online_page_ext and page_ext_init allocate page_ext for each section, but
they do not allocate if the first PFN is !pfn_present(pfn) or
!pfn_valid(pfn).
Though the first page is not valid, page_ext could be useful for other
pages in the section. But checking all PFNs in a section may be time
consuming job. Let's check each (section count / 16) PFN, then prepare
page_ext if any PFN is present or valid.
Signed-off-by: Jaewon Kim <jaewon31.kim@xxxxxxxxxxx>
---
mm/page_ext.c | 25 ++++++++++++++++++++++---
1 file changed, 22 insertions(+), 3 deletions(-)
diff --git a/mm/page_ext.c b/mm/page_ext.c
index 32f18911deda..634f9c5a8b9b 100644
--- a/mm/page_ext.c
+++ b/mm/page_ext.c
@@ -312,7 +312,17 @@ static int __meminit online_page_ext(unsigned long start_pfn,
}
for (pfn = start; !fail && pfn < end; pfn += PAGES_PER_SECTION) {
- if (!pfn_present(pfn))
+ unsigned long t_pfn = pfn;
+ bool present = false;
+
+ while (t_pfn < ALIGN(pfn + 1, PAGES_PER_SECTION)) {
+ if (pfn_present(t_pfn)) {
+ present = true;
+ break;
+ }
+ t_pfn = ALIGN(pfn + 1, PAGES_PER_SECTION >> 4);
+ }
+ if (!present)
continue;
fail = init_section_page_ext(pfn, nid);
}
@@ -391,8 +401,17 @@ void __init page_ext_init(void)
*/
for (pfn = start_pfn; pfn < end_pfn;
pfn = ALIGN(pfn + 1, PAGES_PER_SECTION)) {
-
- if (!pfn_valid(pfn))
+ unsigned long t_pfn = pfn;
+ bool valid = false;
+
+ while (t_pfn < ALIGN(pfn + 1, PAGES_PER_SECTION)) {
+ if (pfn_valid(t_pfn)) {
+ valid = true;
+ break;
+ }
+ t_pfn = ALIGN(pfn + 1, PAGES_PER_SECTION >> 4);
+ }
+ if (!valid)
continue;
/*
* Nodes's pfns can be overlapping.
--
2.13.0
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