From 3c09be5a2be861d7f74b0251a8e77859b4c654cc Mon Sep 17 00:00:00 2001
From: Kemeng Shi <shikemeng@huaweicloud.com>
Date: Fri, 14 Jul 2023 19:47:48 +0800
Subject: mm/page_ext: remove rollback for untouched mem_section in
 online_page_ext

If init_section_page_ext failed, we only need rollback for mem_section
before failed mem_section.  Make rollback end point to failed mem_section
to remove unnecessary rollback.

As pfn += PAGES_PER_SECTION will be executed even if init_section_page_ext
failed.  So pfn points to mem_section after failed mem_section.  Subtract
one mem_section from pfn to get failed mem_section.

Link: https://lkml.kernel.org/r/20230714114749.1743032-3-shikemeng@huaweicloud.com
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 mm/page_ext.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mm/page_ext.c b/mm/page_ext.c
index 096451df1c87..f052397dc70f 100644
--- a/mm/page_ext.c
+++ b/mm/page_ext.c
@@ -424,6 +424,7 @@ static int __meminit online_page_ext(unsigned long start_pfn,
 		return 0;
 
 	/* rollback */
+	end = pfn - PAGES_PER_SECTION;
 	for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION)
 		__free_page_ext(pfn);
 
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