If any page is still online, the section should stay online.
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
---
mm/page_alloc.c | 2 +-
mm/sparse.c | 25 ++++++++++++++++++++++++-
2 files changed, 25 insertions(+), 2 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 2e5dcfdb0908..ae9023da2ca2 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -8013,7 +8013,6 @@ __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
break;
if (pfn == end_pfn)
return;
- offline_mem_sections(pfn, end_pfn);
zone = page_zone(pfn_to_page(pfn));
spin_lock_irqsave(&zone->lock, flags);
pfn = start_pfn;
@@ -8051,6 +8050,7 @@ __offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn)
pfn += (1 << order);
}
spin_unlock_irqrestore(&zone->lock, flags);
+ offline_mem_sections(start_pfn, end_pfn);
}
#endif
diff --git a/mm/sparse.c b/mm/sparse.c
index 58cab483e81b..44978cb18fed 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -623,7 +623,27 @@ void online_mem_sections(unsigned long start_pfn, unsigned long end_pfn)
}
#ifdef CONFIG_MEMORY_HOTREMOVE
-/* Mark all memory sections within the pfn range as online */
+static bool all_pages_in_section_offline(unsigned long section_nr)
+{
+ unsigned long pfn = section_nr_to_pfn(section_nr);
+ struct page *page;
+ int i;
+
+ for (i = 0; i < PAGES_PER_SECTION; i++, pfn++) {
+ if (!pfn_valid(pfn))
+ continue;
+
+ page = pfn_to_page(pfn);
+ if (!PageOffline(page))
+ return false;
+ }
+ return true;
+}
+
+/*
+ * Mark all memory sections within the pfn range as offline (if all pages
+ * of a memory section are already offline)
+ */
void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn)
{
unsigned long pfn;
@@ -639,6 +659,9 @@ void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn)
if (WARN_ON(!valid_section_nr(section_nr)))
continue;
+ if (!all_pages_in_section_offline(section_nr))
+ continue;
+
ms = __nr_to_section(section_nr);
ms->section_mem_map &= ~SECTION_IS_ONLINE;
}
--
2.14.3
