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| author | Kefeng Wang <wangkefeng.wang@huawei.com> | 2024-10-17 22:17:42 +0800 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-11-06 20:11:15 -0800 |
| commit | 5a90c155defa684f3a21f68c3f8e40c056e6114c (patch) | |
| tree | 6ddaabbe5b09aa40d1cdbbeeaddca33c59adf6eb /mm/shmem.c | |
| parent | 7146de5ff504003ed6f61c39c379b5777e7bed29 (diff) | |
| download | lwn-5a90c155defa684f3a21f68c3f8e40c056e6114c.tar.gz lwn-5a90c155defa684f3a21f68c3f8e40c056e6114c.zip | |
tmpfs: don't enable large folios if not supported
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@huawei.com
Fixes: 9aac777aaf94 ("filemap: Convert generic_perform_write() to support large folios")
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/shmem.c')
| -rw-r--r-- | mm/shmem.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/mm/shmem.c b/mm/shmem.c index 6ad50ba60d8e..98fb539434f4 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2842,7 +2842,10 @@ static struct inode *__shmem_get_inode(struct mnt_idmap *idmap, 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: |