d/numam-dpdk
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

doc: add limitations section to cryptoperf guide

Browse Source 
Add limitations to use of the dpdk-test-crypto-perf
tool for hardware accelerator measurements

Signed-off-by: Fiona Trahe <fiona.trahe@intel.com>
Acked-by: Slawomir Mrozowicz <slawomirx.mrozowicz@intel.com>
This commit is contained in:
Fiona Trahe 2017-02-07 16:32:55 +00:00 committed by Pablo de Lara
parent d27befd0b6
commit 4fa706bf48
1 changed files with 15 additions and 0 deletions

15
doc/guides/tools/cryptoperf.rst

@ -41,6 +41,21 @@ chain mode have to be specified in the command line as application
parameters. These parameters are checked using device capabilities
structure.
Limitations
-----------
On hardware devices the cycle-count doesn't always represent the actual offload
cost. The cycle-count only represents the offload cost when the hardware
accelerator is not fully loaded, when loaded the cpu cycles freed up by the
offload are still consumed by the test tool and included in the cycle-count.
These cycles are consumed by retries and inefficient API calls enqueuing and
dequeuing smaller bursts than specified by the cmdline parameter. This results
in a larger cycle-count measurement and should not be interpreted as an offload
cost measurement.
On hardware devices the throughput measurement is not necessarily the maximum
possible for the device, e.g. it may be necessary to use multiple cores to keep
the hardware accelerator fully loaded and so measure maximum throughput.
Compiling the Application
-------------------------