Re: [boost] [serialization] fast array serialization (10x speedup)

From: Robert Ramey (ramey_at_[hidden])
Date: 2005-11-13 12:46:01

Matthias Troyer wrote:
> Regarding the inlining: -O2 inlines all the functions that are
> declared as inline. -O3 in addition attempts to inline small
> functions that are not declared inline. I surely hope that all such
> small functions in the library are declared inline,

Hmm, actually I don't know that for a fact.  I think I did use
inline for all thse functions -but  I might have overlooked some.
Also, the serialization library relies heavily on mpl and other
boost stuff.  I havn't verified that all that imported code
uses inline either.  But now I think about it.  Its not clear to
me that's its not better to leave it off and let the compiler
decide.  That might better permit one to optimise for size
in one compilation while optimising for speed in another.
This is an open question.

> Nobody who cares for performance would use text based I/O. All your
> benchmark shows is that the overhead of the serialization library is
> comparable to that of text/based I/O onto a hard disk. For this
> purpose you are right, the overhead can be ignored. On the other
> hand, my benchmark used binary I/O into files and into memory
> buffers, and that's where the overhead of the serialization library
> really hurts. A 10x slowdown is horrible and makes the library
> unusable for high performance applications.

I'll update my "benchmark" to use stream read/write for raw i/o comparison.

Robert Ramey