On Fri 18-10-19 11:56:04, 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 <mgorman@xxxxxxxxxxxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
> ---
> 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
>
--
Michal Hocko
SUSE Labs
