[PATCH] D148088: [RFC][clangd] Move preamble index task to a seperate task

[Kugan Vivekanandarajah via Phabricator via cfe-commits]

kuganv added a comment.

In D148088#4302092 <https://reviews.llvm.org/D148088#4302092>, @ilya-biryukov wrote:

>> We would like to move the preamble index out of the critical path
>
> Could you provide motivation why you need to do it? What is the underlying problem that this change is trying to solve?
> We rely on preamble being indexed at that particular time for correct results in future steps, it's definitely not a no-op change even if the threading issues are resolved (see the other comment).

Thanks for your comment. Motivation for this is:

1. We see preamble indexing taking as much as 18% of the time for some files.  Moving  preamble indexing out of the critical path helps there.
2. We are also experimenting with preamble caching with clang modules. Early results from this also shows that preamble indexing outside  the critical path improves performance.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D148088/new/

https://reviews.llvm.org/D148088