On 20.01.25 20:18, Usama Arif wrote:
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 :)
And cont-PMD ... hugetlb, cont-PTE hugetlb ... are ? :)
But I don't think thats the official term or standardized across the kernel.
We didn't know better when we designed some of the old interfaces,
that's why I am hoping that we can do better with new interfaces. Either
spell out the PMD size, or have filters for size lists / size ranges.
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
--
Cheers,
David / dhildenb
