From:   Mike Rapoport <rppt@kernel.org>
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     David Hildenbrand <david@redhat.com>,
        Doug Berger <opendmb@gmail.com>,
        Matthew Wilcox <willy@infradead.org>,
        Mel Gorman <mgorman@suse.de>, Michal Hocko <mhocko@kernel.org>,
        Mike Rapoport <rppt@kernel.org>,
        Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
        Vlastimil Babka <vbabka@suse.cz>, linux-kernel@vger.kernel.org,
        linux-mips@vger.kernel.org, linux-mm@kvack.org
Subject: [PATCH v2 04/14] mm: handle hashdist initialization in mm/mm_init.c
Date:   Tue, 21 Mar 2023 19:05:03 +0200
Message-Id: <20230321170513.2401534-5-rppt@kernel.org>
In-Reply-To: <20230321170513.2401534-1-rppt@kernel.org>
References: <20230321170513.2401534-1-rppt@kernel.org>
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From: "Mike Rapoport (IBM)" <rppt@kernel.org>

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

Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
---
 mm/mm_init.c    | 22 ++++++++++++++++++++++
 mm/page_alloc.c | 18 ------------------
 2 files changed, 22 insertions(+), 18 deletions(-)

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();
 }
 
 /**
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index c56c147bdf27..ff6a2fff2880 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -6383,28 +6383,10 @@ static int page_alloc_cpu_online(unsigned int cpu)
 	return 0;
 }
 
-#ifdef CONFIG_NUMA
-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);
-#endif
-
 void __init page_alloc_init(void)
 {
 	int ret;
 
-#ifdef CONFIG_NUMA
-	if (num_node_state(N_MEMORY) == 1)
-		hashdist = 0;
-#endif
-
 	ret = cpuhp_setup_state_nocalls(CPUHP_PAGE_ALLOC,
 					"mm/page_alloc:pcp",
 					page_alloc_cpu_online,
-- 
2.35.1