Re: [PATCH 0/3 v2] nmi perf fixes

[Robert Richter]

On 10.09.10 10:46:34, Ingo Molnar wrote:
> 
> * Don Zickus <dzickus@xxxxxxxxxx> wrote:
> 
> > On Fri, Sep 10, 2010 at 01:41:40PM +0200, Peter Zijlstra wrote:
> > > On Thu, 2010-09-02 at 15:07 -0400, Don Zickus wrote:
> > > > Fixes to allow unknown nmis to pass through the perf nmi handler instead
> > > > of being swallowed.  Contains patches that are already in Ingo's tree.  Added
> > > > here for completeness.  Based on ingo/tip
> > > > 
> > > > Tested on intel/amd
> > > > 
> > > > v2: patch cleanups and consolidation, no code changes
> > > > 
> > > > Don Zickus (1):
> > > >   perf, x86: Fix accidentally ack'ing a second event on intel perf
> > > >     counter
> > > > 
> > > > Peter Zijlstra (1):
> > > >   perf, x86: Fix handle_irq return values
> > > > 
> > > > Robert Richter (1):
> > > >   perf, x86: Try to handle unknown nmis with an enabled PMU
> > > > 
> > > >  arch/x86/kernel/cpu/perf_event.c       |   59 +++++++++++++++++++++++++-------
> > > >  arch/x86/kernel/cpu/perf_event_intel.c |   15 +++++---
> > > >  arch/x86/kernel/cpu/perf_event_p4.c    |    2 +-
> > > >  3 files changed, 56 insertions(+), 20 deletions(-)
> > > 
> > > Both Ingo and I are getting Dazed and confused on our AMD machines, it
> > > started before yesterday (that is, after backing out all my recent
> > > changes it still gets dazed), so I suspect this set.
> > > 
> > > I'll look at getting a trace of the thing, but if any of you has a
> > > bright idea...
> > 
> > What are you running to create the problem?  I can try and duplicate 
> > it here.
> 
> It happens easily here - just running something like:
> 
>    perf record -g ./hackbench 10

I try to reproduce it, which systems are affected?

> 
> a couple of times triggers it. Note, unlike with the earlier bug, the 
> NMIs are not permanently 'stuck' - and everything continues working. 
> Obviously the messages are nasty looking so this is a regression we need 
> to fix.

The patch below adds ratelimits.

-Robert

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