Timing between scans is not consistent

[sms-00]

I am currently using the A1 RPLIDAR unit.

I am running the SDK version 2.0 from GitHub. It appears to be working well except for one small issue with inconsistent time.

I am running the Ultra_simple routine on my Raspberry Pi 4. I have modified the ultra_simple routine to only show the time between scans and commented out the printf showing the values. No other changes.
I have noticed that the timing is not consistent between scans. Every 4th or 5th scan, it takes 250ms to receive a new scan rather than the typical 125miliscond. Why am I seeing this issue?

Times below are in milliseconds:
117
127
134
144
235 - why so long?
132
144
111
125
128
262 - why so long?
140
120
117
137
135
123
255- why so long?
Example code.txt

Thanks for your support!

[WubinXia]

There may be thread contention issues causing the data cache to be scanned, please try to improve the priority of the corresponding thread