1. Patchew
  2. linux
  3. [RFC PATCH v1 0/4] mm/damon: Support hot application detections
  4. View patch

[RFC PATCH v1 2/4] mm/damon: Support for synchrounous huge pages collapse

gutierrez.asier@huawei-partners.com posted 4 patches 1 week ago
[RFC PATCH v1 2/4] mm/damon: Support for synchrounous huge pages collapse
Posted by gutierrez.asier@huawei-partners.com 1 week ago 
From: Asier Gutierrez <gutierrez.asier@huawei-partners.com>

* Support for huge pages collapse, which will be used by
  dynamic_hugepages module.

* Include the new module for compilation

Signed-off-by: Asier Gutierrez <gutierrez.asier@huawei-partners.com>
Co-developed-by: Anatoly Stepanov <stepanov.anatoly@huawei.com>
---
 include/linux/damon.h | 1 +
 mm/damon/Kconfig      | 7 +++++++
 mm/damon/Makefile     | 1 +
 mm/damon/vaddr.c      | 3 +++
 4 files changed, 12 insertions(+)

diff --git a/include/linux/damon.h b/include/linux/damon.h
index 3813373a9200..de5a994f92c2 100644
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -142,6 +142,7 @@ enum damos_action {
 	DAMOS_LRU_DEPRIO,
 	DAMOS_MIGRATE_HOT,
 	DAMOS_MIGRATE_COLD,
+	DAMOS_COLLAPSE,
 	DAMOS_STAT,		/* Do nothing but only record the stat */
 	NR_DAMOS_ACTIONS,
 };
diff --git a/mm/damon/Kconfig b/mm/damon/Kconfig
index 8c868f7035fc..2355aacb6d12 100644
--- a/mm/damon/Kconfig
+++ b/mm/damon/Kconfig
@@ -110,4 +110,11 @@ config DAMON_STAT_ENABLED_DEFAULT
 	  Whether to enable DAMON_STAT by default.  Users can disable it in
 	  boot or runtime using its 'enabled' parameter.
 
+config DAMON_HOT_HUGEPAGE
+	bool "Build DAMON-based collapse of hot regions (DAMON_HOT_HUGEPAGES)"
+	depends on DAMON_VADDR
+	help
+	 Collapse hot region into huge pages. Hot regions are determined by
+	 DAMON-based sampling
+
 endmenu
diff --git a/mm/damon/Makefile b/mm/damon/Makefile
index d8d6bf5f8bff..998bddc17819 100644
--- a/mm/damon/Makefile
+++ b/mm/damon/Makefile
@@ -7,3 +7,4 @@ obj-$(CONFIG_DAMON_SYSFS)	+= sysfs-common.o sysfs-schemes.o sysfs.o
 obj-$(CONFIG_DAMON_RECLAIM)	+= modules-common.o reclaim.o
 obj-$(CONFIG_DAMON_LRU_SORT)	+= modules-common.o lru_sort.o
 obj-$(CONFIG_DAMON_STAT)	+= modules-common.o stat.o
+obj-$(CONFIG_DAMON_HOT_HUGEPAGE)	+= modules-common.o dynamic_hugepages.o
diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c
index 23ed738a0bd6..4acbc1a6a5be 100644
--- a/mm/damon/vaddr.c
+++ b/mm/damon/vaddr.c
@@ -970,6 +970,9 @@ static unsigned long damon_va_apply_scheme(struct damon_ctx *ctx,
 	case DAMOS_NOHUGEPAGE:
 		madv_action = MADV_NOHUGEPAGE;
 		break;
+	case DAMOS_COLLAPSE:
+		madv_action = MADV_COLLAPSE;
+		break;
 	case DAMOS_MIGRATE_HOT:
 	case DAMOS_MIGRATE_COLD:
 		return damos_va_migrate(t, r, scheme, sz_filter_passed);
-- 
2.43.0
Re: [RFC PATCH v1 2/4] mm/damon: Support for synchrounous huge pages collapse
Posted by SeongJae Park 1 week ago 
On Mon, 2 Feb 2026 14:56:47 +0000 <gutierrez.asier@huawei-partners.com> wrote:

> From: Asier Gutierrez <gutierrez.asier@huawei-partners.com>
> 
> * Support for huge pages collapse, which will be used by
>   dynamic_hugepages module.
> 
> * Include the new module for compilation
> 
> Signed-off-by: Asier Gutierrez <gutierrez.asier@huawei-partners.com>
> Co-developed-by: Anatoly Stepanov <stepanov.anatoly@huawei.com>
> ---
>  include/linux/damon.h | 1 +
>  mm/damon/Kconfig      | 7 +++++++
>  mm/damon/Makefile     | 1 +
>  mm/damon/vaddr.c      | 3 +++
>  4 files changed, 12 insertions(+)
> 
> diff --git a/include/linux/damon.h b/include/linux/damon.h
> index 3813373a9200..de5a994f92c2 100644
> --- a/include/linux/damon.h
> +++ b/include/linux/damon.h
> @@ -142,6 +142,7 @@ enum damos_action {
>  	DAMOS_LRU_DEPRIO,
>  	DAMOS_MIGRATE_HOT,
>  	DAMOS_MIGRATE_COLD,
> +	DAMOS_COLLAPSE,

Please update the kernel-doc comments for this new action, by the time you drop
the RFC tag from this patch series.

>  	DAMOS_STAT,		/* Do nothing but only record the stat */
>  	NR_DAMOS_ACTIONS,
>  };
> diff --git a/mm/damon/Kconfig b/mm/damon/Kconfig
> index 8c868f7035fc..2355aacb6d12 100644
> --- a/mm/damon/Kconfig
> +++ b/mm/damon/Kconfig
> @@ -110,4 +110,11 @@ config DAMON_STAT_ENABLED_DEFAULT
>  	  Whether to enable DAMON_STAT by default.  Users can disable it in
>  	  boot or runtime using its 'enabled' parameter.
>  
> +config DAMON_HOT_HUGEPAGE
> +	bool "Build DAMON-based collapse of hot regions (DAMON_HOT_HUGEPAGES)"
> +	depends on DAMON_VADDR
> +	help
> +	 Collapse hot region into huge pages. Hot regions are determined by
> +	 DAMON-based sampling
> +

Apparently you wanted to introduce the above change on the next patch, but
mistakenly added here?

I'm also feeling the name might be better to be simpler.  What about... say,
just DAMON_HUGEPAGE?  We might want to extend that for general access-aware
huge pages.

>  endmenu
> diff --git a/mm/damon/Makefile b/mm/damon/Makefile
> index d8d6bf5f8bff..998bddc17819 100644
> --- a/mm/damon/Makefile
> +++ b/mm/damon/Makefile
> @@ -7,3 +7,4 @@ obj-$(CONFIG_DAMON_SYSFS)	+= sysfs-common.o sysfs-schemes.o sysfs.o
>  obj-$(CONFIG_DAMON_RECLAIM)	+= modules-common.o reclaim.o
>  obj-$(CONFIG_DAMON_LRU_SORT)	+= modules-common.o lru_sort.o
>  obj-$(CONFIG_DAMON_STAT)	+= modules-common.o stat.o
> +obj-$(CONFIG_DAMON_HOT_HUGEPAGE)	+= modules-common.o dynamic_hugepages.o

Ditto.

> diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c
> index 23ed738a0bd6..4acbc1a6a5be 100644
> --- a/mm/damon/vaddr.c
> +++ b/mm/damon/vaddr.c
> @@ -970,6 +970,9 @@ static unsigned long damon_va_apply_scheme(struct damon_ctx *ctx,
>  	case DAMOS_NOHUGEPAGE:
>  		madv_action = MADV_NOHUGEPAGE;
>  		break;
> +	case DAMOS_COLLAPSE:
> +		madv_action = MADV_COLLAPSE;
> +		break;
>  	case DAMOS_MIGRATE_HOT:
>  	case DAMOS_MIGRATE_COLD:
>  		return damos_va_migrate(t, r, scheme, sz_filter_passed);
> -- 
> 2.43.0


Thanks,
SJ

[...]
Re: [RFC PATCH v1 2/4] mm/damon: Support for synchrounous huge pages collapse
Posted by Gutierrez Asier 6 days, 13 hours ago 

On 2/3/2026 4:23 AM, SeongJae Park wrote:
> On Mon, 2 Feb 2026 14:56:47 +0000 <gutierrez.asier@huawei-partners.com> wrote:
> 
>> From: Asier Gutierrez <gutierrez.asier@huawei-partners.com>
>>
>> * Support for huge pages collapse, which will be used by
>>   dynamic_hugepages module.
>>
>> * Include the new module for compilation
>>
>> Signed-off-by: Asier Gutierrez <gutierrez.asier@huawei-partners.com>
>> Co-developed-by: Anatoly Stepanov <stepanov.anatoly@huawei.com>
>> ---
>>  include/linux/damon.h | 1 +
>>  mm/damon/Kconfig      | 7 +++++++
>>  mm/damon/Makefile     | 1 +
>>  mm/damon/vaddr.c      | 3 +++
>>  4 files changed, 12 insertions(+)
>>
>> diff --git a/include/linux/damon.h b/include/linux/damon.h
>> index 3813373a9200..de5a994f92c2 100644
>> --- a/include/linux/damon.h
>> +++ b/include/linux/damon.h
>> @@ -142,6 +142,7 @@ enum damos_action {
>>  	DAMOS_LRU_DEPRIO,
>>  	DAMOS_MIGRATE_HOT,
>>  	DAMOS_MIGRATE_COLD,
>> +	DAMOS_COLLAPSE,
> 
> Please update the kernel-doc comments for this new action, by the time you drop
> the RFC tag from this patch series.
> 
>>  	DAMOS_STAT,		/* Do nothing but only record the stat */
>>  	NR_DAMOS_ACTIONS,
>>  };
>> diff --git a/mm/damon/Kconfig b/mm/damon/Kconfig
>> index 8c868f7035fc..2355aacb6d12 100644
>> --- a/mm/damon/Kconfig
>> +++ b/mm/damon/Kconfig
>> @@ -110,4 +110,11 @@ config DAMON_STAT_ENABLED_DEFAULT
>>  	  Whether to enable DAMON_STAT by default.  Users can disable it in
>>  	  boot or runtime using its 'enabled' parameter.
>>  
>> +config DAMON_HOT_HUGEPAGE
>> +	bool "Build DAMON-based collapse of hot regions (DAMON_HOT_HUGEPAGES)"
>> +	depends on DAMON_VADDR
>> +	help
>> +	 Collapse hot region into huge pages. Hot regions are determined by
>> +	 DAMON-based sampling
>> +
> 
> Apparently you wanted to introduce the above change on the next patch, but
> mistakenly added here?
> 
> I'm also feeling the name might be better to be simpler.  What about... say,
> just DAMON_HUGEPAGE?  We might want to extend that for general access-aware
> huge pages.

I will move the build stuff into a different commit for the next RFC series.

I agree with the name change, I will do it.

>>  endmenu
>> diff --git a/mm/damon/Makefile b/mm/damon/Makefile
>> index d8d6bf5f8bff..998bddc17819 100644
>> --- a/mm/damon/Makefile
>> +++ b/mm/damon/Makefile
>> @@ -7,3 +7,4 @@ obj-$(CONFIG_DAMON_SYSFS)	+= sysfs-common.o sysfs-schemes.o sysfs.o
>>  obj-$(CONFIG_DAMON_RECLAIM)	+= modules-common.o reclaim.o
>>  obj-$(CONFIG_DAMON_LRU_SORT)	+= modules-common.o lru_sort.o
>>  obj-$(CONFIG_DAMON_STAT)	+= modules-common.o stat.o
>> +obj-$(CONFIG_DAMON_HOT_HUGEPAGE)	+= modules-common.o dynamic_hugepages.o
> 
> Ditto.
> 
>> diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c
>> index 23ed738a0bd6..4acbc1a6a5be 100644
>> --- a/mm/damon/vaddr.c
>> +++ b/mm/damon/vaddr.c
>> @@ -970,6 +970,9 @@ static unsigned long damon_va_apply_scheme(struct damon_ctx *ctx,
>>  	case DAMOS_NOHUGEPAGE:
>>  		madv_action = MADV_NOHUGEPAGE;
>>  		break;
>> +	case DAMOS_COLLAPSE:
>> +		madv_action = MADV_COLLAPSE;
>> +		break;
>>  	case DAMOS_MIGRATE_HOT:
>>  	case DAMOS_MIGRATE_COLD:
>>  		return damos_va_migrate(t, r, scheme, sz_filter_passed);
>> -- 
>> 2.43.0
> 
> 
> Thanks,
> SJ
> 
> [...]
> 

-- 
Asier Gutierrez
Huawei

Patchew 2.1-devel-b67e4c2

© 2016 - 2026 Red Hat, Inc.