Re: [PATCH] perf/x86/uncore: Allow single pmu/box within events group

From: Jiri Olsa
Date: Fri Nov 18 2016 - 07:33:34 EST


On Fri, Nov 18, 2016 at 12:28:50PM +0100, Peter Zijlstra wrote:
> On Fri, Nov 18, 2016 at 01:15:28AM +0100, Jiri Olsa wrote:
> > Current uncore_validate_group code expects all events within
> > the group to have same pmu.
> >
> > This leads to constraint code using wrong boxes which leads
> > in my case to touching uninitialized spinlocks, but could
> > be probably worse.. depends on type and box details.
> >
> > I get lockdep warning below for following perf stat:
> > # perf stat -vv -e '{uncore_cbox_0/config=0x0334/,uncore_qpi_0/event=1/}' -a sleep 1
>
> Hurm, we shouldn't be allowing that in the first place I think.
>
>
> Let me stare at the generic group code, the intent was to only allow
> software events to mix with hw events, nothing else.

yep, that's what's happening now.. but after the event_init callback

jirka