* [PATCH] 16K page size in 32 bit kernel
@ 2007-07-31 13:09 Dajie Tan
2007-07-31 9:37 ` Songmao Tian
2007-07-31 10:00 ` Ralf Baechle
0 siblings, 2 replies; 7+ messages in thread
From: Dajie Tan @ 2007-07-31 13:09 UTC (permalink / raw)
To: Ralf Baechle; +Cc: linux-mips
32-bit Kernel for loongson2e currently use 16KB page size to avoid
cache alias problem.So, the definiton of PGDIR_SHIFT muse be 12+14.
Using 22 in 16K page size do not lead to a serious problem but the number
of pages allocated for page table is more than previous. (cat
/proc/vmstat | grep nr_page_table_pages)
It's been tested on FuLong mini PC(loongson2e inside).
Signed-off-by: Dajie Tan <jiankemeng@gmail.com>
---
include/asm-mips/pgtable-32.h | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/include/asm-mips/pgtable-32.h b/include/asm-mips/pgtable-32.h
index 2fbd47e..8d34ebf 100644
--- a/include/asm-mips/pgtable-32.h
+++ b/include/asm-mips/pgtable-32.h
@@ -46,7 +46,7 @@ extern int add_temporary_entry(unsigned long entrylo0, unsigned long entrylo1,
#ifdef CONFIG_64BIT_PHYS_ADDR
#define PGDIR_SHIFT 21
#else
-#define PGDIR_SHIFT 22
+#define PGDIR_SHIFT (PAGE_SHIFT + (PAGE_SHIFT + PTE_ORDER - 2))
#endif
#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
#define PGDIR_MASK (~(PGDIR_SIZE-1))
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH] 16K page size in 32 bit kernel
2007-07-31 13:09 [PATCH] 16K page size in 32 bit kernel Dajie Tan
@ 2007-07-31 9:37 ` Songmao Tian
2007-07-31 9:37 ` Songmao Tian
2007-07-31 10:00 ` Ralf Baechle
1 sibling, 1 reply; 7+ messages in thread
From: Songmao Tian @ 2007-07-31 9:37 UTC (permalink / raw)
Cc: Ralf Baechle, linux-mips
Thanks Dajie:)
With 22 PGDIR_SHIFT, 15 extra page tables is populated when a whole 64M
address space is accessed, the patch can save memory quite a bit:)
Dajie Tan wrote:
> 32-bit Kernel for loongson2e currently use 16KB page size to avoid
> cache alias problem.So, the definiton of PGDIR_SHIFT muse be 12+14.
>
> Using 22 in 16K page size do not lead to a serious problem but the number
> of pages allocated for page table is more than previous. (cat
> /proc/vmstat | grep nr_page_table_pages)
>
> It's been tested on FuLong mini PC(loongson2e inside).
>
>
> Signed-off-by: Dajie Tan <jiankemeng@gmail.com>
> ---
> include/asm-mips/pgtable-32.h | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/include/asm-mips/pgtable-32.h b/include/asm-mips/pgtable-32.h
> index 2fbd47e..8d34ebf 100644
> --- a/include/asm-mips/pgtable-32.h
> +++ b/include/asm-mips/pgtable-32.h
> @@ -46,7 +46,7 @@ extern int add_temporary_entry(unsigned long entrylo0, unsigned long entrylo1,
> #ifdef CONFIG_64BIT_PHYS_ADDR
> #define PGDIR_SHIFT 21
> #else
> -#define PGDIR_SHIFT 22
> +#define PGDIR_SHIFT (PAGE_SHIFT + (PAGE_SHIFT + PTE_ORDER - 2))
> #endif
> #define PGDIR_SIZE (1UL << PGDIR_SHIFT)
> #define PGDIR_MASK (~(PGDIR_SIZE-1))
>
>
>
>
>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] 16K page size in 32 bit kernel
2007-07-31 9:37 ` Songmao Tian
@ 2007-07-31 9:37 ` Songmao Tian
0 siblings, 0 replies; 7+ messages in thread
From: Songmao Tian @ 2007-07-31 9:37 UTC (permalink / raw)
Cc: Ralf Baechle, linux-mips
Thanks Dajie:)
With 22 PGDIR_SHIFT, 15 extra page tables is populated when a whole 64M
address space is accessed, the patch can save memory quite a bit:)
Dajie Tan wrote:
> 32-bit Kernel for loongson2e currently use 16KB page size to avoid
> cache alias problem.So, the definiton of PGDIR_SHIFT muse be 12+14.
>
> Using 22 in 16K page size do not lead to a serious problem but the number
> of pages allocated for page table is more than previous. (cat
> /proc/vmstat | grep nr_page_table_pages)
>
> It's been tested on FuLong mini PC(loongson2e inside).
>
>
> Signed-off-by: Dajie Tan <jiankemeng@gmail.com>
> ---
> include/asm-mips/pgtable-32.h | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/include/asm-mips/pgtable-32.h b/include/asm-mips/pgtable-32.h
> index 2fbd47e..8d34ebf 100644
> --- a/include/asm-mips/pgtable-32.h
> +++ b/include/asm-mips/pgtable-32.h
> @@ -46,7 +46,7 @@ extern int add_temporary_entry(unsigned long entrylo0, unsigned long entrylo1,
> #ifdef CONFIG_64BIT_PHYS_ADDR
> #define PGDIR_SHIFT 21
> #else
> -#define PGDIR_SHIFT 22
> +#define PGDIR_SHIFT (PAGE_SHIFT + (PAGE_SHIFT + PTE_ORDER - 2))
> #endif
> #define PGDIR_SIZE (1UL << PGDIR_SHIFT)
> #define PGDIR_MASK (~(PGDIR_SIZE-1))
>
>
>
>
>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] 16K page size in 32 bit kernel
2007-07-31 13:09 [PATCH] 16K page size in 32 bit kernel Dajie Tan
2007-07-31 9:37 ` Songmao Tian
@ 2007-07-31 10:00 ` Ralf Baechle
2007-07-31 13:49 ` Songmao Tian
1 sibling, 1 reply; 7+ messages in thread
From: Ralf Baechle @ 2007-07-31 10:00 UTC (permalink / raw)
To: Dajie Tan; +Cc: linux-mips
On Tue, Jul 31, 2007 at 05:09:51PM +0400, Dajie Tan wrote:
> 32-bit Kernel for loongson2e currently use 16KB page size to avoid
> cache alias problem.So, the definiton of PGDIR_SHIFT muse be 12+14.
>
> Using 22 in 16K page size do not lead to a serious problem but the number
> of pages allocated for page table is more than previous. (cat
> /proc/vmstat | grep nr_page_table_pages)
>
> It's been tested on FuLong mini PC(loongson2e inside).
Looking good, applied. Thanks!
Did by coincidence any of you try 64K pages with a 32-bit kernel?
Ralf
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] 16K page size in 32 bit kernel
2007-07-31 10:00 ` Ralf Baechle
@ 2007-07-31 13:49 ` Songmao Tian
2007-07-31 20:45 ` Ralf Baechle
0 siblings, 1 reply; 7+ messages in thread
From: Songmao Tian @ 2007-07-31 13:49 UTC (permalink / raw)
To: Ralf Baechle; +Cc: Dajie Tan, linux-mips
Ralf Baechle wrote:
> On Tue, Jul 31, 2007 at 05:09:51PM +0400, Dajie Tan wrote:
>
>
>> 32-bit Kernel for loongson2e currently use 16KB page size to avoid
>> cache alias problem.So, the definiton of PGDIR_SHIFT muse be 12+14.
>>
>> Using 22 in 16K page size do not lead to a serious problem but the number
>> of pages allocated for page table is more than previous. (cat
>> /proc/vmstat | grep nr_page_table_pages)
>>
>> It's been tested on FuLong mini PC(loongson2e inside).
>>
>
> Looking good, applied. Thanks!
>
> Did by coincidence any of you try 64K pages with a 32-bit kernel?
>
> Ralf
>
>
>
>
I think the following is more complete?
#ifdef CONFIG_64BIT_PHYS_ADDR
-#define PGDIR_SHIFT 21
+#define PGDIR_SHIFT (PAGE_SHIFT + (PAGE_SHIFT + PTE_ORDER - 3))
#else
-#define PGDIR_SHIFT 22
+#define PGDIR_SHIFT (PAGE_SHIFT + (PAGE_SHIFT + PTE_ORDER - 2))
#endif
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] 16K page size in 32 bit kernel
2007-07-31 13:49 ` Songmao Tian
@ 2007-07-31 20:45 ` Ralf Baechle
2007-08-01 0:47 ` Songmao Tian
0 siblings, 1 reply; 7+ messages in thread
From: Ralf Baechle @ 2007-07-31 20:45 UTC (permalink / raw)
To: Songmao Tian; +Cc: Dajie Tan, linux-mips
On Tue, Jul 31, 2007 at 09:49:34PM +0800, Songmao Tian wrote:
> I think the following is more complete?
>
> #ifdef CONFIG_64BIT_PHYS_ADDR
> -#define PGDIR_SHIFT 21
> +#define PGDIR_SHIFT (PAGE_SHIFT + (PAGE_SHIFT + PTE_ORDER - 3))
> #else
> -#define PGDIR_SHIFT 22
> +#define PGDIR_SHIFT (PAGE_SHIFT + (PAGE_SHIFT + PTE_ORDER - 2))
> #endif
Better suggestion :-)
Ralf
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/include/asm-mips/pgtable-32.h b/include/asm-mips/pgtable-32.h
index 2fbd47e..ff29485 100644
--- a/include/asm-mips/pgtable-32.h
+++ b/include/asm-mips/pgtable-32.h
@@ -43,11 +43,7 @@ extern int add_temporary_entry(unsigned long entrylo0, unsigned long entrylo1,
*/
/* PGDIR_SHIFT determines what a third-level page table entry can map */
-#ifdef CONFIG_64BIT_PHYS_ADDR
-#define PGDIR_SHIFT 21
-#else
-#define PGDIR_SHIFT 22
-#endif
+#define PGDIR_SHIFT (2 * PAGE_SHIFT + PTE_ORDER - PTE_T_LOG2)
#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
#define PGDIR_MASK (~(PGDIR_SIZE-1))
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH] 16K page size in 32 bit kernel
2007-07-31 20:45 ` Ralf Baechle
@ 2007-08-01 0:47 ` Songmao Tian
0 siblings, 0 replies; 7+ messages in thread
From: Songmao Tian @ 2007-08-01 0:47 UTC (permalink / raw)
To: Ralf Baechle; +Cc: Dajie Tan, linux-mips
Ralf Baechle wrote:
> On Tue, Jul 31, 2007 at 09:49:34PM +0800, Songmao Tian wrote:
>
>
>> I think the following is more complete?
>>
>> #ifdef CONFIG_64BIT_PHYS_ADDR
>> -#define PGDIR_SHIFT 21
>> +#define PGDIR_SHIFT (PAGE_SHIFT + (PAGE_SHIFT + PTE_ORDER - 3))
>> #else
>> -#define PGDIR_SHIFT 22
>> +#define PGDIR_SHIFT (PAGE_SHIFT + (PAGE_SHIFT + PTE_ORDER - 2))
>> #endif
>>
>
> Better suggestion :-)
>
> Ralf
>
> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
>
> diff --git a/include/asm-mips/pgtable-32.h b/include/asm-mips/pgtable-32.h
> index 2fbd47e..ff29485 100644
> --- a/include/asm-mips/pgtable-32.h
> +++ b/include/asm-mips/pgtable-32.h
> @@ -43,11 +43,7 @@ extern int add_temporary_entry(unsigned long entrylo0, unsigned long entrylo1,
> */
>
> /* PGDIR_SHIFT determines what a third-level page table entry can map */
> -#ifdef CONFIG_64BIT_PHYS_ADDR
> -#define PGDIR_SHIFT 21
> -#else
> -#define PGDIR_SHIFT 22
> -#endif
> +#define PGDIR_SHIFT (2 * PAGE_SHIFT + PTE_ORDER - PTE_T_LOG2)
> #define PGDIR_SIZE (1UL << PGDIR_SHIFT)
> #define PGDIR_MASK (~(PGDIR_SIZE-1))
>
>
>
>
Sure:)
Tian
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2007-08-01 0:48 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
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2007-07-31 13:09 [PATCH] 16K page size in 32 bit kernel Dajie Tan
2007-07-31 9:37 ` Songmao Tian
2007-07-31 9:37 ` Songmao Tian
2007-07-31 10:00 ` Ralf Baechle
2007-07-31 13:49 ` Songmao Tian
2007-07-31 20:45 ` Ralf Baechle
2007-08-01 0:47 ` Songmao Tian
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