[Qemu-devel] Re: [PATCH 06/18] kvm: Refactor qemu_kvm_eat_signals

[Paolo Bonzini <pbonzini@redhat.com>]

On 01/10/2011 09:31 AM, Jan Kiszka wrote:
> From: Jan Kiszka<jan.kiszka@siemens.com>
>
> We do not use the timeout, so drop its logic. As we always poll our
> signals, we do not need to drop the global lock. Removing those calls
> allows some further simplifications. Also fix the error processing of
> sigpending at this chance.
>
> Signed-off-by: Jan Kiszka<jan.kiszka@siemens.com>
> ---
>   cpus.c |   23 +++++++----------------
>   1 files changed, 7 insertions(+), 16 deletions(-)
>
> diff --git a/cpus.c b/cpus.c
> index bf0fb85..6da0f8f 100644
> --- a/cpus.c
> +++ b/cpus.c
> @@ -617,31 +617,22 @@ static void sigbus_handler(int n, struct qemu_signalfd_siginfo *siginfo,
>       }
>   }
>
> -static void qemu_kvm_eat_signal(CPUState *env, int timeout)
> +static void qemu_kvm_eat_signals(CPUState *env)
>   {
> -    struct timespec ts;
> -    int r, e;
> +    struct timespec ts = { 0, 0 };
>       siginfo_t siginfo;
>       sigset_t waitset;
>       sigset_t chkset;
> -
> -    ts.tv_sec = timeout / 1000;
> -    ts.tv_nsec = (timeout % 1000) * 1000000;
> +    int r;
>
>       sigemptyset(&waitset);
>       sigaddset(&waitset, SIG_IPI);
>       sigaddset(&waitset, SIGBUS);
>
>       do {
> -        qemu_mutex_unlock(&qemu_global_mutex);
> -
>           r = sigtimedwait(&waitset,&siginfo,&ts);
> -        e = errno;
> -
> -        qemu_mutex_lock(&qemu_global_mutex);
> -
> -        if (r == -1&&  !(e == EAGAIN || e == EINTR)) {
> -            fprintf(stderr, "sigtimedwait: %s\n", strerror(e));
> +        if (r == -1&&  !(errno == EAGAIN || errno == EINTR)) {
> +            perror("sigtimedwait");
>               exit(1);
>           }
>
> @@ -657,7 +648,7 @@ static void qemu_kvm_eat_signal(CPUState *env, int timeout)
>
>           r = sigpending(&chkset);
>           if (r == -1) {
> -            fprintf(stderr, "sigpending: %s\n", strerror(e));
> +            perror("sigpending");
>               exit(1);
>           }
>       } while (sigismember(&chkset, SIG_IPI) || sigismember(&chkset, SIGBUS));
> @@ -668,7 +659,7 @@ static void qemu_kvm_wait_io_event(CPUState *env)
>       while (!cpu_has_work(env))
>           qemu_cond_timedwait(env->halt_cond,&qemu_global_mutex, 1000);
>
> -    qemu_kvm_eat_signal(env, 0);
> +    qemu_kvm_eat_signals(env);
>       qemu_wait_io_event_common(env);
>   }
>

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>

Paolo