Re: [Qemu-devel] [PATCH v3 03/13] qemu-timer: move common code to qemu_rearm_alarm_timer

[TeLeMan]

On Sat, Oct 22, 2011 at 00:26, Paolo Bonzini <address@hidden> wrote:
> Reviewed-by: Anthony Liguori <address@hidden>
> Signed-off-by: Paolo Bonzini <address@hidden>
> ---
>  qemu-timer.c |  129 
> ++++++++++++++++++++++++----------------------------------
>  1 files changed, 53 insertions(+), 76 deletions(-)
>
> diff --git a/qemu-timer.c b/qemu-timer.c
> index acf7a15..e2551f3 100644
> --- a/qemu-timer.c
> +++ b/qemu-timer.c
> @@ -153,7 +153,7 @@ struct qemu_alarm_timer {
>     char const *name;
>     int (*start)(struct qemu_alarm_timer *t);
>     void (*stop)(struct qemu_alarm_timer *t);
> -    void (*rearm)(struct qemu_alarm_timer *t);
> +    void (*rearm)(struct qemu_alarm_timer *t, int64_t nearest_delta_ns);
>  #if defined(__linux__)
>     int fd;
>     timer_t timer;
> @@ -181,12 +181,46 @@ static inline int alarm_has_dynticks(struct 
> qemu_alarm_timer *t)
>     return !!t->rearm;
>  }
>
> +static int64_t qemu_next_alarm_deadline(void)
> +{
> +    int64_t delta;
> +    int64_t rtdelta;
> +
> +    if (!use_icount && vm_clock->active_timers) {
> +        delta = vm_clock->active_timers->expire_time -
> +                     qemu_get_clock_ns(vm_clock);
> +    } else {
> +        delta = INT32_MAX;
> +    }
> +    if (host_clock->active_timers) {
> +        int64_t hdelta = host_clock->active_timers->expire_time -
> +                 qemu_get_clock_ns(host_clock);
> +        if (hdelta < delta) {
> +            delta = hdelta;
> +        }
> +    }
> +    if (rt_clock->active_timers) {
> +        rtdelta = (rt_clock->active_timers->expire_time -
> +                 qemu_get_clock_ns(rt_clock));
> +        if (rtdelta < delta) {
> +            delta = rtdelta;
> +        }
> +    }
> +
> +    return delta;
> +}
> +
>  static void qemu_rearm_alarm_timer(struct qemu_alarm_timer *t)
>  {
> -    if (!alarm_has_dynticks(t))
> +    int64_t nearest_delta_ns;
> +    assert(alarm_has_dynticks(t));
"mmtimer" and "win32" alarms have no rearm. Should we remove these two alarms?

> +    if (!rt_clock->active_timers &&
> +        !vm_clock->active_timers &&
> +        !host_clock->active_timers) {
>         return;
> -
> -    t->rearm(t);
> +    }
> +    nearest_delta_ns = qemu_next_alarm_deadline();
> +    t->rearm(t, nearest_delta_ns);
>  }
>
>  /* TODO: MIN_TIMER_REARM_NS should be optimized */
> @@ -196,23 +230,23 @@ static void qemu_rearm_alarm_timer(struct 
> qemu_alarm_timer *t)
>
>  static int mm_start_timer(struct qemu_alarm_timer *t);
>  static void mm_stop_timer(struct qemu_alarm_timer *t);
> -static void mm_rearm_timer(struct qemu_alarm_timer *t);
> +static void mm_rearm_timer(struct qemu_alarm_timer *t, int64_t delta);
>
>  static int win32_start_timer(struct qemu_alarm_timer *t);
>  static void win32_stop_timer(struct qemu_alarm_timer *t);
> -static void win32_rearm_timer(struct qemu_alarm_timer *t);
> +static void win32_rearm_timer(struct qemu_alarm_timer *t, int64_t delta);
>
>  #else
>
>  static int unix_start_timer(struct qemu_alarm_timer *t);
>  static void unix_stop_timer(struct qemu_alarm_timer *t);
> -static void unix_rearm_timer(struct qemu_alarm_timer *t);
> +static void unix_rearm_timer(struct qemu_alarm_timer *t, int64_t delta);
>
>  #ifdef __linux__
>
>  static int dynticks_start_timer(struct qemu_alarm_timer *t);
>  static void dynticks_stop_timer(struct qemu_alarm_timer *t);
> -static void dynticks_rearm_timer(struct qemu_alarm_timer *t);
> +static void dynticks_rearm_timer(struct qemu_alarm_timer *t, int64_t delta);
>
>  #endif /* __linux__ */
>
> @@ -715,8 +749,6 @@ void qemu_run_all_timers(void)
>     qemu_run_timers(host_clock);
>  }
>
> -static int64_t qemu_next_alarm_deadline(void);
> -
>  #ifdef _WIN32
>  static void CALLBACK host_alarm_handler(PVOID lpParam, BOOLEAN unused)
>  #else
> @@ -781,33 +813,6 @@ int64_t qemu_next_icount_deadline(void)
>     return delta;
>  }
>
> -static int64_t qemu_next_alarm_deadline(void)
> -{
> -    int64_t delta;
> -    int64_t rtdelta;
> -
> -    if (!use_icount && vm_clock->active_timers) {
> -        delta = vm_clock->active_timers->expire_time -
> -                     qemu_get_clock_ns(vm_clock);
> -    } else {
> -        delta = INT32_MAX;
> -    }
> -    if (host_clock->active_timers) {
> -        int64_t hdelta = host_clock->active_timers->expire_time -
> -                 qemu_get_clock_ns(host_clock);
> -        if (hdelta < delta)
> -            delta = hdelta;
> -    }
> -    if (rt_clock->active_timers) {
> -        rtdelta = (rt_clock->active_timers->expire_time -
> -                 qemu_get_clock_ns(rt_clock));
> -        if (rtdelta < delta)
> -            delta = rtdelta;
> -    }
> -
> -    return delta;
> -}
> -
>  #if defined(__linux__)
>
>  #include "compatfd.h"
> @@ -860,20 +865,13 @@ static void dynticks_stop_timer(struct qemu_alarm_timer 
> *t)
>     timer_delete(host_timer);
>  }
>
> -static void dynticks_rearm_timer(struct qemu_alarm_timer *t)
> +static void dynticks_rearm_timer(struct qemu_alarm_timer *t,
> +                                 int64_t nearest_delta_ns)
>  {
>     timer_t host_timer = t->timer;
>     struct itimerspec timeout;
> -    int64_t nearest_delta_ns = INT64_MAX;
>     int64_t current_ns;
>
> -    assert(alarm_has_dynticks(t));
> -    if (!rt_clock->active_timers &&
> -        !vm_clock->active_timers &&
> -        !host_clock->active_timers)
> -        return;
> -
> -    nearest_delta_ns = qemu_next_alarm_deadline();
>     if (nearest_delta_ns < MIN_TIMER_REARM_NS)
>         nearest_delta_ns = MIN_TIMER_REARM_NS;
>
> @@ -915,19 +913,12 @@ static int unix_start_timer(struct qemu_alarm_timer *t)
>     return 0;
>  }
>
> -static void unix_rearm_timer(struct qemu_alarm_timer *t)
> +static void unix_rearm_timer(struct qemu_alarm_timer *t,
> +                             int64_t nearest_delta_ns)
>  {
>     struct itimerval itv;
> -    int64_t nearest_delta_ns = INT64_MAX;
>     int err;
>
> -    assert(alarm_has_dynticks(t));
> -    if (!rt_clock->active_timers &&
> -        !vm_clock->active_timers &&
> -        !host_clock->active_timers)
> -        return;
> -
> -    nearest_delta_ns = qemu_next_alarm_deadline();
>     if (nearest_delta_ns < MIN_TIMER_REARM_NS)
>         nearest_delta_ns = MIN_TIMER_REARM_NS;
>
> @@ -1014,23 +1005,14 @@ static void mm_stop_timer(struct qemu_alarm_timer *t)
>     timeEndPeriod(mm_period);
>  }
>
> -static void mm_rearm_timer(struct qemu_alarm_timer *t)
> +static void mm_rearm_timer(struct qemu_alarm_timer *t, int64_t delta)
>  {
> -    int nearest_delta_ms;
> -
> -    assert(alarm_has_dynticks(t));
> -    if (!rt_clock->active_timers &&
> -        !vm_clock->active_timers &&
> -        !host_clock->active_timers) {
> -        return;
> -    }
> -
> -    timeKillEvent(mm_timer);
> -
> -    nearest_delta_ms = (qemu_next_alarm_deadline() + 999999) / 1000000;
> +    int nearest_delta_ms = (delta + 999999) / 1000000;
>     if (nearest_delta_ms < 1) {
>         nearest_delta_ms = 1;
>     }
> +
> +    timeKillEvent(mm_timer);
>     mm_timer = timeSetEvent(nearest_delta_ms,
>                             mm_period,
>                             mm_alarm_handler,
> @@ -1082,19 +1064,14 @@ static void win32_stop_timer(struct qemu_alarm_timer 
> *t)
>     }
>  }
>
> -static void win32_rearm_timer(struct qemu_alarm_timer *t)
> +static void win32_rearm_timer(struct qemu_alarm_timer *t,
> +                              int64_t nearest_delta_ns)
>  {
>     HANDLE hTimer = t->timer;
>     int nearest_delta_ms;
>     BOOLEAN success;
>
> -    assert(alarm_has_dynticks(t));
> -    if (!rt_clock->active_timers &&
> -        !vm_clock->active_timers &&
> -        !host_clock->active_timers)
> -        return;
> -
> -    nearest_delta_ms = (qemu_next_alarm_deadline() + 999999) / 1000000;
> +    nearest_delta_ms = (nearest_delta_ns + 999999) / 1000000;
>     if (nearest_delta_ms < 1) {
>         nearest_delta_ms = 1;
>     }
> --
> 1.7.6
>
>
>
>