Re: [PATCH v6 5/8] LoongArch: Allow memblock arrays to resize

[Mike Rapoport <rppt@kernel.org>]

On Thu, Nov 05, 2026 at 11:07:01PM +0800, Huacai Chen wrote:
> Hi, Mike,
> 
> On Thu, Nov 5, 2026 at 8:57 PM Mike Rapoport <rppt@kernel.org> wrote:
> >
> > On Fri, Oct 30, 2026 at 02:29:52AM +0900, George Guo wrote:
> > > From: George Guo <guodongtai@kylinos.cn>
> > >
> > > LoongArch never calls memblock_allow_resize(), so the reserved region
> > > array cannot grow beyond INIT_MEMBLOCK_RESERVED_REGIONS entries
> > > (INIT_MEMBLOCK_REGIONS + NR_CPUS).
> >
> > This might be something to fix independent of KHO.
> >
> > Huacai,
> >
> > What's the reason LoongArch never enables memblock resizing and why it
> > defines INIT_MEMBLOCK_RESERVED_REGIONS to include NR_CPUS?
> At first we didn't define INIT_MEMBLOCK_RESERVED_REGIONS, then we got
> boot failures on a 128-cores machine, so define it, and the value is
> similar to arm64.

AFAIR, arm64 had to reserve some per cpu data before they could enable
memblock resizing, so they had to make it static.
 
> The reason LoongArch never enables memblock resizing is because the mm
> code is derived from MIPS, and MIPS never enables it.

If that's the only reason, you might want to revisit that :)
 
> Huacai
> 
> >
> > --
> > Sincerely yours,
> > Mike.

-- 
Sincerely yours,
Mike.