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RGA 2.9.1 and above - Segmentation fault at startup

Open TomClabault opened this issue 7 months ago • 3 comments

Double clicking on the RGA (v2.9.1 or newer) executable doesn't seem to open anything.

Using the commandline instead to start RadeonGPUAnalyzer.exe reveals a Segmentation Fault error:

Image

Running Windows 11 24H2 + 7900XTX drivers 25.3.1.

Is there any workarounds for that?

TomClabault avatar May 01 '25 09:05 TomClabault

Hi @TomClabault,

You mentioned Windows 11 24H2 as your configuration, but the screenshot with the "Segmentation fault" message seems to indicate that you are running on Linux. Can you please clarify?

On a Windows machine, can you try using the installer? It cleans up stale configuration files which might solve your issue.

AmitBM avatar May 01 '25 17:05 AmitBM

This screenshot was taken on Windows but using a git bash, hence the Linux look. Using the installer did fix the issue indeed!

Also, I have some more general question on RGA and how to use/understand it: I've done binary analysis of my HIP kernel and I can see 43 scalar register spills

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  • What is the unit of 43? Is the unit registers? Meaning that ideally, I would need 107+43 = 150 scalar registers to avoid any spilling?
  • Do spills necessary imply additional global memory accesses? If I have 43 spills, does that mean that I have now have 43 more global memory accesses in my kernel? Asked otherwise, how to translate spills to kernel slowdown? How bad is 43 spills and what kind of slowdown can I expect from that?

TomClabault avatar May 01 '25 19:05 TomClabault

Another question on a very large kernel:

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If there is no spilling, why do I have some much scratch memory usage? What are the reasons the compiler can use scratch memory besides register spilling?

TomClabault avatar May 02 '25 06:05 TomClabault