[compiler-rt] [scudo] Add primary option to enable/disable cache blocks. (PR #129794)

[Jordan R AW via llvm-commits]

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@@ -52,7 +52,10 @@ template <typename Config> class SizeClassAllocator32 {
   static_assert((1UL << Config::getRegionSizeLog()) >= SizeClassMap::MaxSize,
                 "");
   typedef SizeClassAllocator32<Config> ThisT;
-  typedef SizeClassAllocatorLocalCache<ThisT> CacheT;
+  using SizeClassAllocatorT =
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ajordanr-google wrote:

Conceptually, this here (and for 64bit) seems to be where a lot of the type logic is coming down to. Replacing `CacheT` with an SCA LocalCache configurable type; one with thread local caching and one without.

My main question is what's the motivation for this change? Are we doing this for very-low memory scudo configurations? If so, we should probably mention this in the option documentation. If not, what advantages does this model give?

Given this is all static configuration, I'm not going to worry about affecting performance of the current state of Scudo.

https://github.com/llvm/llvm-project/pull/129794