On Thu, Jan 26, 2023 at 06:33:54PM +0100, Jules Maselbas wrote:
> @@ -58,9 +61,11 @@ static inline int generic_atomic_fetch_##op(int i, atomic_t *v) \
> static inline void generic_atomic_##op(int i, atomic_t *v) \
> { \
> unsigned long flags; \
> + int c; \
> \
> raw_local_irq_save(flags); \
> - v->counter = v->counter c_op i; \
> + c = arch_atomic_read(v); \
> + arch_atomic_set(v, c c_op i); \
> raw_local_irq_restore(flags); \
> }
This and the others like it are a bit sad, it explicitly dis-allows the
compiler from using memops and forces a load-store.
The alternative is writing it like:
*(volatile int *)&v->counter c_op i;
but that's pretty shit too I suppose.
