The patch titled
Subject: mm: factor out the order calculation into a new helper
has been added to the -mm mm-unstable branch. Its filename is
mm-factor-out-the-order-calculation-into-a-new-helper.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-factor-out-the-order-calculation-into-a-new-helper.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: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Subject: mm: factor out the order calculation into a new helper
Date: Thu, 28 Nov 2024 15:40:39 +0800
Patch series "Support large folios for tmpfs", v3.
Traditionally, tmpfs only supported PMD-sized large folios. However
nowadays with other file systems supporting any sized large folios, and
extending anonymous to support mTHP, we should not restrict tmpfs to
allocating only PMD-sized large folios, making it more special. Instead,
we should allow tmpfs can allocate any sized large folios.
Considering that tmpfs already has the 'huge=' option to control the
PMD-sized large folios allocation, we can extend the 'huge=' option to
allow any sized large folios. The semantics of the 'huge=' mount option
are:
huge=never: no any sized large folios
huge=always: any sized large folios
huge=within_size: like 'always' but respect the i_size
huge=advise: like 'always' if requested with madvise()
Note: for tmpfs mmap() faults, due to the lack of a write size hint, still
allocate the PMD-sized large folios if huge=always/within_size/advise is
set.
Moreover, the 'deny' and 'force' testing options controlled by
'/sys/kernel/mm/transparent_hugepage/shmem_enabled', still retain the same
semantics. The 'deny' can disable any sized large folios for tmpfs, while
the 'force' can enable PMD sized large folios for tmpfs.
This patch (of 6):
Factor out the order calculation into a new helper, which can be reused by
shmem in the following patch.
Link: https://lkml.kernel.org/r/cover.1732779148.git.baolin.wang@xxxxxxxxxxxxxxxxx
Link: https://lkml.kernel.org/r/5505f9ea50942820c1924d1803bfdd3a524e54f6.1732779148.git.baolin.wang@xxxxxxxxxxxxxxxxx
Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Suggested-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Reviewed-by: Barry Song <baohua@xxxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Reviewed-by: Daniel Gomez <da.gomez@xxxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Cc: Lance Yang <ioworker0@xxxxxxxxx>
Cc: Ryan Roberts <ryan.roberts@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/pagemap.h | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)
--- a/include/linux/pagemap.h~mm-factor-out-the-order-calculation-into-a-new-helper
+++ a/include/linux/pagemap.h
@@ -727,6 +727,16 @@ typedef unsigned int __bitwise fgf_t;
#define FGP_WRITEBEGIN (FGP_LOCK | FGP_WRITE | FGP_CREAT | FGP_STABLE)
+static inline unsigned int filemap_get_order(size_t size)
+{
+ unsigned int shift = ilog2(size);
+
+ if (shift <= PAGE_SHIFT)
+ return 0;
+
+ return shift - PAGE_SHIFT;
+}
+
/**
* fgf_set_order - Encode a length in the fgf_t flags.
* @size: The suggested size of the folio to create.
@@ -740,11 +750,11 @@ typedef unsigned int __bitwise fgf_t;
*/
static inline fgf_t fgf_set_order(size_t size)
{
- unsigned int shift = ilog2(size);
+ unsigned int order = filemap_get_order(size);
- if (shift <= PAGE_SHIFT)
+ if (!order)
return 0;
- return (__force fgf_t)((shift - PAGE_SHIFT) << 26);
+ return (__force fgf_t)(order << 26);
}
void *filemap_get_entry(struct address_space *mapping, pgoff_t index);
_
Patches currently in -mm which might be from baolin.wang@xxxxxxxxxxxxxxxxx are
mm-factor-out-the-order-calculation-into-a-new-helper.patch
mm-shmem-change-shmem_huge_global_enabled-to-return-huge-order-bitmap.patch
mm-shmem-add-large-folio-support-for-tmpfs.patch
mm-shmem-add-a-kernel-command-line-to-change-the-default-huge-policy-for-tmpfs.patch
docs-tmpfs-drop-fadvise-from-the-documentation.patch
