Re: [Qemu-devel] [RFC v4 06/71] cpu: introduce process_queued_cpu_work_locked

[Alex Bennée]

Emilio G. Cota <address@hidden> writes:

> This completes the conversion to cpu_mutex_lock/unlock in the file.
>
> Reviewed-by: Richard Henderson <address@hidden>
> Signed-off-by: Emilio G. Cota <address@hidden>

Reviewed-by: Alex Bennée <address@hidden>

> ---
>  cpus-common.c | 17 +++++++++++------
>  1 file changed, 11 insertions(+), 6 deletions(-)
>
> diff --git a/cpus-common.c b/cpus-common.c
> index 3fccee5585..c2ad554d54 100644
> --- a/cpus-common.c
> +++ b/cpus-common.c
> @@ -337,20 +337,19 @@ void async_safe_run_on_cpu(CPUState *cpu, 
> run_on_cpu_func func,
>      queue_work_on_cpu(cpu, wi);
>  }
>
> -void process_queued_cpu_work(CPUState *cpu)
> +/* Called with the CPU's lock held */
> +static void process_queued_cpu_work_locked(CPUState *cpu)
>  {
>      struct qemu_work_item *wi;
>      bool has_bql = qemu_mutex_iothread_locked();
>
> -    qemu_mutex_lock(&cpu->lock);
>      if (QSIMPLEQ_EMPTY(&cpu->work_list)) {
> -        qemu_mutex_unlock(&cpu->lock);
>          return;
>      }
>      while (!QSIMPLEQ_EMPTY(&cpu->work_list)) {
>          wi = QSIMPLEQ_FIRST(&cpu->work_list);
>          QSIMPLEQ_REMOVE_HEAD(&cpu->work_list, node);
> -        qemu_mutex_unlock(&cpu->lock);
> +        cpu_mutex_unlock(cpu);
>          if (wi->exclusive) {
>              /* Running work items outside the BQL avoids the following 
> deadlock:
>               * 1) start_exclusive() is called with the BQL taken while 
> another
> @@ -376,13 +375,19 @@ void process_queued_cpu_work(CPUState *cpu)
>                  qemu_mutex_unlock_iothread();
>              }
>          }
> -        qemu_mutex_lock(&cpu->lock);
> +        cpu_mutex_lock(cpu);
>          if (wi->free) {
>              g_free(wi);
>          } else {
>              atomic_mb_set(&wi->done, true);
>          }
>      }
> -    qemu_mutex_unlock(&cpu->lock);
>      qemu_cond_broadcast(&cpu->cond);
>  }
> +
> +void process_queued_cpu_work(CPUState *cpu)
> +{
> +    cpu_mutex_lock(cpu);
> +    process_queued_cpu_work_locked(cpu);
> +    cpu_mutex_unlock(cpu);
> +}


--
Alex Bennée