ruby: Fixed pipeline squashes caused by aliased requests
Review Request #3179 - Created Oct. 30, 2015 and discarded
| Information | |
|---|---|
| Tony Gutierrez | |
| gem5 | |
| default | |
| Reviewers | |
| Default | |
Changeset 11185:fc3ceeb4a47d --------------------------- ruby: Fixed pipeline squashes caused by aliased requests This patch was created by Bihn Pham during his internship at AMD. This patch fixes a very significant performance bug when using the O3 CPU model and Ruby. The issue was Ruby returned false when it received a request to the same address that already has an outstanding request or when the memory is blocked. As a result, O3 unnecessary squashed the pipeline and re-executed instructions. This fix merges readRequestTable and writeRequestTable in Sequencer into a single request table that keeps track of all requests and allows multiple outstanding requests to the same address. This prevents O3 from squashing the pipeline.
Posted (Nov. 2, 2015, 1:03 p.m.)
Can you clarify the intent with this request? This is the same as the first diff submitted in review request 2787 (http://reviews.gem5.org/r/2787/diff/1/ ), but we have already iterated on that patch multiple times. There are also still open issues with the latest diff in 2787.
I would prefer that this review request be discarded, and we reconvene on 2787, so that we do not lose progress and open issues.