+ mm-swap_cgroup-remove-swap_cgroup_cmpxchg.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm/swap_cgroup: remove swap_cgroup_cmpxchg
has been added to the -mm mm-unstable branch.  Its filename is
     mm-swap_cgroup-remove-swap_cgroup_cmpxchg.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-swap_cgroup-remove-swap_cgroup_cmpxchg.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Kairui Song <kasong@tencent.com>
Subject: mm/swap_cgroup: remove swap_cgroup_cmpxchg
Date: Tue, 10 Dec 2024 17:28:04 +0800

This function is never used after commit 6b611388b626 ("memcg-v1: remove
charge move code").

Link: https://lkml.kernel.org/r/20241210092805.87281-3-ryncsn@gmail.com
Signed-off-by: Kairui Song <kasong@tencent.com>
Reviewed-by: Yosry Ahmed <yosryahmed@google.com>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Chris Li <chrisl@kernel.org>
Cc: Barry Song <baohua@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/swap_cgroup.h |    2 --
 mm/swap_cgroup.c            |   29 -----------------------------
 2 files changed, 31 deletions(-)

--- a/include/linux/swap_cgroup.h~mm-swap_cgroup-remove-swap_cgroup_cmpxchg
+++ a/include/linux/swap_cgroup.h
@@ -6,8 +6,6 @@
 
 #if defined(CONFIG_MEMCG) && defined(CONFIG_SWAP)
 
-extern unsigned short swap_cgroup_cmpxchg(swp_entry_t ent,
-					unsigned short old, unsigned short new);
 extern unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id,
 					 unsigned int nr_ents);
 extern unsigned short lookup_swap_cgroup_id(swp_entry_t ent);
--- a/mm/swap_cgroup.c~mm-swap_cgroup-remove-swap_cgroup_cmpxchg
+++ a/mm/swap_cgroup.c
@@ -46,35 +46,6 @@ static struct swap_cgroup *lookup_swap_c
 }
 
 /**
- * swap_cgroup_cmpxchg - cmpxchg mem_cgroup's id for this swp_entry.
- * @ent: swap entry to be cmpxchged
- * @old: old id
- * @new: new id
- *
- * Returns old id at success, 0 at failure.
- * (There is no mem_cgroup using 0 as its id)
- */
-unsigned short swap_cgroup_cmpxchg(swp_entry_t ent,
-					unsigned short old, unsigned short new)
-{
-	struct swap_cgroup_ctrl *ctrl;
-	struct swap_cgroup *sc;
-	unsigned long flags;
-	unsigned short retval;
-
-	sc = lookup_swap_cgroup(ent, &ctrl);
-
-	spin_lock_irqsave(&ctrl->lock, flags);
-	retval = sc->id;
-	if (retval == old)
-		sc->id = new;
-	else
-		retval = 0;
-	spin_unlock_irqrestore(&ctrl->lock, flags);
-	return retval;
-}
-
-/**
  * swap_cgroup_record - record mem_cgroup for a set of swap entries
  * @ent: the first swap entry to be recorded into
  * @id: mem_cgroup to be recorded
_

Patches currently in -mm which might be from kasong@tencent.com are

zram-refuse-to-use-zero-sized-block-device-as-backing-device.patch
zram-fix-uninitialized-zram-not-releasing-backing-device.patch
mm-memcontrol-avoid-duplicated-memcg-enable-check.patch
mm-swap_cgroup-remove-swap_cgroup_cmpxchg.patch
mm-swap_cgroup-remove-global-swap-cgroup-lock.patch