[Openmp-commits] [openmp] [Libomptarget] Remove requires information from plugin (PR #80345)

[Joseph Huber via Openmp-commits]

jhuber6 wrote:

> Current upstream implementation of auto zero-copy does not support global variables. They need to be handled differently from unified_shared_memory. Thinking about it, we should have all the information in libomptarget as we surfaced it as a requires flag. That is, in libomptarget we know that we are in auto zero-copy and not usm, and that should be sufficient to decide on how to handle global variables.
> 
> I am attending the OpenMP face-2-face this week and I didn't have time to work on the patch to support global variables, but will do next week.
> 
> What we have downstream is support to prepopulate GPU page tables from the CPU without using XNACK. I haven't yet figured out if we need to exclude the usm case (prepopulating could apply to usm as well, as a potential optimization), so I don't yet know if we need the info in the plugin.
> 
> I _think_ we can go on with this and still be able to support global variables for automatic zero-copy.

Alright, sounds good. I'll leave you to it. Hope you're having fun at the F2F.

https://github.com/llvm/llvm-project/pull/80345