Re: [discuss] Re: 2.6.19-rc5: known regressions (v3)

[ebiederm@xmission.com (Eric W. Biederman)]

Andrew Morton <akpm@osdl.org> writes:

> Is it correct to say that oprofile-on-2.6.18 works, and that
> oprofile-on-2.6.19-rc5 does not?
>
> Or is there some sort of workaround for this, or does 2.6.19-rc5 only fail
> in some particular scenarios?
>
> If it's really true that oprofile is simply busted then that's a serious
> problem and we should find some way of unbusting it.  If that means just
> adding a dummy "0" entry which always returns zero or something like that,
> then fine.
>
> But we can't just go and bust it.

The simple question.  If we turn off the NMI watchdog on 2.6.19-rc5 
does oprofile work?  I believe that is what Andi said.

The description I read was a resource conflict. The resources oprofile
just expects it can used are already in use so we tell it no and
the user space oprofile doesn't cope.

Now I don't know the interface allows us to rename the interfaces
from 1 2 3 to 0 1 2.  If we can then that looks like something we can
fix.  Otherwise from the description I tend to agree with Andi.

The user space application assumed it own hardware that it did not.

Hmm.  I bet if nothing else we could move the NMI watchdog from 0 to 3
and make things work that way...


Eric