+ mm-memcg-remove-unneeded-nr_scanned.patch added to -mm tree

+ mm-memcg-remove-unneeded-nr_scanned.patch added to -mm tree

[Andrew Morton]

The patch titled
     Subject: mm/memcg: remove unneeded nr_scanned
has been added to the -mm tree.  Its filename is
     mm-memcg-remove-unneeded-nr_scanned.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mm-memcg-remove-unneeded-nr_scanned.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mm-memcg-remove-unneeded-nr_scanned.patch

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------------------------------------------------------
From: Miaohe Lin <linmiaohe@huawei.com>
Subject: mm/memcg: remove unneeded nr_scanned

The local variable nr_scanned is unneeded as mem_cgroup_soft_reclaim
always does *total_scanned += nr_scanned.  So we can pass total_scanned
directly to the mem_cgroup_soft_reclaim to simplify the code and save some
cpu cycles of adding nr_scanned to total_scanned.

Link: https://lkml.kernel.org/r/20220328114144.53389-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/memcontrol.c |    5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

--- a/mm/memcontrol.c~mm-memcg-remove-unneeded-nr_scanned
+++ a/mm/memcontrol.c
@@ -3387,7 +3387,6 @@ unsigned long mem_cgroup_soft_limit_recl
 	int loop = 0;
 	struct mem_cgroup_tree_per_node *mctz;
 	unsigned long excess;
-	unsigned long nr_scanned;
 
 	if (order > 0)
 		return 0;
@@ -3415,11 +3414,9 @@ unsigned long mem_cgroup_soft_limit_recl
 		if (!mz)
 			break;
 
-		nr_scanned = 0;
 		reclaimed = mem_cgroup_soft_reclaim(mz->memcg, pgdat,
-						    gfp_mask, &nr_scanned);
+						    gfp_mask, total_scanned);
 		nr_reclaimed += reclaimed;
-		*total_scanned += nr_scanned;
 		spin_lock_irq(&mctz->lock);
 		__mem_cgroup_remove_exceeded(mz, mctz);
 
_

Patches currently in -mm which might be from linmiaohe@huawei.com are

mm-memcg-remove-unneeded-nr_scanned.patch
mm-mremap-use-helper-mlock_future_check.patch
mm-mlock-fix-two-bugs-in-user_shm_lock.patch
mm-compaction-use-helper-isolation_suitable.patch