system
September 11, 2020, 10:01am
1
The total time until an error is raised is
real-timeouot * retry_cnt
or
real-timeout * (retry_cnt +1). ?
We get IBV_WC_RETRY_EXC_ERR errors and I want to incrase the timeout or retry numbers as present in struct ibv_qp_attr
struct ibv_qp_attr {
...
uint8_t timeout; /* Local ack timeout for primary path (valid only for RC QPs) */
uint8_t retry_cnt; /* Retry count (valid only for RC QPs) */
...
};
Thank you,
Heiner
march
September 15, 2020, 9:36am
2
Hi,
See this link , it expalis how it is calculated:
Contents1 Description2 Parameters3 Return Values4 Examples5 FAQs5.0.0.1 Calling every time to ibv_query_qp() when I need a QP attribute takes time, can I cache some of the attributes?5.0.0.2 Can I specify exactly which attributes will be filled by...
Est. reading time: 18 minutes
Table of timeut values:
timeoutThe minimum timeout that a QP waits for ACK/NACK from remote QP before retransmitting the packet. The value zero is special value which means wait an infinite time for the ACK/NACK (useful for debugging). For any other value of timeout , the time calculation is: usec.
For your convenience, here is the summary of each value and its timeout:0 - infinite
1 - 8.192 usec (0.000008 sec)
2 - 16.384 usec (0.000016 sec)
3 - 32.768 usec (0.000032 sec)
4 - 65.536 usec (0.000065 sec)
5 - 131.072 usec (0.000131 sec)
6 - 262.144 usec (0.000262 sec)
7 - 524.288 usec (0.000524 sec)
8 - 1048.576 usec (0.00104 sec)
9 - 2097.152 usec (0.00209 sec)
10 - 4194.304 usec (0.00419 sec)
11 - 8388.608 usec (0.00838 sec)
12 - 16777.22 usec (0.01677 sec)
13 - 33554.43 usec (0.0335 sec)
14 - 67108.86 usec (0.0671 sec)
15 - 134217.7 usec (0.134 sec)
16 - 268435.5 usec (0.268 sec)
17 - 536870.9 usec (0.536 sec)
18 - 1073742 usec (1.07 sec)
19 - 2147484 usec (2.14 sec)
20 - 4294967 usec (4.29 sec)
21 - 8589935 usec (8.58 sec)
22 - 17179869 usec (17.1 sec)
23 - 34359738 usec (34.3 sec)
24 - 68719477 usec (68.7 sec)
25 - 137000000 usec (137 sec)
26 - 275000000 usec (275 sec)
27 - 550000000 usec (550 sec)
28 - 1100000000 usec (1100 sec)
29 - 2200000000 usec (2200 sec)
30 - 4400000000 usec (4400 sec)
31 - 8800000000 usec (8800 sec)
Relevant only to RC QPs
Regards
Marc