[027/146] mm/page_alloc: refactor memmap_init_zone_device() page init

Commit Message

Andrew Morton Jan. 14, 2022, 10:04 p.m. UTC

From: Joao Martins <[e-mail]>
Subject: mm/page_alloc: refactor memmap_init_zone_device() page init

Move struct page init to an helper function __init_zone_device_page().

This is in preparation for sharing the storage for compound page metadata.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Joao Martins <[e-mail]>
Reviewed-by: Dan Williams <[e-mail]>
Cc: Christoph Hellwig <[e-mail]>
Cc: Dave Jiang <[e-mail]>
Cc: Jane Chu <[e-mail]>
Cc: Jason Gunthorpe <[e-mail]>
Cc: Jason Gunthorpe <[e-mail]>
Cc: John Hubbard <[e-mail]>
Cc: Jonathan Corbet <[e-mail]>
Cc: Matthew Wilcox (Oracle) <[e-mail]>
Cc: Mike Kravetz <[e-mail]>
Cc: Muchun Song <[e-mail]>
Cc: Naoya Horiguchi <[e-mail]>
Cc: Vishal Verma <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
---

 mm/page_alloc.c |   74 +++++++++++++++++++++++++---------------------
 1 file changed, 41 insertions(+), 33 deletions(-)

Patch

--- a/mm/page_alloc.c~mm-page_alloc-refactor-memmap_init_zone_device-page-init
+++ a/mm/page_alloc.c
@@ -6572,6 +6572,46 @@  void __meminit memmap_init_range(unsigne
 }
 
 #ifdef CONFIG_ZONE_DEVICE
+static void __ref __init_zone_device_page(struct page *page, unsigned long pfn,
+					  unsigned long zone_idx, int nid,
+					  struct dev_pagemap *pgmap)
+{
+
+	__init_single_page(page, pfn, zone_idx, nid);
+
+	/*
+	 * Mark page reserved as it will need to wait for onlining
+	 * phase for it to be fully associated with a zone.
+	 *
+	 * We can use the non-atomic __set_bit operation for setting
+	 * the flag as we are still initializing the pages.
+	 */
+	__SetPageReserved(page);
+
+	/*
+	 * ZONE_DEVICE pages union ->lru with a ->pgmap back pointer
+	 * and zone_device_data.  It is a bug if a ZONE_DEVICE page is
+	 * ever freed or placed on a driver-private list.
+	 */
+	page->pgmap = pgmap;
+	page->zone_device_data = NULL;
+
+	/*
+	 * Mark the block movable so that blocks are reserved for
+	 * movable at startup. This will force kernel allocations
+	 * to reserve their blocks rather than leaking throughout
+	 * the address space during boot when many long-lived
+	 * kernel allocations are made.
+	 *
+	 * Please note that MEMINIT_HOTPLUG path doesn't clear memmap
+	 * because this is done early in section_activate()
+	 */
+	if (IS_ALIGNED(pfn, pageblock_nr_pages)) {
+		set_pageblock_migratetype(page, MIGRATE_MOVABLE);
+		cond_resched();
+	}
+}
+
 void __ref memmap_init_zone_device(struct zone *zone,
 				   unsigned long start_pfn,
 				   unsigned long nr_pages,
@@ -6600,39 +6640,7 @@  void __ref memmap_init_zone_device(struc
 	for (pfn = start_pfn; pfn < end_pfn; pfn++) {
 		struct page *page = pfn_to_page(pfn);
 
-		__init_single_page(page, pfn, zone_idx, nid);
-
-		/*
-		 * Mark page reserved as it will need to wait for onlining
-		 * phase for it to be fully associated with a zone.
-		 *
-		 * We can use the non-atomic __set_bit operation for setting
-		 * the flag as we are still initializing the pages.
-		 */
-		__SetPageReserved(page);
-
-		/*
-		 * ZONE_DEVICE pages union ->lru with a ->pgmap back pointer
-		 * and zone_device_data.  It is a bug if a ZONE_DEVICE page is
-		 * ever freed or placed on a driver-private list.
-		 */
-		page->pgmap = pgmap;
-		page->zone_device_data = NULL;
-
-		/*
-		 * Mark the block movable so that blocks are reserved for
-		 * movable at startup. This will force kernel allocations
-		 * to reserve their blocks rather than leaking throughout
-		 * the address space during boot when many long-lived
-		 * kernel allocations are made.
-		 *
-		 * Please note that MEMINIT_HOTPLUG path doesn't clear memmap
-		 * because this is done early in section_activate()
-		 */
-		if (IS_ALIGNED(pfn, pageblock_nr_pages)) {
-			set_pageblock_migratetype(page, MIGRATE_MOVABLE);
-			cond_resched();
-		}
+		__init_zone_device_page(page, pfn, zone_idx, nid, pgmap);
 	}
 
 	pr_info("%s initialised %lu pages in %ums\n", __func__,