Wireshark-dev: Re: [Wireshark-dev] [Wireshark-commits] rev 50955: /trunk/epan/wmem/ /trunk/epan
On Sat, Jul 27, 2013 at 6:27 PM, <eapache@xxxxxxxxxxxxx> wrote:
> http://anonsvn.wireshark.org/viewvc/viewvc.cgi?view=rev&revision=50955
>
> User: eapache
> Date: 2013/07/27 03:27 PM
>
> Log:
> Redesign of the wmem block allocator.
>
> What was becoming apparent as more dissectors started using wmem was that the
> old block allocator design had issues with memory fragmentation. This keeps the
> same underlying memory layout, but completely changes how free blocks are kept.
> It runs about 3% slower in my tests (still an order of magnitude faster than
> g_malloc) but uses about 1/3 the memory.
>
> I suspect some simple optimizations could reclaim that 3% as well - the design
> is fast, but I did not code particularly for speed.
>
> Thoroughly tested with the existing test suite (which caught half a dozen bugs
> in my first draft) so it should actually work!
>
> Directory: /trunk/epan/wmem/
> Changes Path Action
> +370 -297 wmem_allocator_block.c Modified
Regarding performance, just disabling the assertions gives about 15%
in my tests, but that was true of the old version as well. However,
the code is complicated and the assertions are a good safeguard, so
I'd rather not disable them just yet...
