Re: [PATCH net-next 2/2] virtio-net: get rid of unnecessary container of rq stats

From: Toshiaki Makita
Date: Tue Jul 31 2018 - 21:47:25 EST


On 2018/08/01 10:39, Jason Wang wrote:
> On 2018å07æ31æ 18:02, Toshiaki Makita wrote:
>> On 2018/07/31 18:43, Jason Wang wrote:
>>> We don't maintain tx counters in rx stats any more. There's no need
>>> for an extra container of rq stats.
>>>
>>> Cc: Toshiaki Makita <makita.toshiaki@xxxxxxxxxxxxx>
>>> Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
>>> ---
>>> Â drivers/net/virtio_net.c | 80
>>> ++++++++++++++++++++++--------------------------
>>> Â 1 file changed, 36 insertions(+), 44 deletions(-)
>>>
>>> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
>>> index 72d3f68..14f661c 100644
>>> --- a/drivers/net/virtio_net.c
>>> +++ b/drivers/net/virtio_net.c
>>> @@ -87,7 +87,8 @@ struct virtnet_sq_stats {
>>> ÂÂÂÂÂ u64 kicks;
>>> Â };
>>> Â -struct virtnet_rq_stat_items {
>>> +struct virtnet_rq_stats {
>>> +ÂÂÂ struct u64_stats_sync syncp;
>>> ÂÂÂÂÂ u64 packets;
>>> ÂÂÂÂÂ u64 bytes;
>>> ÂÂÂÂÂ u64 drops;
>>> @@ -98,17 +99,8 @@ struct virtnet_rq_stat_items {
>>> ÂÂÂÂÂ u64 kicks;
>>> Â };
>>> Â -struct virtnet_rq_stats {
>>> -ÂÂÂ struct u64_stats_sync syncp;
>>> -ÂÂÂ struct virtnet_rq_stat_items items;
>>> -};
>> I'm not thinking removing sq stat is needed but even if it is I want to
>> keep virtnet_rq_stats to avoid allocating unnecessary u64_stats_syncp on
>> stack in virtnet_receive. I would just remove virtnet_rx_stats if
>> necessary.
>
> It's a nop on 64bit machines. And an unsigned on 32bit. So it's overhead
> could be ignored I think.

It's not a big problem so that's OK. I just felt like you reverted
unnecessarily too much. Anyway it is already applied and I'm not
thinking of changing this any more.

--
Toshiaki Makita