Re: [git pull] core fixes

[Ingo Molnar]

* Nick Piggin <nickpiggin@xxxxxxxxxxxx> wrote:

> On Tuesday 12 August 2008 16:13, Nick Piggin wrote:
> > On Tuesday 12 August 2008 08:20, Ingo Molnar wrote:
> 
> > > Nick Piggin (1):
> > >       generic-ipi: fix stack and rcu interaction bug in
> > > smp_call_function_mask()
> >
> > I'm still not 100% sure that I have this patch right... I might have 
> > seen a lockup trace implicating the smp call function path... which 
> > may have been due to some other problem or a different bug in the 
> > new call function code, but if some more people can take a look at 
> > it before merging?
> 
> OK indeed it did have a couple of bugs. Firstly, I wasn't freeing the 
> data properly in the alloc && wait case. Secondly, I wasn't resetting 
> CSD_FLAG_WAIT in the for each cpu loop (so only the first CPU would 
> wait).
> 
> After those fixes, the patch boots and runs with the kmalloc commented
> out (so it always executes the slowpath).

thanks! I've applied the delta fix below to tip/core/urgent. In my 
testing the previous version didnt cause problems either because we 
seldom excercise this slowpath. (Jeremy had trouble reproducing the 
on-stack corruption even with targeted tests.)

We'll soon start using the generic-ipi facilities for TLB flushes on x86 
and perhaps even reuse the IPI itself for the reschedule IPI - that 
should put it all under heavier scrutiny.

	Ingo

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