Re: [PATCH v2] xen/lib: introduce generic find next bit operations

[Julien Grall <julien@xxxxxxx>]

Hi Oleksii,

On 09/02/2024 17:58, Oleksii Kurochko wrote:
> find-next-bit.c is common for Arm64, PPC and RISCV64,
> so it is moved to xen/lib.
>
> PPC has been transitioned to generic functions from find-next-bit.c
> since it now shares the same implementation as the PPC-specific code.
>
> The MISRA exclude list has been updated to verify
> lib/find-next-bit.c instead of Arm's find_next_bit.c,
> as Arm's find_next_bit.c has been relocated to xen/lib/.
>
> Despite CONFIG_GENERIC_FIND_FIRST_BIT not currently being used in
> Xen and being removed from the Linux kernel [1], it could theoretically
> prove useful for Xen. This is because the Linux kernel transitioned
> Arm to the generic version of find_first_bit() and
> find_first_zero_bit() due to improvements [1] in both performance
> and .text size.
> It would be prudent to investigate whether [1] is applicable to Xen
> as well and, if so, implement the necessary changes in a separate patch.
>
> [1] 
> https://lore.kernel.org/linux-arch/20211005054059.475634-5-yury.norov@xxxxxxxxx/
>
> Suggested-by: Jan Beulich <jbeulich@xxxxxxxx>
> Signed-off-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
Reviewed-by: Julien Grall <jgrall@xxxxxxxxxx>

Cheers,

--
Julien Grall