mm/damon/lru_sort: cover all system rams

DAMON_LRU_SORT allows users to set the physical address range to monitor
and do the work on.  When users don't explicitly set the range, the
biggest system ram resource of the system is selected as the monitoring
target address range.  The intention was to reduce the overhead from
monitoring non-System RAM areas because monitoring non-System RAM may be
meaningless.  However, because of the sampling based access check and
adaptive regions adjustment, the overhead should be negligible.  It makes
more sense to just cover all system rams of the system.  Do so.

Link: https://lore.kernel.org/20260429041232.90257-4-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: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.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/mm/damon/lru_sort.c b/mm/damon/lru_sort.c
index 7569e471160a0dde8560220727cc6c2d68fef91b..2eb559d913b62224f3a4ff887196e54d990f9dc6 100644 (file)
--- a/mm/damon/lru_sort.c
+++ b/mm/damon/lru_sort.c
@@ -139,7 +139,8 @@ DEFINE_DAMON_MODULES_MON_ATTRS_PARAMS(damon_lru_sort_mon_attrs);
  * Start of the target memory region in physical address.
  *
  * The start physical address of memory region that DAMON_LRU_SORT will do work
- * against.  By default, biggest System RAM is used as the region.
+ * against.  By default, the system's entire physical memory is used as the
+ * region.
  */
 static unsigned long monitor_region_start __read_mostly;
 module_param(monitor_region_start, ulong, 0600);
@@ -148,7 +149,8 @@ module_param(monitor_region_start, ulong, 0600);
  * End of the target memory region in physical address.
  *
  * The end physical address of memory region that DAMON_LRU_SORT will do work
- * against.  By default, biggest System RAM is used as the region.
+ * against.  By default, the system's entire physical memory is used as the
+ * region.
  */
 static unsigned long monitor_region_end __read_mostly;
 module_param(monitor_region_end, ulong, 0600);
@@ -326,7 +328,7 @@ static int damon_lru_sort_apply_parameters(void)
        if (err)
                goto out;
 
-       err = damon_set_region_biggest_system_ram_default(param_target,
+       err = damon_set_region_system_rams_default(param_target,
                                        &monitor_region_start,
                                        &monitor_region_end,
                                        param_ctx->addr_unit,