[PATCH 2/4] mm/swap_cgroup: remove swap_cgroup_cmpxchg

Kairui Song
2024-12-02T18:42:20Z

From: Kairui Song <kasong@tencent.com>

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

Signed-off-by: Kairui Song <kasong@tencent.com>
---
include/linux/swap_cgroup.h | 2 --
mm/swap_cgroup.c | 29 -----------------------------
2 files changed, 31 deletions(-)

diff --git a/include/linux/swap_cgroup.h b/include/linux/swap_cgroup.h
index ae73a87775b3..d521ad1c4164 100644
--- a/include/linux/swap_cgroup.h
+++ b/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);
diff --git a/mm/swap_cgroup.c b/mm/swap_cgroup.c
index f63d1aa072a1..1770b076f6b7 100644
--- a/mm/swap_cgroup.c
+++ b/mm/swap_cgroup.c
@@ -45,35 +45,6 @@ static struct swap_cgroup *lookup_swap_cgroup(swp_entry_t ent,
return &ctrl->map[offset];
}

-/**
- * 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
--
2.47.0