Re: [Boost-users] [serialization] Runtime overhead of serialization archives

Subject: Re: [Boost-users] [serialization] Runtime overhead of serialization archives
From: Georg Gast (georg_at_[hidden])
Date: 2016-09-22 15:43:49

Am 22.09.2016 um 08:35 schrieb georg_at_[hidden]:

> I just found out one issue on Windows:
> 
> static void to_wire_xml(benchmark::State& state)
> {
> 	//std::locale::global(std::locale("C"));
> 
> 	while (state.KeepRunning())
> 	{
> 		boost_test<boost_xml_trait>::to_wire(ev_test());
> 	}
> }
> 
> If i toggle the commented line, the cost goes down to the half. With the
> Windows profiler i found out, that the construction of the locale takes so
> much time.
> 
> Without global set locale:
> Benchmark       Time(ns)    CPU(ns) Iterations
> ----------------------------------------------
> to_wire_xml        78066      77177       7479
> from_wire_xml      95638      95949       7479
> 
> With global set locale:
> 09/22/16 08:32:49
> Benchmark       Time(ns)    CPU(ns) Iterations
> ----------------------------------------------
> to_wire_xml        41399      41302      16619
> from_wire_xml      52841      52844      11218
> 
> Thats amazing! Thats the Level of the Linux implementation.
> 
> One riddle is solved :)
> 
> 

After fiddling around on linux with clang 3.8 and gcc optimizer options
i got down to this. With gcc and -O3.

Benchmark          Time(ns)    CPU(ns) Iterations
-------------------------------------------------
to_wire_xml           11174      11178     381818
to_wire_text           5148       5149     820313
to_wire_binary         3327       3330    1141304
to_wire_cstyle           63         63   65217391
from_wire_xml         27170      27183     155096
from_wire_text         5371       5370     783582
from_wire_binary       3226       3228    1296296
from_wire_cstyle         45         45   93750000

This results look very nice. <6µs for serilize/deserialize a structure
to a portable text archive seems very nice :)

Now is the difference again pretty big compared to windows .....

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