Re: [Qemu-devel] [PATCH v5 11/12] rdma: core logic

[Paolo Bonzini <pbonzini@redhat.com>]

Il 23/04/2013 03:55, mrhines@linux.vnet.ibm.com ha scritto:
> +static size_t qemu_rdma_get_max_size(QEMUFile *f, void *opaque,
> +                                     uint64_t transferred_bytes,
> +                                     uint64_t time_spent,
> +                                     uint64_t max_downtime)
> +{
> +    static uint64_t largest = 1;
> +    uint64_t max_size = ((double) (transferred_bytes / time_spent))
> +                            * max_downtime / 1000000;
> +
> +    if (max_size > largest) {
> +        largest = max_size;
> +    }
> +
> +    DPRINTF("MBPS: %f, max_size: %" PRIu64 " largest: %" PRIu64 "\n",
> +                qemu_get_mbps(), max_size, largest);
> +
> +    return largest;
> +}

Can you point me to the discussion of this algorithmic change and
qemu_get_max_size?  It seems to me that it assumes that the IB link is
basically dedicated to migration.

I think it is a big assumption and it may be hiding a bug elsewhere.  At
the very least, it should be moved to a separate commit and described in
the commit message, but actually I'd prefer to not include it in the
first submission.

Paolo