From: Eli Zaretskii <eliz@gnu.org>
To: Stefan Monnier <monnier@iro.umontreal.ca>,
2790@emacsbugs.donarmstrong.com
Cc: tutufan@gmail.com
Subject: bug#2790: emacs 22.1.1 cannot open 5GB file on 64GB 64-bit GNU/Linux box
Date: Sat, 28 Mar 2009 11:45:35 +0300 [thread overview]
Message-ID: <uzlf6kpcg.fsf@gnu.org> (raw)
In-Reply-To: <jwv63hueaoo.fsf-monnier+emacsbugreports@gnu.org>
> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Date: Fri, 27 Mar 2009 22:12:54 -0400
> Cc: 2790@emacsbugs.donarmstrong.com
>
> > Okay, tried it (emacs-23.0.91), but no luck. Looks very nice, but
> > finding that large file produced the same error. The value of
> > 'most-positive-fixnum' prints correctly, though (which is different).
>
> There was an incorrect check that limited the size to INT_MAX/4
> (i.e. 512MB for systems where ints are 32bit). I've removed this check
> in the CVS code (see patch below).
The patch below does this:
> - || st.st_size > INT_MAX / 4)
> + /* Actually, it should test either INT_MAX or LONG_MAX
> + depending on which one is used for EMACS_INT. But in
> + any case, in practice, this test is redundant with the
> + one above.
> + || st.st_size > INT_MAX / 4 */)
> error ("Maximum buffer size exceeded");
But what about the commentary immediately preceding the modified code:
The calculations below double the file size twice, so check that it
can be multiplied by 4 safely.
I'm not sure to which calculations it alludes, but if you think they
are no longer relevant, please remove that part of the comment,
otherwise we will wonder in a couple of years why the code does not do
what the comment says it should.
Personally, I would change INT_MAX/4 to LONG_MAX/4, because that does
TRT on all supported platforms, 32-bit and 64-bit alike (long and int
are both 32-bit wide on 32-bit machines). That would avoid too
radical changes during a pretest, which is a Good Thing, IMO.
> Note also that when you open large files, it's worthwhile to use
> find-file-literally to be sure it's opened in unibyte mode;
> otherwise it gets decoded which takes ages.
Perhaps the prompt we pop for large file should suggest visiting
literally as an option.
> Also if the file has many lines (my
> 800MB file was made up by copying a C file many times, so it had
> millions of lines), turning off line-number-mode is is needed to recover
> responsiveness when navigating near the end of the buffer.
Perhaps we should make the default value of line-number-display-limit
non-nil, at least in 64-bit builds.
next prev parent reply other threads:[~2009-03-28 8:45 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-26 15:50 bug#2790: emacs 22.1.1 cannot open 5GB file on 64GB 64-bit Linux box Mike Coleman
2009-03-26 19:58 ` Eli Zaretskii
2009-03-26 21:01 ` Mike Coleman
2009-03-26 21:14 ` Eli Zaretskii
2009-03-26 21:33 ` Mike Coleman
2009-03-27 0:32 ` Stefan Monnier
2009-03-27 0:39 ` Mike Coleman
2009-03-27 3:08 ` bug#2790: emacs 22.1.1 cannot open 5GB file on 64GB 64-bit Linux Stefan Monnier
2009-03-27 16:29 ` Mike Coleman
2009-03-27 8:46 ` bug#2790: emacs 22.1.1 cannot open 5GB file on 64GB 64-bit Linux box Eli Zaretskii
2009-03-27 11:21 ` Andreas Schwab
2009-03-27 4:59 ` bug#2790: emacs 22.1.1 cannot open 5GB file on 64GB 64-bit GNU/Linux box Richard M Stallman
2009-03-27 16:27 ` Mike Coleman
2009-03-27 17:42 ` Eli Zaretskii
2009-03-28 2:12 ` Stefan Monnier
2009-03-28 5:24 ` Mike Coleman
2009-03-29 19:59 ` bug#2790: emacs 22.1.1 cannot open 5GB file on 64GB 64-bit Stefan Monnier
2009-03-28 8:45 ` Eli Zaretskii [this message]
2009-03-28 11:12 ` bug#2790: emacs 22.1.1 cannot open 5GB file on 64GB 64-bit GNU/Linux box Andreas Schwab
2009-03-28 12:03 ` Eli Zaretskii
2009-03-28 12:40 ` Andreas Schwab
2009-03-28 13:52 ` Eli Zaretskii
2009-03-29 20:13 ` Stefan Monnier
2009-03-29 20:10 ` Stefan Monnier
2009-03-29 20:44 ` Andreas Schwab
2009-03-30 0:59 ` Stefan Monnier
2009-03-30 8:08 ` Andreas Schwab
2009-03-30 13:01 ` Stefan Monnier
2009-03-30 13:22 ` Andreas Schwab
2009-03-29 2:15 ` Richard M Stallman
2009-03-29 20:14 ` Stefan Monnier
2009-03-28 15:17 ` Richard M Stallman
2009-03-28 16:27 ` Mike Coleman
[not found] ` <mailman.4163.1238258635.31690.bug-gnu-emacs@gnu.org>
2009-03-31 14:17 ` Ted Zlatanov
2011-09-11 22:10 ` bug#2790: emacs 22.1.1 cannot open 5GB file on 64GB 64-bit Linux box Lars Magne Ingebrigtsen
2011-09-12 2:59 ` Eli Zaretskii
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