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greatscottgadgets / ubertooth

Software, firmware, and hardware designs for Ubertooth
https://greatscottgadgets.com/ubertoothone/
GNU General Public License v2.0
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Controlling ubertooth-rx memory usage #444

Closed ziXet closed 3 years ago

ziXet commented 3 years ago

Steps to reproduce

  1. Run "ubertooth-rx" without any extra parameter
  2. use htop to monitor memory usage

Expected behaviour

Why the memory usage should go to 64MB? Is there any internal buffering?

Actual behaviour

The memory usage of ubertooth-rx goes to 64MB and stays there.

Version information

Operating system: Ubuntu

ubertoth-rx -V libubertooth 1.1 (2018-12-R1), libbtbb 1.0 (2018-06-R1)

orgua commented 3 years ago

i think thats based on the reversing of the hopping pattern - its done on the cpu. Nothing unusual

ziXet commented 3 years ago

i think thats based on the reversing of the hopping pattern - its done on the cpu. Nothing unusual

I don't really understand what you mean by "it's done on the CPU" !

orgua commented 3 years ago

as you might know the ubertooth has at least one microcontroller. But it is not capable enough to bluetooth on its own. that's all i wanted to imply. whats the trouble with the 64 MB? What is there to control?

The problem with breaking into the bluetooth-communication is similar to a rainbow-table. it saves a lot of compute time, but costs storage.

ziXet commented 3 years ago

as you might know the ubertooth has at least one microcontroller. But it is not capable enough to bluetooth on its own. that's all i wanted to imply. whats the trouble with the 64 MB? What is there to control?

The problem with breaking into the bluetooth-communication is similar to a rainbow-table. it saves a lot of compute time, but costs storage.

I think I know where the confusion is coming from!

I believe you didn't try to reproduce the situation.

The issue is that the 64MB memory is not consumed at the beginning of running the program. It start with 1MB and gradually increase to 64MB in 3-4 minutes and will stay in 64 for ever. This doesn't look like a normal memory usage profile to me.

miek commented 3 years ago

64MB is the size of the rx packet FIFO: https://github.com/greatscottgadgets/ubertooth/blob/d1feeccbd2fba266695a0052caab872ca5bcc263/host/libubertooth/src/ubertooth_fifo.h#L27-L34 the reason why it doesn't all show up immediately is that Linux will not actually allocate it all immediately, only as it is used.

ziXet commented 3 years ago

64MB is the size of the rx packet FIFO: https://github.com/greatscottgadgets/ubertooth/blob/d1feeccbd2fba266695a0052caab872ca5bcc263/host/libubertooth/src/ubertooth_fifo.h#L27-L34

the reason why it doesn't all show up immediately is that Linux will not actually allocate it all immediately, only as it is used.

That was the answer I was looking for! Thank you!