bug#2685: Emergency (alloc): Warning: past 85% of memory limit

bug#2685: Emergency (alloc): Warning: past 85% of memory limit

[Chong Yidong]

> I compiled using GCC 4.3.2 from debian lenny (abi=32):
>
> GNU Emacs 23.0.91.1 (mips64el-unknown-linux-gnu, X toolkit) of
> 2009-03-15 on gcc51   
>
> When launching emacs (in text mode) I get a *Warnings* window
> with the following message:
>
> Emergency (alloc): Warning: past 85% of memory limit
>
> The machine gcc51 has 1GB of RAM so this warning seems surprising.

I can't reproduce this on x86.  I don't have access to any mipsel
machine; could either of you give me a temporary account so that I can
try to debug this (if so, please contact me by private email).

bug#2685: Emergency (alloc): Warning: past 85% of memory limit

[Chong Yidong]

The problem is that Emacs is not determining the start of the data
segment properly on MIPS machines.  In src/m/mips.h, we define
DATA_START as 0x10000000.  There must be a reason for this, but it's
wrong on the machine you provided for testing; there, __morecore reports
the memory break (which must lie inside the data segment) as a value
less than 0x10000000.

If I comment out DATA_START, so that Emacs uses another method to
determine the start of the data segment size, everything seems to work
OK.  But I don't know if this may lead to a different bug elsewhere.

*** trunk/src/m/mips.h.~1.42.~	2009-03-12 09:42:54.000000000 -0400
--- trunk/src/m/mips.h	2009-05-22 00:34:03.000000000 -0400
***************
*** 49,55 ****
  /* Describe layout of the address space in an executing process.  */
  
  #define TEXT_START      0x00400000
! #define DATA_START      0x10000000
  
  \f
  #if 0 /* These definitions were advantageous when not using
--- 49,55 ----
  /* Describe layout of the address space in an executing process.  */
  
  #define TEXT_START      0x00400000
! /* #define DATA_START      0x10000000 */
  
  \f
  #if 0 /* These definitions were advantageous when not using

bug#2685: Emergency (alloc): Warning: past 85% of memory limit

[Laurent GUERBY]

Hi,

I compiled using GCC 4.3.2 from debian lenny (abi=32):

GNU Emacs 23.0.91.1 (mips64el-unknown-linux-gnu, X toolkit) of
2009-03-15 on gcc51   

When launching emacs (in text mode) I get a *Warnings* window
with the following message:

Emergency (alloc): Warning: past 85% of memory limit

The machine gcc51 has 1GB of RAM so this warning seems surprising.

Sincerely,

Laurent

bug#2685: marked as done (Emergency (alloc): Warning: past 85% of memory limit)

[Emacs bug Tracking System]

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Your message dated Fri, 22 May 2009 14:46:56 -0400
with message-id <87ljop561r.fsf@cyd.mit.edu>
and subject line Re: Emergency (alloc): Warning: past 85% of memory limit
has caused the Emacs bug report #2685,
regarding Emergency (alloc): Warning: past 85% of memory limit
to be marked as done.

This means that you claim that the problem has been dealt with.
If this is not the case it is now your responsibility to reopen the
bug report if necessary, and/or fix the problem forthwith.

(NB: If you are a system administrator and have no idea what this
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-- 
2685: http://emacsbugs.donarmstrong.com/cgi-bin/bugreport.cgi?bug=2685
Emacs Bug Tracking System
Contact owner@emacsbugs.donarmstrong.com with problems

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From: Laurent GUERBY <laurent@guerby.net>
To: emacs-pretest-bug@gnu.org
Subject: Emergency (alloc): Warning: past 85% of memory limit
Date: Mon, 16 Mar 2009 12:13:55 +0100
Message-ID: <1237202035.8383.2.camel@localhost>

Hi,

I compiled using GCC 4.3.2 from debian lenny (abi=32):

GNU Emacs 23.0.91.1 (mips64el-unknown-linux-gnu, X toolkit) of
2009-03-15 on gcc51   

When launching emacs (in text mode) I get a *Warnings* window
with the following message:

Emergency (alloc): Warning: past 85% of memory limit

The machine gcc51 has 1GB of RAM so this warning seems surprising.

Sincerely,

Laurent





[-- Attachment #3: Type: message/rfc822, Size: 2011 bytes --]

From: Chong Yidong <cyd@stupidchicken.com>
To: Laurent GUERBY <laurent@guerby.net>
Cc: John Sullivan <johns@fsf.org>, 2685-done@emacsbugs.donarmstrong.com
Subject: Re: Emergency (alloc): Warning: past 85% of memory limit
Date: Fri, 22 May 2009 14:46:56 -0400
Message-ID: <87ljop561r.fsf@cyd.mit.edu>

> The problem is that Emacs is not determining the start of the data
> segment properly on MIPS machines.  In src/m/mips.h, we define
> DATA_START as 0x10000000

On further research, I think this is wrong for GNU/Linux.  It was
probably written for other operating systems in mind.  Undefining
DATA_START on GNU/Linux is pretty harmless; as I said, this causes Emacs
to fall back on another heuristic method for determining the start of
the data segment.  (Anyway, this change only affects this particular
platform).  So, I've checked in the change.

bug#2685: Emergency (alloc): Warning: past 85% of memory limit

[John Sullivan]

Chong Yidong <cyd@stupidchicken.com> writes:

>> The problem is that Emacs is not determining the start of the data
>> segment properly on MIPS machines.  In src/m/mips.h, we define
>> DATA_START as 0x10000000
>
> On further research, I think this is wrong for GNU/Linux.  It was
> probably written for other operating systems in mind.  Undefining
> DATA_START on GNU/Linux is pretty harmless; as I said, this causes Emacs
> to fall back on another heuristic method for determining the start of
> the data segment.  (Anyway, this change only affects this particular
> platform).  So, I've checked in the change.
>

I just built the pretest and the error is gone. Thanks!