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From:   Doug Berger <opendmb@gmail.com>
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     Jonathan Corbet <corbet@lwn.net>, Mike Rapoport <rppt@kernel.org>,
        Borislav Petkov <bp@suse.de>,
        "Paul E. McKenney" <paulmck@kernel.org>,
        Neeraj Upadhyay <quic_neeraju@quicinc.com>,
        Randy Dunlap <rdunlap@infradead.org>,
        Damien Le Moal <damien.lemoal@opensource.wdc.com>,
        Muchun Song <songmuchun@bytedance.com>,
        Vlastimil Babka <vbabka@suse.cz>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Michal Hocko <mhocko@suse.com>,
        KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
        Mel Gorman <mgorman@suse.de>,
        Mike Kravetz <mike.kravetz@oracle.com>,
        Florian Fainelli <f.fainelli@gmail.com>,
        David Hildenbrand <david@redhat.com>,
        Oscar Salvador <osalvador@suse.de>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>,
        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org, Doug Berger <opendmb@gmail.com>
Subject: [PATCH v3 2/9] mm/page_alloc: calculate node_spanned_pages from pfns
Date:   Thu, 20 Oct 2022 14:53:11 -0700
Message-Id: <20221020215318.4193269-3-opendmb@gmail.com>
In-Reply-To: <20221020215318.4193269-1-opendmb@gmail.com>
References: <20221020215318.4193269-1-opendmb@gmail.com>
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Since the start and end pfns of the node are passed as arguments
to calculate_node_totalpages() they might as well be used to
specify the node_spanned_pages value for the node rather than
accumulating the spans of member zones.

This prevents the need for additional adjustments if zones are
allowed to overlap.

The realtotalpages name is reverted to just totalpages to reduce
the burden of supporting multiple realities.

Signed-off-by: Doug Berger <opendmb@gmail.com>
---
 mm/page_alloc.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index e20ade858e71..92908c51f1c3 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -7542,7 +7542,7 @@ static void __init calculate_node_totalpages(struct pglist_data *pgdat,
 						unsigned long node_start_pfn,
 						unsigned long node_end_pfn)
 {
-	unsigned long realtotalpages = 0, totalpages = 0;
+	unsigned long totalpages = 0;
 	enum zone_type i;
 
 	for (i = 0; i < MAX_NR_ZONES; i++) {
@@ -7573,13 +7573,12 @@ static void __init calculate_node_totalpages(struct pglist_data *pgdat,
 		zone->present_early_pages = real_size;
 #endif
 
-		totalpages += size;
-		realtotalpages += real_size;
+		totalpages += real_size;
 	}
 
-	pgdat->node_spanned_pages = totalpages;
-	pgdat->node_present_pages = realtotalpages;
-	pr_debug("On node %d totalpages: %lu\n", pgdat->node_id, realtotalpages);
+	pgdat->node_spanned_pages = node_end_pfn - node_start_pfn;
+	pgdat->node_present_pages = totalpages;
+	pr_debug("On node %d totalpages: %lu\n", pgdat->node_id, totalpages);
 }
 
 #ifndef CONFIG_SPARSEMEM
-- 
2.25.1