Re: [PATCH] ext4: rralloc - (former rotalloc) improved round-robin allocation policy

[Andreas Dilger]

On Feb 25, 2026, at 13:15, Mario Lohajner <mario_lohajner@xxxxxxxxxxxxxx> wrote:
> 
> V2 patch incorporating feedback from previous discussion:
> 
> - per-inode atomic cursors to enforce stream sequentiality
> - per-CPU starting points to reduce contention
> - allocator isolation maintained; regular allocator untouched
> - name changed to rralloc to avoid confusion with "rotational"
> - preliminary tests confirm expected performance

Mario, can you please include a summary of the performance test
results into the commit message so that the effectiveness of the
patch can be evaluated.  This should include test(s) run and
their arguments, along with table of before/after numbers.

Cheers, Andreas

> Files modified:
> - fs/ext4/ext4.h
> rralloc policy declared, per-CPU cursors & allocator vector
> 
> - fs/ext4/ialloc.c
> initialize (zero) per-inode cursor
> 
> - fs/ext4/mballoc.h
> expose allocator functions for vectoring in super.c
> 
> - fs/ext4/super.c
> parse rralloc option, init per-CPU cursors and allocator vector
> 
> - fs/ext4/mballoc.c
> add rotating allocator, vectored allocator
> 
> Signed-off-by: Mario Lohajner <mario_lohajner@xxxxxxxxxxxxxx>