+ huge-tmpfs-remove-shrinklist-addition-from-shmem_setattr.patch added to -mm tree

+ huge-tmpfs-remove-shrinklist-addition-from-shmem_setattr.patch added to -mm tree

[akpm]

The patch titled
     Subject: huge tmpfs: remove shrinklist addition from shmem_setattr()
has been added to the -mm tree.  Its filename is
     huge-tmpfs-remove-shrinklist-addition-from-shmem_setattr.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/huge-tmpfs-remove-shrinklist-addition-from-shmem_setattr.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/huge-tmpfs-remove-shrinklist-addition-from-shmem_setattr.patch

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------------------------------------------------------
From: Hugh Dickins <hughd@google.com>
Subject: huge tmpfs: remove shrinklist addition from shmem_setattr()

There's a block of code in shmem_setattr() to add the inode to
shmem_unused_huge_shrink()'s shrinklist when lowering i_size: it dates
from before 5.7 changed truncation to do split_huge_page() for itself, and
should have been removed at that time.

I am over-stating that: split_huge_page() can fail (notably if there's an
extra reference to the page at that time), so there might be value in
retrying.  But there were already retries as truncation worked through the
tails, and this addition risks repeating unsuccessful retries
indefinitely: I'd rather remove it now, and work on reducing the chance of
split_huge_page() failures separately, if we need to.

Link: https://lkml.kernel.org/r/b73b3492-8822-18f9-83e2-938528cdde94@google.com
Fixes: 71725ed10c40 ("mm: huge tmpfs: try to split_huge_page() when punching hole")
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/shmem.c |   19 -------------------
 1 file changed, 19 deletions(-)

--- a/mm/shmem.c~huge-tmpfs-remove-shrinklist-addition-from-shmem_setattr
+++ a/mm/shmem.c
@@ -1058,7 +1058,6 @@ static int shmem_setattr(struct user_nam
 {
 	struct inode *inode = d_inode(dentry);
 	struct shmem_inode_info *info = SHMEM_I(inode);
-	struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
 	int error;
 
 	error = setattr_prepare(&init_user_ns, dentry, attr);
@@ -1094,24 +1093,6 @@ static int shmem_setattr(struct user_nam
 			if (oldsize > holebegin)
 				unmap_mapping_range(inode->i_mapping,
 							holebegin, 0, 1);
-
-			/*
-			 * Part of the huge page can be beyond i_size: subject
-			 * to shrink under memory pressure.
-			 */
-			if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) {
-				spin_lock(&sbinfo->shrinklist_lock);
-				/*
-				 * _careful to defend against unlocked access to
-				 * ->shrink_list in shmem_unused_huge_shrink()
-				 */
-				if (list_empty_careful(&info->shrinklist)) {
-					list_add_tail(&info->shrinklist,
-							&sbinfo->shrinklist);
-					sbinfo->shrinklist_len++;
-				}
-				spin_unlock(&sbinfo->shrinklist_lock);
-			}
 		}
 	}
 
_

Patches currently in -mm which might be from hughd@google.com are

fs-mm-fix-race-in-unlinking-swapfile.patch
huge-tmpfs-fix-fallocatevanilla-advance-over-huge-pages.patch
huge-tmpfs-fix-split_huge_page-after-falloc_fl_keep_size.patch
huge-tmpfs-remove-shrinklist-addition-from-shmem_setattr.patch
huge-tmpfs-revert-shmems-use-of-transhuge_vma_enabled.patch
huge-tmpfs-move-shmem_huge_enabled-upwards.patch
huge-tmpfs-sgp_noalloc-to-stop-collapse_file-on-race.patch
huge-tmpfs-shmem_is_hugevma-inode-index.patch
huge-tmpfs-decide-statst_blksize-by-shmem_is_huge.patch
shmem-shmem_writepage-split-unlikely-i915-thp.patch