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From: "Ludwig, Mark" <ludwig.mark@siemens.com>
To: Eli Zaretskii <eliz@gnu.org>,
	"help-gnu-emacs@gnu.org" <help-gnu-emacs@gnu.org>
Subject: RE: Performance problems (CPU 100%) with NULs in files
Date: Sat, 24 Sep 2011 13:32:10 +0000	[thread overview]
Message-ID: <BC5672F8AD4C054BAF167C9801500D1A510C38F9@USSLMMBX003.net.plm.eds.com> (raw)
In-Reply-To: <83aa9uqxwg.fsf@gnu.org>

I filed bug#9589 before your message.  Since you know about this sort of problem generally, I assume the description will make sense.

Cheers,

Mark

-----Original Message-----
From: help-gnu-emacs-bounces+ludwig.mark=siemens.com@gnu.org [mailto:help-gnu-emacs-bounces+ludwig.mark=siemens.com@gnu.org] On Behalf Of Eli Zaretskii
Sent: Saturday, September 24, 2011 1:04 AM
To: help-gnu-emacs@gnu.org
Subject: Re: Performance problems (CPU 100%) with NULs in files

> From: "Ludwig, Mark" <ludwig.mark@siemens.com>
> Date: Sat, 24 Sep 2011 00:20:24 +0000
> 
> What I have found is that the "problem" is due to a "line" of text being extremely long.  In the test file I have, it is ~800,000 characters (bytes).  (It came to me with NULs, but I can replace those with any other printable character and get the same result.)

Yes, this is a well-known case that causes the current display engine
become very slow.  IIRC, it has been like that since Emacs 21.1.

> OTOH, if you guys really think this is worth asking any developer to fix, I'll file a bug report.  I don't need to send any data, because it's easy to reproduce this behavior starting with an empty buffer.

Please file a bug report.  It is not unreasonable to expect the code
to be optimized in some way to cater to such use cases.

And thanks for taking your time to investigate this.




  reply	other threads:[~2011-09-24 13:32 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-09-21 21:08 Performance problems (CPU 100%) with NULs in files Ludwig, Mark
2011-09-22  4:30 ` Drew Adams
2011-09-22 13:00   ` Ludwig, Mark
2011-09-22  5:44 ` Eli Zaretskii
2011-09-22 12:58   ` Ludwig, Mark
2011-09-24  0:20   ` Ludwig, Mark
2011-09-24  0:50     ` Le Wang
2011-09-24  6:04     ` Eli Zaretskii
2011-09-24 13:32       ` Ludwig, Mark [this message]
2011-09-24 14:15         ` Eli Zaretskii
2011-09-22  6:09 ` XeCycle
2011-09-22 12:58   ` Ludwig, Mark

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