* [PATCH 1/2] mm/damon/lru_sort: support addr_unit for DAMON_LRU_SORT
2025-09-10 11:32 [PATCH 0/2] mm/damon: add addr_unit for DAMON_LRU_SORT and DAMON_RECLAIM Quanmin Yan
@ 2025-09-10 11:32 ` Quanmin Yan
2025-09-11 2:19 ` SeongJae Park
2025-09-10 11:32 ` [PATCH 2/2] mm/damon/reclaim: support addr_unit for DAMON_RECLAIM Quanmin Yan
1 sibling, 1 reply; 5+ messages in thread
From: Quanmin Yan @ 2025-09-10 11:32 UTC (permalink / raw)
To: sj
Cc: akpm, damon, linux-kernel, linux-mm, yanquanmin1,
wangkefeng.wang, zuoze1
Implement a sysfs file to expose addr_unit for DAMON_LRU_SORT
users. During parameter application, use the configured
addr_unit parameter to perform the necessary initialization.
Similar to the core layer, prevent setting addr_unit to zero.
It is worth noting that when monitor_region_start and
monitor_region_end are unset (i.e., 0), their values will
later be set to biggest_system_ram. At that point, addr_unit
may not be the default value 1. Although we could divide the
biggest_system_ram value by addr_unit, changing addr_unit
without setting monitor_region_start/end should be considered
a user misoperation. And biggest_system_ram is only within
the 0~ULONG_MAX range, system can clearly work correctly with
addr_unit=1. Therefore, if monitor_region_start/end are unset,
always silently reset addr_unit to 1.
Signed-off-by: Quanmin Yan <yanquanmin1@huawei.com>
---
mm/damon/lru_sort.c | 40 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 40 insertions(+)
diff --git a/mm/damon/lru_sort.c b/mm/damon/lru_sort.c
index b5a5ed16a7a5..14d31009c09e 100644
--- a/mm/damon/lru_sort.c
+++ b/mm/damon/lru_sort.c
@@ -111,6 +111,13 @@ module_param(monitor_region_start, ulong, 0600);
static unsigned long monitor_region_end __read_mostly;
module_param(monitor_region_end, ulong, 0600);
+/*
+ * Scale factor for DAMON_LRU_SORT to ops address conversion.
+ *
+ * This parameter must not be set to 0.
+ */
+static unsigned long addr_unit __read_mostly = 1;
+
/*
* PID of the DAMON thread
*
@@ -198,6 +205,15 @@ static int damon_lru_sort_apply_parameters(void)
if (err)
return err;
+ /*
+ * If monitor_region_start/end are unset, always silently
+ * reset addr_unit to 1.
+ */
+ if (!monitor_region_start && !monitor_region_end)
+ addr_unit = 1;
+ param_ctx->addr_unit = addr_unit;
+ param_ctx->min_sz_region = max(DAMON_MIN_REGION / addr_unit, 1);
+
if (!damon_lru_sort_mon_attrs.sample_interval) {
err = -EINVAL;
goto out;
@@ -290,6 +306,30 @@ static int damon_lru_sort_turn(bool on)
return damon_call(ctx, &call_control);
}
+static int damon_lru_sort_addr_unit_store(const char *val,
+ const struct kernel_param *kp)
+{
+ unsigned long input_addr_unit;
+ int err = kstrtoul(val, 0, &input_addr_unit);
+
+ if (err)
+ return err;
+ if (!input_addr_unit)
+ return -EINVAL;
+
+ addr_unit = input_addr_unit;
+ return 0;
+}
+
+static const struct kernel_param_ops addr_unit_param_ops = {
+ .set = damon_lru_sort_addr_unit_store,
+ .get = param_get_ulong,
+};
+
+module_param_cb(addr_unit, &addr_unit_param_ops, &addr_unit, 0600);
+MODULE_PARM_DESC(addr_unit,
+ "Scale factor for DAMON_LRU_SORT to ops address conversion (default: 1)");
+
static int damon_lru_sort_enabled_store(const char *val,
const struct kernel_param *kp)
{
--
2.43.0
^ permalink raw reply [flat|nested] 5+ messages in thread* [PATCH 2/2] mm/damon/reclaim: support addr_unit for DAMON_RECLAIM
2025-09-10 11:32 [PATCH 0/2] mm/damon: add addr_unit for DAMON_LRU_SORT and DAMON_RECLAIM Quanmin Yan
2025-09-10 11:32 ` [PATCH 1/2] mm/damon/lru_sort: support addr_unit for DAMON_LRU_SORT Quanmin Yan
@ 2025-09-10 11:32 ` Quanmin Yan
2025-09-11 2:20 ` SeongJae Park
1 sibling, 1 reply; 5+ messages in thread
From: Quanmin Yan @ 2025-09-10 11:32 UTC (permalink / raw)
To: sj
Cc: akpm, damon, linux-kernel, linux-mm, yanquanmin1,
wangkefeng.wang, zuoze1
Implement a sysfs file to expose addr_unit for DAMON_RECLAIM
users. During parameter application, use the configured
addr_unit parameter to perform the necessary initialization.
Similar to the core layer, prevent setting addr_unit to zero.
It is worth noting that when monitor_region_start and
monitor_region_end are unset (i.e., 0), their values will
later be set to biggest_system_ram. At that point, addr_unit
may not be the default value 1. Although we could divide the
biggest_system_ram value by addr_unit, changing addr_unit
without setting monitor_region_start/end should be considered
a user misoperation. And biggest_system_ram is only within
the 0~ULONG_MAX range, system can clearly work correctly with
addr_unit=1. Therefore, if monitor_region_start/end are unset,
always silently reset addr_unit to 1.
Signed-off-by: Quanmin Yan <yanquanmin1@huawei.com>
---
mm/damon/reclaim.c | 40 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 40 insertions(+)
diff --git a/mm/damon/reclaim.c b/mm/damon/reclaim.c
index fb7c982a0018..590f9d6c55ef 100644
--- a/mm/damon/reclaim.c
+++ b/mm/damon/reclaim.c
@@ -128,6 +128,13 @@ module_param(monitor_region_start, ulong, 0600);
static unsigned long monitor_region_end __read_mostly;
module_param(monitor_region_end, ulong, 0600);
+/*
+ * Scale factor for DAMON_RECLAIM to ops address conversion.
+ *
+ * This parameter must not be set to 0.
+ */
+static unsigned long addr_unit __read_mostly = 1;
+
/*
* Skip anonymous pages reclamation.
*
@@ -194,6 +201,15 @@ static int damon_reclaim_apply_parameters(void)
if (err)
return err;
+ /*
+ * If monitor_region_start/end are unset, always silently
+ * reset addr_unit to 1.
+ */
+ if (!monitor_region_start && !monitor_region_end)
+ addr_unit = 1;
+ param_ctx->addr_unit = addr_unit;
+ param_ctx->min_sz_region = max(DAMON_MIN_REGION / addr_unit, 1);
+
if (!damon_reclaim_mon_attrs.aggr_interval) {
err = -EINVAL;
goto out;
@@ -294,6 +310,30 @@ static int damon_reclaim_turn(bool on)
return damon_call(ctx, &call_control);
}
+static int damon_reclaim_addr_unit_store(const char *val,
+ const struct kernel_param *kp)
+{
+ unsigned long input_addr_unit;
+ int err = kstrtoul(val, 0, &input_addr_unit);
+
+ if (err)
+ return err;
+ if (!input_addr_unit)
+ return -EINVAL;
+
+ addr_unit = input_addr_unit;
+ return 0;
+}
+
+static const struct kernel_param_ops addr_unit_param_ops = {
+ .set = damon_reclaim_addr_unit_store,
+ .get = param_get_ulong,
+};
+
+module_param_cb(addr_unit, &addr_unit_param_ops, &addr_unit, 0600);
+MODULE_PARM_DESC(addr_unit,
+ "Scale factor for DAMON_RECLAIM to ops address conversion (default: 1)");
+
static int damon_reclaim_enabled_store(const char *val,
const struct kernel_param *kp)
{
--
2.43.0
^ permalink raw reply [flat|nested] 5+ messages in thread