Commit 7db551fc authored by Quanmin Yan's avatar Quanmin Yan Committed by Andrew Morton
Browse files

mm/damon/reclaim: support addr_unit for DAMON_RECLAIM 

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.

Link: https://lkml.kernel.org/r/20250910113221.1065764-3-yanquanmin1@huawei.com


Signed-off-by: default avatarQuanmin Yan <yanquanmin1@huawei.com>
Reviewed-by: default avatarSeongJae Park <sj@kernel.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: ze zuo <zuoze1@huawei.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 2e0fe924

mm/damon/reclaim.c

+40 −0
Original line number Diff line number Diff line
@@ -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)

{