From ef4984384172e93cc95e0e8cd102536d67e8a787 Mon Sep 17 00:00:00 2001
From: Pintu Kumar <pintu@codeaurora.org>
Date: Tue, 4 May 2021 18:36:48 -0700
Subject: [PATCH] mm/compaction: remove unused variable sysctl_compact_memory

The sysctl_compact_memory is mostly unused in mm/compaction.c It just
acts as a place holder for sysctl to store .data.

But the .data itself is not needed here.

So we can get ride of this variable completely and make .data as NULL.
This will also eliminate the extern declaration from header file.  No
functionality is broken or changed this way.

Link: https://lkml.kernel.org/r/1614852224-14671-1-git-send-email-pintu@codeaurora.org
Signed-off-by: Pintu Kumar <pintu@codeaurora.org>
Signed-off-by: Pintu Agarwal <pintu.ping@gmail.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 include/linux/compaction.h | 1 -
 kernel/sysctl.c            | 2 +-
 mm/compaction.c            | 3 ---
 3 files changed, 1 insertion(+), 5 deletions(-)

diff --git a/include/linux/compaction.h b/include/linux/compaction.h
index ed4070ed41ef5..4221888bdcd65 100644
--- a/include/linux/compaction.h
+++ b/include/linux/compaction.h
@@ -81,7 +81,6 @@ static inline unsigned long compact_gap(unsigned int order)
 }
 
 #ifdef CONFIG_COMPACTION
-extern int sysctl_compact_memory;
 extern unsigned int sysctl_compaction_proactiveness;
 extern int sysctl_compaction_handler(struct ctl_table *table, int write,
 			void *buffer, size_t *length, loff_t *ppos);
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index f91d327273c1b..14edf84cc571f 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2830,7 +2830,7 @@ static struct ctl_table vm_table[] = {
 #ifdef CONFIG_COMPACTION
 	{
 		.procname	= "compact_memory",
-		.data		= &sysctl_compact_memory,
+		.data		= NULL,
 		.maxlen		= sizeof(int),
 		.mode		= 0200,
 		.proc_handler	= sysctl_compaction_handler,
diff --git a/mm/compaction.c b/mm/compaction.c
index 335862f1661c1..027eb794e747f 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -2692,9 +2692,6 @@ static void compact_nodes(void)
 		compact_node(nid);
 }
 
-/* The written value is actually unused, all memory is compacted */
-int sysctl_compact_memory;
-
 /*
  * Tunable for proactive compaction. It determines how
  * aggressively the kernel should compact memory in the
-- 
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