[PATCH V2] mm: Generalize HUGETLB_PAGE_SIZE_VARIABLE

[PATCH V2] mm: Generalize HUGETLB_PAGE_SIZE_VARIABLE

[Anshuman Khandual]

HUGETLB_PAGE_SIZE_VARIABLE need not be defined for each individual
platform subscribing it. Instead just make it generic.

Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: linux-ia64@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
This change was originally suggested in an earilier discussion. This
applies on v5.12-rc1 and has been build tested on all applicable
platforms i.e ia64 and powerpc.

https://patchwork.kernel.org/project/linux-mm/patch/1613024531-19040-3-git-send-email-anshuman.khandual@arm.com/

Changes in V2:

- Added a description for HUGETLB_PAGE_SIZE_VARIABLE
- Added HUGETLB_PAGE dependency while selecting HUGETLB_PAGE_SIZE_VARIABLE

Changes in V1:

https://patchwork.kernel.org/project/linux-mm/patch/1614577853-7452-1-git-send-email-anshuman.khandual@arm.com/

 arch/ia64/Kconfig    | 6 +-----
 arch/powerpc/Kconfig | 6 +-----
 mm/Kconfig           | 9 +++++++++
 3 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 2ad7a8d29fcc..dccf5bfebf48 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -32,6 +32,7 @@ config IA64
 	select TTY
 	select HAVE_ARCH_TRACEHOOK
 	select HAVE_VIRT_CPU_ACCOUNTING
+	select HUGETLB_PAGE_SIZE_VARIABLE if HUGETLB_PAGE
 	select VIRT_TO_BUS
 	select GENERIC_IRQ_PROBE
 	select GENERIC_PENDING_IRQ if SMP
@@ -82,11 +83,6 @@ config STACKTRACE_SUPPORT
 config GENERIC_LOCKBREAK
 	def_bool n
 
-config HUGETLB_PAGE_SIZE_VARIABLE
-	bool
-	depends on HUGETLB_PAGE
-	default y
-
 config GENERIC_CALIBRATE_DELAY
 	bool
 	default y
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 3778ad17f56a..3fdec3e53256 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -232,6 +232,7 @@ config PPC
 	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI && !HAVE_HARDLOCKUP_DETECTOR_ARCH
 	select HAVE_PERF_REGS
 	select HAVE_PERF_USER_STACK_DUMP
+	select HUGETLB_PAGE_SIZE_VARIABLE	if PPC_BOOK3S_64 && HUGETLB_PAGE
 	select MMU_GATHER_RCU_TABLE_FREE
 	select MMU_GATHER_PAGE_SIZE
 	select HAVE_REGS_AND_STACK_ACCESS_API
@@ -416,11 +417,6 @@ config HIGHMEM
 
 source "kernel/Kconfig.hz"
 
-config HUGETLB_PAGE_SIZE_VARIABLE
-	bool
-	depends on HUGETLB_PAGE && PPC_BOOK3S_64
-	default y
-
 config MATH_EMULATION
 	bool "Math emulation"
 	depends on 4xx || PPC_8xx || PPC_MPC832x || BOOKE
diff --git a/mm/Kconfig b/mm/Kconfig
index 24c045b24b95..64f1e0503e4f 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -274,6 +274,15 @@ config ARCH_ENABLE_HUGEPAGE_MIGRATION
 config ARCH_ENABLE_THP_MIGRATION
 	bool
 
+config HUGETLB_PAGE_SIZE_VARIABLE
+	bool "Allows dynamic pageblock_order"
+	def_bool n
+	depends on HUGETLB_PAGE
+	help
+	  Allows the pageblock_order value to be dynamic instead of just standard
+	  HUGETLB_PAGE_ORDER when there are multiple HugeTLB page sizes available
+	  on a platform.
+
 config CONTIG_ALLOC
 	def_bool (MEMORY_ISOLATION && COMPACTION) || CMA
 
-- 
2.20.1

Re: [PATCH V2] mm: Generalize HUGETLB_PAGE_SIZE_VARIABLE

[Christophe Leroy]

Le 02/03/2021 à 06:13, Anshuman Khandual a écrit :
> HUGETLB_PAGE_SIZE_VARIABLE need not be defined for each individual
> platform subscribing it. Instead just make it generic.
> 
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: linux-ia64@vger.kernel.org
> Cc: linuxppc-dev@lists.ozlabs.org
> Cc: linux-mm@kvack.org
> Cc: linux-kernel@vger.kernel.org
> Suggested-by: Christoph Hellwig <hch@lst.de>
> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
> ---
> This change was originally suggested in an earilier discussion. This
> applies on v5.12-rc1 and has been build tested on all applicable
> platforms i.e ia64 and powerpc.
> 
> https://patchwork.kernel.org/project/linux-mm/patch/1613024531-19040-3-git-send-email-anshuman.khandual@arm.com/
> 
> Changes in V2:
> 
> - Added a description for HUGETLB_PAGE_SIZE_VARIABLE

You are doing more than adding a description: you are making it user selectable. Is that what you want ?

> - Added HUGETLB_PAGE dependency while selecting HUGETLB_PAGE_SIZE_VARIABLE
> 
> Changes in V1:
> 
> https://patchwork.kernel.org/project/linux-mm/patch/1614577853-7452-1-git-send-email-anshuman.khandual@arm.com/
> 
>   arch/ia64/Kconfig    | 6 +-----
>   arch/powerpc/Kconfig | 6 +-----
>   mm/Kconfig           | 9 +++++++++
>   3 files changed, 11 insertions(+), 10 deletions(-)
> 
> diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
> index 2ad7a8d29fcc..dccf5bfebf48 100644
> --- a/arch/ia64/Kconfig
> +++ b/arch/ia64/Kconfig
> @@ -32,6 +32,7 @@ config IA64
>   	select TTY
>   	select HAVE_ARCH_TRACEHOOK
>   	select HAVE_VIRT_CPU_ACCOUNTING
> +	select HUGETLB_PAGE_SIZE_VARIABLE if HUGETLB_PAGE
>   	select VIRT_TO_BUS
>   	select GENERIC_IRQ_PROBE
>   	select GENERIC_PENDING_IRQ if SMP
> @@ -82,11 +83,6 @@ config STACKTRACE_SUPPORT
>   config GENERIC_LOCKBREAK
>   	def_bool n
>   
> -config HUGETLB_PAGE_SIZE_VARIABLE
> -	bool
> -	depends on HUGETLB_PAGE
> -	default y
> -
>   config GENERIC_CALIBRATE_DELAY
>   	bool
>   	default y
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index 3778ad17f56a..3fdec3e53256 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -232,6 +232,7 @@ config PPC
>   	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI && !HAVE_HARDLOCKUP_DETECTOR_ARCH
>   	select HAVE_PERF_REGS
>   	select HAVE_PERF_USER_STACK_DUMP
> +	select HUGETLB_PAGE_SIZE_VARIABLE	if PPC_BOOK3S_64 && HUGETLB_PAGE
>   	select MMU_GATHER_RCU_TABLE_FREE
>   	select MMU_GATHER_PAGE_SIZE
>   	select HAVE_REGS_AND_STACK_ACCESS_API
> @@ -416,11 +417,6 @@ config HIGHMEM
>   
>   source "kernel/Kconfig.hz"
>   
> -config HUGETLB_PAGE_SIZE_VARIABLE
> -	bool
> -	depends on HUGETLB_PAGE && PPC_BOOK3S_64
> -	default y
> -
>   config MATH_EMULATION
>   	bool "Math emulation"
>   	depends on 4xx || PPC_8xx || PPC_MPC832x || BOOKE
> diff --git a/mm/Kconfig b/mm/Kconfig
> index 24c045b24b95..64f1e0503e4f 100644
> --- a/mm/Kconfig
> +++ b/mm/Kconfig
> @@ -274,6 +274,15 @@ config ARCH_ENABLE_HUGEPAGE_MIGRATION
>   config ARCH_ENABLE_THP_MIGRATION
>   	bool
>   
> +config HUGETLB_PAGE_SIZE_VARIABLE
> +	bool "Allows dynamic pageblock_order"
> +	def_bool n
> +	depends on HUGETLB_PAGE
> +	help
> +	  Allows the pageblock_order value to be dynamic instead of just standard
> +	  HUGETLB_PAGE_ORDER when there are multiple HugeTLB page sizes available
> +	  on a platform.
> +
>   config CONTIG_ALLOC
>   	def_bool (MEMORY_ISOLATION && COMPACTION) || CMA
>   
> 

Re: [PATCH V2] mm: Generalize HUGETLB_PAGE_SIZE_VARIABLE

[Anshuman Khandual]

On 3/2/21 11:13 AM, Christophe Leroy wrote:
> 
> 
> Le 02/03/2021 à 06:13, Anshuman Khandual a écrit :
>> HUGETLB_PAGE_SIZE_VARIABLE need not be defined for each individual
>> platform subscribing it. Instead just make it generic.
>>
>> Cc: Michael Ellerman <mpe@ellerman.id.au>
>> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
>> Cc: Paul Mackerras <paulus@samba.org>
>> Cc: Andrew Morton <akpm@linux-foundation.org>
>> Cc: Christoph Hellwig <hch@lst.de>
>> Cc: linux-ia64@vger.kernel.org
>> Cc: linuxppc-dev@lists.ozlabs.org
>> Cc: linux-mm@kvack.org
>> Cc: linux-kernel@vger.kernel.org
>> Suggested-by: Christoph Hellwig <hch@lst.de>
>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
>> ---
>> This change was originally suggested in an earilier discussion. This
>> applies on v5.12-rc1 and has been build tested on all applicable
>> platforms i.e ia64 and powerpc.
>>
>> https://patchwork.kernel.org/project/linux-mm/patch/1613024531-19040-3-git-send-email-anshuman.khandual@arm.com/
>>
>> Changes in V2:
>>
>> - Added a description for HUGETLB_PAGE_SIZE_VARIABLE
> 
> You are doing more than adding a description: you are making it user selectable. Is that what you want ?

No, this was unintended. Will drop that description.

Re: [PATCH V2] mm: Generalize HUGETLB_PAGE_SIZE_VARIABLE

[Christophe Leroy]

Le 02/03/2021 à 07:37, Anshuman Khandual a écrit :
> 
> 
> On 3/2/21 11:13 AM, Christophe Leroy wrote:
>>
>>
>> Le 02/03/2021 à 06:13, Anshuman Khandual a écrit :
>>> HUGETLB_PAGE_SIZE_VARIABLE need not be defined for each individual
>>> platform subscribing it. Instead just make it generic.
>>>
>>> Cc: Michael Ellerman <mpe@ellerman.id.au>
>>> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
>>> Cc: Paul Mackerras <paulus@samba.org>
>>> Cc: Andrew Morton <akpm@linux-foundation.org>
>>> Cc: Christoph Hellwig <hch@lst.de>
>>> Cc: linux-ia64@vger.kernel.org
>>> Cc: linuxppc-dev@lists.ozlabs.org
>>> Cc: linux-mm@kvack.org
>>> Cc: linux-kernel@vger.kernel.org
>>> Suggested-by: Christoph Hellwig <hch@lst.de>
>>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
>>> ---
>>> This change was originally suggested in an earilier discussion. This
>>> applies on v5.12-rc1 and has been build tested on all applicable
>>> platforms i.e ia64 and powerpc.
>>>
>>> https://patchwork.kernel.org/project/linux-mm/patch/1613024531-19040-3-git-send-email-anshuman.khandual@arm.com/
>>>
>>> Changes in V2:
>>>
>>> - Added a description for HUGETLB_PAGE_SIZE_VARIABLE
>>
>> You are doing more than adding a description: you are making it user selectable. Is that what you want ?
> 
> No, this was unintended. Will drop that description.
> 

The description in the help section is OK.

It is only the text after the "bool" that makes it selectable.

	bool "Allows dynamic pageblock_order"

Re: [PATCH V2] mm: Generalize HUGETLB_PAGE_SIZE_VARIABLE

[Anshuman Khandual]

On 3/2/21 10:43 AM, Anshuman Khandual wrote:
> HUGETLB_PAGE_SIZE_VARIABLE need not be defined for each individual
> platform subscribing it. Instead just make it generic.
> 
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: linux-ia64@vger.kernel.org
> Cc: linuxppc-dev@lists.ozlabs.org
> Cc: linux-mm@kvack.org
> Cc: linux-kernel@vger.kernel.org
> Suggested-by: Christoph Hellwig <hch@lst.de>
> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
> ---
> This change was originally suggested in an earilier discussion. This
> applies on v5.12-rc1 and has been build tested on all applicable
> platforms i.e ia64 and powerpc.
> 
> https://patchwork.kernel.org/project/linux-mm/patch/1613024531-19040-3-git-send-email-anshuman.khandual@arm.com/
> 
> Changes in V2:
> 
> - Added a description for HUGETLB_PAGE_SIZE_VARIABLE
> - Added HUGETLB_PAGE dependency while selecting HUGETLB_PAGE_SIZE_VARIABLE
> 
> Changes in V1:
> 
> https://patchwork.kernel.org/project/linux-mm/patch/1614577853-7452-1-git-send-email-anshuman.khandual@arm.com/
> 
>  arch/ia64/Kconfig    | 6 +-----
>  arch/powerpc/Kconfig | 6 +-----
>  mm/Kconfig           | 9 +++++++++
>  3 files changed, 11 insertions(+), 10 deletions(-)
> 
> diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
> index 2ad7a8d29fcc..dccf5bfebf48 100644
> --- a/arch/ia64/Kconfig
> +++ b/arch/ia64/Kconfig
> @@ -32,6 +32,7 @@ config IA64
>  	select TTY
>  	select HAVE_ARCH_TRACEHOOK
>  	select HAVE_VIRT_CPU_ACCOUNTING
> +	select HUGETLB_PAGE_SIZE_VARIABLE if HUGETLB_PAGE
>  	select VIRT_TO_BUS
>  	select GENERIC_IRQ_PROBE
>  	select GENERIC_PENDING_IRQ if SMP
> @@ -82,11 +83,6 @@ config STACKTRACE_SUPPORT
>  config GENERIC_LOCKBREAK
>  	def_bool n
>  
> -config HUGETLB_PAGE_SIZE_VARIABLE
> -	bool
> -	depends on HUGETLB_PAGE
> -	default y
> -
>  config GENERIC_CALIBRATE_DELAY
>  	bool
>  	default y
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index 3778ad17f56a..3fdec3e53256 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -232,6 +232,7 @@ config PPC
>  	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI && !HAVE_HARDLOCKUP_DETECTOR_ARCH
>  	select HAVE_PERF_REGS
>  	select HAVE_PERF_USER_STACK_DUMP
> +	select HUGETLB_PAGE_SIZE_VARIABLE	if PPC_BOOK3S_64 && HUGETLB_PAGE
>  	select MMU_GATHER_RCU_TABLE_FREE
>  	select MMU_GATHER_PAGE_SIZE
>  	select HAVE_REGS_AND_STACK_ACCESS_API
> @@ -416,11 +417,6 @@ config HIGHMEM
>  
>  source "kernel/Kconfig.hz"
>  
> -config HUGETLB_PAGE_SIZE_VARIABLE
> -	bool
> -	depends on HUGETLB_PAGE && PPC_BOOK3S_64
> -	default y
> -
>  config MATH_EMULATION
>  	bool "Math emulation"
>  	depends on 4xx || PPC_8xx || PPC_MPC832x || BOOKE
> diff --git a/mm/Kconfig b/mm/Kconfig
> index 24c045b24b95..64f1e0503e4f 100644
> --- a/mm/Kconfig
> +++ b/mm/Kconfig
> @@ -274,6 +274,15 @@ config ARCH_ENABLE_HUGEPAGE_MIGRATION
>  config ARCH_ENABLE_THP_MIGRATION
>  	bool
>  
> +config HUGETLB_PAGE_SIZE_VARIABLE
> +	bool "Allows dynamic pageblock_order"
> +	def_bool n
> +	depends on HUGETLB_PAGE

Seems like this dependency on HUGETLB_PAGE is redundant, as it is
already being ensured on the platforms while selecting the config.

> +	help
> +	  Allows the pageblock_order value to be dynamic instead of just standard
> +	  HUGETLB_PAGE_ORDER when there are multiple HugeTLB page sizes available
> +	  on a platform.
> +
>  config CONTIG_ALLOC
>  	def_bool (MEMORY_ISOLATION && COMPACTION) || CMA
>  
>