From 534ef4e19160b1034430c4c4fbc1bf94c0253a51 Mon Sep 17 00:00:00 2001
From: "Mike Rapoport (IBM)" <rppt@kernel.org>
Date: Tue, 21 Mar 2023 19:05:03 +0200
Subject: mm: handle hashdist initialization in mm/mm_init.c

The hashdist variable must be initialized before the first call to
alloc_large_system_hash() and free_area_init() looks like a better place
for it than page_alloc_init().

Move hashdist handling to mm/mm_init.c

Link: https://lkml.kernel.org/r/20230321170513.2401534-5-rppt@kernel.org
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Doug Berger <opendmb@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 mm/mm_init.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

(limited to 'mm/mm_init.c')

diff --git a/mm/mm_init.c b/mm/mm_init.c
index 68d0187c7886..2e60c7186132 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -607,6 +607,25 @@ int __meminit early_pfn_to_nid(unsigned long pfn)
 
 	return nid;
 }
+
+int hashdist = HASHDIST_DEFAULT;
+
+static int __init set_hashdist(char *str)
+{
+	if (!str)
+		return 0;
+	hashdist = simple_strtoul(str, &str, 0);
+	return 1;
+}
+__setup("hashdist=", set_hashdist);
+
+static inline void fixup_hashdist(void)
+{
+	if (num_node_state(N_MEMORY) == 1)
+		hashdist = 0;
+}
+#else
+static inline void fixup_hashdist(void) {}
 #endif /* CONFIG_NUMA */
 
 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
@@ -1855,6 +1874,9 @@ void __init free_area_init(unsigned long *max_zone_pfn)
 	}
 
 	memmap_init();
+
+	/* disable hash distribution for systems with a single node */
+	fixup_hashdist();
 }
 
 /**
-- 
cgit