> On 19 Feb 2023, at 20:35, Stephen Hemminger <step...@networkplumber.org>
> wrote:
>
> On Sun, 19 Feb 2023 03:30:59 +0300
> Levend Sayar <levendsa...@gmail.com <mailto:levendsa...@gmail.com>> wrote:
>
>> rx no_mbufs stats counter update is added for another error case.
>>
>> Fixes: 4f6b1dd8240c ("net/gve: support basic statistics")
>> Cc: junfeng....@intel.com
>>
>> Signed-off-by: Levend Sayar <levendsa...@gmail.com>
>> ---
>> drivers/net/gve/gve_rx.c | 7 ++++++-
>> 1 file changed, 6 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/net/gve/gve_rx.c b/drivers/net/gve/gve_rx.c
>> index 66fbcf3930..b0427731f8 100644
>> --- a/drivers/net/gve/gve_rx.c
>> +++ b/drivers/net/gve/gve_rx.c
>> @@ -24,6 +24,7 @@ gve_rx_refill(struct gve_rx_queue *rxq)
>> nmb = rte_pktmbuf_alloc(rxq->mpool);
>> if (!nmb)
>> break;
>> +
>> rxq->sw_ring[idx + i] = nmb;
>> }
>> if (i != nb_alloc) {
>
> Looks like accidental whitespace change included in this patch.
LS: Right. Let me correct.
>> @@ -59,9 +60,13 @@ gve_rx_refill(struct gve_rx_queue *rxq)
>> nmb = rte_pktmbuf_alloc(rxq->mpool);
>> if (!nmb)
>> break;
>> +
>> rxq->sw_ring[idx + i] = nmb;
>> }
>> - nb_alloc = i;
>> + if (i != nb_alloc) {
>> + rxq->no_mbufs += nb_alloc - i;
>> + nb_alloc = i;
>> + }
>
> Would be better to add unlikely() here like:
> if (unlikely(i < nb_alloc)) {
> rxq->no_mbufs += nb_alloc - i;
> nb_alloc = i;
> }
>
> Or eliminate conditional branch in hot path completely.
> rxq->no_mbufs += nb_alloc - i;
> nb_alloc = i;
>
> Or better yet refactor code here to use rte_pktmbuf_alloc_bulk() which
> does single ring operation.
>
>> }
>> rxq->nb_avail -= nb_alloc;
>> next_avail += nb_alloc;
LS: “unlikely” can be added. You’re right. Code already tries to make a bulk
allocation first.
If that bulk allocation does not work, it tries to allocate one my one.
I will supersede this one and create v2.
Thanks Stephen.
Best,
Levend
