[PATCH 1/1] kho: fix KHO_TREE_MAX_DEPTH for non-4KB page sizes

Mike Rapoport rppt at kernel.org
Wed May 13 00:50:40 PDT 2026


On Mon, May 11, 2026 at 12:40:01PM +0200, Pratyush Yadav wrote:
> On Sat, May 09 2026, George Guo wrote:
> 
> > From: George Guo <guodongtai at kylinos.cn>
> >
> > KHO_TREE_MAX_DEPTH is calculated as:
> >
> >   DIV_ROUND_UP(KHO_ORDER_0_LOG2 - KHO_BITMAP_SIZE_LOG2,
> >                KHO_TABLE_SIZE_LOG2) + 1
> >
> > For systems with 16KB pages (e.g. LoongArch), this gives a depth of 4,
> 
> As of now, we only support KHO on x86 and arm64. Support for other
> architectures is not there. Are you working on supporting it for
> LoongArch? What is your use case?

arm64 can have 16k pages, but ...
 
> So based on this, looks to me that the 5th level table won't ever go
> above index 0 and the 4th level is enough to represent all possible
> keys.
 
... as it looks like your math is correct, I'm going to drop the patch for
now.

> -- 
> Regards,
> Pratyush Yadav

-- 
Sincerely yours,
Mike.



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