Re: [Emacs-diffs] /srv/bzr/emacs/trunk r109187: Adjust consing_since_gc when objects are explicitly freed.

[Dmitry Antipov]

On 07/25/2012 01:59 AM, Stefan Monnier wrote:

> What about the overall running time.  How much is saved by your patch,
> and how much additional is saved by the "decrement consing_since_gc in
> free_marker"?

Hm. The test is:

(defun scroll-benchmark ()
  (interactive)
  (let ((oldgc gcs-done)
        (oldtime (float-time)))
    (condition-case nil (while t (scroll-up) (redisplay))
      (error (message "GCs: %d Elapsed time: %f seconds"
                      (- gcs-done oldgc) (- (float-time) oldtime))))))

For xdisp.c, the original results are 600 GCs and 32.65 seconds.

When free_cons and free_misc subtracts from consing_since_gc,
and save_restriction_restore frees it's data explicitly, results
are 560 GCs and 31.95 seconds.

Of course, explicit free in  save_restriction_restore makes no sense
if we fool GC with consing_since_gc: 600 GCs and 32.95 seconds.

I don't understand why we're still wast^W^Wspending our time with
such a simple and almost obvious thing.

Dmitry