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Re: Less good ;-) results from Rittle's string allocator
- From: Phil Edwards <pedwards at disaster dot jaj dot com>
- To: Paolo Carlini <pcarlini at unitus dot it>
- Cc: libstdc++ at gcc dot gnu dot org, rittle at latour dot rsch dot comm dot mot dot edu
- Date: Tue, 27 Nov 2001 14:04:55 -0500
- Subject: Re: Less good ;-) results from Rittle's string allocator
- References: <3C03962D.A893E65D@unitus.it>
As an aside, Paolo, your mailreader program is wrapping lines at something
like 95 columns. If convenient, please consider wrapping at around 75 or 80.
On Tue, Nov 27, 2001 at 02:33:33PM +0100, Paolo Carlini wrote:
> In the next few days I'd like to test a little bit the effect of Phil Edwards proposal to
> increase _MAX_BYTES to 256 in stl_alloc.h (the new one would be modified s/256/512/).
I'm a bit nervous there. How often do we plan on requesting chunks of
half a kilobyte?
More specifically, how often will memory clients /other than basic_string/
be requesting chunks of a half-K at a time?
I wanted to raise it past 128 because I've been seeing a fair number
of programs lately using containers of Foo where sizeof(Foo) > 128, and
they weren't benefitting from the memory pool. If we raise _MAX_BYTES to
something large, I'm worried that basic_string would be the only client,
and that we're making non-string-using programs pay for it.
Let me throw out an idea I had while typing the last paragraph: we could
make the _MAX_BYTES a template parameter of the allocator:
new: __default_alloc_template<true,0, _MAX_BYTES=256>
or something similar. Then basic_string can have its own memory pool.
> As regards this last point, what do you all believe of including stl_alloc.h in
It already is, via std_memory.h.
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