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

[Matthew Wilcox]

On Thu, Mar 11, 2021 at 10:48:34PM +0100, Oscar Salvador wrote:
> 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.

I can reproduce this with next-20210329.

.config attached.

Attachment: config-for-osal.xz
Description: application/xz