On 06/05/2017 10:38 AM, Michael S. Tsirkin wrote: > On Mon, Jun 05, 2017 at 04:57:29PM +0800, Wei Wang wrote: >> This patch enables the virtio-net tx queue size to be configurable >> between 256 and 1024 by the user. The queue size specified by the >> user should be power of 2. If "tx_queue_size" is not offered by the >> user, the default queue size, 1024, will be used. >>
>> + if (n->net_conf.tx_queue_size < VIRTIO_NET_TX_QUEUE_MIN_SIZE ||
>> + n->net_conf.tx_queue_size > VIRTQUEUE_MAX_SIZE ||
>> + (n->net_conf.tx_queue_size & (n->net_conf.tx_queue_size - 1))) {
>
> Pls use is_power_of_2.
>
>> + error_setg(errp, "Invalid tx_queue_size (= %" PRIu16 "), "
>> + "must be a power of 2 between %d and %d.",
No trailing '.' in error_setg() messages, please.
>> + n->net_conf.tx_queue_size, VIRTIO_NET_TX_QUEUE_MIN_SIZE,
>> + VIRTQUEUE_MAX_SIZE);
>
> I think management will need a way to discover the limits for
> this value. Not sure how. Cc QAPI maintainers.
Is this something that can be documented? Or is it a runtime-variable
limit, where you will need to query the limit on a per-machine basis?
Given that it looks like compile-time documentation, I'm leaning towards
documentation being sufficient.
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3266
Virtualization: qemu.org | libvirt.org
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