cpu: Tidy up the MemTest and make false sharing more obvious

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Submitter:	Andreas Hansson
Repository:	gem5
Branch:	default
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Description

Changeset 10671:94bc71e83168
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cpu: Tidy up the MemTest and make false sharing more obvious

The MemTest class really only tests false sharing, and as such there
was a lot of old cruft that could be removed. This patch cleans up the
tester, and also makes it more clear what the assumptions are. As part
of this simplification the reference functional memory is also
removed.

The regression configs using MemTest are updated to reflect the
changes, and the stats will be bumped in a separate patch. The example
config will be updated in a separate patch due to more extensive
re-work.

In a follow-on patch a new tester will be introduced that uses the
MemChecker to implement true sharing.

Testing Done

Issue Summary

Description	From	Last Updated	Status
Are you sure this should be dropped? I think the coherence protocols that provide a dma controller need this for ...	Nilay Vaish	Jan. 31, 2015, 1:43 a.m.	Dropped

src/cpu/testers/memtest/MemTest.py (Diff revision 1)

Are you sure this should be dropped?  I think the coherence protocols that provide a dma controller need this for testing.

Show all issues

Andreas Hansson Jan. 31, 2015, 1:43 a.m. (Jan. 31, 2015, 1:43 a.m.)

All regressions work just fine (with stats updates).

I am about to post a separate test script that actually shares data (not just false sharing), doing so based on the TrafficGen and MemChecker.

Andreas Hansson Feb. 2, 2015, 1:11 p.m. (Feb. 2, 2015, 1:11 p.m.)

You're ok with this Nilay? I'll post the true-sharing checker later this week.

Andreas Hansson Feb. 3, 2015, 9:34 a.m. (Feb. 3, 2015, 9:34 a.m.)
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Pretty please :-)
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Andreas Hansson Feb. 3, 2015, 12:02 p.m. (Feb. 3, 2015, 12:02 p.m.)
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http://reviews.gem5.org/r/2626/ actually tests true sharing
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Andreas Hansson Feb. 7, 2015, 9:08 a.m. (Feb. 7, 2015, 9:08 a.m.)

Would really appreciate getting this pushed, so if there are any more comments please let me know.

Looks fine to me.  In the abstract I agree with Nilay that DMA operations need to be included in the memory tester; we're having some internal trouble with DMA operations in Ruby right now in fact.  Concretely, though, I don't see what the 'dma' option in this tester really does other than issue requests of a different size, so I don't see how it actually supported that abstract goal.

You have a pending review.

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Issue Summary

Status: Closed (submitted)