+ mm-migration-remove-unneeded-local-variable-mapping_locked.patch added to -mm tree

+ mm-migration-remove-unneeded-local-variable-mapping_locked.patch added to -mm tree

[Andrew Morton]

The patch titled
     Subject: mm/migration: remove unneeded local variable mapping_locked
has been added to the -mm tree.  Its filename is
     mm-migration-remove-unneeded-local-variable-mapping_locked.patch

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

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next and is updated
there every 3-4 working days

------------------------------------------------------
From: Miaohe Lin <linmiaohe@huawei.com>
Subject: mm/migration: remove unneeded local variable mapping_locked

Patch series "A few cleanup and fixup patches for migration", v2.

This series contains a few patches to remove unneeded variables, jump
label and use helper to simplify the code.  Also we fix some bugs such as
page refcounts leak , invalid node access and so on.  More details can be
found in the respective changelogs.


This patch (of 11):

When mapping_locked is true, TTU_RMAP_LOCKED is always set to ttu.  We can
check ttu instead so mapping_locked can be removed.  And ttu is either 0
or TTU_RMAP_LOCKED now.  Change '|=' to '=' to reflect this.

Link: https://lkml.kernel.org/r/20220318111709.60311-1-linmiaohe@huawei.com
Link: https://lkml.kernel.org/r/20220318111709.60311-2-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Alistair Popple <apopple@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/migrate.c |    6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

--- a/mm/migrate.c~mm-migration-remove-unneeded-local-variable-mapping_locked
+++ a/mm/migrate.c
@@ -1230,7 +1230,6 @@ static int unmap_and_move_huge_page(new_
 		goto put_anon;
 
 	if (page_mapped(hpage)) {
-		bool mapping_locked = false;
 		enum ttu_flags ttu = 0;
 
 		if (!PageAnon(hpage)) {
@@ -1244,14 +1243,13 @@ static int unmap_and_move_huge_page(new_
 			if (unlikely(!mapping))
 				goto unlock_put_anon;
 
-			mapping_locked = true;
-			ttu |= TTU_RMAP_LOCKED;
+			ttu = TTU_RMAP_LOCKED;
 		}
 
 		try_to_migrate(src, ttu);
 		page_was_mapped = 1;
 
-		if (mapping_locked)
+		if (ttu & TTU_RMAP_LOCKED)
 			i_mmap_unlock_write(mapping);
 	}
 
_

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

mm-shmem-make-shmem_init-return-void.patch
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
mm-migration-remove-unneeded-local-variable-mapping_locked.patch
mm-migration-remove-unneeded-out-label.patch
mm-migration-remove-unneeded-local-variable-page_lru.patch
mm-migration-fix-the-confusing-pagetranshuge-check.patch
mm-migration-use-helper-function-vma_lookup-in-add_page_for_migration.patch
mm-migration-use-helper-macro-min-in-do_pages_stat.patch
mm-migration-avoid-unneeded-nodemask_t-initialization.patch
mm-migration-remove-some-duplicated-codes-in-migrate_pages.patch
mm-migration-fix-potential-page-refcounts-leak-in-migrate_pages.patch
mm-migration-fix-potential-invalid-node-access-for-reclaim-based-migration.patch
mm-migration-fix-possible-do_pages_stat_array-racing-with-memory-offline.patch