The patch titled
Subject: tmpfs: don't enable large folios if not supported
has been added to the -mm mm-unstable branch. Its filename is
tmpfs-dont-enable-large-folios-if-not-supported.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/tmpfs-dont-enable-large-folios-if-not-supported.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Subject: tmpfs: don't enable large folios if not supported
Date: Thu, 17 Oct 2024 22:17:42 +0800
tmpfs can support large folios, but there are some configurable options
(mount options and runtime deny/force) to enable/disable large folio
allocation, so there is a performance issue when performing writes without
large folios. The issue is similar to commit 4e527d5841e2 ("iomap: fault
in smaller chunks for non-large folio mappings").
Since 'deny' is for emergencies and 'force' is for testing, performance
issues should not be a problem in real production environments, so don't
call mapping_set_large_folios() in __shmem_get_inode() when large folio is
disabled with mount huge=never option (default policy).
Link: https://lkml.kernel.org/r/20241017141742.1169404-1-wangkefeng.wang@xxxxxxxxxx
Fixes: 9aac777aaf94 ("filemap: Convert generic_perform_write() to support large folios")
Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Cc: Christian Brauner <brauner@xxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/shmem.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
--- a/mm/shmem.c~tmpfs-dont-enable-large-folios-if-not-supported
+++ a/mm/shmem.c
@@ -2845,7 +2845,10 @@ static struct inode *__shmem_get_inode(s
cache_no_acl(inode);
if (sbinfo->noswap)
mapping_set_unevictable(inode->i_mapping);
- mapping_set_large_folios(inode->i_mapping);
+
+ /* Don't consider 'deny' for emergencies and 'force' for testing */
+ if (sbinfo->huge)
+ mapping_set_large_folios(inode->i_mapping);
switch (mode & S_IFMT) {
default:
_
Patches currently in -mm which might be from wangkefeng.wang@xxxxxxxxxx are
mm-remove-unused-hugepage-for-vma_alloc_folio.patch
tmpfs-dont-enable-large-folios-if-not-supported.patch
