Bug identified [was RE: perl - segfault on "free unused scalar"]

[Gerrit P. Haase]

Christopher Faylor wrote:

> On Fri, Jul 29, 2005 at 12:16:42AM +0200, Gerrit P. Haase wrote:
> 
>>Dave,
>>
>>Some comments on your analysis.
>>
>>The latest perl uses auto-image-base and the base address should be 
>>different than default.  It fails anyway.
>>
>>Perl uses its own malloc, rebuilding with the system malloc shows
>>that it behaves similar than the C examples, I think the recent
>>changes in Cygwin do what they should do: make setting the heap
>>size superflous.
> 
> 
> Could someone point to what these changes are that are supposed to
> make setting the heap size irrelevant?  Dave mentioned "cygload".  I
> don't really know what that is, unless it has something to do with
> the minor changes made to get cygwin somewhat working when loaded
> dynamically.
> 
> I'm not really aware of any changes which would make setting the heap
> size irrelevant.

I don't know ;)

At least we figured that perl crashes when it uses more than 384 MB RAM,
similar C programs don't crash.  This could be fixed with setting the 
heap size in te registry to a suitable maximum.  Perl used its own 
malloc, now with the latest release of Cygwin Perl it uses cygwin malloc
and it works better (setting the heap size is no longer neccessary, it
works without patching the registry now in this special case, may well 
be that it still breaks in other scripts).

IIRC it was you who said that there were some changes to malloc (in Feb.
2003): "Maybe the overflow code in the new malloc is actually working."

  -> http://www.cygwin.com/ml/cygwin/2003-02/msg00166.html


This is quite old news, however it seems that it really helps.  At least
since I build perl it used the included malloc instead of cygwin malloc.

I also received a report about a problem with automake/autoconf crashing
which seems to work ok now.


Gerrit
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