Re: [PATCH] [v2] smp: fix smp_call_function_single_async prototype

[Huang, Ying]

Arnd Bergmann <arnd@xxxxxxxxxx> writes:

> From: Arnd Bergmann <arnd@xxxxxxxx>
>
> As of commit 966a967116e6 ("smp: Avoid using two cache lines for struct
> call_single_data"), the smp code prefers 32-byte aligned call_single_data
> objects for performance reasons, but the block layer includes an instance
> of this structure in the main 'struct request' that is more senstive
> to size than to performance here, see 4ccafe032005 ("block: unalign
> call_single_data in struct request").
>
> The result is a violation of the calling conventions that clang correctly
> points out:
>
> block/blk-mq.c:630:39: warning: passing 8-byte aligned argument to 32-byte aligned parameter 2 of 'smp_call_function_single_async' may result in an unaligned pointer access [-Walign-mismatch]
>                 smp_call_function_single_async(cpu, &rq->csd);

Can this be silenced by

		smp_call_function_single_async(cpu, (call_single_data_t *)&rq->csd);

Best Regards,
Huang, Ying

[snip]