From: Alan Mackenzie <acm@muc.de>
To: Eli Zaretskii <eliz@gnu.org>
Cc: 16526@debbugs.gnu.org
Subject: bug#16526: 24.3.50; scroll-conservatively & c-mode regression
Date: Sun, 2 Feb 2014 17:40:50 +0000 [thread overview]
Message-ID: <20140202174050.GA5365__39445.5885202207$1391367777$gmane$org@acm.acm> (raw)
In-Reply-To: <834n4j5d3k.fsf@gnu.org>
Hello, Eli.
On Sat, Feb 01, 2014 at 12:41:51PM +0200, Eli Zaretskii wrote:
> > Date: Thu, 30 Jan 2014 19:58:17 +0100
> > From: martin rudalics <rudalics@gmx.at>
> > CC: acm@muc.de, 16526@debbugs.gnu.org
> > > It takes about 11 sec here. But reverting the patch doesn't change
> > > this timing, I still get 11 sec.
> > But it does take longer with a maximized window?
> Yes, it does.
> > If so, do you have an explanation?
> Those 11 seconds are spent inside 'recenter', which is called by
> end-of-buffer:
> ;; If we went to a place in the middle of the buffer,
> ;; adjust it to the beginning of a line.
> (cond ((and arg (not (consp arg))) (forward-line 1))
> ((and (eq (current-buffer) (window-buffer))
> (> (point) (window-end nil t)))
> ;; If the end of the buffer is not already on the screen,
> ;; then scroll specially to put it near, but not at, the bottom.
> (overlay-recenter (point))
> (recenter -3)))) <<<<<<<<<<<<<<<<<<<<<<<<<<
> Stepping through 'recenter', I see the following:
> . It treats GUI frames specially (and indeed, in "emacs -nw", I
> don't see this slowdown). The special handling is that it
> attempts to find the window-start point that corresponds to the -3
> argument, by interpreting that argument as the number of pixels
> equivalent to 3 canonical-height lines.
> . To this end, 'recenter' calls move_it_vertically_backward with the
> -3 argument converted to pixels. move_it_vertically_backward then
> tries to find that place, by simulating display.
> . As part of the display simulation, jit-lock-function is called
> (because we hit a buffer position which has a non-nil 'fontified'
> property) with a single argument: buffer position 948757. This
> single call takes almost all of the 11 seconds.
> When the frame is not maximized, the window height is smaller, so
> 'recenter' moves back a smaller amount of pixels, and calls
> jit-lock-function at a different buffer position. That call takes
> only about 2 sec (still quite a lot, IMO).
> Perhaps Alan could explain why the CC Mode fontification takes such a
> long time for buffer position 948757.
No, sorry I can't explain it. Except that CC Mode will be scanning
forward through the entire buffer once (hopefully only once) to get the
"parse state" near EOB.
On a normally optimised 24.3 build, M-x goto-char 948757 is taking me a
little over a second. This is in a GUI frame in X Windows, maximised by
clicking on the maximise button at the top right of the frame.
On my non-optimised 24.3.50 build with tracing built in, the same action,
M-x goto-char 948757 takes 9 seconds. In a non-maximised frame it takes
8 seconds. In this build, M-> takes ~2 seconds regardless of whether the
frame is maximised or not. I can't explain this difference.
I've committed my patch. I hope it clears up the bug (which I haven't
yet closed) more or less satisfactorally.
--
Alan Mackenzie (Nuremberg, Germany).
next prev parent reply other threads:[~2014-02-02 17:40 UTC|newest]
Thread overview: 93+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <mailman.12613.1390467262.10748.bug-gnu-emacs@gnu.org>
2014-01-23 8:53 ` bug#16526: 24.3.50; scroll-conservatively & c-mode regression martin rudalics
2014-01-24 15:45 ` martin rudalics
2014-01-24 20:48 ` Alan Mackenzie
[not found] ` <lbujij$1scv$1@colin.muc.de>
2014-01-25 3:50 ` Juanma Barranquero
2014-01-25 9:23 ` martin rudalics
[not found] ` <52E38286.1050306@gmx.at>
2014-01-25 10:30 ` Eli Zaretskii
2014-01-25 14:58 ` martin rudalics
[not found] ` <52E3D131.2090705@gmx.at>
2014-01-25 16:30 ` Eli Zaretskii
2014-01-25 16:48 ` martin rudalics
2014-01-25 17:29 ` Eli Zaretskii
2014-01-25 18:25 ` martin rudalics
[not found] ` <52E4019C.5080905@gmx.at>
2014-01-25 18:31 ` Eli Zaretskii
2014-01-25 18:40 ` Eli Zaretskii
2014-01-26 11:20 ` martin rudalics
[not found] ` <52E4EF61.3050404@gmx.at>
2014-01-26 17:20 ` Eli Zaretskii
2014-01-26 20:43 ` Alan Mackenzie
2014-01-27 8:21 ` martin rudalics
[not found] ` <52E61704.6050807@gmx.at>
2014-01-27 14:49 ` Stefan Monnier
[not found] ` <jwvvbx5fq2b.fsf-monnier+emacsbugs@gnu.org>
2014-01-27 17:25 ` martin rudalics
[not found] ` <52E69695.5040703@gmx.at>
2014-01-28 0:16 ` Stefan Monnier
2014-01-29 22:36 ` Alan Mackenzie
[not found] ` <20140129223626.GD3092@acm.acm>
2014-01-30 7:37 ` martin rudalics
2014-01-30 13:47 ` martin rudalics
[not found] ` <52EA57D6.5080403@gmx.at>
2014-01-30 17:15 ` Eli Zaretskii
2014-01-30 18:58 ` martin rudalics
[not found] ` <52EAA0C9.1090000@gmx.at>
2014-02-01 10:41 ` Eli Zaretskii
2014-02-02 13:18 ` martin rudalics
2014-02-02 17:40 ` Alan Mackenzie [this message]
[not found] ` <20140202174050.GA5365@acm.acm>
2014-02-02 18:07 ` Eli Zaretskii
2014-02-02 19:20 ` Alan Mackenzie
2014-02-02 20:53 ` Eli Zaretskii
2014-02-05 23:00 ` Alan Mackenzie
2014-02-06 6:01 ` Eli Zaretskii
2014-06-22 16:49 ` Eli Zaretskii
2014-06-22 19:32 ` Alan Mackenzie
2014-06-22 20:04 ` Eli Zaretskii
2014-06-25 21:32 ` Alan Mackenzie
2014-06-26 2:51 ` Stefan Monnier
2014-06-27 20:34 ` Alan Mackenzie
2014-06-27 22:33 ` Stefan Monnier
2014-06-27 22:54 ` Stefan Monnier
[not found] ` <jwv8uoim0bm.fsf-monnier+emacsbugs@gnu.org>
2014-06-28 13:00 ` Alan Mackenzie
2014-06-28 14:00 ` martin rudalics
2014-06-28 14:34 ` Stefan Monnier
[not found] ` <53AECA88.7010401@gmx.at>
2014-06-28 14:55 ` Alan Mackenzie
2014-06-28 15:12 ` Eli Zaretskii
2014-06-28 16:30 ` Alan Mackenzie
2014-06-29 8:44 ` martin rudalics
2014-06-29 9:17 ` Alan Mackenzie
2014-06-29 10:06 ` martin rudalics
[not found] ` <53AFE536.7010407@gmx.at>
2014-06-29 12:48 ` Alan Mackenzie
2014-06-29 14:18 ` martin rudalics
2014-06-29 14:41 ` Alan Mackenzie
[not found] ` <20140629144151.GD2948@acm.acm>
2014-06-29 16:01 ` martin rudalics
[not found] ` <53B03876.9070307@gmx.at>
2014-06-29 17:49 ` Alan Mackenzie
2014-06-30 7:55 ` martin rudalics
2014-06-30 13:48 ` Stefan Monnier
[not found] ` <53B117D6.1050306@gmx.at>
2014-07-02 20:05 ` Alan Mackenzie
[not found] ` <20140702200522.GB3823@acm.acm>
2014-07-03 1:57 ` Stefan Monnier
2014-07-03 8:40 ` martin rudalics
[not found] ` <jwv61jf2owy.fsf-monnier+emacsbugs@gnu.org>
2014-07-03 14:59 ` Stefan Monnier
2014-07-04 18:27 ` Alan Mackenzie
2014-07-04 19:11 ` Stefan Monnier
2014-07-04 19:43 ` Stefan Monnier
2014-07-05 2:23 ` Stefan Monnier
2014-07-06 13:48 ` Alan Mackenzie
2014-07-07 1:52 ` Stefan Monnier
2014-07-07 7:07 ` martin rudalics
[not found] ` <jwvsimevsvz.fsf-monnier+emacsbugs@gnu.org>
2014-07-07 7:07 ` martin rudalics
2014-07-05 20:25 ` Alan Mackenzie
2014-07-05 23:06 ` Stefan Monnier
2014-07-04 19:29 ` Alan Mackenzie
2014-07-05 1:52 ` Stefan Monnier
2014-07-05 7:47 ` Alan Mackenzie
2014-06-29 22:14 ` Stefan Monnier
[not found] ` <jwvionjjrn7.fsf-monnier+emacsbugs@gnu.org>
2014-07-02 18:40 ` Alan Mackenzie
[not found] ` <20140702184013.GA3823@acm.acm>
2014-07-02 19:40 ` Stefan Monnier
[not found] ` <jwvsimpksv1.fsf-monnier+emacsbugs@gnu.org>
2014-06-28 17:33 ` Alan Mackenzie
[not found] ` <20140628173334.GB2632@acm.acm>
2014-06-29 21:39 ` Stefan Monnier
2014-01-29 21:52 ` Alan Mackenzie
2014-01-30 17:16 ` Eli Zaretskii
2014-01-31 20:00 ` Alan Mackenzie
2014-01-31 20:16 ` Eli Zaretskii
2014-01-27 8:20 ` martin rudalics
2014-01-27 16:23 ` Eli Zaretskii
2014-01-27 17:26 ` martin rudalics
2014-01-26 11:19 ` martin rudalics
2014-01-25 20:27 ` bug#16526: 24.3.50; scroll-conservatively & c-mode regression. The purpose of revision 116070 Alan Mackenzie
[not found] ` <20140125202721.GA3630@acm.acm>
2014-01-25 23:02 ` Stefan Monnier
2014-01-26 3:41 ` Eli Zaretskii
2014-01-26 9:54 ` Alan Mackenzie
2014-01-26 16:33 ` Eli Zaretskii
2014-01-26 17:35 ` Eli Zaretskii
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
List information: https://www.gnu.org/software/emacs/
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='20140202174050.GA5365__39445.5885202207$1391367777$gmane$org@acm.acm' \
--to=acm@muc.de \
--cc=16526@debbugs.gnu.org \
--cc=eliz@gnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://git.savannah.gnu.org/cgit/emacs.git
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).