On Thu, Feb 25, 2021 at 07:26:50PM +0100, David Hildenbrand wrote:
> On 09.02.21 14:38, Oscar Salvador wrote:
> > When struct page's size is not multiple of PMD, these do not get
> > fully populated when adding sections, hence two sections will
> > intersect the same the PMD. This goes against the vmemmap-per-device
> > premise, so reject it if that is the case.
> >
> > Signed-off-by: Oscar Salvador <osalvador@xxxxxxx>
> > ---
> > mm/memory_hotplug.c | 5 +++--
> > 1 file changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> > index 95695483a622..d3fb036d33fd 100644
> > --- a/mm/memory_hotplug.c
> > +++ b/mm/memory_hotplug.c
> > @@ -57,10 +57,11 @@ static __meminit int memmap_on_memory_store(const char *val,
> > const struct kernel_param *kp)
> > {
> > /*
> > - * Fail silently in case we cannot enable it due to platform constraints.
> > + * Fail silently in case we cannot enable it due to system constraints.
> > * User can always check whether it is enabled or not via /sys/module.
> > */
> > - if (!IS_ENABLED(CONFIG_ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE))
> > + if (!IS_ENABLED(CONFIG_ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE) ||
> > + (PMD_SIZE % sizeof(struct page)))
> > return 0;
> > return param_set_bool(val, kp);
> >
>
> Squash that into #1 - it's part of basic operation.
Just to be sure we are on the same page.
You mean to move this patch and patch#5 into the runtime check in
mhp_supports_memmap_on_memory(), right?
--
Oscar Salvador
SUSE L3
