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Groups > linux.kernel > #1620858 > unrolled thread
| Started by | js1304@gmail.com |
|---|---|
| First post | 2017-04-11 05:20 +0200 |
| Last post | 2017-04-21 03:40 +0200 |
| Articles | 3 — 3 participants |
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[PATCH v7 1/7] mm/page_alloc: don't reserve ZONE_HIGHMEM for ZONE_MOVABLE request js1304@gmail.com - 2017-04-11 05:20 +0200
Re: [PATCH v7 1/7] mm/page_alloc: don't reserve ZONE_HIGHMEM for ZONE_MOVABLE request Minchan Kim <minchan@kernel.org> - 2017-04-17 09:40 +0200
Re: [PATCH v7 1/7] mm/page_alloc: don't reserve ZONE_HIGHMEM for ZONE_MOVABLE request Joonsoo Kim <js1304@gmail.com> - 2017-04-21 03:40 +0200
| From | js1304@gmail.com |
|---|---|
| Date | 2017-04-11 05:20 +0200 |
| Subject | [PATCH v7 1/7] mm/page_alloc: don't reserve ZONE_HIGHMEM for ZONE_MOVABLE request |
| Message-ID | <tuUvw-1sy-5@gated-at.bofh.it> |
From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
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.
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
---
include/linux/mmzone.h | 2 +-
mm/page_alloc.c | 11 ++++++-----
2 files changed, 7 insertions(+), 6 deletions(-)
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index ebaccd4..96194bf 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -869,7 +869,7 @@ 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 32b31d6..60ffa4e 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -203,17 +203,18 @@ 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,
+ [ZONE_DMA] = 256,
#endif
#ifdef CONFIG_ZONE_DMA32
- 256,
+ [ZONE_DMA32] = 256,
#endif
+ [ZONE_NORMAL] = 32,
#ifdef CONFIG_HIGHMEM
- 32,
+ [ZONE_HIGHMEM] = INT_MAX,
#endif
- 32,
+ [ZONE_MOVABLE] = INT_MAX,
};
EXPORT_SYMBOL(totalram_pages);
--
2.7.4
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| From | Minchan Kim <minchan@kernel.org> |
|---|---|
| Date | 2017-04-17 09:40 +0200 |
| Subject | Re: [PATCH v7 1/7] mm/page_alloc: don't reserve ZONE_HIGHMEM for ZONE_MOVABLE request |
| Message-ID | <tx9qq-6lX-9@gated-at.bofh.it> |
| In reply to | #1620858 |
Hi Joonsoo,
On Tue, Apr 11, 2017 at 12:17:14PM +0900, js1304@gmail.com wrote:
> From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
>
> 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.
>
> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> Acked-by: Vlastimil Babka <vbabka@suse.cz>
> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
> ---
> include/linux/mmzone.h | 2 +-
> mm/page_alloc.c | 11 ++++++-----
> 2 files changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
> index ebaccd4..96194bf 100644
> --- a/include/linux/mmzone.h
> +++ b/include/linux/mmzone.h
> @@ -869,7 +869,7 @@ 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 32b31d6..60ffa4e 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -203,17 +203,18 @@ 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,
> + [ZONE_DMA] = 256,
> #endif
> #ifdef CONFIG_ZONE_DMA32
> - 256,
> + [ZONE_DMA32] = 256,
> #endif
> + [ZONE_NORMAL] = 32,
> #ifdef CONFIG_HIGHMEM
> - 32,
> + [ZONE_HIGHMEM] = INT_MAX,
> #endif
> - 32,
> + [ZONE_MOVABLE] = INT_MAX,
> };
We need to update lowmem_reserve_ratio in Documentation/sysctl/vm.txt.
And to me, INT_MAX is rather awkward.
# cat /proc/sys/vm/lowmem_reserve_ratio
256 256 32 2147483647 2147483647
What do you think about to use 0 or -1 as special meaning
instead 2147483647?
Anyway, it could be separate patch regardless of zone_cma
so I hope Andrew to merge this patch regardless of other patches
in this patchset.
Thanks.
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| From | Joonsoo Kim <js1304@gmail.com> |
|---|---|
| Date | 2017-04-21 03:40 +0200 |
| Subject | Re: [PATCH v7 1/7] mm/page_alloc: don't reserve ZONE_HIGHMEM for ZONE_MOVABLE request |
| Message-ID | <tyvId-7Y8-3@gated-at.bofh.it> |
| In reply to | #1624582 |
On Mon, Apr 17, 2017 at 04:38:08PM +0900, Minchan Kim wrote:
> Hi Joonsoo,
>
> On Tue, Apr 11, 2017 at 12:17:14PM +0900, js1304@gmail.com wrote:
> > From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
> >
> > 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.
> >
> > Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> > Acked-by: Vlastimil Babka <vbabka@suse.cz>
> > Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
> > ---
> > include/linux/mmzone.h | 2 +-
> > mm/page_alloc.c | 11 ++++++-----
> > 2 files changed, 7 insertions(+), 6 deletions(-)
> >
> > diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
> > index ebaccd4..96194bf 100644
> > --- a/include/linux/mmzone.h
> > +++ b/include/linux/mmzone.h
> > @@ -869,7 +869,7 @@ 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 32b31d6..60ffa4e 100644
> > --- a/mm/page_alloc.c
> > +++ b/mm/page_alloc.c
> > @@ -203,17 +203,18 @@ 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,
> > + [ZONE_DMA] = 256,
> > #endif
> > #ifdef CONFIG_ZONE_DMA32
> > - 256,
> > + [ZONE_DMA32] = 256,
> > #endif
> > + [ZONE_NORMAL] = 32,
> > #ifdef CONFIG_HIGHMEM
> > - 32,
> > + [ZONE_HIGHMEM] = INT_MAX,
> > #endif
> > - 32,
> > + [ZONE_MOVABLE] = INT_MAX,
> > };
>
> We need to update lowmem_reserve_ratio in Documentation/sysctl/vm.txt.
Okay!
> And to me, INT_MAX is rather awkward.
I also think so.
> # cat /proc/sys/vm/lowmem_reserve_ratio
> 256 256 32 2147483647 2147483647
>
> What do you think about to use 0 or -1 as special meaning
> instead 2147483647?
I have thought it but drop it. In setup_per_zone_lowmem_reserve(),
there is a code to adjust the value to 1 if the value is less than 1.
There might be someone who (ab)use this adjustment so it's safe to use
INT_MAX.
> Anyway, it could be separate patch regardless of zone_cma
> so I hope Andrew to merge this patch regardless of other patches
> in this patchset.
Okay. I will send updated version soon.
Thanks.
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