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Message-ID: <fd3457bc-b16a-680a-0bed-80cc8505a4cc@redhat.com>
Date:   Mon, 31 Jul 2023 14:25:19 +0800
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Subject: Re: [PATCH net-next V4 2/3] virtio_net: support per queue interrupt
 coalesce command
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To:     "Michael S. Tsirkin" <mst@redhat.com>,
        Paolo Abeni <pabeni@redhat.com>
Cc:     Gavin Li <gavinl@nvidia.com>, xuanzhuo@linux.alibaba.com,
        davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
        ast@kernel.org, daniel@iogearbox.net, hawk@kernel.org,
        john.fastabend@gmail.com, jiri@nvidia.com, dtatulea@nvidia.com,
        gavi@nvidia.com, virtualization@lists.linux-foundation.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        bpf@vger.kernel.org, Heng Qi <hengqi@linux.alibaba.com>
References: <20230725130709.58207-1-gavinl@nvidia.com>
 <20230725130709.58207-3-gavinl@nvidia.com>
 <f5823996fffad2f3c1862917772c182df74c74e7.camel@redhat.com>
 <20230728014601-mutt-send-email-mst@kernel.org>
From:   Jason Wang <jasowang@redhat.com>
In-Reply-To: <20230728014601-mutt-send-email-mst@kernel.org>
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在 2023/7/28 13:46, Michael S. Tsirkin 写道:
> On Thu, Jul 27, 2023 at 03:28:32PM +0200, Paolo Abeni wrote:
>> On Tue, 2023-07-25 at 16:07 +0300, Gavin Li wrote:
>>> Add interrupt_coalesce config in send_queue and receive_queue to cache user
>>> config.
>>>
>>> Send per virtqueue interrupt moderation config to underlying device in
>>> order to have more efficient interrupt moderation and cpu utilization of
>>> guest VM.
>>>
>>> Additionally, address all the VQs when updating the global configuration,
>>> as now the individual VQs configuration can diverge from the global
>>> configuration.
>>>
>>> Signed-off-by: Gavin Li <gavinl@nvidia.com>
>>> Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com>
>>> Reviewed-by: Jiri Pirko <jiri@nvidia.com>
>>> Acked-by: Michael S. Tsirkin <mst@redhat.com>
>> FTR, this patch is significantly different from the version previously
>> acked/reviewed, I'm unsure if all the reviewers are ok with the new
>> one.
>>
>> [...]
> still ok by me
>
> Acked-by: Michael S. Tsirkin <mst@redhat.com>
>
> let's wait for Jason too.


I'm fine with this series (I've acked each patch).

Thanks


>
>>>   static int virtnet_set_coalesce(struct net_device *dev,
>>>   				struct ethtool_coalesce *ec,
>>>   				struct kernel_ethtool_coalesce *kernel_coal,
>>>   				struct netlink_ext_ack *extack)
>>>   {
>>>   	struct virtnet_info *vi = netdev_priv(dev);
>>> -	int ret, i, napi_weight;
>>> +	int ret, queue_number, napi_weight;
>>>   	bool update_napi = false;
>>>   
>>>   	/* Can't change NAPI weight if the link is up */
>>>   	napi_weight = ec->tx_max_coalesced_frames ? NAPI_POLL_WEIGHT : 0;
>>> -	if (napi_weight ^ vi->sq[0].napi.weight) {
>>> -		if (dev->flags & IFF_UP)
>>> -			return -EBUSY;
>>> -		else
>>> -			update_napi = true;
>>> +	for (queue_number = 0; queue_number < vi->max_queue_pairs; queue_number++) {
>>> +		ret = virtnet_should_update_vq_weight(dev->flags, napi_weight,
>>> +						      vi->sq[queue_number].napi.weight,
>>> +						      &update_napi);
>>> +		if (ret)
>>> +			return ret;
>>> +
>>> +		if (update_napi) {
>>> +			/* All queues that belong to [queue_number, queue_count] will be
>>> +			 * updated for the sake of simplicity, which might not be necessary
>> It looks like the comment above still refers to the old code. Should
>> be:
>> 	[queue_number, vi->max_queue_pairs]
>> 			
>> Otherwise LGTM, thanks!
>>
>> Paolo