[RFC PATCH 04/19] mm/damon/core: commit probes

SeongJae Park
2026-04-26T20:52:36Z

Update damon_commit_ctx() to commit installed data probes, too.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
mm/damon/core.c | 104 ++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 104 insertions(+)

diff --git a/mm/damon/core.c b/mm/damon/core.c
index 170abba8fdf2a..2ab1d6dd47da4 100644
--- a/mm/damon/core.c
+++ b/mm/damon/core.c
@@ -129,11 +129,34 @@ void damon_add_filter(struct damon_probe *p, struct damon_filter *f)
list_add_tail(&f->list, &p->filters);
}

+static void damon_del_filter(struct damon_filter *f)
+{
+ list_del(&f->list);
+}
+
static void damon_free_filter(struct damon_filter *f)
{
kfree(f);
}

+static void damon_destroy_filter(struct damon_filter *f)
+{
+ damon_del_filter(f);
+ damon_free_filter(f);
+}
+
+static struct damon_filter *damon_nth_filter(int n, struct damon_probe *p)
+{
+ struct damon_filter *f;
+ int i = 0;
+
+ damon_for_each_filter(f, p) {
+ if (i++ == n)
+ return f;
+ }
+ return NULL;
+}
+
struct damon_probe *damon_new_probe(void)
{
struct damon_probe *p;
@@ -171,6 +194,18 @@ static void damon_destroy_probe(struct damon_probe *p)
damon_free_probe(p);
}

+static struct damon_probe *damon_nth_probe(int n, struct damon_ctx *ctx)
+{
+ struct damon_probe *p;
+ int i = 0;
+
+ damon_for_each_probe(p, ctx) {
+ if (i++ == n)
+ return p;
+ }
+ return NULL;
+}
+
#ifdef CONFIG_DAMON_DEBUG_SANITY
static void damon_verify_new_region(unsigned long start, unsigned long end)
{
@@ -1412,6 +1447,72 @@ static int damon_commit_targets(
return 0;
}

+static void damon_commit_filter(struct damon_filter *dst,
+ struct damon_filter *src)
+{
+ dst->type = src->type;
+ dst->matching = src->matching;
+ dst->allow = src->allow;
+}
+
+static int damon_commit_filters(struct damon_probe *dst,
+ struct damon_probe *src)
+{
+ struct damon_filter *dst_filter, *next, *src_filter, *new_filter;
+ int i = 0, j = 0;
+
+ damon_for_each_filter_safe(dst_filter, next, dst) {
+ src_filter = damon_nth_filter(i++, src);
+ if (src_filter)
+ damon_commit_filter(dst_filter, src_filter);
+ else
+ damon_destroy_filter(dst_filter);
+ }
+
+ damon_for_each_filter_safe(src_filter, next, src) {
+ if (j++ < i)
+ continue;
+
+ new_filter = damon_new_filter(src_filter->type,
+ src_filter->matching, src_filter->allow);
+ if (!new_filter)
+ return -ENOMEM;
+ damon_add_filter(dst, new_filter);
+ }
+ return 0;
+}
+
+static int damon_commit_probes(struct damon_ctx *dst, struct damon_ctx *src)
+{
+ struct damon_probe *dst_probe, *next, *src_probe, *new_probe;
+ int i = 0, j = 0, err;
+
+ damon_for_each_probe_safe(dst_probe, next, dst) {
+ src_probe = damon_nth_probe(i++, src);
+ if (src_probe) {
+ err = damon_commit_filters(dst_probe, src_probe);
+ if (err)
+ return err;
+ } else {
+ damon_destroy_probe(dst_probe);
+ }
+ }
+
+ damon_for_each_probe_safe(src_probe, next, src) {
+ if (j++ < i)
+ continue;
+
+ new_probe = damon_new_probe();
+ if (!new_probe)
+ return -ENOMEM;
+ damon_add_probe(dst, new_probe);
+ err = damon_commit_filters(new_probe, src_probe);
+ if (err)
+ return err;
+ }
+ return 0;
+}
+
/**
* damon_commit_ctx() - Commit parameters of a DAMON context to another.
* @dst: The commit destination DAMON context.
@@ -1453,6 +1554,9 @@ int damon_commit_ctx(struct damon_ctx *dst, struct damon_ctx *src)
}
dst->pause = src->pause;
dst->ops = src->ops;
+ err = damon_commit_probes(dst, src);
+ if (err)
+ return err;
dst->addr_unit = src->addr_unit;
dst->min_region_sz = src->min_region_sz;

--
2.47.3