Re:Glibc sysdeps: dl_platform detection effectively performs...
by admax88q on Monday September 09, 2019 @09:46AM
(#20918084)
If the original patch contained a benchmark showing that it was slower on the current AMD processors then this would be a reasonable argument.
It did not, because no such testing was done.
I think there's a pretty low baseline of effort they can put in. I also think that if they enabled new code paths for newer instructions that turned out to be slower on AMD, very few people would claim this was Intel being evil. Most would blame AMD for selling a defective product.
Re:Glibc sysdeps: dl_platform detection effectively performs...
by cptskippy on Monday September 09, 2019 @01:10PM
(#20920026)
I would argue it's absurd ask for Intel to maintain test platforms for a competitor.
At best you could ask them to flag platform specific code in such a way that others, who are better equipped, can test against other platforms.
What happens if the implementation is slower but still works on AMD? Is Intel responsible for also performance testing and determining if/when to disable an implementation on a given chip? You're putting a lot of burden on Intel to do extensive testing and also not protecting them from criticism if a change is suboptimal for a competitor.
I think it's fine to submit a patch that's known to be good for a subset of CPUs and perhaps it should be tagged for another maintainer (e.g. AMD) to review and contribute to as well.