Comment 5 for bug 2024019

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Chris Halse Rogers (raof) wrote :

SRU review: Ok. From digging around I see that in one benchmark there's a 1% performance decrease measured on ARMv8.0 processors, which seems like an acceptable tradeoff for the very significant performance increase on ARMv8.1 processors¹.

Since we *have* this very nice performance test, could we *also* run it on an ARMv8.0 system as a part of validation? That would give us the relevant performance penalty for v8.0 systems - which would be good to verify is not significant - and also check that the code *works* on v8.0 systems!

So, in summary: this looks like an acceptable SRU, as long as we test on both an ARMv8.0 system and an ARMv8.1 system, and the v8.0 system does not significantly regress performance (around 1% seems ok, much more is iffy).

¹: Although it would be *nice* to have some sort of data as to how prevalent these chips are - is this a big win for almost everyone, with only a few chips that don't support v8.1, or a big win only on uncommon chips?