Re: [PATCH v6 3/4] x86/vmemmap: Handle unpopulated sub-pmd ranges

[Oscar Salvador]

On Thu, Mar 11, 2021 at 01:29:39PM -0800, Dave Hansen wrote:
> On 3/9/21 1:40 PM, Oscar Salvador wrote:
> > +static void __meminit vmemmap_use_new_sub_pmd(unsigned long start, unsigned long end)
> > +{
> > +	/*
> > +	 * Could be our memmap page is filled with PAGE_UNUSED already from a
> > +	 * previous remove. Make sure to reset it.
> > +	 */
> > +	vmemmap_use_sub_pmd(start);
> > +
> > +	/*
> > +	 * Mark with PAGE_UNUSED the unused parts of the new memmap range
> > +	 */
> > +	if (!IS_ALIGNED(start, PMD_SIZE))
> > +		memset((void *)start, PAGE_UNUSED,
> > +		        start - ALIGN_DOWN(start, PMD_SIZE));
> > +	if (!IS_ALIGNED(end, PMD_SIZE))
> > +		memset((void *)end, PAGE_UNUSED,
> > +		        ALIGN(end, PMD_SIZE) - end);
> > +}
> > +#endif
> 
> This is apparently under both CONFIG_SPARSEMEM_VMEMMAP and
> CONFIG_MEMORY_HOTPLUG #ifdefs.  It errors out at compile-time with this
> config: https://sr71.net/~dave/intel/config-mmotm-20210311

It seems that mmotm still has v5.
v6 (this one) fixed that up. I basically moved the code out of
MEMORY_HOTPLUG #ifdefs.

I could not reproduce your error on v6.


-- 
Oscar Salvador
SUSE L3