From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Tassilo Horn Newsgroups: gmane.emacs.devel Subject: Re: Unfreezing the display during auto-repeated scrolling. Simpler approach. Date: Sun, 23 Nov 2014 20:44:39 +0100 Message-ID: <87egstaehk.fsf@thinkpad-t440p.tsdh.org> 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> <20141123104038.GA3542@acm.acm> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1416771909 26899 80.91.229.3 (23 Nov 2014 19:45:09 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sun, 23 Nov 2014 19:45:09 +0000 (UTC) Cc: Eli Zaretskii , Stefan Monnier , emacs-devel@gnu.org To: Alan Mackenzie Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sun Nov 23 20:45:03 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 1Xsd5h-000150-Em for ged-emacs-devel@m.gmane.org; Sun, 23 Nov 2014 20:45:01 +0100 Original-Received: from localhost ([::1]:49818 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xsd5g-0001BK-Um for ged-emacs-devel@m.gmane.org; Sun, 23 Nov 2014 14:45:00 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:39743) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xsd5Y-0001B2-A5 for emacs-devel@gnu.org; Sun, 23 Nov 2014 14:44:57 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Xsd5S-0003Pm-Rm for emacs-devel@gnu.org; Sun, 23 Nov 2014 14:44:52 -0500 Original-Received: from out4-smtp.messagingengine.com ([66.111.4.28]:42319) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Xsd5S-0003Pi-Nk for emacs-devel@gnu.org; Sun, 23 Nov 2014 14:44:46 -0500 Original-Received: from compute6.internal (compute6.nyi.internal [10.202.2.46]) by mailout.nyi.internal (Postfix) with ESMTP id 79F4C21891 for ; Sun, 23 Nov 2014 14:44:46 -0500 (EST) Original-Received: from frontend2 ([10.202.2.161]) by compute6.internal (MEProxy); Sun, 23 Nov 2014 14:44:46 -0500 DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d= messagingengine.com; h=x-sasl-enc:from:to:cc:subject:references :date:in-reply-to:message-id:mime-version:content-type; s= smtpout; bh=I6o0yB6SOxVnr9GRAXNIjaTX/lA=; b=kIDaZo7LkrgJG8DXNOEa V/eVjaVVWzIJOdn0Rau6g4b28lqqNtnKp7wLnNzfpJXBsNVJkJTglbpnSUDkGkti Sjf9/MIXNfng1dRh4lcVbaljzSx4R2AAXuhguf4VACvPlqYF3lsnecgrNmDR50tg lmK5lwaFU/rbf64/aGRshtY= X-Sasl-enc: eSoDIos8fB2iDZjlPzTwYeso8CYrmHb12VA0Mo9rA3ez 1416771885 Original-Received: from thinkpad-t440p.tsdh.org (unknown [2.160.222.143]) by mail.messagingengine.com (Postfix) with ESMTPA id 4B5996800E5; Sun, 23 Nov 2014 14:44:45 -0500 (EST) Mail-Followup-To: Alan Mackenzie , Stefan Monnier , Eli Zaretskii , emacs-devel@gnu.org In-Reply-To: <20141123104038.GA3542@acm.acm> (Alan Mackenzie's message of "Sun, 23 Nov 2014 10:40:38 +0000") User-Agent: Gnus/5.130012 (Ma Gnus v0.12) Emacs/25.0.50 (gnu/linux) X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 66.111.4.28 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:178116 Archived-At: Alan Mackenzie writes: Hi Alan, >> 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. Oh, indeed. My machine is pretty fast at least for a laptop, but when holding C-v the display freezes very quickly as you say. With `use-default-face-for-fast-scrolling' I don't get such freezes, so this looks like a very good feature to me (2nd best after "make the display engine faster"). But still I think the variable's name is a bit misleading. I expected to see the text that scrolls by black on white, i.e., using the default face similar to having `jit-lock-defer-time' set to some non-nil value. But instead the text that scrolls by and is visible is fontified using the normal font-lock faces. Bye, Tassilo