Re: [Qemu-devel] [PATCH v3 4/9] qcow2-threads: qcow2_co_do_compress: protect queuing by mutex

[Paolo Bonzini <pbonzini@redhat.com>]

On 08/01/19 18:06, Vladimir Sementsov-Ogievskiy wrote:
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> ---
>  block/qcow2-threads.c | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)
> 
> diff --git a/block/qcow2-threads.c b/block/qcow2-threads.c
> index 20b2616529..156e0667be 100644
> --- a/block/qcow2-threads.c
> +++ b/block/qcow2-threads.c
> @@ -158,15 +158,19 @@ qcow2_co_do_compress(BlockDriverState *bs, void *dest, size_t dest_size,
>          .func = func,
>      };
>  
> +    qemu_co_mutex_lock(&s->lock);
>      while (s->nb_compress_threads >= MAX_COMPRESS_THREADS) {
> -        qemu_co_queue_wait(&s->compress_wait_queue, NULL);
> +        qemu_co_queue_wait(&s->compress_wait_queue, &s->lock);
>      }
> -
>      s->nb_compress_threads++;
> +    qemu_co_mutex_unlock(&s->lock);
> +
>      thread_pool_submit_co(pool, qcow2_compress_pool_func, &arg);
> -    s->nb_compress_threads--;
>  
> +    qemu_co_mutex_lock(&s->lock);
> +    s->nb_compress_threads--;
>      qemu_co_queue_next(&s->compress_wait_queue);
> +    qemu_co_mutex_unlock(&s->lock);
>  
>      return arg.ret;
>  }
> 

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

but, some information would be nice to have in the commit message.

Paolo