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

[Noam Postavsky]

Aaron Jensen <aaronjensen@gmail.com> writes:

> I don't know how to tell the length of my all_buffers or to see how many
> killed buffers I have.

Try applying Martin's patch from #18522:

https://debbugs.gnu.org/cgi/bugreport.cgi?bug=18522#198

Then you can do M-: (killed-buffer-names) RET.

Although my understanding of the resolution of Bug#18522 is that dead
buffers should no longer affect the time for let-binding variables, just
live ones (but maybe the fix missed something).