[PATCH] D26967: Put opt-viewer critical items in parallel

Tue Nov 29 18:06:00 PST 2016

bcain added a comment.

In https://reviews.llvm.org/D26967#604923, @fhahn wrote:

> Here are some numbers I gathered for analyzing 250 opt.yaml files generated by compiling clang/llvm with the following options: "-O2 -g -fsave-optimization-record -mllvm -pass-remarks -mllvm -pass-remarks-missed". The size of the .opt.yaml files varies between a few kB and a few MB.

...

> I'm not sure if I did something wrong. How big were the opt.yaml files you used?

I wasn't able to reproduce these results on an i7 4x2 machine either.  I switched from CPython to Apache Thrift.  It's a C++ project so it will leverage `c++filt` more.   I varied the number of processes and the time either improved or was neutral as I added processes.  I tried with and without `-source-dir` because I noticed your experiments omitted it.  Nothing that I measured was ever slower than the baseline.

Florian, can you upload your specific subset of the LLVM `.yaml` files somewhere?  That way I can try to isolate whether the problem is only visible in that test case or something else.  If it's convenient, can you do an experiment where the `yaml` files are in a `tmpfs` partition like `/dev/shm` and see if this patch is still slower than the baseline?

Repository:
  rL LLVM

https://reviews.llvm.org/D26967