commit 172ffeb9b9c284c6676ce03721cccf9b4ec6680b
author Wei Yang <richard.weiyang@gmail.com> Thu Jul 06 15:36:53 2017 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> Thu Jul 06 16:24:31 2017 -0700
tree 687c145e37bd9d7ffb9f2f41f0ea4f1575764714
parent f2f43e566a02a3bdde0a65e6a2e88d707c212a29

mm/nobootmem.c: return 0 when start_pfn equals end_pfn

When start_pfn equals end_pfn, __free_pages_memory() has no effect and
__free_memory_core() will finally return (end_pfn - start_pfn) = 0.

This patch returns 0 directly when start_pfn equals end_pfn.

Link: http://lkml.kernel.org/r/20170502131115.6650-1-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/nobootmem.c

diff --git a/mm/nobootmem.c b/mm/nobootmem.c
index 487dad6..36454d0f 100644
--- a/mm/nobootmem.c
+++ b/mm/nobootmem.c
@@ -118,7 +118,7 @@ static unsigned long __init __free_memory_core(phys_addr_t start,
 	unsigned long end_pfn = min_t(unsigned long,
 				      PFN_DOWN(end), max_low_pfn);
 
-	if (start_pfn > end_pfn)
+	if (start_pfn >= end_pfn)
 		return 0;
 
 	__free_pages_memory(start_pfn, end_pfn);