Andreas Hansson got review request #3003!
mem: Remove extraneous acquire/release flags and attributes
Review Request #3003 - Created Aug. 5, 2015 and submitted
| Information | |
|---|---|
| Andreas Hansson | |
| gem5 | |
| default | |
| Reviewers | |
| Default | |
Changeset 11001:5b78d01bf635 --------------------------- mem: Remove extraneous acquire/release flags and attributes This patch removes the extraneous flags and attributes from the request and packet, and simply leaves the new commands. The change introduced when adding acquire/release breaks all compatibility with existing traces, and there is really no need for any new flags and attributes. The commands should be sufficient. This patch fixes packet tracing (urgent), and also removes the unnecessary complexity.
You can go ahead an ship it, but we'll likely keep this conversation going. There arem more flags our APU model - which we plan to release publically soon - has added as well.
Hi Andreas,
I was going to look at addressing this today for AMD. I'm not extremely familiar with the organization of the request flags, packet commands, packet attributes, and packet flags. That said, I was under the impression that the request is supposed to capture information that exist at the instruction level. To me, acquire and release are at the instruction level (not a spurious command between two memory controllers like flush command).
Also, the 32 bits that we have to work with in the request seems rather small. Especially, when you consider that it needs to capture all of the possible attributes for a memory request across all of the different ISAs...
How would armv8 ldra and strl instructions convey to the cache hierarchy acquire/release attributes from the instruction (if it were necessary).
Hey Andreas,
Go ahead and ship this. But I would appreciate your thoughts on my comment. I will move that over to an email thread on gem5-dev. Simply put, we need to get this information down to the cache controllers, and I would like to do it in a way that everyone is happy with and can even leverage in their own work.
Thanks,
Marc
Ship It!