From daf3538ad5a4800507b13bea6f37601da9cc28d5 Mon Sep 17 00:00:00 2001
From: Oscar Salvador <osalvador@suse.de>
Date: Tue, 5 Mar 2019 15:48:53 -0800
Subject: [PATCH] mm,memory_hotplug: explicitly pass the head to
isolate_huge_page
isolate_huge_page() expects we pass the head of hugetlb page to it:
bool isolate_huge_page(...)
{
...
VM_BUG_ON_PAGE(!PageHead(page), page);
...
}
While I really cannot think of any situation where we end up with a
non-head page between hands in do_migrate_range(), let us make sure the
code is as sane as possible by explicitly passing the Head. Since we
already got the pointer, it does not take us extra effort.
Link: http://lkml.kernel.org/r/20190208090604.975-1-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Anthony Yznaga <anthony.yznaga@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
mm/memory_hotplug.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index eb1a28469b66e..ebc8c1e75355d 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1378,12 +1378,12 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
if (PageHuge(page)) {
struct page *head = compound_head(page);
- pfn = page_to_pfn(head) + (1<<compound_order(head)) - 1;
if (compound_order(head) > PFN_SECTION_SHIFT) {
ret = -EBUSY;
break;
}
- isolate_huge_page(page, &source);
+ pfn = page_to_pfn(head) + (1<<compound_order(head)) - 1;
+ isolate_huge_page(head, &source);
continue;
} else if (PageTransHuge(page))
pfn = page_to_pfn(compound_head(page))
--
GitLab