Re: [Qemu-devel] [PATCH 2/3] qemu-progress: Fix progress printing on SIGUSR1

["Benoît Canet" <benoit.canet@irqsave.net>]

Le Monday 20 Jan 2014 à 15:17:20 (+0100), Kevin Wolf a écrit :
> Since commit a7aae221 ('Switch SIG_IPI to SIGUSR1'), SIGUSR1 is blocked
> during startup, breaking the progress report in tools.
> 
> This patch reenables the signal when initialising a progress report.
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  util/qemu-progress.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/util/qemu-progress.c b/util/qemu-progress.c
> index ad33fee..4ee5cd0 100644
> --- a/util/qemu-progress.c
> +++ b/util/qemu-progress.c
> @@ -82,12 +82,22 @@ static void progress_dummy_init(void)
>  {
>  #ifdef CONFIG_POSIX
>      struct sigaction action;
> +    sigset_t set;
>  
>      memset(&action, 0, sizeof(action));
>      sigfillset(&action.sa_mask);
>      action.sa_handler = sigusr_print;
>      action.sa_flags = 0;
>      sigaction(SIGUSR1, &action, NULL);
> +
> +    /*
> +     * SIGUSR1 is SIG_IPI and gets blocked in qemu_init_main_loop(). In the
> +     * tools that use the progress report SIGUSR1 isn't used in this meaning
> +     * and instead should print the progress, so reenable it.
> +     */
> +    sigemptyset(&set);
> +    sigaddset(&set, SIGUSR1);
> +    pthread_sigmask(SIG_UNBLOCK, &set, NULL);
>  #endif
>  
>      state.print = progress_dummy_print;
> -- 
> 1.8.1.4
> 
> 

I wonder if it worth it to restore the signal blocking state in
progress_dummy_end to avoid future side effects.

Reviewed-by: Benoit Canet <benoit@irqsave.net>