mm: swap_cgroup: get rid of __lookup_swap_cgroup()

Because swap_cgroup map is now virtually contiguous, swap_cgroup_record()
can be simplified, which eliminates a need to use __lookup_swap_cgroup().

Now as __lookup_swap_cgroup() is really trivial and is used only once, it
can be inlined.

Link: https://lkml.kernel.org/r/20241115190229.676440-2-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/swap_cgroup.c b/mm/swap_cgroup.c
index 76f645537e9611aabf93409cebeee5b5bdccc1df..f63d1aa072a19fde8defa0362065fc2684bf261e 100644 (file)
--- a/mm/swap_cgroup.c
+++ b/mm/swap_cgroup.c
@@ -33,13 +33,6 @@ static struct swap_cgroup_ctrl swap_cgroup_ctrl[MAX_SWAPFILES];
  *
  * TODO: we can push these buffers out to HIGHMEM.
  */
-
-static struct swap_cgroup *__lookup_swap_cgroup(struct swap_cgroup_ctrl *ctrl,
-                                               pgoff_t offset)
-{
-       return &ctrl->map[offset];
-}
-
 static struct swap_cgroup *lookup_swap_cgroup(swp_entry_t ent,
                                        struct swap_cgroup_ctrl **ctrlp)
 {
@@ -49,7 +42,7 @@ static struct swap_cgroup *lookup_swap_cgroup(swp_entry_t ent,
        ctrl = &swap_cgroup_ctrl[swp_type(ent)];
        if (ctrlp)
                *ctrlp = ctrl;
-       return __lookup_swap_cgroup(ctrl, offset);
+       return &ctrl->map[offset];
 }
 
 /**
@@ -104,16 +97,9 @@ unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id,
 
        spin_lock_irqsave(&ctrl->lock, flags);
        old = sc->id;
-       for (;;) {
+       for (; offset < end; offset++, sc++) {
                VM_BUG_ON(sc->id != old);
                sc->id = id;
-               offset++;
-               if (offset == end)
-                       break;
-               if (offset % SC_PER_PAGE)
-                       sc++;
-               else
-                       sc = __lookup_swap_cgroup(ctrl, offset);
        }
        spin_unlock_irqrestore(&ctrl->lock, flags);