From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Alan Mackenzie Newsgroups: gmane.emacs.devel Subject: Re: Unfreezing the display during auto-repeated scrolling. Simpler approach. Date: Sun, 23 Nov 2014 10:40:38 +0000 Message-ID: <20141123104038.GA3542@acm.acm> References: <20141029145211.GB2953@acm.acm> <20141029212525.GD2953@acm.acm> <20141030220919.GB2721@acm.acm> <83oasszn9e.fsf@gnu.org> <20141121154420.GA24582@acm.acm> <87vbm6z1lc.fsf@thinkpad-t440p.tsdh.org> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: ger.gmane.org 1416739292 16633 80.91.229.3 (23 Nov 2014 10:41:32 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sun, 23 Nov 2014 10:41:32 +0000 (UTC) To: Stefan Monnier , Eli Zaretskii , emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sun Nov 23 11:41:24 2014 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1XsUbc-0003px-KC for ged-emacs-devel@m.gmane.org; Sun, 23 Nov 2014 11:41:24 +0100 Original-Received: from localhost ([::1]:48121 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XsUbc-0005M5-83 for ged-emacs-devel@m.gmane.org; Sun, 23 Nov 2014 05:41:24 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:43080) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XsUbT-0005LE-Te for emacs-devel@gnu.org; Sun, 23 Nov 2014 05:41:21 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XsUbO-00034Q-2T for emacs-devel@gnu.org; Sun, 23 Nov 2014 05:41:15 -0500 Original-Received: from colin.muc.de ([193.149.48.1]:22081 helo=mail.muc.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XsUbN-000348-PL for emacs-devel@gnu.org; Sun, 23 Nov 2014 05:41:10 -0500 Original-Received: (qmail 78368 invoked by uid 3782); 23 Nov 2014 10:41:08 -0000 Original-Received: from acm.muc.de (pD951B4A5.dip0.t-ipconnect.de [217.81.180.165]) by colin.muc.de (tmda-ofmipd) with ESMTP; Sun, 23 Nov 2014 11:41:06 +0100 Original-Received: (qmail 3612 invoked by uid 1000); 23 Nov 2014 10:40:38 -0000 Content-Disposition: inline In-Reply-To: <87vbm6z1lc.fsf@thinkpad-t440p.tsdh.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-Delivery-Agent: TMDA/1.1.12 (Macallan) X-Primary-Address: acm@muc.de X-detected-operating-system: by eggs.gnu.org: FreeBSD 8.x X-Received-From: 193.149.48.1 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:178067 Archived-At: Hello, Tassilo. On Sun, Nov 23, 2014 at 10:51:43AM +0100, Tassilo Horn wrote: > Alan Mackenzie writes: > Hi Alan, > > Just a short summary of this change: introduce a new user option, off > > by default, which suppresses fontification (by binding > > fontification-functions to nil) when the user scrolls by whole > > screens. > Just as a data point: i think I'd have a use for such a feature even > with a pretty recent machine. > But I've applied your patch and run "make", fired up a new emacs and set > `use-default-face-for-fast-scrolling' to t, then found a large file and > pressed and held `C-v'. I couldn't see any difference compared to not > having the option enabled. All the text that's passing by is still > fontified and scrolling doesn't seem faster. The main point is, text continues to pass by. What was happening was that on an auto-repeated C-v, Emacs would hang (without scrolling), and after releasing the key, it took quite a few seconds before the display would be updated. During this time Emacs was completely unresponsive. With `use-default-face-for-fast-scrolling' at nil, all the text scrolled over gets fontified, and lesser machines (such as mine) cannot keep up. With the option set to t, only the text being displayed gets fontified. The appearance may be of text continually scrolling, but this is an illusion; only parts of the scrolled over text get fontified and displayed. To see the effect, make your window as large as possible (mine was 66 lines deep) and try with a file like .../src/xdisp.c. Toggle font-lock-mode off and on between each try. If you still don't see any difference, then your machine is powerful enough not to need the feature. > I've tried with C files and the persistency files of my working group's > graph database (which would be my primer use-case for that feature). As I say, maximise your frame first. > Bye, > Tassilo -- Alan Mackenzie (Nuremberg, Germany).