[PATCH] D69825: [Clang][Driver] Re-use the calling process instead of creating a new process for the cc1 invocation

Mon Nov 25 08:55:58 PST 2019

aganea added a comment.

Thanks for the feedback Russell!

Can you possibly try again with `/MT`? (ie. `-DLLVM_USE_CRT_RELEASE=MT`)

In the `abba_test.ps1` script, `ninja check-all` is only used for preparing clang.exe with the patch. The A/B loop //does not// use `check-all`.

I've modified the `abba_test.ps1` script to only build `llvm/`, with the same options as you do. There was also a bug in the timespan calculation, the test would last a lot more than you specified.

I also found out that on some of our multi-socket servers, Ninja defaulted to only the # threads from the first socket. If you had a 2x 18-core system, Ninja would default to 38 threads (18 x 2 + 2) instead of 74 threads (2 x 18 x 2 + 2). This behavior seems to be random,  depending on the system. This has been fixed by Ninja PR 1674 <https://github.com/ninja-build/ninja/pull/1674>, I've tested all our systems with this patch and they now all default to the proper # of threads.

I'm doing a new round of tests, I'll get back with updated figures.

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D69825/new/

https://reviews.llvm.org/D69825