[Pcsclite-muscle] High CPU load with pcscd and Kerkey security Module

Oliver Graute oliver.graute
Mon Nov 21 02:47:09 PST 2016

On Fri, Nov 18, 2016 at 1:37 PM, Ludovic Rousseau
<ludovic.rousseau at gmail.com> wrote:
> 2016-11-18 10:24 GMT+01:00 Oliver Graute <oliver.graute at gmail.com>:
>> On Wed, Nov 16, 2016 at 2:31 PM, Ludovic Rousseau
>> <ludovic.rousseau at gmail.com> wrote:

> I could not find a real problem in your logs.
> Your PC/SC application is NOT efficient and you could gain of lot of CPU cycle.
> - replace SCardStatus() busy loop by SCardGetStatusChange()
> - do not use SCardBeginTransaction()/SCardEndTransaction() with no
> APDU exchange in between. It is useless, unless I missed something.

Many thanks for your analysis and your comment.
My pcscd-spy debugging leads to similar results

Results sorted by total execution time
total time: 597.958052 sec
42.015016 sec (308 calls)  7.03% SCardTransmit
9.974089 sec (1687 calls)  1.67% SCardStatus

> Are you the author of the PC/SC application running on your board?

No, we are using a custom libpkk11 PKCS11# Host middleware on
top of pcscd, unfortunately this lib is closed source for me. So I need to
contact the Libkkp11 team  (ST Microsystem) to investigate this further.

Best Regards,


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