Re: [RFC][PATCH 0/5] Introduce checks for preemptable code for this_cpu_read/write()

Peter Zijlstra
2011-09-20T15:08:02Z

On Tue, 2011-09-20 at 10:03 -0500, Christoph Lameter wrote:
>
> Well yes the misunderstanding of per cpu operations was one reason why I
> proposed the discussion on the subject of esoteric kernel synchronization.
> I do not think that it was accepted.

I don't think anybody here misunderstands it, we're just all very angry
that its causing so much problems.

__this_cpu doesn't have preempt debug checks, and there's a lot of
this_cpu usage that really should have been __this_cpu.

The very fact that a quick scan still reveals actual bugs should be a
warning sign that this crap doesn't have enough sanity checks.