197 questions
2
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0
answers
50
views
How to get listen() backlog value for a port used by libfabric (verbs) on Ubuntu?
I have a server application using libfabric (verbs provider) that is listening on port 8082 on Ubuntu Linux.
Is there a way to retrieve the backlog value for that listening port?
Something similar to ...
- 131
-3
votes
0
answers
44
views
Libfabric ofi server with multiple listen thread possible
I am using Libfabric to start an OFI listener on port 8088 with the following code:
.....
ret = fi_getinfo(OFI_VERSION, "172.0.0.1", "8088", FI_SOURCE, hint.get(), &fi); //...
- 131
2
votes
0
answers
62
views
Is it possible to specify a source port in libfabric's DRMA client side?
I'm working with libfabric and trying to specify a source port for my application. I've set up my fi_info structure and assigned the source address and port, but it doesn't seem to be working as ...
- 131
0
votes
0
answers
56
views
GPUDirect Implementation Challenges with NVIDIA RTX A4000
We are currently working on transitioning from AMD (Radeon PRO W6800) to NVIDIA graphics cards due to hardware availability and implementing NVIDIA’s GPUDirect feature.
We implemented the following ...
- 1
0
votes
0
answers
14
views
Why rdma_connect failed will have to free the resources?
In RDMA programming with librdmacm, when client thread try to connect the remote server thread with rdma_connect(), what is the reason that we have to release the rdma_cm_id resources?
- 127
0
votes
1
answer
108
views
Unable to Receive Messages with InfiniBand UD (Unreliable Datagram) Communication
I am currently writing a sample program for RDMA communication using InfiniBand. The setup involves two servers, each running a single process. The goal is to send data from one server (Sender) to the ...
0
votes
0
answers
106
views
How to solve disagrees about version of symbols?
I am working on a kernel module, after insmod I got such errors in dmesg:
[ 5839.116224] mcswap: disagrees about version of symbol rdma_leave_multicast
[ 5839.116234] mcswap: Unknown symbol ...
- 13
0
votes
0
answers
24
views
How to transfer large message(>MTU) using RDMA UD mode?
RDMA UD (Unreliable Datagram) mode support Send/Recv operation only, and with the limit that only one packet can be sent with a send wr, which causes that the transfered message's size should less ...
- 127
0
votes
0
answers
25
views
In libibverbs, when does completion entry get pushed to CQ?
After a wr has been posted through ibv_post_send to a RC, does completion entry get pushed to sender's cq when data has been written to destination buffer and the sender receive an acknowledgement?
...
0
votes
0
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48
views
Go-Back-N in RoCE: when does the senders waits for ACK?
In this paper explaining Go-Back-N algorithm in RoCE (RDMA over Ethernet protocol), that the sender is requesting an ACK not for every packet but for every X packets:
As for middle packets, sender ...
- 1,642
0
votes
1
answer
108
views
How RDMA map remote memory into local virtual memory?
I am new to RDMA and have just started looking into OPENSHMEM and UCP. I saw that both of them allow mapping remote memory region into local virtual memory space and access it using regular load and ...
0
votes
1
answer
76
views
When using RDMA to access memory on another machine, does it incur memory bandwidth overhead on both side?
Assuming that Machine-1 accesses data in the memory of Machine-2 via RDMA, will this action incur memory bandwidth overhead on both Machine-1 and Machine-2?
If a regular network card is used for data ...
- 739
0
votes
0
answers
51
views
Is system call always involved in issuing a RDMA operation?
I read the following from ibverbs' website:
"InfiniBand host channel adapters (HCAs) and iWARP NICs commonly support direct hardware access from userspace (kernel bypass), and libibverbs supports ...
2
votes
2
answers
227
views
verbs: Difference between a Shared Completion Queue and a Shared Receive Queue?
I am trying to manage multiple Queue Pairs connections in the same thread. To do that, I can share the same Completion Queue with multiple Queue Pairs and poll it in a single thread.
I don't see what ...
- 1,642
0
votes
1
answer
93
views
RDMA access flags validation
If we receive Send or Send with Immediate packets but don't have local write access right in RC, UC, or UD, what behavior should we expect?
I think that there’s a local protection error in the target, ...
- 11