Re: [libmicrohttpd] mmap()

[Christian Grothoff]

I see two (theoretical) benefits:
1) mmap cannot result in memory fragmentation, which could be an issue
with malloc();
2) the allocations can be large-ish, which may mean that malloc() would
internally fall back to mmap() anyway (of course depending on malloc()
and the actual size).

I'm not sure VRAM "pollution" by one map per concurrent connection is a
"real" issue. If it is, we could also consider a meta-pool where we
allocate memorypools for say 32 (but generally configurable number of)
connections in one larger mmap.  Can you show any actual problems with
the current situation, or is this "cosmetic" because your pmap output is
long-ish?

Happy hacking!

Christian

On 3/10/22 11:36, Markus Doppelbauer wrote:
> Hello,
> 
> Is there some benefit using 'mmap()' in 'memorypool.c' instead 'malloc()'?
> It somehow pollutes VRAM - inspecting with: `pmap -x <pid>`
> (even if we have plenty of VRAM on x64)
> 
> Best wishes
> Markus