I felt these days main waterfall clobber builds are slow. Then I found goma DepsCache is not used at all.
DepsCache data was saved to output directory before. It's moved to /b/c/goma_deps_cache/ directory, but there is no such a directory. So, goma failed to save the DepsCache data.
Even if /b/c/goma_deps_cache/ directory exists, there is another problem if we save the data to /b/c/goma_deps_cache/. DepsCache should be per-builder file. Otherwise, a lot of entries are saved in one file, and older entries are removed soon.
We have /b/c/goma_cache/ for compiler info cache (also better if it's per-builder file). Maybe good to make /b/c/goma_cache/<builder-name>, and use it for goma cache directory?
See b/31356415
Comment 1 by shinyak@chromium.org
, Sep 8 2016