Re: [PATCH] provide arch_test_bit_acquire for architectures that define test_bit

[Linus Torvalds]

On Fri, Aug 26, 2022 at 1:43 PM Mikulas Patocka <mpatocka@xxxxxxxxxx> wrote:
>
> I'm wondering why do the architectures redefine test_bit, if their
> definition is equivalent to the generic one? We could just delete
> arch_test_bit and use "#define arch_test_bit generic_test_bit" as well.

I think generic_test_bit() came after many of them, and when it
didn't, people copied earlier architectures where they had already
done their own.

> Another untested patch ... tomorrow, I'll try to compile it, at least for
> architectures where Debian provides cross-compiling gcc.

Looks good to me, except I'd just do

#define arch_test_bit_acquire arch_test_bit

on hexagon rather than duplicate that function.

>From my reading, Hexagon doesn't have any fancy memory ordering, it's
just the usual UP with barriers basically for instruction cache
coherence etc.

                 Linus