Re: [PATCH v5 2/3] RDMA/rxe: add SENT/RCVD bytes

[Zhu Yanjun <yanjun.zhu@linux.dev>]

在 2026/4/10 15:37, yanjun.zhu 写道:
> On 4/7/26 5:09 PM, zhenwei pi wrote:
>> There is a lack of sent/received counter in bytes.
>>
>> Signed-off-by: zhenwei pi <zhenwei.pi@linux.dev>
>> ---
>>   drivers/infiniband/sw/rxe/rxe_hw_counters.c | 2 ++
>>   drivers/infiniband/sw/rxe/rxe_hw_counters.h | 2 ++
>>   drivers/infiniband/sw/rxe/rxe_net.c         | 2 ++
>>   drivers/infiniband/sw/rxe/rxe_recv.c        | 2 ++
>>   drivers/infiniband/sw/rxe/rxe_verbs.h       | 6 ++++++
>>   5 files changed, 14 insertions(+)
>>
>> diff --git a/drivers/infiniband/sw/rxe/rxe_hw_counters.c 
>> b/drivers/infiniband/sw/rxe/rxe_hw_counters.c
>> index 437917a7d8f2..17edaa9a9b9b 100644
>> --- a/drivers/infiniband/sw/rxe/rxe_hw_counters.c
>> +++ b/drivers/infiniband/sw/rxe/rxe_hw_counters.c
>> @@ -22,6 +22,8 @@ static const struct rdma_stat_desc 
>> rxe_counter_descs[] = {
>>       [RXE_CNT_LINK_DOWNED].name         =  "link_downed",
>>       [RXE_CNT_RDMA_SEND].name           =  "rdma_sends",
>>       [RXE_CNT_RDMA_RECV].name           =  "rdma_recvs",
>> +    [RXE_CNT_SENT_BYTES].name          =  "sent_bytes",
>> +    [RXE_CNT_RCVD_BYTES].name          =  "rcvd_bytes",
>>   };
>>     int rxe_ib_get_hw_stats(struct ib_device *ibdev,
>> diff --git a/drivers/infiniband/sw/rxe/rxe_hw_counters.h 
>> b/drivers/infiniband/sw/rxe/rxe_hw_counters.h
>> index 051f9e1c3852..01b355103cbc 100644
>> --- a/drivers/infiniband/sw/rxe/rxe_hw_counters.h
>> +++ b/drivers/infiniband/sw/rxe/rxe_hw_counters.h
>> @@ -26,6 +26,8 @@ enum rxe_counters {
>>       RXE_CNT_LINK_DOWNED,
>>       RXE_CNT_RDMA_SEND,
>>       RXE_CNT_RDMA_RECV,
>> +    RXE_CNT_SENT_BYTES,
>> +    RXE_CNT_RCVD_BYTES,
>>       RXE_NUM_OF_COUNTERS
>>   };
>>   diff --git a/drivers/infiniband/sw/rxe/rxe_net.c 
>> b/drivers/infiniband/sw/rxe/rxe_net.c
>> index 6621d01ac32d..86660031ffa2 100644
>> --- a/drivers/infiniband/sw/rxe/rxe_net.c
>> +++ b/drivers/infiniband/sw/rxe/rxe_net.c
>> @@ -503,6 +503,7 @@ int rxe_xmit_packet(struct rxe_qp *qp, struct 
>> rxe_pkt_info *pkt,
>>       int err;
>>       int is_request = pkt->mask & RXE_REQ_MASK;
>>       struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
>> +    unsigned int skblen = skb->len;
>>       unsigned long flags;
>>         spin_lock_irqsave(&qp->state_lock, flags);
>> @@ -526,6 +527,7 @@ int rxe_xmit_packet(struct rxe_qp *qp, struct 
>> rxe_pkt_info *pkt,
>>       }
>>         rxe_counter_inc(rxe, RXE_CNT_SENT_PKTS);
>> +    rxe_counter_add(rxe, RXE_CNT_SENT_BYTES, skblen);
>>       goto done;
>>     drop:
>> diff --git a/drivers/infiniband/sw/rxe/rxe_recv.c 
>> b/drivers/infiniband/sw/rxe/rxe_recv.c
>> index 5861e4244049..e7bab89e7d8d 100644
>> --- a/drivers/infiniband/sw/rxe/rxe_recv.c
>> +++ b/drivers/infiniband/sw/rxe/rxe_recv.c
>> @@ -318,6 +318,7 @@ void rxe_rcv(struct sk_buff *skb)
>>       int err;
>>       struct rxe_pkt_info *pkt = SKB_TO_PKT(skb);
>>       struct rxe_dev *rxe = pkt->rxe;
>> +    unsigned int skblen = skb->len - skb_network_offset(skb);
>>         if (unlikely(skb->len < RXE_BTH_BYTES))
>>           goto drop;
>> @@ -341,6 +342,7 @@ void rxe_rcv(struct sk_buff *skb)
>>       if (unlikely(err))
>>           goto drop;
>>   +    rxe_counter_add(rxe, RXE_CNT_RCVD_BYTES, skblen);
>>       rxe_counter_inc(rxe, RXE_CNT_RCVD_PKTS);
>>         if (unlikely(bth_qpn(pkt) == IB_MULTICAST_QPN))
>
> int rxe_xmit_packet(struct rxe_qp *qp, struct rxe_pkt_info *pkt,
>                     struct sk_buff *skb)
> {
>         int err;
>         int is_request = pkt->mask & RXE_REQ_MASK;
>         struct rxe_dev *rxe = to_rdev(qp->ibqp.device);
>         unsigned long flags;
>
> skb->len is printed here, that is len1
> ...
>         if (pkt->mask & RXE_LOOPBACK_MASK)
>                 err = rxe_loopback(skb, pkt);
>         else
>                 err = rxe_send(skb, pkt);
> ...
> }
>
> In the following function
>
> static int rxe_loopback(struct sk_buff *skb, struct rxe_pkt_info *pkt)
> {
> ...
>         if (skb->protocol == htons(ETH_P_IP))
>                 skb_pull(skb, sizeof(struct iphdr));
>         else
>                 skb_pull(skb, sizeof(struct ipv6hdr));
>
> ...
>         /* remove udp header */
>         skb_pull(skb, sizeof(struct udphdr));
>
> print skb->len here, that is len2
>
>         rxe_rcv(skb);
>
> ...
> }
>
> Does len1 equal to len2?

I have made tests. The difference between len1 and len2 is 28.

It should be the total of ipv4 header + udp header because I use ipv4 
address to make tests.

I am not sure if the bytes of recv data should equal to the bytes of 
xmit data.


Zhu Yanjun

>
> If not, the transmitted length appears to differ from the received 
> length when using loopback.
>
> I am not sure whether this is expected behavior.
>
> The same observation also applies to the non-loopback case.
>
> Zhu Yanjun
>
>> diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.h 
>> b/drivers/infiniband/sw/rxe/rxe_verbs.h
>> index e800545d1046..0f5ffd94643f 100644
>> --- a/drivers/infiniband/sw/rxe/rxe_verbs.h
>> +++ b/drivers/infiniband/sw/rxe/rxe_verbs.h
>> @@ -455,6 +455,12 @@ static inline void rxe_counter_inc(struct 
>> rxe_dev *rxe, enum rxe_counters index)
>>       atomic64_inc(&rxe->stats_counters[index]);
>>   }
>>   +static inline void rxe_counter_add(struct rxe_dev *rxe, enum 
>> rxe_counters index,
>> +                   s64 val)
>> +{
>> +    atomic64_add(val, &rxe->stats_counters[index]);
>> +}
>> +
>>   static inline struct rxe_dev *to_rdev(struct ib_device *dev)
>>   {
>>       return dev ? container_of(dev, struct rxe_dev, ib_dev) : NULL;

-- 
Best Regards,
Yanjun.Zhu