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cambridgehackers / connectal

Connectal is a framework for software-driven hardware development.
MIT License
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Change aws poller time: 10 times speed. #146

Closed threonorm closed 6 years ago

jankcorn commented 6 years ago

I am not sure why you want to reduce the poll timeout interval down to 1ms. This will cause the 'event indication'/listening thread in the host program to pop back back and forth between user space & kernel when an indication has not been raised. (If an indication is detected, then the polling will immediately return to the user, without waiting).

I don't object to accepting this change, but am just wondering if the core problem might be dropped PCIe interrupt indications. If these indications are being dropped on AWS, then the change is perfectly fine (otherwise, interrupt latency is quite long).

Thanks for looking into this!

threonorm commented 6 years ago

I believe interrupts are not working on AWS right now. That is the reason why we currently need this active polling. That will sacrifice one thread to that active polling on AWS, but as an intermediate solution waiting for interrupts, that makes the speed much more acceptable.

jameyhicks commented 6 years ago

Deleted 1 character, sped up 10x :) Need to fix AWS interrupts

On Thu, Nov 9, 2017 at 7:57 PM jankcorn notifications@github.com wrote:

Merged #146 https://github.com/cambridgehackers/connectal/pull/146.

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jameyhicks commented 6 years ago

Yes, it is a ridiculous timeout and will change it back once interrupts are debugged.