From 3b23a44f1f196741596616082e759f7f3a400e78 Mon Sep 17 00:00:00 2001 From: Nhat Pham Date: Tue, 18 Mar 2025 11:30:28 -0700 Subject: [PATCH] mm/damon: implement a new DAMOS filter type for active pages Patch series "mm/damon: introduce DAMOS filter type for active pages". The memory reclaim algorithm categorizes pages into active and inactive lists, separately for file and anon pages. The system's performance relies heavily on the (relative and absolute) accuracy of this categorization. This patch series add a new DAMOS filter for pages' activeness, giving us visibility into the access frequency of the pages on each list. This insight can help us diagnose issues with the active-inactive balancing dynamics, and make decisions to optimize reclaim efficiency and memory utilization. For instance, we might decide to enable DAMON_LRU_SORT, if we find that there are pages on the active list that are infrequently accessed, or less frequently accessed than pages on the inactive list. This patch (of 2): Implement a DAMOS filter type for active pages on DAMON kernel API, and add support of it from the physical address space DAMON operations set (paddr). Link: https://lkml.kernel.org/r/20250318183029.2062917-1-nphamcs@gmail.com Link: https://lkml.kernel.org/r/20250318183029.2062917-2-nphamcs@gmail.com Signed-off-by: Nhat Pham Suggested-by: SeongJae Park Reviewed-by: SeongJae Park Signed-off-by: Andrew Morton --- include/linux/damon.h | 2 ++ mm/damon/paddr.c | 3 +++ mm/damon/sysfs-schemes.c | 1 + 3 files changed, 6 insertions(+) diff --git a/include/linux/damon.h b/include/linux/damon.h index 3db4f77261f5..47e36e6ea203 100644 --- a/include/linux/damon.h +++ b/include/linux/damon.h @@ -334,6 +334,7 @@ struct damos_stat { /** * enum damos_filter_type - Type of memory for &struct damos_filter * @DAMOS_FILTER_TYPE_ANON: Anonymous pages. + * @DAMOS_FILTER_TYPE_ACTIVE: Active 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. @@ -355,6 +356,7 @@ struct damos_stat { */ enum damos_filter_type { DAMOS_FILTER_TYPE_ANON, + DAMOS_FILTER_TYPE_ACTIVE, DAMOS_FILTER_TYPE_MEMCG, DAMOS_FILTER_TYPE_YOUNG, DAMOS_FILTER_TYPE_HUGEPAGE_SIZE, diff --git a/mm/damon/paddr.c b/mm/damon/paddr.c index b08847ef9b81..1b70d3f36046 100644 --- a/mm/damon/paddr.c +++ b/mm/damon/paddr.c @@ -217,6 +217,9 @@ static bool damos_pa_filter_match(struct damos_filter *filter, case DAMOS_FILTER_TYPE_ANON: matched = folio_test_anon(folio); break; + case DAMOS_FILTER_TYPE_ACTIVE: + matched = folio_test_active(folio); + break; case DAMOS_FILTER_TYPE_MEMCG: rcu_read_lock(); memcg = folio_memcg_check(folio); diff --git a/mm/damon/sysfs-schemes.c b/mm/damon/sysfs-schemes.c index 5023f2b690d6..23b562df0839 100644 --- a/mm/damon/sysfs-schemes.c +++ b/mm/damon/sysfs-schemes.c @@ -344,6 +344,7 @@ static struct damon_sysfs_scheme_filter *damon_sysfs_scheme_filter_alloc( /* Should match with enum damos_filter_type */ static const char * const damon_sysfs_scheme_filter_type_strs[] = { "anon", + "active", "memcg", "young", "hugepage_size",