[CRIU] [PATCH] parasite: send PARASITE_CMD_FINI before resuming the target process

[Pavel Emelyanov]

On 09/16/2014 10:39 PM, Andrey Vagin wrote:
> The control socket has enough buffer for one command and the target
> process will not wait a new command, so we will avoid extra context
> switches.

Can you describe exactly what will change after that? Will parasite
perform one more syscall w/o step-by-step? Or what?

> Signed-off-by: Andrey Vagin <avagin at openvz.org>
> ---
>  parasite-syscall.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/parasite-syscall.c b/parasite-syscall.c
> index 6f56617..354f0e9 100644
> --- a/parasite-syscall.c
> +++ b/parasite-syscall.c
> @@ -863,17 +863,17 @@ static int parasite_fini_seized(struct parasite_ctl *ctl)
>  		return -1;
>  	}
>  
> +	ret = __parasite_execute_daemon(PARASITE_CMD_FINI, ctl);
> +	close_safe(&ctl->tsock);
> +	if (ret)
> +		return -1;
> +
>  	ret = ptrace(PTRACE_SYSCALL, pid, NULL, NULL);
>  	if (ret) {
>  		pr_perror("ptrace");
>  		return -1;
>  	}
>  
> -	ret = __parasite_execute_daemon(PARASITE_CMD_FINI, ctl);
> -	close_safe(&ctl->tsock);
> -	if (ret)
> -		return -1;
> -
>  	if (parasite_stop_on_syscall(1, __NR_rt_sigreturn))
>  		return -1;
>  
>