[PATCH v4 1/5] mm/sparse.c: introduce new function fill_subsection_map()

From: Baoquan He
Date: Thu Mar 12 2020 - 08:44:33 EST


Factor out the code that fills the subsection map from section_activate()
into fill_subsection_map(), this makes section_activate() cleaner and
easier to follow.

Signed-off-by: Baoquan He <bhe@xxxxxxxxxx>
Reviewed-by: Wei Yang <richard.weiyang@xxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
---
mm/sparse.c | 32 +++++++++++++++++++++-----------
1 file changed, 21 insertions(+), 11 deletions(-)

diff --git a/mm/sparse.c b/mm/sparse.c
index cf28505e82c5..5919bc5b1547 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -792,24 +792,15 @@ static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
ms->section_mem_map = (unsigned long)NULL;
}

-static struct page * __meminit section_activate(int nid, unsigned long pfn,
- unsigned long nr_pages, struct vmem_altmap *altmap)
+static int fill_subsection_map(unsigned long pfn, unsigned long nr_pages)
{
- DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 };
struct mem_section *ms = __pfn_to_section(pfn);
- struct mem_section_usage *usage = NULL;
+ DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 };
unsigned long *subsection_map;
- struct page *memmap;
int rc = 0;

subsection_mask_set(map, pfn, nr_pages);

- if (!ms->usage) {
- usage = kzalloc(mem_section_usage_size(), GFP_KERNEL);
- if (!usage)
- return ERR_PTR(-ENOMEM);
- ms->usage = usage;
- }
subsection_map = &ms->usage->subsection_map[0];

if (bitmap_empty(map, SUBSECTIONS_PER_SECTION))
@@ -820,6 +811,25 @@ static struct page * __meminit section_activate(int nid, unsigned long pfn,
bitmap_or(subsection_map, map, subsection_map,
SUBSECTIONS_PER_SECTION);

+ return rc;
+}
+
+static struct page * __meminit section_activate(int nid, unsigned long pfn,
+ unsigned long nr_pages, struct vmem_altmap *altmap)
+{
+ struct mem_section *ms = __pfn_to_section(pfn);
+ struct mem_section_usage *usage = NULL;
+ struct page *memmap;
+ int rc = 0;
+
+ if (!ms->usage) {
+ usage = kzalloc(mem_section_usage_size(), GFP_KERNEL);
+ if (!usage)
+ return ERR_PTR(-ENOMEM);
+ ms->usage = usage;
+ }
+
+ rc = fill_subsection_map(pfn, nr_pages);
if (rc) {
if (usage)
ms->usage = NULL;
--
2.17.2