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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 v3 16/25] mm: Make prep_transhuge_page return its argument
Date: Wed, 29 Apr 2020 06:36:48 -0700	[thread overview]
Message-ID: <20200429133657.22632-17-willy@infradead.org> (raw)
In-Reply-To: <20200429133657.22632-1-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 1f6245091917..6a8502278f41 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);
 
@@ -358,7 +358,10 @@ 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 6ecd1045113b..7a5e2b470bc7 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:[~2020-04-29 13:41 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-29 13:36 [PATCH v3 00/25] Large pages in the page cache Matthew Wilcox
2020-04-29 13:36 ` [PATCH v3 01/25] mm: Allow hpages to be arbitrary order Matthew Wilcox
2020-04-29 13:36 ` [PATCH v3 02/25] mm: Introduce thp_size Matthew Wilcox
2020-05-06 17:59   ` Yang Shi
2020-04-29 13:36 ` [PATCH v3 03/25] mm: Introduce thp_order Matthew Wilcox
2020-04-29 13:36 ` [PATCH v3 04/25] mm: Introduce offset_in_thp Matthew Wilcox
2020-04-29 13:36 ` [PATCH v3 05/25] fs: Add a filesystem flag for large pages Matthew Wilcox
2020-04-29 13:36 ` [PATCH v3 06/25] fs: Introduce i_blocks_per_page Matthew Wilcox
2020-04-29 13:36 ` [PATCH v3 07/25] fs: Make page_mkwrite_check_truncate thp-aware Matthew Wilcox
2020-04-29 13:36 ` [PATCH v3 08/25] fs: Support THPs in zero_user_segments Matthew Wilcox
2020-04-29 13:36 ` [PATCH v3 09/25] bio: Add bio_for_each_thp_segment_all Matthew Wilcox
2020-04-29 13:36 ` [PATCH v3 10/25] iomap: Support arbitrarily many blocks per page Matthew Wilcox
2020-04-29 13:36 ` [PATCH v3 11/25] iomap: Support large pages in iomap_adjust_read_range Matthew Wilcox
2020-04-29 13:36 ` [PATCH v3 12/25] iomap: Support large pages in read paths Matthew Wilcox
2020-04-29 13:36 ` [PATCH v3 13/25] iomap: Support large pages in write paths Matthew Wilcox
2020-04-29 13:36 ` [PATCH v3 14/25] iomap: Inline data shouldn't see large pages Matthew Wilcox
2020-04-29 13:36 ` [PATCH v3 15/25] xfs: Support " Matthew Wilcox
2020-04-29 13:36 ` Matthew Wilcox [this message]
2020-04-29 13:36 ` [PATCH v3 17/25] mm: Add __page_cache_alloc_order Matthew Wilcox
2020-05-06 18:03   ` Yang Shi
2020-06-07  3:08     ` Matthew Wilcox
2020-06-09 17:38       ` Yang Shi
2020-04-29 13:36 ` [PATCH v3 18/25] mm: Allow large pages to be added to the page cache Matthew Wilcox
2020-05-04  3:10   ` Matthew Wilcox
2020-05-06 18:32     ` Yang Shi
2020-06-07  3:04     ` Matthew Wilcox
2020-04-29 13:36 ` [PATCH v3 19/25] mm: Allow large pages to be removed from " Matthew Wilcox
2020-04-29 13:36 ` [PATCH v3 20/25] mm: Remove page fault assumption of compound page size Matthew Wilcox
2020-04-29 13:36 ` [PATCH v3 21/25] mm: Add DEFINE_READAHEAD Matthew Wilcox
2020-04-29 13:36 ` [PATCH v3 22/25] mm: Make page_cache_readahead_unbounded take a readahead_control Matthew Wilcox
2020-04-29 13:36 ` [PATCH v3 23/25] mm: Make __do_page_cache_readahead " Matthew Wilcox
2020-04-29 13:36 ` [PATCH v3 24/25] mm: Add large page readahead Matthew Wilcox
2020-04-29 13:36 ` [PATCH v3 25/25] mm: Align THP mappings for non-DAX Matthew Wilcox
2020-04-29 15:40 ` [PATCH v3 00/25] Large pages in the page cache Kirill A. Shutemov
2020-04-29 15:45   ` Kirill A. Shutemov
2020-04-30 11:34 ` Matthew Wilcox

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