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

Commit Message

Andrew Morton April 7, 2020, 3:06 a.m. UTC

From: David Hildenbrand <[e-mail]>
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/[e-mail]
Signed-off-by: David Hildenbrand <[e-mail]>
Reviewed-by: Baoquan He <[e-mail]>
Reviewed-by: Wei Yang <[e-mail]>
Cc: Segher Boessenkool <[e-mail]>
Cc: Oscar Salvador <[e-mail]>
Cc: Michal Hocko <[e-mail]>
Cc: Dan Williams <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
---

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

Patch

--- 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();