* [PATCH 1/2] powerpc: mm: use macro PGTABLE_EADDR_SIZE instead of digital
@ 2013-11-21 2:17 Liu Ping Fan
2013-11-21 2:17 ` [PATCH 2/2] powerpc: mm: change pgtable index size for 64K page Liu Ping Fan
2014-04-30 5:30 ` [PATCH 1/2] powerpc: mm: use macro PGTABLE_EADDR_SIZE instead of digital Aneesh Kumar K.V
0 siblings, 2 replies; 6+ messages in thread
From: Liu Ping Fan @ 2013-11-21 2:17 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Paul Mackerras
In case of extending the eaddr in future, use this macro
PGTABLE_EADDR_SIZE to ease the maintenance of the code.
Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com>
---
arch/powerpc/mm/slb_low.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/mm/slb_low.S b/arch/powerpc/mm/slb_low.S
index 17aa6df..e0b3cf4 100644
--- a/arch/powerpc/mm/slb_low.S
+++ b/arch/powerpc/mm/slb_low.S
@@ -35,7 +35,7 @@ _GLOBAL(slb_allocate_realmode)
* check for bad kernel/user address
* (ea & ~REGION_MASK) >= PGTABLE_RANGE
*/
- rldicr. r9,r3,4,(63 - 46 - 4)
+ rldicr. r9,r3,4,(63 - PGTABLE_EADDR_SIZE - 4)
bne- 8f
srdi r9,r3,60 /* get region */
--
1.8.1.4
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 2/2] powerpc: mm: change pgtable index size for 64K page
2013-11-21 2:17 [PATCH 1/2] powerpc: mm: use macro PGTABLE_EADDR_SIZE instead of digital Liu Ping Fan
@ 2013-11-21 2:17 ` Liu Ping Fan
2013-11-21 22:11 ` Paul Mackerras
2014-04-30 5:30 ` [PATCH 1/2] powerpc: mm: use macro PGTABLE_EADDR_SIZE instead of digital Aneesh Kumar K.V
1 sibling, 1 reply; 6+ messages in thread
From: Liu Ping Fan @ 2013-11-21 2:17 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Paul Mackerras
For 64K page, we waste half of the pte_t page. With this patch, after
changing PGD_INDEX_SIZE from 12 to 11, PTE_INDEX_SIZE from 8 to 9,
we can improve the usage of pte_t page and shrink the continuous phys
size for pgd_t.
Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com>
---
arch/powerpc/include/asm/pgtable-ppc64-64k.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/include/asm/pgtable-ppc64-64k.h b/arch/powerpc/include/asm/pgtable-ppc64-64k.h
index a56b82f..f6955ff 100644
--- a/arch/powerpc/include/asm/pgtable-ppc64-64k.h
+++ b/arch/powerpc/include/asm/pgtable-ppc64-64k.h
@@ -4,10 +4,10 @@
#include <asm-generic/pgtable-nopud.h>
-#define PTE_INDEX_SIZE 8
+#define PTE_INDEX_SIZE 9
#define PMD_INDEX_SIZE 10
#define PUD_INDEX_SIZE 0
-#define PGD_INDEX_SIZE 12
+#define PGD_INDEX_SIZE 11
#ifndef __ASSEMBLY__
#define PTE_TABLE_SIZE (sizeof(real_pte_t) << PTE_INDEX_SIZE)
--
1.8.1.4
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH 2/2] powerpc: mm: change pgtable index size for 64K page
2013-11-21 2:17 ` [PATCH 2/2] powerpc: mm: change pgtable index size for 64K page Liu Ping Fan
@ 2013-11-21 22:11 ` Paul Mackerras
2013-11-21 23:46 ` Benjamin Herrenschmidt
0 siblings, 1 reply; 6+ messages in thread
From: Paul Mackerras @ 2013-11-21 22:11 UTC (permalink / raw)
To: Liu Ping Fan; +Cc: linuxppc-dev
On Thu, Nov 21, 2013 at 10:17:55AM +0800, Liu Ping Fan wrote:
> For 64K page, we waste half of the pte_t page. With this patch, after
> changing PGD_INDEX_SIZE from 12 to 11, PTE_INDEX_SIZE from 8 to 9,
> we can improve the usage of pte_t page and shrink the continuous phys
> size for pgd_t.
>
> Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com>
> ---
> arch/powerpc/include/asm/pgtable-ppc64-64k.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/pgtable-ppc64-64k.h b/arch/powerpc/include/asm/pgtable-ppc64-64k.h
> index a56b82f..f6955ff 100644
> --- a/arch/powerpc/include/asm/pgtable-ppc64-64k.h
> +++ b/arch/powerpc/include/asm/pgtable-ppc64-64k.h
> @@ -4,10 +4,10 @@
> #include <asm-generic/pgtable-nopud.h>
>
>
> -#define PTE_INDEX_SIZE 8
> +#define PTE_INDEX_SIZE 9
> #define PMD_INDEX_SIZE 10
> #define PUD_INDEX_SIZE 0
> -#define PGD_INDEX_SIZE 12
> +#define PGD_INDEX_SIZE 11
Nack. Those definitions are the way they are in order to have the PMD
map 16MB, which is our large page size, so that transparent huge pages
work.
Paul.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 2/2] powerpc: mm: change pgtable index size for 64K page
2013-11-21 22:11 ` Paul Mackerras
@ 2013-11-21 23:46 ` Benjamin Herrenschmidt
2013-11-22 2:06 ` Michael Ellerman
0 siblings, 1 reply; 6+ messages in thread
From: Benjamin Herrenschmidt @ 2013-11-21 23:46 UTC (permalink / raw)
To: Liu Ping Fan; +Cc: Paul Mackerras, linuxppc-dev
On Fri, 2013-11-22 at 09:11 +1100, Paul Mackerras wrote:
> On Thu, Nov 21, 2013 at 10:17:55AM +0800, Liu Ping Fan wrote:
> > For 64K page, we waste half of the pte_t page. With this patch, after
> > changing PGD_INDEX_SIZE from 12 to 11, PTE_INDEX_SIZE from 8 to 9,
> > we can improve the usage of pte_t page and shrink the continuous phys
> > size for pgd_t.
Also you did you miss that we use the second half to store the
per-subpage hash info when using 64k on top of HW 4k ?
Cheers,
Ben.
> > Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com>
> > ---
> > arch/powerpc/include/asm/pgtable-ppc64-64k.h | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/powerpc/include/asm/pgtable-ppc64-64k.h b/arch/powerpc/include/asm/pgtable-ppc64-64k.h
> > index a56b82f..f6955ff 100644
> > --- a/arch/powerpc/include/asm/pgtable-ppc64-64k.h
> > +++ b/arch/powerpc/include/asm/pgtable-ppc64-64k.h
> > @@ -4,10 +4,10 @@
> > #include <asm-generic/pgtable-nopud.h>
> >
> >
> > -#define PTE_INDEX_SIZE 8
> > +#define PTE_INDEX_SIZE 9
> > #define PMD_INDEX_SIZE 10
> > #define PUD_INDEX_SIZE 0
> > -#define PGD_INDEX_SIZE 12
> > +#define PGD_INDEX_SIZE 11
>
> Nack. Those definitions are the way they are in order to have the PMD
> map 16MB, which is our large page size, so that transparent huge pages
> work.
>
> Paul.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 2/2] powerpc: mm: change pgtable index size for 64K page
2013-11-21 23:46 ` Benjamin Herrenschmidt
@ 2013-11-22 2:06 ` Michael Ellerman
0 siblings, 0 replies; 6+ messages in thread
From: Michael Ellerman @ 2013-11-22 2:06 UTC (permalink / raw)
To: Benjamin Herrenschmidt; +Cc: linuxppc-dev, Paul Mackerras, Liu Ping Fan
On Fri, 2013-11-22 at 10:46 +1100, Benjamin Herrenschmidt wrote:
> On Fri, 2013-11-22 at 09:11 +1100, Paul Mackerras wrote:
> > On Thu, Nov 21, 2013 at 10:17:55AM +0800, Liu Ping Fan wrote:
> > > For 64K page, we waste half of the pte_t page. With this patch, after
> > > changing PGD_INDEX_SIZE from 12 to 11, PTE_INDEX_SIZE from 8 to 9,
> > > we can improve the usage of pte_t page and shrink the continuous phys
> > > size for pgd_t.
>
> Also you did you miss that we use the second half to store the
> per-subpage hash info when using 64k on top of HW 4k ?
Given the subtleties perhaps a nice big block comment is in order ? :)
cheers
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] powerpc: mm: use macro PGTABLE_EADDR_SIZE instead of digital
2013-11-21 2:17 [PATCH 1/2] powerpc: mm: use macro PGTABLE_EADDR_SIZE instead of digital Liu Ping Fan
2013-11-21 2:17 ` [PATCH 2/2] powerpc: mm: change pgtable index size for 64K page Liu Ping Fan
@ 2014-04-30 5:30 ` Aneesh Kumar K.V
1 sibling, 0 replies; 6+ messages in thread
From: Aneesh Kumar K.V @ 2014-04-30 5:30 UTC (permalink / raw)
To: Liu Ping Fan, linuxppc-dev; +Cc: Paul Mackerras
Liu Ping Fan <kernelfans@gmail.com> writes:
> In case of extending the eaddr in future, use this macro
> PGTABLE_EADDR_SIZE to ease the maintenance of the code.
>
> Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> ---
> arch/powerpc/mm/slb_low.S | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/mm/slb_low.S b/arch/powerpc/mm/slb_low.S
> index 17aa6df..e0b3cf4 100644
> --- a/arch/powerpc/mm/slb_low.S
> +++ b/arch/powerpc/mm/slb_low.S
> @@ -35,7 +35,7 @@ _GLOBAL(slb_allocate_realmode)
> * check for bad kernel/user address
> * (ea & ~REGION_MASK) >= PGTABLE_RANGE
> */
> - rldicr. r9,r3,4,(63 - 46 - 4)
> + rldicr. r9,r3,4,(63 - PGTABLE_EADDR_SIZE - 4)
> bne- 8f
>
> srdi r9,r3,60 /* get region */
> --
> 1.8.1.4
>
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev@lists.ozlabs.org
> https://lists.ozlabs.org/listinfo/linuxppc-dev
^ permalink raw reply [flat|nested] 6+ messages in thread
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2013-11-21 2:17 [PATCH 1/2] powerpc: mm: use macro PGTABLE_EADDR_SIZE instead of digital Liu Ping Fan
2013-11-21 2:17 ` [PATCH 2/2] powerpc: mm: change pgtable index size for 64K page Liu Ping Fan
2013-11-21 22:11 ` Paul Mackerras
2013-11-21 23:46 ` Benjamin Herrenschmidt
2013-11-22 2:06 ` Michael Ellerman
2014-04-30 5:30 ` [PATCH 1/2] powerpc: mm: use macro PGTABLE_EADDR_SIZE instead of digital Aneesh Kumar K.V
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