awslabs/damo

Does damo support multiple "damo record"?

honggyukim opened this issue · 4 comments

honggyukim commented

Hi SeongJae,

I have tried to run damo record in two different terminals together while the other is running, but see that the second damo record gets the following failure.

$ sudo ./damo record -o damon.stairs3.data "./masim/masim ./masim/configs/stairs.cfg"
could not turn DAMON on (writing on to /sys/kernel/mm/damon/admin/kdamonds/0/state failed ([Errno 16] Device or resource busy))

As I understand, /sys/kernel/mm/damon/admin/kdamonds/nr_kdamonds can be larger than 1 and it can create multiple kdamonds, but I'm wondering why this failure is shown in damo.

I guess it might be a problem only in damo, but not from DAMON framework inside kernel.

Could you please confirm if my assumption is correct or not?

Thanks.

honggyukim commented

The same problem is shown with multiple damo start.

sj-aws commented

In short, your assumption is correct. DAMON supports the use case, but damo's current official interface doesn't support the use case. We're aiming to support such use case with the next generation of the interface, though. Please bear in mind with me until the next generation interface is ready.

Could you further clarify your use case in detail, though? Maybe I could provide you some workaround, let you know some damo feature that not-yet-official but could be used for you, or adjust the next generation interface design to better fit your use case from the beginning of its official support.

honggyukim commented

In short, your assumption is correct. DAMON supports the use case, but damo's current official interface doesn't support the use case.

Thanks for the confirmation. Then I think it’s fine now.

Could you further clarify your use case in detail, though?

I can’t clearly state the concrete use case for now. I will think more and talk to other colleagues then get back to you.

Thanks for your help!