[pve-devel] qemu + tcmalloc for rbd

["DERUMIER, Alexandre" <alexandre.derumier@groupe-cyllene.com>]

Hi,

I still have this last year patch pending

https://lists.proxmox.com/pipermail/pve-devel/2023-May/056815.html

to enabled conditionnaly tcmalloc in qemu 

It's still required for performance with librbd with last qemu /lirbd
I get a 30-40% performance boost in iops and latency for small
read/writes.


I would like to have a solution in proxmox repo, instead of maintain it
on my side.


Currently, In production, I compile qemu with tcmalloc at build.

This patch serie, allow to do use LD_PRELOAD +  disable malloc_trim()
call in qemu.

I'm not expert in C (I re-used code from haproxy, which is doing
exactly the same thing with tcmalloc && trim). 
So if somebody can review it, it could be great :)



Another way (maybe safer), is to build 2 binary in same package 
(/usr/bin/kvm-tcmalloc  && /usr/bin/kvm), and give option to user to
choose it.