[patch 057/166] mm/memory_hotplug.c: cleanup __add_pages()

Andrew Morton
2020-04-07T03:06:59Z

From: David Hildenbrand <david@redhat.com>
Subject: mm/memory_hotplug.c: cleanup __add_pages()

Let's drop the basically unused section stuff and simplify. The logic now
matches the logic in __remove_pages().

Link: http://lkml.kernel.org/r/20200228095819.10750-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Wei Yang <richard.weiyang@gmail.com>
Cc: Segher Boessenkool <segher@kernel.crashing.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

mm/memory_hotplug.c | 18 +++++++-----------
1 file changed, 7 insertions(+), 11 deletions(-)

--- a/mm/memory_hotplug.c~mm-memory_hotplug-cleanup-__add_pages
+++ a/mm/memory_hotplug.c
@@ -307,8 +307,9 @@ static int check_hotplug_memory_addressa
int __ref __add_pages(int nid, unsigned long pfn, unsigned long nr_pages,
struct mhp_restrictions *restrictions)
{
+ const unsigned long end_pfn = pfn + nr_pages;
+ unsigned long cur_nr_pages;
int err;
- unsigned long nr, start_sec, end_sec;
struct vmem_altmap *altmap = restrictions->altmap;

err = check_hotplug_memory_addressable(pfn, nr_pages);
@@ -331,18 +332,13 @@ int __ref __add_pages(int nid, unsigned
if (err)
return err;

- start_sec = pfn_to_section_nr(pfn);
- end_sec = pfn_to_section_nr(pfn + nr_pages - 1);
- for (nr = start_sec; nr <= end_sec; nr++) {
- unsigned long pfns;
-
- pfns = min(nr_pages, PAGES_PER_SECTION
- - (pfn & ~PAGE_SECTION_MASK));
- err = sparse_add_section(nid, pfn, pfns, altmap);
+ for (; pfn < end_pfn; pfn += cur_nr_pages) {
+ /* Select all remaining pages up to the next section boundary */
+ cur_nr_pages = min(end_pfn - pfn,
+ SECTION_ALIGN_UP(pfn + 1) - pfn);
+ err = sparse_add_section(nid, pfn, cur_nr_pages, altmap);
if (err)
break;
- pfn += pfns;
- nr_pages -= pfns;
cond_resched();
}
vmemmap_populate_print_last();
_