# Custom allocator for wasm
**URL:** https://discourse.vtk.org/t/custom-allocator-for-wasm/14186
**Category:** vtk.wasm
**Created:** [July 9, 2024, 3:03am UTC](https://discourse.vtk.org/t/custom-allocator-for-wasm/14186 "2024-07-09T03:03:07Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@Jens\_Munk\_Hansen](https://discourse.vtk.org/u/Jens_Munk_Hansen)
#### Post date: [July 9, 2024, 3:03am UTC](https://discourse.vtk.org/t/custom-allocator-for-wasm/14186/1 "2024-07-09T03:03:07Z")
Just throwing out a question knowing that WASM does not support virtual memory.
Is there a benefit of compling VTK wasm using memkind? Or perhaps another allocator?
Anyone with experience in this area?
Thanks in advance
Jens
---
### Author:  [@jaswantp](https://discourse.vtk.org/u/jaswantp)
#### Post date: [July 9, 2024, 3:08am UTC](https://discourse.vtk.org/t/custom-allocator-for-wasm/14186/2 "2024-07-09T03:08:40Z")
i don’t know the best about memkind, but as far as wasm in browser goes, there’s just the ‘standard’ heap, which is backed by a javascript `Uint8Array`. Afaik, there’s no different kind of virtual memory available from js.
Probably wasi is a good platform that may support memkind.
---
### Author:  [@Jens\_Munk\_Hansen](https://discourse.vtk.org/u/Jens_Munk_Hansen)
#### Post date: [July 9, 2024, 3:43am UTC](https://discourse.vtk.org/t/custom-allocator-for-wasm/14186/3 "2024-07-09T03:43:54Z")
As a start, I will create some heap fragmentation tests and see how thing goes. It really sounds scary that WASM doesn’t support virtual memory. I will experiment with different allocators and if I find a good solution, I will let you know. My current issue is that I am use an implicit function for drawing on a mesh and I fear that will be extremely slow on WASM. But again, it is nice that it is easy to globally replace the allocator in VTK