From: Baolin Wang Date: Thu, 28 Nov 2024 07:40:39 +0000 (+0800) Subject: mm: factor out the order calculation into a new helper X-Git-Tag: v6.14-rc1~77^2~294 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=da243c5479add600bdd58c910c9fae3355b4f026;p=thirdparty%2Flinux.git mm: factor out the order calculation into a new helper 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@linux.alibaba.com Link: https://lkml.kernel.org/r/5505f9ea50942820c1924d1803bfdd3a524e54f6.1732779148.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang Suggested-by: Matthew Wilcox Reviewed-by: Barry Song Reviewed-by: David Hildenbrand Reviewed-by: Daniel Gomez Cc: Hugh Dickins Cc: Kefeng Wang Cc: Lance Yang Cc: Ryan Roberts Signed-off-by: Andrew Morton --- diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index bcf0865a38ae3..d796c8a336478 100644 --- a/include/linux/pagemap.h +++ b/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);