Re: [PATCH] riscv: Don't use hugepage mappings for vmemmap if it's not supported

[Alexandre Ghiti]

Hi Nam,

On 08/05/2024 20:46, Nam Cao wrote:
> On Wed, May 08, 2024 at 08:22:43PM +0200, Alexandre Ghiti wrote:
> > Hi Nam,
> Hi Alex,
>
> > > Commit ff172d4818ad ("riscv: Use hugepage mappings for vmemmap") broke XIP
> > > kernel, because huge pages are not supported on XIP kernel.
> > I don't understand why XIP kernels can't support huge vmalloc mappings,
> Me neither.
>
> > so I
> > think the right fix would be to enable such mappings on XIP. WDYT?
> I agree that is the ideal solution. But I don't want to send any new
> feature to the stable trees (stable folks may even reject such patch).
> So I intend that to be in another patch.


I have been thinking about that, and I actually think that the real fix 
is enabling huge vmalloc mappings for XIP as it was an oversight/mistake 
in the first place. On 64-bit kernels, there are no reasons we can't use 
PMD mappings for vmalloc. So I'd rather not go with this fix.

Thanks,

Alex


> Best regards,
> Nam