mm/damon: introduce DAMOS filter type hugepage_size

Patch series "mm/damon: add support for hugepage_size DAMOS filter", v5.

hugepage_size DAMOS filter can be used to gather statistics to check if
memory regions of specific access tempratures are backed by hugepages of a
size in a specific range.  This filter can help to observe and prove the
effectivenes of different schemes for shrinking/collapsing hugepages.

This patch (of 4):

This is to gather statistics to check if memory regions of specific access
tempratures are backed by pages of a size in a specific range.  This
filter can help to observe and prove the effectivenes of different schemes
for shrinking/collapsing hugepages.

Link: https://lkml.kernel.org/r/20250211124437.278873-1-usamaarif642@gmail.com
Link: https://lkml.kernel.org/r/20250211124437.278873-2-usamaarif642@gmail.com
Signed-off-by: Usama Arif <usamaarif642@gmail.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Usama Arif <usamaarif642@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/damon.h b/include/linux/damon.h
index a390af84cf0f51221bd113aa8e48b88a2bbc81bf..0adfc2f4ca754c6a1d9a955d0950e51f22f99604 100644 (file)
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -35,6 +35,16 @@ struct damon_addr_range {
        unsigned long end;
 };
 
+/**
+ * struct damon_size_range - Represents size for filter to operate on [@min, @max].
+ * @min:       Min size (inclusive).
+ * @max:       Max size (inclusive).
+ */
+struct damon_size_range {
+       unsigned long min;
+       unsigned long max;
+};
+
 /**
  * struct damon_region - Represents a monitoring target region.
  * @ar:                        The address range of the region.
@@ -326,6 +336,7 @@ 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_SIZE:   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 +356,7 @@ enum damos_filter_type {
        DAMOS_FILTER_TYPE_ANON,
        DAMOS_FILTER_TYPE_MEMCG,
        DAMOS_FILTER_TYPE_YOUNG,
+       DAMOS_FILTER_TYPE_HUGEPAGE_SIZE,
        DAMOS_FILTER_TYPE_ADDR,
        DAMOS_FILTER_TYPE_TARGET,
        NR_DAMOS_FILTER_TYPES,
@@ -376,6 +388,7 @@ struct damos_filter {
                unsigned short memcg_id;
                struct damon_addr_range addr_range;
                int target_idx;
+               struct damon_size_range sz_range;
        };
        struct list_head list;
 };

diff --git a/mm/damon/core.c b/mm/damon/core.c
index c3d9b96b786aa82af88236993d3b6d5eb89268fc..38f545fea5858edb01e124894ba17bc87db831b7 100644 (file)
--- a/mm/damon/core.c
+++ b/mm/damon/core.c
@@ -776,6 +776,9 @@ static void damos_commit_filter_arg(
        case DAMOS_FILTER_TYPE_TARGET:
                dst->target_idx = src->target_idx;
                break;
+       case DAMOS_FILTER_TYPE_HUGEPAGE_SIZE:
+               dst->sz_range = src->sz_range;
+               break;
        default:
                break;
        }

diff --git a/mm/damon/paddr.c b/mm/damon/paddr.c
index c33b91c7596018de39aa8f1abd72a896fec1a275..9f03e1980b8da8d71278337738e58b9bfa78ffe6 100644 (file)
--- a/mm/damon/paddr.c
+++ b/mm/damon/paddr.c
@@ -211,6 +211,7 @@ static bool damos_pa_filter_match(struct damos_filter *filter,
 {
        bool matched = false;
        struct mem_cgroup *memcg;
+       size_t folio_sz;
 
        switch (filter->type) {
        case DAMOS_FILTER_TYPE_ANON:
@@ -230,6 +231,11 @@ static bool damos_pa_filter_match(struct damos_filter *filter,
                if (matched)
                        damon_folio_mkold(folio);
                break;
+       case DAMOS_FILTER_TYPE_HUGEPAGE_SIZE:
+               folio_sz = folio_size(folio);
+               matched = filter->sz_range.min <= folio_sz &&
+                         folio_sz <= filter->sz_range.max;
+               break;
        default:
                break;
        }

diff --git a/mm/damon/sysfs-schemes.c b/mm/damon/sysfs-schemes.c
index 98f93ae9f59e7d6419f048315b605b56331fcfb6..9020bc9befac4f6fe2afb2f93eecab8f06be4c41 100644 (file)
--- a/mm/damon/sysfs-schemes.c
+++ b/mm/damon/sysfs-schemes.c
@@ -329,6 +329,7 @@ static const char * const damon_sysfs_scheme_filter_type_strs[] = {
        "anon",
        "memcg",
        "young",
+       "hugepage_size",
        "addr",
        "target",
 };