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From:   Mel Gorman <mgorman@techsingularity.net>
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     Michal Hocko <mhocko@suse.com>, Vlastimil Babka <vbabka@suse.cz>,
        Thomas Gleixner <tglx@linutronix.de>,
        Matt Fleming <matt@codeblueprint.co.uk>,
        Borislav Petkov <bp@alien8.de>, Linux-MM <linux-mm@kvack.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Mel Gorman <mgorman@techsingularity.net>
Subject: [PATCH 1/3] mm, pcp: Share common code between memory hotplug and percpu sysctl handler
Date:   Fri, 18 Oct 2019 11:56:04 +0100
Message-Id: <20191018105606.3249-2-mgorman@techsingularity.net>
In-Reply-To: <20191018105606.3249-1-mgorman@techsingularity.net>
References: <20191018105606.3249-1-mgorman@techsingularity.net>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Both the percpu_pagelist_fraction sysctl handler and memory hotplug
have a common requirement of updating the pcpu page allocation batch
and high values. Split the relevant helper to share common code.

No functional change.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
---
 mm/page_alloc.c | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index c0b2e0306720..cafe568d36f6 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -7983,6 +7983,15 @@ int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write,
 	return 0;
 }
 
+static void __zone_pcp_update(struct zone *zone)
+{
+	unsigned int cpu;
+
+	for_each_possible_cpu(cpu)
+		pageset_set_high_and_batch(zone,
+				per_cpu_ptr(zone->pageset, cpu));
+}
+
 /*
  * percpu_pagelist_fraction - changes the pcp->high for each zone on each
  * cpu.  It is the fraction of total pages in each zone that a hot per cpu
@@ -8014,13 +8023,8 @@ int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *table, int write,
 	if (percpu_pagelist_fraction == old_percpu_pagelist_fraction)
 		goto out;
 
-	for_each_populated_zone(zone) {
-		unsigned int cpu;
-
-		for_each_possible_cpu(cpu)
-			pageset_set_high_and_batch(zone,
-					per_cpu_ptr(zone->pageset, cpu));
-	}
+	for_each_populated_zone(zone)
+		__zone_pcp_update(zone);
 out:
 	mutex_unlock(&pcp_batch_high_lock);
 	return ret;
@@ -8519,11 +8523,8 @@ void free_contig_range(unsigned long pfn, unsigned int nr_pages)
  */
 void __meminit zone_pcp_update(struct zone *zone)
 {
-	unsigned cpu;
 	mutex_lock(&pcp_batch_high_lock);
-	for_each_possible_cpu(cpu)
-		pageset_set_high_and_batch(zone,
-				per_cpu_ptr(zone->pageset, cpu));
+	__zone_pcp_update(zone);
 	mutex_unlock(&pcp_batch_high_lock);
 }
 #endif
-- 
2.16.4