On 20/01/2025 18:57, David Hildenbrand wrote:
> On 20.01.25 19:19, Usama Arif wrote:
>> This is to gather statistics to check if memory regions of specific
>> access tempratures are backed by hugepages. This includes both THPs
>> and hugetlbfs.
>> This filter can help to observe and prove the effectivenes of
>> different schemes for shrinking/collapsing hugepages.
>>
>> Signed-off-by: Usama Arif <usamaarif642@xxxxxxxxx>
>> ---
>> v2 -> v3:
>> - expose hugepage via sysfs even if the kernel is
>> built without hugepage support. DAMON will just
>> just return 0. (SJ Park)
>>
>> v1 -> v2:
>> - Wrap DAMOS_FILTER_TYPE_HUGEPAGE case with
>> CONFIG_PGTABLE_HAS_HUGE_LEAVES (SJ Park)
>> ---
>> include/linux/damon.h | 2 ++
>> mm/damon/paddr.c | 5 +++++
>> mm/damon/sysfs-schemes.c | 1 +
>> 3 files changed, 8 insertions(+)
>>
>> diff --git a/include/linux/damon.h b/include/linux/damon.h
>> index af525252b853..1d94d7d88b36 100644
>> --- a/include/linux/damon.h
>> +++ b/include/linux/damon.h
>> @@ -326,6 +326,7 @@ struct damos_stat {
>> * @DAMOS_FILTER_TYPE_ANON: Anonymous pages.
>> * @DAMOS_FILTER_TYPE_MEMCG: Specific memcg's pages.
>> * @DAMOS_FILTER_TYPE_YOUNG: Recently accessed pages.
>> + * @DAMOS_FILTER_TYPE_HUGEPAGE: Page is part of a hugepage.
>> * @DAMOS_FILTER_TYPE_ADDR: Address range.
>> * @DAMOS_FILTER_TYPE_TARGET: Data Access Monitoring target.
>> * @NR_DAMOS_FILTER_TYPES: Number of filter types.
>> @@ -345,6 +346,7 @@ enum damos_filter_type {
>> DAMOS_FILTER_TYPE_ANON,
>> DAMOS_FILTER_TYPE_MEMCG,
>> DAMOS_FILTER_TYPE_YOUNG,
>> + DAMOS_FILTER_TYPE_HUGEPAGE,
>> DAMOS_FILTER_TYPE_ADDR,
>> DAMOS_FILTER_TYPE_TARGET,
>> NR_DAMOS_FILTER_TYPES,
>> diff --git a/mm/damon/paddr.c b/mm/damon/paddr.c
>> index c0ccf4fade24..224308140441 100644
>> --- a/mm/damon/paddr.c
>> +++ b/mm/damon/paddr.c
>> @@ -222,6 +222,11 @@ static bool damos_pa_filter_match(struct damos_filter *filter,
>> if (matched)
>> damon_folio_mkold(folio);
>> break;
>> +#if defined(CONFIG_PGTABLE_HAS_HUGE_LEAVES)
>> + case DAMOS_FILTER_TYPE_HUGEPAGE:
>> + matched = folio_size(folio) == HPAGE_PMD_SIZE;
>
>
> Can we directly embed in the name and the comments/docs that we are only talking about PMD size (both, THP and hugetlb)?
>
> DAMOS_FILTER_TYPE_PMD_HUGEPAGE or sth. like that.
>
>
I always think of gigantic page as PUD size, hugepage as PMD size (and not anything smaller), mTHP as smaller than PMD :)
But I don't think thats the official term or standardized across the kernel.
I can send a v4, or maybe Andrew could apply the diff below?
diff --git a/include/linux/damon.h b/include/linux/damon.h
index 1d94d7d88b36..261c0741dd0f 100644
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -326,7 +326,7 @@ struct damos_stat {
* @DAMOS_FILTER_TYPE_ANON: Anonymous pages.
* @DAMOS_FILTER_TYPE_MEMCG: Specific memcg's pages.
* @DAMOS_FILTER_TYPE_YOUNG: Recently accessed pages.
- * @DAMOS_FILTER_TYPE_HUGEPAGE: Page is part of a hugepage.
+ * @DAMOS_FILTER_TYPE_PMD_HUGEPAGE: Page is part of a hugepage (THP/hugetlb).
* @DAMOS_FILTER_TYPE_ADDR: Address range.
* @DAMOS_FILTER_TYPE_TARGET: Data Access Monitoring target.
* @NR_DAMOS_FILTER_TYPES: Number of filter types.
@@ -346,7 +346,7 @@ enum damos_filter_type {
DAMOS_FILTER_TYPE_ANON,
DAMOS_FILTER_TYPE_MEMCG,
DAMOS_FILTER_TYPE_YOUNG,
- DAMOS_FILTER_TYPE_HUGEPAGE,
+ DAMOS_FILTER_TYPE_PMD_HUGEPAGE,
DAMOS_FILTER_TYPE_ADDR,
DAMOS_FILTER_TYPE_TARGET,
NR_DAMOS_FILTER_TYPES,
diff --git a/mm/damon/paddr.c b/mm/damon/paddr.c
index 224308140441..e374ea952308 100644
--- a/mm/damon/paddr.c
+++ b/mm/damon/paddr.c
@@ -223,7 +223,7 @@ static bool damos_pa_filter_match(struct damos_filter *filter,
damon_folio_mkold(folio);
break;
#if defined(CONFIG_PGTABLE_HAS_HUGE_LEAVES)
- case DAMOS_FILTER_TYPE_HUGEPAGE:
+ case DAMOS_FILTER_TYPE_PMD_HUGEPAGE:
matched = folio_size(folio) == HPAGE_PMD_SIZE;
break;
#endif
