[PATCH] D119784: [Symbolize] LRU cache binaries in llvm-symbolizer.

[Daniel Thornburgh via Phabricator via llvm-commits]

mysterymath added a comment.

It doesn't look like the memory usage improvements of either patch are a proper subset of each other.

This patch operates file-at-a-time; it ejects all of the debug information for a given file at once. This includes data that isn't covered by the other patch: PDB debug info, the lists and ancillary data structures parsed in the ObjectFiles, and the contents of the binary files themselves (which may not have been mmapped if they were small).
It should completely subsume the other patch with regards to long-term leak protection; everything should be discarded between symbolization requests.

However, since the other patch operates at a finer granularity, it can reduce memory usage even when only one single binary present, as in the example provided in https://reviews.llvm.org/D90006, which showed a reduction when symbolizing clang alone.

If we start with coarse-grained caching, we could replace disable caching for objects like DWARFContext with finer grained caching as it becomes available.
If we instead starting with finer-grained caching on a subset of the data (DWARFContext), it would help reduce the leakiness of llvm-symbolizer, but it kicks the can down the road. I'm not sure exactly how far, though; maybe quite far.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D119784/new/

https://reviews.llvm.org/D119784