Re: 2.6.20-rc6-mm1

Herbert Xu
2007-01-29T07:22:48Z

On Sun, Jan 28, 2007 at 10:43:12PM -0800, Andrew Morton wrote:
>
> > IIRC Ingo had made fixes for the networking stack in his rt tree since
> > the networking code assumes in lots of places that rcu_read_lock
> > disables preemption.
>
> oh. We'd better find those fixes then. I wonder what other code made that
> (rather hacky) assumption? I guess we have enough debug stuff in there to
> find out..

Actually, maybe I was confusing this with the fixes Ingo had for
local_bh_disable vs. preemption in the -rt tree. Ingo, do you
have preemptible RCU support in your -rt tree and if so did you
have to fix the networking stack to behave correctly with it?

It could also be that the fixes for local_bh_disable also masked
any problems that would trigger under preemptible RCU.

Cheers,
--
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