[PATCH 1/3] mm, pcp: Share common code between memory hotplug and percpu sysctl handler

[Mel Gorman]

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 <mgor...@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