Re: [Qemu-devel] [PATCH] virtio-balloon: free pbp more aggressively

[David Hildenbrand <david@redhat.com>]

> -static void virtio_balloon_pbp_free(PartiallyBalloonedPage *pbp)
> +static void virtio_balloon_pbp_free(PartiallyBalloonedPage **pbp)
>  {
> -    if (!pbp) {
> +    if (!*pbp) {
>          return;
>      }
> -    g_free(pbp->bitmap);
> -    g_free(pbp);
> +    g_free(*pbp->bitmap);

This has to be

g_free((*pbp)->bitmap);

to compile.

> +    g_free(*pbp);
> +    *pbp = NULL;
>  }
>  
>  static PartiallyBalloonedPage *virtio_balloon_pbp_alloc(ram_addr_t base_gpa,
> @@ -108,8 +109,7 @@ static void balloon_inflate_page(VirtIOBalloon *balloon,
>          /* We've partially ballooned part of a host page, but now
>           * we're trying to balloon part of a different one.  Too hard,
>           * give up on the old partial page */
> -        virtio_balloon_pbp_free(*pbp);
> -        *pbp = NULL;
> +        virtio_balloon_pbp_free(pbp);
>      }
>  
>      if (!*pbp) {
> @@ -127,8 +127,7 @@ static void balloon_inflate_page(VirtIOBalloon *balloon,
>          /* We ignore errors from ram_block_discard_range(), because it
>           * has already reported them, and failing to discard a balloon
>           * page is not fatal */
> -        virtio_balloon_pbp_free(*pbp);
> -        *pbp = NULL;
> +        virtio_balloon_pbp_free(pbp);
>      }
>  }
>  
> @@ -379,9 +378,8 @@ static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq)
>          virtqueue_push(vq, elem, offset);
>          virtio_notify(vdev, vq);
>          g_free(elem);
> +        virtio_balloon_pbp_free(&pbp);

You could move the "PartiallyBalloonedPage *pbp = NULL;" now into the loop.

>      }
> -
> -    virtio_balloon_pbp_free(pbp);
>  }
>  
>  static void virtio_balloon_receive_stats(VirtIODevice *vdev, VirtQueue *vq)
> 

Gave it a quick test with a hugepage backing on x86 - still works. Would
be good if somebody could test with 64k PPC guest.

Reviewed-by: David Hildenbrand <david@redhat.com>

-- 

Thanks,

David / dhildenb