Commit e035c280 authored by SeongJae Park's avatar SeongJae Park Committed by Andrew Morton
Browse files

mm/damon/reclaim: support online inputs update 

DAMON_RECLAIM reads the user input parameters only when it starts.  To
allow more efficient online tuning, this commit implements a new input
parameter called 'commit_inputs'.  Writing true to the parameter makes
DAMON_RECLAIM reads the input parameters again.

Link: https://lkml.kernel.org/r/20220429160606.127307-14-sj@kernel.org


Signed-off-by: default avatarSeongJae Park <sj@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent adc286e6

mm/damon/reclaim.c

+62 −33
Original line number Diff line number Diff line
@@ -29,6 +29,18 @@ 
 */

static bool enabled __read_mostly;



/*

 * Make DAMON_RECLAIM reads the input parameters again, except ``enabled``.

 *

 * Input parameters that updated while DAMON_RECLAIM is running are not applied

 * by default.  Once this parameter is set as ``Y``, DAMON_RECLAIM reads values

 * of parametrs except ``enabled`` again.  Once the re-reading is done, this

 * parameter is set as ``N``.  If invalid parameters are found while the

 * re-reading, DAMON_RECLAIM will be disabled.

 */

static bool commit_inputs __read_mostly;

module_param(commit_inputs, bool, 0600);



/*

 * Time threshold for cold memory regions identification in microseconds.

 *
@@ -289,59 +301,58 @@ static struct damos *damon_reclaim_new_scheme(void) 
	return scheme;

}



static int damon_reclaim_turn(bool on)

static int damon_reclaim_apply_parameters(void)

{

	struct damon_region *region;

	struct damos *scheme;

	int err;



	if (!on) {

		err = damon_stop(&ctx, 1);

		if (!err)

			kdamond_pid = -1;

		return err;

	}

	struct damon_addr_range addr_range;

	int err = 0;



	err = damon_set_attrs(ctx, sample_interval, aggr_interval, 0,

			min_nr_regions, max_nr_regions);

	if (err)

		return err;



	/* Will be freed by next 'damon_set_schemes()' below */

	scheme = damon_reclaim_new_scheme();

	if (!scheme)

		return -ENOMEM;

	err = damon_set_schemes(ctx, &scheme, 1);

	if (err)

		return err;



	if (monitor_region_start > monitor_region_end)

		return -EINVAL;

	if (!monitor_region_start && !monitor_region_end &&

			!get_monitoring_region(&monitor_region_start,

				&monitor_region_end))

		return -EINVAL;

	/* DAMON will free this on its own when finish monitoring */

	region = damon_new_region(monitor_region_start, monitor_region_end);

	if (!region)

		return -ENOMEM;

	damon_add_region(region, target);

	addr_range.start = monitor_region_start;

	addr_range.end = monitor_region_end;

	return damon_set_regions(target, &addr_range, 1);

}



	/* Will be freed by 'damon_set_schemes()' below */

	scheme = damon_reclaim_new_scheme();

	if (!scheme) {

		err = -ENOMEM;

		goto free_region_out;

static int damon_reclaim_turn(bool on)

{

	int err;



	if (!on) {

		err = damon_stop(&ctx, 1);

		if (!err)

			kdamond_pid = -1;

		return err;

	}

	err = damon_set_schemes(ctx, &scheme, 1);



	err = damon_reclaim_apply_parameters();

	if (err)

		goto free_scheme_out;

		return err;



	err = damon_start(&ctx, 1, true);

	if (!err) {

	if (err)

		return err;

	kdamond_pid = ctx->kdamond->pid;

	return 0;

}



free_scheme_out:

	damon_destroy_scheme(scheme);

free_region_out:

	damon_destroy_region(region, target);

	return err;

}



#define ENABLE_CHECK_INTERVAL_MS	1000

static struct delayed_work damon_reclaim_timer;

static void damon_reclaim_timer_fn(struct work_struct *work)
@@ -389,6 +400,7 @@ MODULE_PARM_DESC(enabled, 
static int damon_reclaim_after_aggregation(struct damon_ctx *c)

{

	struct damos *s;

	int err = 0;



	/* update the stats parameter */

	damon_for_each_scheme(s, c) {
@@ -398,7 +410,23 @@ static int damon_reclaim_after_aggregation(struct damon_ctx *c) 
		bytes_reclaimed_regions = s->stat.sz_applied;

		nr_quota_exceeds = s->stat.qt_exceeds;

	}

	return 0;



	if (commit_inputs) {

		err = damon_reclaim_apply_parameters();

		commit_inputs = false;

	}

	return err;

}



static int damon_reclaim_after_wmarks_check(struct damon_ctx *c)

{

	int err = 0;



	if (commit_inputs) {

		err = damon_reclaim_apply_parameters();

		commit_inputs = false;

	}

	return err;

}



static int __init damon_reclaim_init(void)
@@ -410,6 +438,7 @@ static int __init damon_reclaim_init(void) 
	if (damon_select_ops(ctx, DAMON_OPS_PADDR))

		return -EINVAL;



	ctx->callback.after_wmarks_check = damon_reclaim_after_wmarks_check;

	ctx->callback.after_aggregation = damon_reclaim_after_aggregation;



	target = damon_new_target();