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

[Michal Hocko]

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 

Acked-by: Michal Hocko 

> ---
>  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

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

[Matt Fleming]

On Fri, 18 Oct, at 11:56:04AM, 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 
> ---
>  mm/page_alloc.c | 23 ---
>  1 file changed, 12 insertions(+), 11 deletions(-)
 
Tested-by: Matt Fleming 

[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 
---
 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