Commit f64539dc authored by SeongJae Park's avatar SeongJae Park Committed by Andrew Morton
Browse files

mm/damon/sysfs: use damon_call() for update_schemes_stats 

DAMON sysfs interface uses damon_callback with its own synchronization
facility to handle update_schemes_stats kdamond command.  But damon_call()
can support the use case without the additional synchronizations.  Convert
the code to use damon_call() instead.

Link: https://lkml.kernel.org/r/20250103174400.54890-5-sj@kernel.org


Signed-off-by: default avatarSeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 42b7491a

mm/damon/sysfs.c

+21 −10
Original line number Diff line number Diff line
@@ -1214,19 +1214,19 @@ static void damon_sysfs_before_terminate(struct damon_ctx *ctx) 


/*

 * damon_sysfs_upd_schemes_stats() - Update schemes stats sysfs files.

 * @kdamond:	The kobject wrapper that associated to the kdamond thread.

 * @data:	The kobject wrapper that associated to the kdamond thread.

 *

 * This function reads the schemes stats of specific kdamond and update the

 * related values for sysfs files.  This function should be called from DAMON

 * callbacks while holding ``damon_syfs_lock``, to safely access the DAMON

 * contexts-internal data and DAMON sysfs variables.

 * worker thread,to safely access the DAMON contexts-internal data.  Caller

 * should also ensure holding ``damon_syfs_lock``, and ->damon_ctx of @data is

 * not NULL but a valid pointer, to safely access DAMON sysfs variables.

 */

static int damon_sysfs_upd_schemes_stats(struct damon_sysfs_kdamond *kdamond)

static int damon_sysfs_upd_schemes_stats(void *data)

{

	struct damon_sysfs_kdamond *kdamond = data;

	struct damon_ctx *ctx = kdamond->damon_ctx;



	if (!ctx)

		return -EINVAL;

	damon_sysfs_schemes_update_stats(

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

	return 0;
@@ -1371,9 +1371,6 @@ static int damon_sysfs_cmd_request_callback(struct damon_ctx *c, bool active, 
	if (!kdamond || kdamond->damon_ctx != c)

		goto out;

	switch (damon_sysfs_cmd_request.cmd) {

	case DAMON_SYSFS_CMD_UPDATE_SCHEMES_STATS:

		err = damon_sysfs_upd_schemes_stats(kdamond);

		break;

	case DAMON_SYSFS_CMD_COMMIT:

		if (!after_aggregation)

			goto out;
@@ -1511,6 +1508,18 @@ static int damon_sysfs_turn_damon_off(struct damon_sysfs_kdamond *kdamond) 
	 */

}



static int damon_sysfs_damon_call(int (*fn)(void *data),

		struct damon_sysfs_kdamond *kdamond)

{

	struct damon_call_control call_control = {};



	if (!kdamond->damon_ctx)

		return -EINVAL;

	call_control.fn = fn;

	call_control.data = kdamond;

	return damon_call(kdamond->damon_ctx, &call_control);

}



/*

 * damon_sysfs_handle_cmd() - Handle a command for a specific kdamond.

 * @cmd:	The command to handle.
@@ -1529,12 +1538,14 @@ static int damon_sysfs_handle_cmd(enum damon_sysfs_cmd cmd, 
{

	bool need_wait = true;



	/* Handle commands that doesn't access DAMON context-internal data */

	switch (cmd) {

	case DAMON_SYSFS_CMD_ON:

		return damon_sysfs_turn_damon_on(kdamond);

	case DAMON_SYSFS_CMD_OFF:

		return damon_sysfs_turn_damon_off(kdamond);

	case DAMON_SYSFS_CMD_UPDATE_SCHEMES_STATS:

		return damon_sysfs_damon_call(

				damon_sysfs_upd_schemes_stats, kdamond);

	case DAMON_SYSFS_CMD_CLEAR_SCHEMES_TRIED_REGIONS:

		return damon_sysfs_schemes_clear_regions(

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