Are these files used anywhere?

[Phil Edwards]

On Mon, Nov 26, 2001 at 10:44:18AM +0100, Stefan Olsson wrote:
> We are currently using the stl_pthread_alloc.h files and underlying implementation
> to get the best performance in our MT application.

But you're not using them through the V3 headers, right?

I think maybe I'll just move them into 'backward' instead of removing
them altogether.


> There are a couple of things in this implementation that makes sense to us in
> terms of MT and multiprocessor support, such as the SGI_SOURCE that tries to align
> to cacheboundries:
[...]
> One idea would be to look into a modification of the standard stl_alloc
> implementation so that this could be thread aware and tries to do more alignment
> than it currently does.

Patches welcome.  I'm /very/ keen on providing multiple options for users
to tune memory management.  We just need to find a coherent way of doing so.


> I.e. stl_alloc could keep a small per thread free list (ifdef __STL_THREADS) and
> one "per process/threadinspecific" free list (as it currently does) and the
> interface to malloc for chunks bigger than 128 bytes (the current limit).

Upping that limit is on my to-do list; 256 bytes is the number I have
in mind.  I'm wondering about wasted memory overhead on low-memory systems...


> In any case i think that we (newbies to the internal stuff of STL) could use a
> discussion/get an explanation about the design decisions made about the diffrent
> layers of memory caching. I am aware that this is hard to do since each platform
> has it's own malloc() implementation, but for instance under Linux it feels like
> we are doing cacheing on several levels (since the malloc() under linux keeps free
> lists of it's own).

I'm working on that right now.  Parts of stl_alloc.h have been doxygenated.
I have more changes in my local tree for additional comments and proper
uglification (gads, that alloc -> __alloc change is propogating everywhere).
Please look those comments over (via doxygen if you like *grin*).

Once that's done, docs/html/ext/howto.html#3 will finally get some contents.

Phil

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