
> > 0 or 100) or kernel(limit 1 to 99), or maybe it is the bug of
> > hardware(too many hardware interruptions)?
>
> I think the best would be if the fuzzer would not set 0,100, those are
> clearly 'unsafe' settings and you pretty much get to keep the pieces.
>
> I would like to preserve these settings for people that 'know' what
> they're doing and are willing to take the risk, but clearly, when you
> take the guard-rails off, things can come apart.
sorry for the delay responding, these e-mails ended up in the spam folder
somehow.
I could add a new "avoid stupid things as root" flag for the perf_fuzzer.
Besides this issue, are there other known things to skip?
Generally running a fuzzer as root can be a bad idea which is why I don't
test that use case very often.
I think there were other issues in the past, like certain ftrace
combinations being known to lock the system.
Vince
On 2017/3/14 2:35, Vince Weaver wrote:
> On Sat, 25 Feb 2017, Peter Zijlstra wrote:
>
>> On Sat, Feb 25, 2017 at 04:10:37PM +0800, Tan Xiaojun wrote:
>>
>>> 2)If it is, where we will fix it more appropriate, perf_fuzzer(not set
>>> 0 or 100) or kernel(limit 1 to 99), or maybe it is the bug of
>>> hardware(too many hardware interruptions)?
>>
>> I think the best would be if the fuzzer would not set 0,100, those are
>> clearly 'unsafe' settings and you pretty much get to keep the pieces.
>>
>> I would like to preserve these settings for people that 'know' what
>> they're doing and are willing to take the risk, but clearly, when you
>> take the guard-rails off, things can come apart.
>
> sorry for the delay responding, these e-mails ended up in the spam folder
> somehow.
>
> I could add a new "avoid stupid things as root" flag for the perf_fuzzer.
>
> Besides this issue, are there other known things to skip?
>
> Generally running a fuzzer as root can be a bad idea which is why I don't
> test that use case very often.
> I think there were other issues in the past, like certain ftrace
> combinations being known to lock the system.
>
> Vince
>
It would be better if you could add such a flag to the perf_fuzzer. And I
have not found any other problems yet.
By the way. Use Non-root user to test is OK, and they do not have permission
to configure these parameters.
Thank you for your reply.
Xiaojun.
> .
>