Re: [PATCH] mm: add zblock allocator

[Shakeel Butt <shakeel.butt@linux.dev>]

Hi Vitaly,

On Tue, Apr 01, 2025 at 07:17:54PM +0200, Vitaly Wool wrote:
> zblock is a special purpose allocator for storing compressed pages.
> It stores integer number of compressed objects per its block. These
> blocks consist of several physical pages (2**n, i. e. 1/2/4/8).
> 
> With zblock, it is possible to densely arrange objects of various sizes
> resulting in low internal fragmentation. Also this allocator tries to
> fill incomplete blocks instead of adding new ones,  in many cases
> providing a compression ratio substantially higher than z3fold and zbud
> (though lower than zmalloc's).
> 
> zblock does not require MMU

Can you explain why not requiring MMU is important for your use-case?
Also what exactly is your use-case? Are you planning to use zblock
through zram or zswap or something new?

> to operate and also is superior to zsmalloc
> with regard to average performance and worst execution times, thus
> allowing for better response time and real-time characteristics of the
> whole system.
> 
> E. g. on a series of stress-ng tests run on a Raspberry Pi 5, we get
> 5-10% higher value for bogo ops/s in zblock/zsmalloc comparison.

Can you explain a bit more on this test? How is this test using zblock?

thanks,
Shakeel