[compiler-rt] [scudo] Enable "Delayed release to OS" feature for Android (PR #65942)

[Mitch Phillips via llvm-commits]

hctim wrote:

Anders has been working on MTE performance specifically with GeekBench multicore numbers. This patch shows a pretty significant improvement on MTE, which I assume is due to the decreased mmap-sem lock contention in the kernel because on MTE we go from two-syscalls to one-syscall per free.

It does sound like the right place might be changing the Android-specific configuration though (sorry I missed that earlier).

Chia-Hung and Christopher, do you think you can help Anders with evaluating system-level impact of the change? I think we know it's good for perf, at the cost of some RSS, but I don't think he (or I for that matter) know the best way to actually measure the negative RSS impact.

https://github.com/llvm/llvm-project/pull/65942