Re: [Qemu-devel] [PATCH 4/4] block: avoid creating oversized writes in multiwrite_merge

[Paolo Bonzini <pbonzini@redhat.com>]

Il 05/09/2014 18:51, Peter Lieven ha scritto:
> Signed-off-by: Peter Lieven <pl@kamp.de>
> ---
>  block.c |    5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/block.c b/block.c
> index fa4c34b..db3f842 100644
> --- a/block.c
> +++ b/block.c
> @@ -4554,6 +4554,11 @@ static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs,
>              merge = 0;
>          }
>  
> +        if (bs->bl.max_transfer_length && reqs[outidx].nb_sectors +
> +            reqs[i].nb_sectors > bs->bl.max_transfer_length) {
> +            merge = 0;
> +        }
> +
>          if (merge) {
>              size_t size;
>              QEMUIOVector *qiov = g_malloc0(sizeof(*qiov));
> 

So I think if we treat it just as a hint for multiwrite, we can avoid
writing code to split oversized requests.  They always worked so far, we
can certainly wait until we have a real bugfix.

Can you drop patch 2 and resend the rest?

Thanks,

Paolo