> There is a problem with (en|dis)able_bh(). The problem is that if these
> calls are not protected by some other locking mechanism, things might not
> work correctly on SMP machines.
Yes, I seen the subtle mask race the day after I fixed the running bug
(making bh_mask_count atomic_t). atomic_t seems far enough in real world
though.
I just fixed the subtle race with a `slow' spinlock here. The new spinlock
make atomic the bh_mask_count and bh_mask settings. Obviously with a
spinlock bh_mask_count return to be a simple int. I should have posted my
patch here some weeks ago. Browse or ask if you need it.
I can't se a way to fix the thing without using a spinlock. To see the
subtle race you can imagine an mdelay(1000) between the atomic_t operation
and the bh_mask setting (or the reverse).
Andrea Arcangeli
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