mm/damon/core: introduce damon_filter

Define a data structure for constructing damon_probe's attributes check,
namely damon_filter.  It is very similar to damos_filter but works only
for monitoring purposes.  Also embed that into damon_probe, implement
essential handling of the link, with fundamental helpers.

Link: https://lore.kernel.org/20260518234119.97569-4-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/damon.h b/include/linux/damon.h
index 43d71eb24ccb6a5b32a5f58c593390af39617139..f8b679dd944d97a2087a06547924afec0c232526 100644 (file)
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -730,12 +730,38 @@ struct damon_intervals_goal {
        unsigned long max_sample_us;
 };
 
+/**
+ * enum damon_filter_type - Type of &struct damon_filter
+ *
+ * @DAMON_FILTER_TYPE_ANON:    Anonymous pages.
+ */
+enum damon_filter_type {
+       DAMON_FILTER_TYPE_ANON,
+};
+
+/**
+ * struct damon_filter - DAMON region filter for &struct damon_probe.
+ *
+ * @type:      Type of the region.
+ * @matching:  Whether this filter is for the type-matching ones.
+ * @allow:     Whether the @type-@matching ones should pass this filter.
+ * @list:      Siblings list.
+ */
+struct damon_filter {
+       enum damon_filter_type type;
+       bool matching;
+       bool allow;
+       struct list_head list;
+};
+
 /**
  * struct damon_probe - Data region attribute probe.
  *
+ * @filters:   Filters for assessing if a given region is for this probe.
  * @list:      Siblings list.
  */
 struct damon_probe {
+       struct list_head filters;
        struct list_head list;
 };
 
@@ -910,6 +936,12 @@ static inline unsigned long damon_sz_region(struct damon_region *r)
        return r->ar.end - r->ar.start;
 }
 
+#define damon_for_each_filter(f, p) \
+       list_for_each_entry(f, &(p)->filters, list)
+
+#define damon_for_each_filter_safe(f, next, p) \
+       list_for_each_entry_safe(f, next, &(p)->filters, list)
+
 #define damon_for_each_probe(p, ctx) \
        list_for_each_entry(p, &(ctx)->probes, list)
 
@@ -957,6 +989,10 @@ static inline unsigned long damon_sz_region(struct damon_region *r)
 
 #ifdef CONFIG_DAMON
 
+struct damon_filter *damon_new_filter(enum damon_filter_type type,
+               bool matching, bool allow);
+void damon_add_filter(struct damon_probe *probe, struct damon_filter *f);
+
 struct damon_probe *damon_new_probe(void);
 void damon_add_probe(struct damon_ctx *ctx, struct damon_probe *probe);
 

diff --git a/mm/damon/core.c b/mm/damon/core.c
index 8a55cc61d2972b4984cc3455dfa98ff6d2d63a75..d01417955a3b4130c61483023b657b0f7cd2be1d 100644 (file)
--- a/mm/damon/core.c
+++ b/mm/damon/core.c
@@ -113,6 +113,31 @@ int damon_select_ops(struct damon_ctx *ctx, enum damon_ops_id id)
        return err;
 }
 
+struct damon_filter *damon_new_filter(enum damon_filter_type type,
+               bool matching, bool allow)
+{
+       struct damon_filter *filter;
+
+       filter = kmalloc_obj(*filter);
+       if (!filter)
+               return NULL;
+       filter->type = type;
+       filter->matching = matching;
+       filter->allow = allow;
+       INIT_LIST_HEAD(&filter->list);
+       return filter;
+}
+
+void damon_add_filter(struct damon_probe *p, struct damon_filter *f)
+{
+       list_add_tail(&f->list, &p->filters);
+}
+
+static void damon_free_filter(struct damon_filter *f)
+{
+       kfree(f);
+}
+
 struct damon_probe *damon_new_probe(void)
 {
        struct damon_probe *p;
@@ -120,6 +145,7 @@ struct damon_probe *damon_new_probe(void)
        p = kmalloc_obj(*p);
        if (!p)
                return NULL;
+       INIT_LIST_HEAD(&p->filters);
        INIT_LIST_HEAD(&p->list);
        return p;
 }
@@ -136,6 +162,10 @@ static void damon_del_probe(struct damon_probe *p)
 
 static void damon_free_probe(struct damon_probe *p)
 {
+       struct damon_filter *f, *next;
+
+       damon_for_each_filter_safe(f, next, p)
+               damon_free_filter(f);
        kfree(p);
 }