On Thu, 2022-02-17 at 13:19 +0100, Christophe Leroy wrote:
> All functions defined as static inline in net/checksum.h are
> meant to be inlined for performance reason.
>
> But since commit ac7c3e4ff401 ("compiler: enable
> CONFIG_OPTIMIZE_INLINING forcibly") the compiler is allowed to
> uninline functions when it wants.
>
> Fair enough in the general case, but for tiny performance critical
> checksum helpers that's counter-productive.
Thanks. Trivial style notes:
> diff --git a/include/net/checksum.h b/include/net/checksum.h
[]
> @@ -22,7 +22,7 @@
> #include <asm/checksum.h>
>
> #ifndef _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
> -static inline
> +static __always_inline
> __wsum csum_and_copy_from_user (const void __user *src, void *dst,
> int len)
> {
__wsum might be better placed on the previous line.
[]
> @@ -45,7 +45,7 @@ static __inline__ __wsum csum_and_copy_to_user
> #endif
>
> #ifndef _HAVE_ARCH_CSUM_AND_COPY
> -static inline __wsum
> +static __always_inline __wsum
> csum_partial_copy_nocheck(const void *src, void *dst, int len)
To be consistent with the location of the __wsum return value
when splitting the function definitions across multiple lines.
(like the below)
> @@ -88,42 +88,43 @@ static inline __wsum csum_shift(__wsum sum, int offset)
> return sum;
> }
>
> -static inline __wsum
> +static __always_inline __wsum
> csum_block_add(__wsum csum, __wsum csum2, int offset)
> {
> return csum_add(csum, csum_shift(csum2, offset));
> }
>
> -static inline __wsum
> +static __always_inline __wsum
> csum_block_add_ext(__wsum csum, __wsum csum2, int offset, int len)
> {
> return csum_block_add(csum, csum2, offset);
> }
>
> -static inline __wsum
> +static __always_inline __wsum
> csum_block_sub(__wsum csum, __wsum csum2, int offset)
> {
> return csum_block_add(csum, ~csum2, offset);
> }
>
> -static inline __wsum csum_unfold(__sum16 n)
> +static __always_inline __wsum csum_unfold(__sum16 n)
> {
> return (__force __wsum)n;
> }
>
[]
> -static inline __wsum csum_partial_ext(const void *buff, int len, __wsum sum)
> +static __always_inline
> +__wsum csum_partial_ext(const void *buff, int len, __wsum sum)
> {
> return csum_partial(buff, len, sum);
> }
And this __wsum could be moved too.
> @@ -150,15 +151,15 @@ void inet_proto_csum_replace16(__sum16 *sum, struct
> sk_buff *skb,
[]
> -static inline __wsum remcsum_adjust(void *ptr, __wsum csum,
> +static __always_inline __wsum remcsum_adjust(void *ptr, __wsum csum,
> int start, int offset)
> {
> __sum16 *psum = (__sum16 *)(ptr + offset);
And this one could be split like the above
static __always_inline __wsum
remcsum_adjust(void *ptr, __wsum csum, int start, int offset)
