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

Subject: Re: [Boost-users] [serialization] Runtime overhead of serialization archives
From: Chris Glover (c.d.glover_at_[hidden])
Date: 2016-09-22 16:38:24

>
> 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 .....
>
>
For what it's worth, in tests I've done in the past, binary serialization
using boost.serialization and other similar systems was not this big of a
difference compared to memcpy. I was seeing maybe a 5x to 10x difference
compared to memcpy (yours is 50x).

Of course, this depends on a lot of factors, like how much data this is
because it would determine if you are memory bound or not, but I am
wondering if your cstyle tests are actually being completely optimized
away. Have you examined the disassembly? If you find the code is being
optimized away, Google Benchmark has a handy "benchmark::DoNotOptimize"
function to help keep the optimizer from throwing away the side effects of
a particular address.

-- chris