[Lldb-commits] [lldb] [lldb] Keep L1 memory cache chunks disjoint (PR #208347)

[Yao Qi via lldb-commits]

qiyao wrote:

> My main concern with this is that it can lead to quadratic complexity under certain insertion patterns, and that it is making the L1 cache much more complicated. We probably need to use some better data structures to keep track of overlapping ranges and allow fast invalidation of all ranges mutated by a given write.
> 

I thought about it, it was simpler indeed.  My intuition tells me that is it fragile to have a cache allowing overlap.  

> A side note about the commenting style: if we were to keep this patch, I wanted to highlight that we are adding a new invariant to the L1 cache ("ranges are non overlapping"), and there are _many_ comments in the PR repeating this and using it to justify algorithmic decisions. IMO we would be better off having a single line in the header file stating that "the L1 consists of non-overlapping segments", and virtually no comments inside the functions themselves.
> 

I can simplify and re-organize them if we agree on this approach.  When I realized that the overlap chunk scenario wasn't considered when the L1 cache was introduced *11 years ago*,  I wanted to emphasize every step of the fix, and make them clear.



https://github.com/llvm/llvm-project/pull/208347