Patch "mm: memcontrol: avoid unused function warning" has been added to the 4.4-stable tree

Patch "mm: memcontrol: avoid unused function warning" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    mm: memcontrol: avoid unused function warning

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     mm-memcontrol-avoid-unused-function-warning.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 358c07fcc3b60ab08d77f1684de8bd81bcf49a1a Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd@arndb.de>
Date: Thu, 25 Aug 2016 15:17:08 -0700
Subject: mm: memcontrol: avoid unused function warning

From: Arnd Bergmann <arnd@arndb.de>

commit 358c07fcc3b60ab08d77f1684de8bd81bcf49a1a upstream.

A bugfix in v4.8-rc2 introduced a harmless warning when
CONFIG_MEMCG_SWAP is disabled but CONFIG_MEMCG is enabled:

  mm/memcontrol.c:4085:27: error: 'mem_cgroup_id_get_online' defined but not used [-Werror=unused-function]
   static struct mem_cgroup *mem_cgroup_id_get_online(struct mem_cgroup *memcg)

This moves the function inside of the #ifdef block that hides the
calling function, to avoid the warning.

Fixes: 1f47b61fb407 ("mm: memcontrol: fix swap counter leak on swapout from offline cgroup")
Link: http://lkml.kernel.org/r/20160824113733.2776701-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 mm/memcontrol.c |   36 ++++++++++++++++++------------------
 1 file changed, 18 insertions(+), 18 deletions(-)

--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4150,24 +4150,6 @@ static void mem_cgroup_id_get_many(struc
 	atomic_add(n, &memcg->id.ref);
 }
 
-static struct mem_cgroup *mem_cgroup_id_get_online(struct mem_cgroup *memcg)
-{
-	while (!atomic_inc_not_zero(&memcg->id.ref)) {
-		/*
-		 * The root cgroup cannot be destroyed, so it's refcount must
-		 * always be >= 1.
-		 */
-		if (WARN_ON_ONCE(memcg == root_mem_cgroup)) {
-			VM_BUG_ON(1);
-			break;
-		}
-		memcg = parent_mem_cgroup(memcg);
-		if (!memcg)
-			memcg = root_mem_cgroup;
-	}
-	return memcg;
-}
-
 static void mem_cgroup_id_put_many(struct mem_cgroup *memcg, unsigned int n)
 {
 	if (atomic_sub_and_test(n, &memcg->id.ref)) {
@@ -5751,6 +5733,24 @@ static int __init mem_cgroup_init(void)
 subsys_initcall(mem_cgroup_init);
 
 #ifdef CONFIG_MEMCG_SWAP
+static struct mem_cgroup *mem_cgroup_id_get_online(struct mem_cgroup *memcg)
+{
+	while (!atomic_inc_not_zero(&memcg->id.ref)) {
+		/*
+		 * The root cgroup cannot be destroyed, so it's refcount must
+		 * always be >= 1.
+		 */
+		if (WARN_ON_ONCE(memcg == root_mem_cgroup)) {
+			VM_BUG_ON(1);
+			break;
+		}
+		memcg = parent_mem_cgroup(memcg);
+		if (!memcg)
+			memcg = root_mem_cgroup;
+	}
+	return memcg;
+}
+
 /**
  * mem_cgroup_swapout - transfer a memsw charge to swap
  * @page: page whose memsw charge to transfer


Patches currently in stable-queue which might be from arnd@arndb.de are

queue-4.4/mips-ip27-disable-qlge-driver-in-defconfig.patch
queue-4.4/mips-update-ip27_defconfig-for-scsi_dh-change.patch
queue-4.4/mtd-pmcmsp-use-kstrndup-instead-of-kmalloc-strncpy.patch
queue-4.4/cpmac-remove-hopeless-warning.patch
queue-4.4/mm-memcontrol-avoid-unused-function-warning.patch
queue-4.4/mips-ip22-fix-ip28-build-for-modern-gcc.patch
queue-4.4/mips-update-lemote2f_defconfig-for-cpu_freq_stat-change.patch
queue-4.4/crypto-improve-gcc-optimization-flags-for-serpent-and-wp512.patch
queue-4.4/mips-ralink-remove-unused-rt-_wdt_reset-functions.patch
queue-4.4/mips-ralink-remove-unused-timer-functions.patch
queue-4.4/mips-update-defconfigs-for-nf_ct_proto_dccp-udplite-change.patch