Re: [PATCH 2/5] x86: ret_from_fork - get rid of jump back

[Andi Kleen]

gorcunov@xxxxxxxxx writes:
> --- a/arch/x86/kernel/entry_64.S
> +++ b/arch/x86/kernel/entry_64.S
> @@ -379,7 +379,10 @@ ENTRY(ret_from_fork)
>  	GET_THREAD_INFO(%rcx)
>  	testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT),TI_flags(%rcx)
>  	CFI_REMEMBER_STATE
> -	jnz rff_trace
> +	jz rff_action
> +	movq %rsp,%rdi
> +	call syscall_trace_leave
> +	GET_THREAD_INFO(%rcx)

The uncommon path is supposed to be out of line. I don't think
the CPU will like that.

-Andi

>  rff_action:

-- 
ak@xxxxxxxxxxxxxxx
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