[PATCH] D58271: [ELF] --gdb-index: split off GdbSymbol::CuVector and add a separate CuVectors

Wed Mar 6 00:14:03 PST 2019

MaskRay abandoned this revision.
MaskRay added a comment.

I'll abandon this revision. This does decrease memory footprint (~3.85% in two of our large internal executables) for glibc allocator based lld without a performance hit, but unexpectedly increases memory footprint for out internal tcmalloc based lld. I also don't like the additional complexity.

I have a strong belief: (I actually wanted to call it impossible but just didn't want to make an absolute assertion :) ) we can't decrease the memory usage of `.gdb_index` without a performance hit. I sorta blame the function has been optimized tell well for performance :( If we can emphasize less on performance, https://reviews.llvm.org/D58276 (and https://reviews.llvm.org/differential/diff/187004) is a more feasible direction to decrease memory usage (internally, we care memory usage a lot. The performance is already very good (2x ~ 4x faster compared with gold for a wide range of applications). Some sacrifice on it is totally acceptable, but on the other hand, we have some hard memory usage limits and the current memory footprint characterstics make some huge targets unable to link).

Repository:
  rLLD LLVM Linker

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D58271/new/

https://reviews.llvm.org/D58271