Hi,
I am looking at memory ordering and a question hit me.
I was looking at the kfifo code. kfifo_put() has a barrier:
)[__kfifo->in & __tmp->kfifo.mask] = \
(typeof(*__tmp->type))__val; \
smp_wmb(); \
__kfifo->in++; \
Looking at kfifo_get()
__ret = !kfifo_is_empty(__tmp); \
if (__ret) { \
*(typeof(__tmp->type))__val = \
(__is_kfifo_ptr(__tmp) ? \
A thought struck me. There is no corresponding barrier. I cannot
help myself, but I think there needs to be a smp_read_barrier_depends()
between reading kfifo->in (in kfifo_is empty) and reading val.
What do you think?
Regards
Oliver
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