[PATCH 2/3] mm, pcp: Share common code between memory hotplug and percpu sysctl handler

Mel Gorman
2019-10-21T09:48:17Z

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>
Acked-by: Michal Hocko <mhocko@suse.com>
---
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 f972076d0f6b..4179376bb336 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -7991,6 +7991,15 @@ 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
@@ -8022,13 +8031,8 @@ 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;
@@ -8527,11 +8531,8 @@ 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