Re: [PATCH 1/6] sparc64: Add FORCE_MAX_ZONEORDER and default to 13

[David Miller]

From: tndave 
Date: Mon, 24 Oct 2016 11:31:14 -0700

> 
> 
> On 10/24/2016 10:45 AM, David Miller wrote:
>> From: Tushar Dave 
>> Date: Mon, 10 Oct 2016 11:12:02 -0700
>>
>>> From: Dave Kleikamp 
>>>
>>> This change allows ATU (new IOMMU) in SPARC systems to request
>>> large (32M) contiguous memory during boot for creating IOTSB backing
>>> store.
>>>
>>> Signed-off-by: Dave Kleikamp 
>>> Signed-off-by: Tushar Dave 
>>
>> If you need 32MB allocations, wouldn't a max zone order of 12 be
>> sufficient?  (8K << 12 == 32MB)
> Yes, but config FORCE_MAX_ZONEORDER is actually maximum order plus
> one.
> For example, a value of 13 means that the largest free memory block is
> 2^12 pages. For 32MB we need 2^12 8K pages, hence FORCE_MAX_ZONEORDER
> must be MAX_ORDER + 1 i.e. 13.

Ok, thanks for explaining.

Re: [PATCH 1/6] sparc64: Add FORCE_MAX_ZONEORDER and default to 13

[David Miller]

From: tndave 
Date: Mon, 24 Oct 2016 11:31:14 -0700

> 
> 
> On 10/24/2016 10:45 AM, David Miller wrote:
>> From: Tushar Dave 
>> Date: Mon, 10 Oct 2016 11:12:02 -0700
>>
>>> From: Dave Kleikamp 
>>>
>>> This change allows ATU (new IOMMU) in SPARC systems to request
>>> large (32M) contiguous memory during boot for creating IOTSB backing
>>> store.
>>>
>>> Signed-off-by: Dave Kleikamp 
>>> Signed-off-by: Tushar Dave 
>>
>> If you need 32MB allocations, wouldn't a max zone order of 12 be
>> sufficient?  (8K << 12 == 32MB)
> Yes, but config FORCE_MAX_ZONEORDER is actually maximum order plus
> one.
> For example, a value of 13 means that the largest free memory block is
> 2^12 pages. For 32MB we need 2^12 8K pages, hence FORCE_MAX_ZONEORDER
> must be MAX_ORDER + 1 i.e. 13.

Ok, thanks for explaining.

Re: [PATCH 1/6] sparc64: Add FORCE_MAX_ZONEORDER and default to 13

[tndave]

On 10/24/2016 10:45 AM, David Miller wrote:

From: Tushar Dave 
Date: Mon, 10 Oct 2016 11:12:02 -0700


From: Dave Kleikamp 

This change allows ATU (new IOMMU) in SPARC systems to request
large (32M) contiguous memory during boot for creating IOTSB backing
store.

Signed-off-by: Dave Kleikamp 
Signed-off-by: Tushar Dave 


If you need 32MB allocations, wouldn't a max zone order of 12 be
sufficient?  (8K << 12 == 32MB)

Yes, but config FORCE_MAX_ZONEORDER is actually maximum order plus one.
For example, a value of 13 means that the largest free memory block is
2^12 pages. For 32MB we need 2^12 8K pages, hence FORCE_MAX_ZONEORDER
must be MAX_ORDER + 1 i.e. 13.

Thanks.

-Tushar

Re: [PATCH 1/6] sparc64: Add FORCE_MAX_ZONEORDER and default to 13

[tndave]

On 10/24/2016 10:45 AM, David Miller wrote:

From: Tushar Dave 
Date: Mon, 10 Oct 2016 11:12:02 -0700


From: Dave Kleikamp 

This change allows ATU (new IOMMU) in SPARC systems to request
large (32M) contiguous memory during boot for creating IOTSB backing
store.

Signed-off-by: Dave Kleikamp 
Signed-off-by: Tushar Dave 


If you need 32MB allocations, wouldn't a max zone order of 12 be
sufficient?  (8K << 12 == 32MB)

Yes, but config FORCE_MAX_ZONEORDER is actually maximum order plus one.
For example, a value of 13 means that the largest free memory block is
2^12 pages. For 32MB we need 2^12 8K pages, hence FORCE_MAX_ZONEORDER
must be MAX_ORDER + 1 i.e. 13.

Thanks.

-Tushar

Re: [PATCH 1/6] sparc64: Add FORCE_MAX_ZONEORDER and default to 13

[David Miller]

From: Tushar Dave 
Date: Mon, 10 Oct 2016 11:12:02 -0700

> From: Dave Kleikamp 
> 
> This change allows ATU (new IOMMU) in SPARC systems to request
> large (32M) contiguous memory during boot for creating IOTSB backing
> store.
> 
> Signed-off-by: Dave Kleikamp 
> Signed-off-by: Tushar Dave 

If you need 32MB allocations, wouldn't a max zone order of 12 be
sufficient?  (8K << 12 == 32MB)

Re: [PATCH 1/6] sparc64: Add FORCE_MAX_ZONEORDER and default to 13

[David Miller]

From: Tushar Dave 
Date: Mon, 10 Oct 2016 11:12:02 -0700

> From: Dave Kleikamp 
> 
> This change allows ATU (new IOMMU) in SPARC systems to request
> large (32M) contiguous memory during boot for creating IOTSB backing
> store.
> 
> Signed-off-by: Dave Kleikamp 
> Signed-off-by: Tushar Dave 

If you need 32MB allocations, wouldn't a max zone order of 12 be
sufficient?  (8K << 12 == 32MB)

[PATCH 1/6] sparc64: Add FORCE_MAX_ZONEORDER and default to 13

[Tushar Dave]

From: Dave Kleikamp 

This change allows ATU (new IOMMU) in SPARC systems to request
large (32M) contiguous memory during boot for creating IOTSB backing
store.

Signed-off-by: Dave Kleikamp 
Signed-off-by: Tushar Dave 
---
 arch/sparc/Kconfig | 18 ++
 1 file changed, 18 insertions(+)

diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index f5d60f1..a7482bc 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -90,6 +90,10 @@ config ARCH_DEFCONFIG
 config ARCH_PROC_KCORE_TEXT
def_bool y
 
+config ARCH_ATU
+   bool
+   default y if SPARC64
+
 config IOMMU_HELPER
bool
default y if SPARC64
@@ -305,6 +309,20 @@ config ARCH_SPARSEMEM_ENABLE
 config ARCH_SPARSEMEM_DEFAULT
def_bool y if SPARC64
 
+config FORCE_MAX_ZONEORDER
+   int "Maximum zone order"
+   default "13"
+   help
+ The kernel memory allocator divides physically contiguous memory
+ blocks into "zones", where each zone is a power of two number of
+ pages.  This option selects the largest power of two that the kernel
+ keeps in the memory allocator.  If you need to allocate very large
+ blocks of physically contiguous memory, then you may need to
+ increase this value.
+
+ This config option is actually maximum order plus one. For example,
+ a value of 13 means that the largest free memory block is 2^12 pages.
+
 source "mm/Kconfig"
 
 if SPARC64
-- 
1.9.1

[PATCH 1/6] sparc64: Add FORCE_MAX_ZONEORDER and default to 13

[Tushar Dave]

From: Dave Kleikamp 

This change allows ATU (new IOMMU) in SPARC systems to request
large (32M) contiguous memory during boot for creating IOTSB backing
store.

Signed-off-by: Dave Kleikamp 
Signed-off-by: Tushar Dave 
---
 arch/sparc/Kconfig | 18 ++
 1 file changed, 18 insertions(+)

diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index f5d60f1..a7482bc 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -90,6 +90,10 @@ config ARCH_DEFCONFIG
 config ARCH_PROC_KCORE_TEXT
def_bool y
 
+config ARCH_ATU
+   bool
+   default y if SPARC64
+
 config IOMMU_HELPER
bool
default y if SPARC64
@@ -305,6 +309,20 @@ config ARCH_SPARSEMEM_ENABLE
 config ARCH_SPARSEMEM_DEFAULT
def_bool y if SPARC64
 
+config FORCE_MAX_ZONEORDER
+   int "Maximum zone order"
+   default "13"
+   help
+ The kernel memory allocator divides physically contiguous memory
+ blocks into "zones", where each zone is a power of two number of
+ pages.  This option selects the largest power of two that the kernel
+ keeps in the memory allocator.  If you need to allocate very large
+ blocks of physically contiguous memory, then you may need to
+ increase this value.
+
+ This config option is actually maximum order plus one. For example,
+ a value of 13 means that the largest free memory block is 2^12 pages.
+
 source "mm/Kconfig"
 
 if SPARC64
-- 
1.9.1

[RFC PATCH 1/6] sparc64: Add FORCE_MAX_ZONEORDER and default to 13

[Tushar Dave]

From: Dave Kleikamp 

This change allows ATU (new IOMMU) in SPARC systems to request
large (32M) contiguous memory during boot for creating IOTSB backing
store.

Signed-off-by: Dave Kleikamp 
Signed-off-by: Tushar Dave 
---
 arch/sparc/Kconfig | 18 ++
 1 file changed, 18 insertions(+)

diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 59b0960..338282d 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -91,6 +91,10 @@ config ARCH_DEFCONFIG
 config ARCH_PROC_KCORE_TEXT
def_bool y
 
+config ARCH_ATU
+   bool
+   default y if SPARC64
+
 config IOMMU_HELPER
bool
default y if SPARC64
@@ -306,6 +310,20 @@ config ARCH_SPARSEMEM_ENABLE
 config ARCH_SPARSEMEM_DEFAULT
def_bool y if SPARC64
 
+config FORCE_MAX_ZONEORDER
+   int "Maximum zone order"
+   default "13"
+   help
+ The kernel memory allocator divides physically contiguous memory
+ blocks into "zones", where each zone is a power of two number of
+ pages.  This option selects the largest power of two that the kernel
+ keeps in the memory allocator.  If you need to allocate very large
+ blocks of physically contiguous memory, then you may need to
+ increase this value.
+
+ This config option is actually maximum order plus one. For example,
+ a value of 13 means that the largest free memory block is 2^12 pages.
+
 source "mm/Kconfig"
 
 if SPARC64
-- 
1.9.1

[RFC PATCH 1/6] sparc64: Add FORCE_MAX_ZONEORDER and default to 13

[Tushar Dave]

From: Dave Kleikamp 

This change allows ATU (new IOMMU) in SPARC systems to request
large (32M) contiguous memory during boot for creating IOTSB backing
store.

Signed-off-by: Dave Kleikamp 
Signed-off-by: Tushar Dave 
---
 arch/sparc/Kconfig | 18 ++
 1 file changed, 18 insertions(+)

diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 59b0960..338282d 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -91,6 +91,10 @@ config ARCH_DEFCONFIG
 config ARCH_PROC_KCORE_TEXT
def_bool y
 
+config ARCH_ATU
+   bool
+   default y if SPARC64
+
 config IOMMU_HELPER
bool
default y if SPARC64
@@ -306,6 +310,20 @@ config ARCH_SPARSEMEM_ENABLE
 config ARCH_SPARSEMEM_DEFAULT
def_bool y if SPARC64
 
+config FORCE_MAX_ZONEORDER
+   int "Maximum zone order"
+   default "13"
+   help
+ The kernel memory allocator divides physically contiguous memory
+ blocks into "zones", where each zone is a power of two number of
+ pages.  This option selects the largest power of two that the kernel
+ keeps in the memory allocator.  If you need to allocate very large
+ blocks of physically contiguous memory, then you may need to
+ increase this value.
+
+ This config option is actually maximum order plus one. For example,
+ a value of 13 means that the largest free memory block is 2^12 pages.
+
 source "mm/Kconfig"
 
 if SPARC64
-- 
1.9.1