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

Commit Message

Mel Gorman Oct. 21, 2019, 9:48 a.m. UTC

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 <[e-mail]>
Acked-by: Michal Hocko <[e-mail]>
---
 mm/page_alloc.c | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

Comments

Vlastimil Babka Oct. 21, 2019, 11:44 a.m. UTC | #1

On 10/21/19 11:48 AM, Mel Gorman wrote:
> 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 <[e-mail]>
> Acked-by: Michal Hocko <[e-mail]>

Acked-by: Vlastimil Babka <[e-mail]>

Patch

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