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From: Matthew Wilcox <willy@infradead.org>
To: linux-fsdevel@vger.kernel.org
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Subject: [PATCH v6 33/51] mm: Make prep_transhuge_page return its argument
Date: Wed, 10 Jun 2020 13:13:27 -0700	[thread overview]
Message-ID: <20200610201345.13273-34-willy@infradead.org> (raw)
In-Reply-To: <20200610201345.13273-1-willy@infradead.org>

From: "Matthew Wilcox (Oracle)" <willy@infradead.org>

By permitting NULL or order-0 pages as an argument, and returning the
argument, callers can write:

	return prep_transhuge_page(alloc_pages(...));

instead of assigning the result to a temporary variable and conditionally
passing that to prep_transhuge_page().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
 include/linux/huge_mm.h | 7 +++++--
 mm/huge_memory.c        | 9 +++++++--
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index d125912a3e0d..61de7e8683cd 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -193,7 +193,7 @@ extern unsigned long thp_get_unmapped_area(struct file *filp,
 		unsigned long addr, unsigned long len, unsigned long pgoff,
 		unsigned long flags);
 
-extern void prep_transhuge_page(struct page *page);
+extern struct page *prep_transhuge_page(struct page *page);
 extern void free_transhuge_page(struct page *page);
 bool is_transparent_hugepage(struct page *page);
 
@@ -381,7 +381,10 @@ static inline bool transhuge_vma_suitable(struct vm_area_struct *vma,
 	return false;
 }
 
-static inline void prep_transhuge_page(struct page *page) {}
+static inline struct page *prep_transhuge_page(struct page *page)
+{
+	return page;
+}
 
 static inline bool is_transparent_hugepage(struct page *page)
 {
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 78c84bee7e29..80fb38e93837 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -508,15 +508,20 @@ static inline struct deferred_split *get_deferred_split_queue(struct page *page)
 }
 #endif
 
-void prep_transhuge_page(struct page *page)
+struct page *prep_transhuge_page(struct page *page)
 {
+	if (!page || compound_order(page) == 0)
+		return page;
 	/*
-	 * we use page->mapping and page->indexlru in second tail page
+	 * we use page->mapping and page->index in second tail page
 	 * as list_head: assuming THP order >= 2
 	 */
+	BUG_ON(compound_order(page) == 1);
 
 	INIT_LIST_HEAD(page_deferred_list(page));
 	set_compound_page_dtor(page, TRANSHUGE_PAGE_DTOR);
+
+	return page;
 }
 
 bool is_transparent_hugepage(struct page *page)
-- 
2.26.2


  parent reply	other threads:[~2020-06-10 20:15 UTC|newest]

Thread overview: 60+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-10 20:12 [RFC v6 00/51] Large pages in the page cache Matthew Wilcox
2020-06-10 20:12 ` [PATCH v6 01/51] mm: Print head flags in dump_page Matthew Wilcox
2020-06-10 20:12 ` [PATCH v6 02/51] mm: Print the inode number " Matthew Wilcox
2020-06-10 20:12 ` [PATCH v6 03/51] mm: Print hashed address of struct page Matthew Wilcox
2020-06-10 20:12 ` [PATCH v6 04/51] mm: Move PageDoubleMap bit Matthew Wilcox
2020-06-11 15:03   ` Zi Yan
2020-06-10 20:12 ` [PATCH v6 05/51] mm: Simplify PageDoubleMap with PF_SECOND policy Matthew Wilcox
2020-06-11 15:14   ` Zi Yan
2020-06-10 20:13 ` [PATCH v6 06/51] mm: Store compound_nr as well as compound_order Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 07/51] mm: Move page-flags include to top of file Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 08/51] mm: Add thp_order Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 09/51] mm: Add thp_size Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 10/51] mm: Replace hpage_nr_pages with thp_nr_pages Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 11/51] mm: Add thp_head Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 12/51] mm: Introduce offset_in_thp Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 13/51] mm: Support arbitrary THP sizes Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 14/51] fs: Add a filesystem flag for THPs Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 15/51] fs: Do not update nr_thps for mappings which support THPs Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 16/51] fs: Introduce i_blocks_per_page Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 17/51] fs: Make page_mkwrite_check_truncate thp-aware Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 18/51] mm: Support THPs in zero_user_segments Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 19/51] mm: Zero the head page, not the tail page Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 20/51] block: Add bio_for_each_thp_segment_all Matthew Wilcox
2020-06-11 18:20   ` Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 21/51] block: Support THPs in page_is_mergeable Matthew Wilcox
2020-06-12 16:17   ` Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 22/51] iomap: Support arbitrarily many blocks per page Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 23/51] iomap: Support THPs in iomap_adjust_read_range Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 24/51] iomap: Support THPs in invalidatepage Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 25/51] iomap: Support THPs in read paths Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 26/51] iomap: Convert iomap_write_end types Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 27/51] iomap: Change calling convention for zeroing Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 28/51] iomap: Change iomap_write_begin calling convention Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 29/51] iomap: Support THPs in write paths Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 30/51] iomap: Inline data shouldn't see THPs Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 31/51] iomap: Handle tail pages in iomap_page_mkwrite Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 32/51] xfs: Support THPs Matthew Wilcox
2020-06-10 20:13 ` Matthew Wilcox [this message]
2020-06-10 20:13 ` [PATCH v6 34/51] mm: Add __page_cache_alloc_order Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 35/51] mm: Allow THPs to be added to the page cache Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 36/51] mm: Allow THPs to be removed from " Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 37/51] mm: Remove page fault assumption of compound page size Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 38/51] mm: Fix total_mapcount assumption of " Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 39/51] mm: Remove assumptions of THP size Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 40/51] mm: Avoid splitting THPs Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 41/51] mm: Fix truncation for pages of arbitrary size Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 42/51] mm: Handle truncates that split THPs Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 43/51] mm: Support storing shadow entries for THPs Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 44/51] mm: Support retrieving tail pages from the page cache Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 45/51] mm: Support tail pages in wait_for_stable_page Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 46/51] mm: Add DEFINE_READAHEAD Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 47/51] mm: Make page_cache_readahead_unbounded take a readahead_control Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 48/51] mm: Make __do_page_cache_readahead " Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 49/51] mm: Allow PageReadahead to be set on head pages Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 50/51] mm: Add THP readahead Matthew Wilcox
2020-06-10 20:13 ` [PATCH v6 51/51] mm: Align THP mappings for non-DAX Matthew Wilcox
2020-06-11  6:59 ` [RFC v6 00/51] Large pages in the page cache Christoph Hellwig
2020-06-11 11:24   ` Matthew Wilcox
2020-06-15 13:32     ` Christoph Hellwig
2020-06-14 16:26 ` Matthew Wilcox

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