mm, pcp: share common code between memory hotplug and percpu sysctl handler

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.

Link: http://lkml.kernel.org/r/20191021094808.28824-3-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Qian Cai <cai@lca.pw>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 2e47398ba4985ce7841562e3713e041525612496..7c3bee1e98ec1464b2ad10f268bc21beedfdf63d 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -7988,6 +7988,15 @@ 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
@@ -8019,13 +8028,8 @@ 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;
@@ -8624,11 +8628,8 @@ 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);
 }