Re: [PATCH 4.14 023/159] mm/sparsemem: Allocate mem_section at runtime for CONFIG_SPARSEMEM_EXTREME=y

[Kirill A. Shutemov]

On Mon, Jan 08, 2018 at 08:46:53PM +0300, Kirill A. Shutemov wrote:
> On Mon, Jan 08, 2018 at 04:04:44PM +0000, Ingo Molnar wrote:
> > 
> > hi Kirill,
> > 
> > As Mike reported it below, your 5-level paging related upstream commit 
> > 83e3c48729d9 and all its followup fixes:
> > 
> >  83e3c48729d9: mm/sparsemem: Allocate mem_section at runtime for CONFIG_SPARSEMEM_EXTREME=y
> >  629a359bdb0e: mm/sparsemem: Fix ARM64 boot crash when CONFIG_SPARSEMEM_EXTREME=y
> >  d09cfbbfa0f7: mm/sparse.c: wrong allocation for mem_section
> > 
> > ... still breaks kexec - and that now regresses -stable as well.
> > 
> > Given that 5-level paging now syntactically depends on having this commit, if we 
> > fully revert this then we'll have to disable 5-level paging as well.

This *should* help.

Mike, could you test this? (On top of the rest of the fixes.)

Sorry for the mess.