We've measured significant performance improvements for several benchmarks by using 64K pages (SPECint, sysbench mysql, and kernel compiling)[*]. I'd therefore like to discuss whether or not we should switch to 64K pages in vivid.
There's the question of whether or not we would be penalizing the performance of other classes of workloads people want to run on arm64. If there are some representative tests we should be looking at, please let me know. Also, a known tradeoff is that we'd lose compatibility with existing ARMv7 binaries. This is because, until very recently, binutils did not guarantee 64k section alignment for 32-bit binaries: http://www.spinics.net/lists/arm-kernel/msg383869.html I'm not sure how much interest there is for ARMv7 compat in Ubuntu. There is the developer use case of using the same hardware for armhf and arm64 porting - which, theoretically, we could also achieve by rebuilding those ports w/ an updated binutils. But otherwise, I'm not aware of many legacy ARMv7 apps that users are likely to want to bring over to Ubuntu/arm64 that couldn't be rebuilt. As points of reference, both OpenSuSE and Fedora appear to be using 64K pages, while Debian is currently using 4K. [*] Unfortunately I'm not allowed to share these results outside of Canonical due to NDAs - but I can provide details on the tests we ran for people who may want to run them on their own hardware. -- ubuntu-devel mailing list [email protected] Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel
