[PATCH v6 0/4] entry: Move ret_from_fork() to C and inline syscall_exit_to_user_mode()

[Thomas Gleixner]

On Thu, Mar 20 2025 at 10:29, Charlie Jenkins wrote:
> Similar to commit 221a164035fd ("entry: Move
> syscall_enter_from_user_mode() to header file"), move
> syscall_exit_to_user_mode() to the header file as well.
>
> Testing was done with the byte-unixbench [1] syscall benchmark (which
> calls getpid) and QEMU. On riscv I measured a 7.09246% improvement, on
> x86 a 2.98843% improvement, on loongarch a 6.07954% improvement, and on
> s390 a 11.1328% improvement.
>
> The Intel bot also reported "kernel test robot noticed a 1.9%
> improvement of stress-ng.seek.ops_per_sec" [2]
>
> Since this is on QEMU, I know these numbers are not perfect, but they
> show a trend of general improvement across all architectures that use
> the generic entry code.

This looks sane now. I've bookmarked it as post-merge window material.

Thanks,

        tglx