top says usage is <1%, I start jtop and then usage is at 100%...

[AlexisWilke]

Is your feature request related to a problem? Please describe.
A tool such as top is expected to have a minimal impact on the CPUs otherwise it's really difficult to know what uses the CPU(s).

The current version uses between 5% and 25% of each of my 4 CPUs. Most often around a total of 100% CPU time.

Describe the solution you'd like
The tool should somehow be faster. For example, top uses just 0.7% to 1%.

One thing top does is redraw only what's necessary in an attempt to reduce the time to send characters to the screen as much as possible.

Describe alternatives you've considered
For now I use top and sudo tegrastats which give me the data I'm interested in although not as good as jtop, these tools are fast.

Additional context
I run on a Jetson AGX Xavier.

Also, I run remotely (but I would imagine many of us do). Since top is not affected by that part, I would think that jtop wouldn't either.

Note that the jetson_stats does not seem to use much CPU at all. Under 1% most of the time.

[rbonghi]

Thank you for your message and detail about jetson_stats. This is a know issue #73 ( and other issues that I do not remember).
The main reason now is the use of sub-processes to read the status of the Jetson board.
At this time jtop run different supbrocess in background to print the status:

• tegrastats
• jetson_clocks
• /proc/meminfo
• fan

but the heavy processes that I notice are tegrastats and jetson_clocks.
It's in a plan for the next revision to rewrite that parts directly reading from the system the status of the board.
I expect to reduce the usage of jtop for another 10-15% but I do not think the status of jtop will be less than top
I do not have right now an experience to improve the performance of jtop in a python script, but I am working on that.

[AlexisWilke]

Ah. I see that #73 is closed, which would be why I did not see it when for looking to make sure I don't open a duplicate.

Yes. Directly reading the files could be much faster. I did not realize that you ran tegrastats to get that info. In top/htop, though, tegrastats does not appear to use much CPU. On the other hand, I can see jetson_clocks quite a bit. Well... I hope you can reduce the the usage. Right now it's great to tweak a few things and check the NVDEC and such parameters, but CPU wise, it's not practical while running my own app.