akiuni |
10-26-2012 08:27 AM |
need help to localise a bad performance on cryptographic operations
Hello everybody
I'm facing a lack of performance on a server equiped with an offload cryptographic card and I'm wondering if it's a driver problem...
The hardware seems to working well :
Quote:
#openssl speed rsa1024 -engine cavium
sign verify sign/s verify/s
rsa 1024 bits 0.000009s 0.000004s 116775.0 256471.1
#openssl speed rsa1024
sign verify sign/s verify/s
rsa 1024 bits 0.002285s 0.000099s 437.7 10080.4
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but if I run openssl in elapsed mode, here are the results :
Quote:
#openssl speed rsa1024 -engine cavium -elapsed
sign verify sign/s verify/s
rsa 1024 bits 0.000715s 0.000104s 1399.0 9607.3
#openssl speed rsa1024 -elapsed
sign verify sign/s verify/s
rsa 1024 bits 0.002283s 0.000099s 438.0 10053.0
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As you can see, the "elapsed" perfs are very bad compared to the cpu time perfs... I would like to know why. The server is doing absolutely nothing else... Here are the headers of the "top commands" during a benchmarking test:
no tests:
Quote:
Cpu(s): 2.0%us, 1.2%sy, 0.0%ni, 96.8%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
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tests without cavium engine:
Quote:
Cpu(s): 53.7%us, 0.2%sy, 0.0%ni, 45.9%id, 0.0%wa, 0.0%hi, 0.1%si, 0.0%st
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tests with cavium engine loaded:
Quote:
Cpu(s): 4.8%us, 10.6%sy, 0.0%ni, 84.1%id, 0.0%wa, 0.0%hi, 0.4%si, 0.0%st
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I'm suspecting the s/w or driver to spend a lot of time waiting for the crypto accelerator to respond to crypto operations, but I don't know how to confirm this...
Does anybody have an idea about my problem ? or, can someone tell me how to check the "daughter card response time" ?
Thanks a lot
bests regards
Julien
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