Commit 772c15e5 authored by SeongJae Park's avatar SeongJae Park Committed by Andrew Morton
Browse files

mm/damon/sysfs-schemes: implement DAMOS-tried regions clear command 

When there are huge number of DAMON regions that specific scheme actions
are tried to be applied, directories and files under 'tried_regions'
scheme directory could waste some memory.  Add another special input
keyword ('clear_schemes_tried_regions') for 'state' file of each kdamond
sysfs directory that can be used for cleanup of the 'tried_regions'
sub-directories.

[sj@kernel.org: skip regions clearing if the scheme directory was removed]
  Link: https://lkml.kernel.org/r/20221114182954.4745-3-sj@kernel.org
Link: https://lkml.kernel.org/r/20221101220328.95765-6-sj@kernel.org


Signed-off-by: default avatarSeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent f1d13cac

mm/damon/sysfs-common.h

+4 −0
Original line number Diff line number Diff line
@@ -50,3 +50,7 @@ int damon_sysfs_schemes_update_regions_start( 
		struct damon_ctx *ctx);



int damon_sysfs_schemes_update_regions_stop(struct damon_ctx *ctx);



int damon_sysfs_schemes_clear_regions(

		struct damon_sysfs_schemes *sysfs_schemes,

		struct damon_ctx *ctx);

mm/damon/sysfs-schemes.c

+13 −1
Original line number Diff line number Diff line
@@ -1292,7 +1292,7 @@ static int damon_sysfs_before_damos_apply(struct damon_ctx *ctx, 
}



/* Called from damon_sysfs_cmd_request_callback under damon_sysfs_lock */

int damon_sysfs_schemes_update_regions_start(

int damon_sysfs_schemes_clear_regions(

		struct damon_sysfs_schemes *sysfs_schemes,

		struct damon_ctx *ctx)

{
@@ -1302,11 +1302,23 @@ int damon_sysfs_schemes_update_regions_start( 
	damon_for_each_scheme(scheme, ctx) {

		struct damon_sysfs_scheme *sysfs_scheme;



		/* user could have removed the scheme sysfs dir */

		if (schemes_idx >= sysfs_schemes->nr)

			break;



		sysfs_scheme = sysfs_schemes->schemes_arr[schemes_idx++];

		damon_sysfs_scheme_regions_rm_dirs(

				sysfs_scheme->tried_regions);

	}

	return 0;

}



/* Called from damon_sysfs_cmd_request_callback under damon_sysfs_lock */

int damon_sysfs_schemes_update_regions_start(

		struct damon_sysfs_schemes *sysfs_schemes,

		struct damon_ctx *ctx)

{

	damon_sysfs_schemes_clear_regions(sysfs_schemes, ctx);

	damon_sysfs_schemes_for_damos_callback = sysfs_schemes;

	ctx->callback.before_damos_apply = damon_sysfs_before_damos_apply;

	return 0;

mm/damon/sysfs.c

+20 −0
Original line number Diff line number Diff line
@@ -1004,6 +1004,11 @@ enum damon_sysfs_cmd { 
	 * regions

	 */

	DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_REGIONS,

	/*

	 * @DAMON_SYSFS_CMD_CLEAR_SCHEMES_TRIED_REGIONS: Clear schemes tried

	 * regions

	 */

	DAMON_SYSFS_CMD_CLEAR_SCHEMES_TRIED_REGIONS,

	/*

	 * @NR_DAMON_SYSFS_CMDS: Total number of DAMON sysfs commands.

	 */
@@ -1017,6 +1022,7 @@ static const char * const damon_sysfs_cmd_strs[] = { 
	"commit",

	"update_schemes_stats",

	"update_schemes_tried_regions",

	"clear_schemes_tried_regions",

};



/*
@@ -1262,6 +1268,17 @@ static int damon_sysfs_upd_schemes_regions_stop( 
	return damon_sysfs_schemes_update_regions_stop(ctx);

}



static int damon_sysfs_clear_schemes_regions(

		struct damon_sysfs_kdamond *kdamond)

{

	struct damon_ctx *ctx = kdamond->damon_ctx;



	if (!ctx)

		return -EINVAL;

	return damon_sysfs_schemes_clear_regions(

			kdamond->contexts->contexts_arr[0]->schemes, ctx);

}



static inline bool damon_sysfs_kdamond_running(

		struct damon_sysfs_kdamond *kdamond)

{
@@ -1343,6 +1360,9 @@ static int damon_sysfs_cmd_request_callback(struct damon_ctx *c) 
			damon_sysfs_schemes_regions_updating = false;

		}

		break;

	case DAMON_SYSFS_CMD_CLEAR_SCHEMES_TRIED_REGIONS:

		err = damon_sysfs_clear_schemes_regions(kdamond);

		break;

	default:

		break;

	}