Re: [PATCH v5 1/6] mm/page_alloc: don't reserve ZONE_HIGHMEM for ZONE_MOVABLE request

2016-09-21 Thread Joonsoo Kim 
On Fri, Sep 16, 2016 at 08:44:17AM +0530, Aneesh Kumar K.V wrote:
> js1...@gmail.com writes:
> 
> > From: Joonsoo Kim 
> >
> > Freepage on ZONE_HIGHMEM doesn't work for kernel memory so it's not that
> > important to reserve. When ZONE_MOVABLE is used, this problem would
> > theorectically cause to decrease usable memory for GFP_HIGHUSER_MOVABLE
> > allocation request which is mainly used for page cache and anon page
> > allocation. So, fix it.
> >
> > And, defining sysctl_lowmem_reserve_ratio array by MAX_NR_ZONES - 1 size
> > makes code complex. For example, if there is highmem system, following
> > reserve ratio is activated for *NORMAL ZONE* which would be easyily
> > misleading people.
> >
> >  #ifdef CONFIG_HIGHMEM
> >  32
> >  #endif
> >
> > This patch also fix this situation by defining sysctl_lowmem_reserve_ratio
> > array by MAX_NR_ZONES and place "#ifdef" to right place.
> >
> > Signed-off-by: Joonsoo Kim 
> > ---
> >  include/linux/mmzone.h | 2 +-
> >  mm/page_alloc.c| 7 ---
> >  2 files changed, 5 insertions(+), 4 deletions(-)
> >
> > diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
> > index d572b78..e3f39af 100644
> > --- a/include/linux/mmzone.h
> > +++ b/include/linux/mmzone.h
> > @@ -877,7 +877,7 @@ int min_free_kbytes_sysctl_handler(struct ctl_table *, 
> > int,
> > void __user *, size_t *, loff_t *);
> >  int watermark_scale_factor_sysctl_handler(struct ctl_table *, int,
> > void __user *, size_t *, loff_t *);
> > -extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1];
> > +extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES];
> >  int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int,
> > void __user *, size_t *, loff_t *);
> >  int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int,
> > diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> > index 4f7d5d7..a8310de 100644
> > --- a/mm/page_alloc.c
> > +++ b/mm/page_alloc.c
> > @@ -198,17 +198,18 @@ static void __free_pages_ok(struct page *page, 
> > unsigned int order);
> >   * TBD: should special case ZONE_DMA32 machines here - in those we normally
> >   * don't need any ZONE_NORMAL reservation
> >   */
> > -int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = {
> > +int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES] = {
> >  #ifdef CONFIG_ZONE_DMA
> >  256,
> >  #endif
> >  #ifdef CONFIG_ZONE_DMA32
> >  256,
> >  #endif
> > -#ifdef CONFIG_HIGHMEM
> >  32,
> > +#ifdef CONFIG_HIGHMEM
> > +INT_MAX,
> >  #endif
> > -32,
> > +INT_MAX,
> >  };
> >
> >  EXPORT_SYMBOL(totalram_pages);
> > -- 
> > 1.9.1
> 
> We can also do things like below to make it readable ?
> 
> #ifdef CONFIG_ZONE_DMA
>   [ZONE_DMA] = 256,
> #endif

It looks more readable! I will change it.

> 
> Reviewed-by: Aneesh Kumar K.V 

Thanks!

Re: [PATCH v5 1/6] mm/page_alloc: don't reserve ZONE_HIGHMEM for ZONE_MOVABLE request

2016-09-21 Thread Vlastimil Babka 

On 08/29/2016 07:07 AM, js1...@gmail.com wrote:

From: Joonsoo Kim 

Freepage on ZONE_HIGHMEM doesn't work for kernel memory so it's not that
important to reserve. When ZONE_MOVABLE is used, this problem would
theorectically cause to decrease usable memory for GFP_HIGHUSER_MOVABLE
allocation request which is mainly used for page cache and anon page
allocation. So, fix it.

And, defining sysctl_lowmem_reserve_ratio array by MAX_NR_ZONES - 1 size
makes code complex. For example, if there is highmem system, following
reserve ratio is activated for *NORMAL ZONE* which would be easyily
misleading people.

 #ifdef CONFIG_HIGHMEM
 32
 #endif

This patch also fix this situation by defining sysctl_lowmem_reserve_ratio
array by MAX_NR_ZONES and place "#ifdef" to right place.

Signed-off-by: Joonsoo Kim 


Acked-by: Vlastimil Babka

Re: [PATCH v5 1/6] mm/page_alloc: don't reserve ZONE_HIGHMEM for ZONE_MOVABLE request

2016-09-15 Thread Aneesh Kumar K.V 
js1...@gmail.com writes:

> From: Joonsoo Kim 
>
> Freepage on ZONE_HIGHMEM doesn't work for kernel memory so it's not that
> important to reserve. When ZONE_MOVABLE is used, this problem would
> theorectically cause to decrease usable memory for GFP_HIGHUSER_MOVABLE
> allocation request which is mainly used for page cache and anon page
> allocation. So, fix it.
>
> And, defining sysctl_lowmem_reserve_ratio array by MAX_NR_ZONES - 1 size
> makes code complex. For example, if there is highmem system, following
> reserve ratio is activated for *NORMAL ZONE* which would be easyily
> misleading people.
>
>  #ifdef CONFIG_HIGHMEM
>  32
>  #endif
>
> This patch also fix this situation by defining sysctl_lowmem_reserve_ratio
> array by MAX_NR_ZONES and place "#ifdef" to right place.
>
> Signed-off-by: Joonsoo Kim 
> ---
>  include/linux/mmzone.h | 2 +-
>  mm/page_alloc.c| 7 ---
>  2 files changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
> index d572b78..e3f39af 100644
> --- a/include/linux/mmzone.h
> +++ b/include/linux/mmzone.h
> @@ -877,7 +877,7 @@ int min_free_kbytes_sysctl_handler(struct ctl_table *, 
> int,
>   void __user *, size_t *, loff_t *);
>  int watermark_scale_factor_sysctl_handler(struct ctl_table *, int,
>   void __user *, size_t *, loff_t *);
> -extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1];
> +extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES];
>  int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int,
>   void __user *, size_t *, loff_t *);
>  int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int,
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 4f7d5d7..a8310de 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -198,17 +198,18 @@ static void __free_pages_ok(struct page *page, unsigned 
> int order);
>   * TBD: should special case ZONE_DMA32 machines here - in those we normally
>   * don't need any ZONE_NORMAL reservation
>   */
> -int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1] = {
> +int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES] = {
>  #ifdef CONFIG_ZONE_DMA
>256,
>  #endif
>  #ifdef CONFIG_ZONE_DMA32
>256,
>  #endif
> -#ifdef CONFIG_HIGHMEM
>32,
> +#ifdef CONFIG_HIGHMEM
> +  INT_MAX,
>  #endif
> -  32,
> +  INT_MAX,
>  };
>
>  EXPORT_SYMBOL(totalram_pages);
> -- 
> 1.9.1

We can also do things like below to make it readable ?

#ifdef CONFIG_ZONE_DMA
[ZONE_DMA] = 256,
#endif

Reviewed-by: Aneesh Kumar K.V