Re: Kernel crash after using new Intel NIC (igb)

From: Eric Dumazet
Date: Fri May 27 2011 - 15:57:10 EST


Le vendredi 27 mai 2011 Ã 10:52 -0700, Arun Sharma a Ãcrit :
> On 5/26/11 8:27 PM, Eric Dumazet wrote:
>
> Looks good. Thanks for taking care of this.
>
> > +static bool atomic_add_unless_return(atomic_t *ptr, int a, int u, int *newv)
> > +{
> > + int cur, old = atomic_read(ptr);
> > +
> > + while (old != u) {
> > + *newv = old + a;
> > + cur = atomic_cmpxchg(ptr, old, *newv);
> > + if (cur == old)
> > + return true;
> > + old = cur;
> > + }
> > + return false;
> > +}
>
> This looks very similar to atomic_add_unless(). If we had a
>
> __atomic_add_unless() that returned "old", we could then do:
>
> atomic_add_unless() { return __atomic_add_unless() != u }
> atomic_add_unless_return() { return __atomic_add_unless() + a}
>

Sure !

I preferred to not touch lot of files in kernel (atomic_add_unless() is
defined in several files) because its a stable candidate patch (2.6.36+)

So a cleanup patch for 2.6.40+ is certainly doable, do you want to do
this ?

Thanks



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