Messages in this thread | | | Subject | Re: [PATCH v2 5/7] mm,memory_hotplug: Enforce pageblock alignment when memmap_on_memory | From | David Hildenbrand <> | Date | Thu, 25 Feb 2021 19:27:33 +0100 |
| |
On 09.02.21 14:38, Oscar Salvador wrote: > Many places expects us to pass a pageblock aligned range. > E.g: memmap_init_zone() needs a pageblock aligned range in order > to set the proper migrate type for it. > online_pages() needs to operate on a pageblock aligned range for > isolation purposes. > > Make sure we disable the feature in case we cannot guarantee the > right alignment. > > Signed-off-by: Oscar Salvador <osalvador@suse.de> > --- > mm/memory_hotplug.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index d3fb036d33fd..1a4d5dd1a2c8 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -56,12 +56,16 @@ static int memmap_on_memory_show(char *buffer, const struct kernel_param *kp) > static __meminit int memmap_on_memory_store(const char *val, > const struct kernel_param *kp) > { > + unsigned long pageblock_size = PFN_PHYS(pageblock_nr_pages); > + > /* > * 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) || > - (PMD_SIZE % sizeof(struct page))) > + (PMD_SIZE % sizeof(struct page)) || > + !(MIN_MEMORY_BLOCK_SIZE - PMD_SIZE) || > + !(MIN_MEMORY_BLOCK_SIZE - PMD_SIZE) % pageblock_size) > return 0; > > return param_set_bool(val, kp); >
Dito, rather squash in #1 and add a comment explaining what's happening there.
-- Thanks,
David / dhildenb
| |