The patch titled
Subject: fs: add a filesystem flag for THPs
has been added to the -mm tree. Its filename is
fs-add-a-filesystem-flag-for-thps.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/fs-add-a-filesystem-flag-for-thps.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/fs-add-a-filesystem-flag-for-thps.patch
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*** 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: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: fs: add a filesystem flag for THPs
The page cache needs to know whether the filesystem supports THPs so that
it doesn't send THPs to filesystems which can't handle them. Dave Chinner
points out that getting from the page mapping to the filesystem type is
too many steps (mapping->host->i_sb->s_type->fs_flags) so cache that
information in the address space flags.
Link: https://lkml.kernel.org/r/20200916032717.22917-1-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Song Liu <songliubraving@xxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxxx>
Cc: "Kirill A . Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Dave Chinner <dchinner@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/inode.c | 2 ++
include/linux/fs.h | 1 +
include/linux/pagemap.h | 6 ++++++
mm/shmem.c | 2 +-
4 files changed, 10 insertions(+), 1 deletion(-)
--- a/fs/inode.c~fs-add-a-filesystem-flag-for-thps
+++ a/fs/inode.c
@@ -181,6 +181,8 @@ int inode_init_always(struct super_block
mapping->a_ops = &empty_aops;
mapping->host = inode;
mapping->flags = 0;
+ if (sb->s_type->fs_flags & FS_THP_SUPPORT)
+ __set_bit(AS_THP_SUPPORT, &mapping->flags);
mapping->wb_err = 0;
atomic_set(&mapping->i_mmap_writable, 0);
#ifdef CONFIG_READ_ONLY_THP_FOR_FS
--- a/include/linux/fs.h~fs-add-a-filesystem-flag-for-thps
+++ a/include/linux/fs.h
@@ -2219,6 +2219,7 @@ struct file_system_type {
#define FS_HAS_SUBTYPE 4
#define FS_USERNS_MOUNT 8 /* Can be mounted by userns root */
#define FS_DISALLOW_NOTIFY_PERM 16 /* Disable fanotify permission events */
+#define FS_THP_SUPPORT 8192 /* Remove once all fs converted */
#define FS_RENAME_DOES_D_MOVE 32768 /* FS will handle d_move() during rename() internally. */
int (*init_fs_context)(struct fs_context *);
const struct fs_parameter_spec *parameters;
--- a/include/linux/pagemap.h~fs-add-a-filesystem-flag-for-thps
+++ a/include/linux/pagemap.h
@@ -29,6 +29,7 @@ enum mapping_flags {
AS_EXITING = 4, /* final truncate in progress */
/* writeback related tags are not used */
AS_NO_WRITEBACK_TAGS = 5,
+ AS_THP_SUPPORT = 6, /* THPs supported */
};
/**
@@ -119,6 +120,11 @@ static inline void mapping_set_gfp_mask(
m->gfp_mask = mask;
}
+static inline bool mapping_thp_support(struct address_space *mapping)
+{
+ return test_bit(AS_THP_SUPPORT, &mapping->flags);
+}
+
void release_pages(struct page **pages, int nr);
/*
--- a/mm/shmem.c~fs-add-a-filesystem-flag-for-thps
+++ a/mm/shmem.c
@@ -3983,7 +3983,7 @@ static struct file_system_type shmem_fs_
.parameters = shmem_fs_parameters,
#endif
.kill_sb = kill_litter_super,
- .fs_flags = FS_USERNS_MOUNT,
+ .fs_flags = FS_USERNS_MOUNT | FS_THP_SUPPORT,
};
int __init shmem_init(void)
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
mm-debug-do-not-dereference-i_ino-blindly.patch
mm-factor-find_get_incore_page-out-of-mincore_page.patch
mm-use-find_get_incore_page-in-memcontrol.patch
mm-optimise-madvise-willneed.patch
mm-optimise-madvise-willneed-fix.patch
proc-optimise-smaps-for-shmem-entries.patch
i915-use-find_lock_page-instead-of-find_lock_entry.patch
mm-convert-find_get_entry-to-return-the-head-page.patch
mm-convert-find_get_entry-to-return-the-head-page-fix.patch
mm-shmem-return-head-page-from-find_lock_entry.patch
mm-shmem-return-head-page-from-find_lock_entry-fix.patch
mm-add-find_lock_head.patch
mm-filemap-fix-filemap_map_pages-for-thp.patch
mm-account-pmd-tables-like-pte-tables.patch
mm-move-pagedoublemap-bit.patch
mm-simplify-pagedoublemap-with-pf_second-policy.patch
xarray-add-xa_get_order.patch
xarray-add-xas_split.patch
xarray-add-xas_split-fix-2.patch
mm-filemap-fix-storing-to-a-thp-shadow-entry.patch
mm-filemap-fix-page-cache-removal-for-arbitrary-sized-thps.patch
mm-memory-remove-page-fault-assumption-of-compound-page-size.patch
mm-page_owner-change-split_page_owner-to-take-a-count.patch
mm-huge_memory-fix-page_trans_huge_mapcount-assumption-of-thp-size.patch
mm-huge_memory-fix-can_split_huge_page-assumption-of-thp-size.patch
mm-rmap-fix-assumptions-of-thp-size.patch
mm-truncate-fix-truncation-for-pages-of-arbitrary-size.patch
mm-page-writeback-support-tail-pages-in-wait_for_stable_page.patch
mm-vmscan-allow-arbitrary-sized-pages-to-be-paged-out.patch
fs-add-a-filesystem-flag-for-thps.patch
fs-do-not-update-nr_thps-for-mappings-which-support-thps.patch
mm-readahead-add-define_readahead.patch
mm-readahead-make-page_cache_ra_unbounded-take-a-readahead_control.patch
mm-readahead-make-do_page_cache_ra-take-a-readahead_control.patch
mm-readahead-add-page_cache_sync_ra-and-page_cache_async_ra.patch
harden-autofs-ioctl-table.patch
