On Fri, Nov 2, 2018 at 2:32 PM Ben Peart <peartben@xxxxxxxxx> wrote: > > From: Ben Peart <benpeart@xxxxxxxxxxxxx> > > During an "add", a call is made to run_diff_files() which calls > check_remove() for each index-entry. The preload_index() code distributes > some of the costs across multiple threads. Instead of doing this site by site. How about we make read_cache() always do multithread preload? The only downside I see is preload may actually harm when there are too few cache entries (but more than 500), but this needs to be verified. If the penalty is small enough, I think we could live with it since everything is fast when you have few entries anyway. But if that's not true, we could add a threshold to activate preload. Something like "if you have 50k files or more, then activate preload" would do. I notice THREAD_COST in preload code, but I don't think it's the same thing. > > Because the files checked are restricted to pathspec, adding individual > files makes no measurable impact but on a Windows repo with ~200K files, > 'git add .' drops from 6.3 seconds to 3.3 seconds for a 47% savings. > > Signed-off-by: Ben Peart <benpeart@xxxxxxxxxxxxx> > --- > > Notes: > Base Ref: master > Web-Diff: https://github.com/benpeart/git/commit/fc4830b545 > Checkout: git fetch https://github.com/benpeart/git add-preload-index-v1 && git checkout fc4830b545 > > builtin/add.c | 9 ++++----- > 1 file changed, 4 insertions(+), 5 deletions(-) > > diff --git a/builtin/add.c b/builtin/add.c > index ad49806ebf..f65c172299 100644 > --- a/builtin/add.c > +++ b/builtin/add.c > @@ -445,11 +445,6 @@ int cmd_add(int argc, const char **argv, const char *prefix) > return 0; > } > > - if (read_cache() < 0) > - die(_("index file corrupt")); > - > - die_in_unpopulated_submodule(&the_index, prefix); > - > /* > * Check the "pathspec '%s' did not match any files" block > * below before enabling new magic. > @@ -459,6 +454,10 @@ int cmd_add(int argc, const char **argv, const char *prefix) > PATHSPEC_SYMLINK_LEADING_PATH, > prefix, argv); > > + if (read_cache_preload(&pathspec) < 0) > + die(_("index file corrupt")); > + > + die_in_unpopulated_submodule(&the_index, prefix); > die_path_inside_submodule(&the_index, &pathspec); > > if (add_new_files) { > > base-commit: 4ede3d42dfb57f9a41ac96a1f216c62eb7566cc2 > -- > 2.18.0.windows.1 > -- Duy
