[Libreoffice] --with-alloc setting

[Stephan Bergmann]

On 10/06/2011 07:04 PM, Michael Meeks wrote:
> Hi Neil,
>
> On Thu, 2011-10-06 at 13:45 -0300, Neil Leathers wrote:
>> In running through my build settings I was trying to decide which
>> value to use for --with-alloc=???.
>
> 	Wow - that's a blast from the past. Intel did some work to enable
> tcmalloc to be used - one of those micro-optimisations that people hope
> will make things faster and often do - but only linearly.
>
>> Currently it defaults to "internal" perhaps this should be changed to
>> default to "system". If there is a good reason why "internal" is
>> better then it should be documented on the wiki page. Or the trade
>> offs and recommendations should be documented on the wiki.
>
> 	Right - so, we should do some performance tests of characteristic
> documents with the internal vs. system allocator. AFAIR the system
> allocator is rather good on Linux, and terrible on Windows ;-) so
> possibly we should have a platform-dependent default.

The main reason, IIRC, for inventing the internal malloc replacement was 
that it sometimes happens that OOo needs large amounts of heap for a 
rather short time (while loading calc documents, I think), and 
traditional malloc implementations never give pages that have become 
free again back to the OS.  No idea whether that is still a realistic 
issue today, though.

-Stephan