bug#31853: 27.0.50; binding case-fold-search is slow when there are many buffers

[Aaron Jensen <aaronjensen@gmail.com>]

On Fri, Jun 15, 2018 at 11:45 PM Eli Zaretskii <eliz@gnu.org> wrote:
> It is related to that bug only if you have a lot of dead buffers.  The
> URL pointed out by Noam includes a patch that would allow you to count
> dead buffers you have; can you do that?

I've got it compiled in now and will report back when it repros as
badly as it did originally.

> In a session that has 291 buffers, I get 2.8 microseconds, whereas in
> fresh "emacs -Q", I get 1.5 microseconds.  This is 3 orders of
> magnitude faster than what you get, and the difference between a large
> session and a new one is much smaller.

I think I missed a zero on my original fresh emacs report. The report
of 1ms per for a long running emacs was correct though.
These should be accurate:
On emacs -Q I get 2 microseconds.
On a newly launched emacs w/ my config I get 3 microseconds with 9
buffers and 1 killed buffer.
On an emacs I've been running for a bit I get 40 microseconds with 71
buffers and 237 killed buffers.