[PATCH 1/3] mm: Add __page_cache_alloc_order

From: Matthew Wilcox <willy@infradead.org>
To: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>,
	Kirill Shutemov <kirill@shutemov.name>,
	Song Liu <songliubraving@fb.com>,
	William Kucharski <william.kucharski@oracle.com>,
	Johannes Weiner <jweiner@fb.com>
Subject: [PATCH 1/3] mm: Add __page_cache_alloc_order
Date: Thu,  5 Sep 2019 11:23:46 -0700	[thread overview]
Message-ID: <20190905182348.5319-2-willy@infradead.org> (raw)
In-Reply-To: <20190905182348.5319-1-willy@infradead.org>

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

This new function allows page cache pages to be allocated that are
larger than an order-0 page.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 include/linux/pagemap.h | 14 +++++++++++---
 mm/filemap.c            | 11 +++++++----
 2 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 103205494ea0..d2147215d415 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -208,14 +208,22 @@ static inline int page_cache_add_speculative(struct page *page, int count)
 }
 
 #ifdef CONFIG_NUMA
-extern struct page *__page_cache_alloc(gfp_t gfp);
+extern struct page *__page_cache_alloc_order(gfp_t gfp, unsigned int order);
 #else
-static inline struct page *__page_cache_alloc(gfp_t gfp)
+static inline
+struct page *__page_cache_alloc_order(gfp_t gfp, unsigned int order)
 {
-	return alloc_pages(gfp, 0);
+	if (order > 0)
+		gfp |= __GFP_COMP;
+	return alloc_pages(gfp, order);
 }
 #endif
 
+static inline struct page *__page_cache_alloc(gfp_t gfp)
+{
+	return __page_cache_alloc_order(gfp, 0);
+}
+
 static inline struct page *page_cache_alloc(struct address_space *x)
 {
 	return __page_cache_alloc(mapping_gfp_mask(x));
diff --git a/mm/filemap.c b/mm/filemap.c
index 05a5aa82cd32..041c77c4ca56 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -957,24 +957,27 @@ int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
 EXPORT_SYMBOL_GPL(add_to_page_cache_lru);
 
 #ifdef CONFIG_NUMA
-struct page *__page_cache_alloc(gfp_t gfp)
+struct page *__page_cache_alloc_order(gfp_t gfp, unsigned int order)
 {
 	int n;
 	struct page *page;
 
+	if (order > 0)
+		gfp |= __GFP_COMP;
+
 	if (cpuset_do_page_mem_spread()) {
 		unsigned int cpuset_mems_cookie;
 		do {
 			cpuset_mems_cookie = read_mems_allowed_begin();
 			n = cpuset_mem_spread_node();
-			page = __alloc_pages_node(n, gfp, 0);
+			page = __alloc_pages_node(n, gfp, order);
 		} while (!page && read_mems_allowed_retry(cpuset_mems_cookie));
 
 		return page;
 	}
-	return alloc_pages(gfp, 0);
+	return alloc_pages(gfp, order);
 }
-EXPORT_SYMBOL(__page_cache_alloc);
+EXPORT_SYMBOL(__page_cache_alloc_order);
 #endif
 
 /*
-- 
2.23.0.rc1

