Commit d682f5f6 authored by SeongJae Park's avatar SeongJae Park Committed by Andrew Morton
Browse files

mm/damon/sysfs: remove damon_sysfs_cmd_request and its readers 

damon_sysfs_cmd_request is DAMON sysfs interface's own synchronization
mechanism for accessing DAMON internal data via damon_callback hooks.  All
the users are now migrated to damon_call() and damos_walk(), so nobody
really uses it.  No one writes to the data structure but reading code is
still remained.  Remove the reading code and the entire data structure.

Link: https://lkml.kernel.org/r/20250306175908.66300-8-sj@kernel.org


Signed-off-by: default avatarSeongJae Park <sj@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 311f34ff

mm/damon/sysfs.c

+1 −23
Original line number Diff line number Diff line
@@ -1238,25 +1238,6 @@ static const char * const damon_sysfs_cmd_strs[] = { 
	"update_tuned_intervals",

};



/*

 * struct damon_sysfs_cmd_request - A request to the DAMON callback.

 * @cmd:	The command that needs to be handled by the callback.

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

 *

 * This structure represents a sysfs command request that need to access some

 * DAMON context-internal data.  Because DAMON context-internal data can be

 * safely accessed from DAMON callbacks without additional synchronization, the

 * request will be handled by the DAMON callback.  None-``NULL`` @kdamond means

 * the request is valid.

 */

struct damon_sysfs_cmd_request {

	enum damon_sysfs_cmd cmd;

	struct damon_sysfs_kdamond *kdamond;

};



/* Current DAMON callback request.  Protected by damon_sysfs_lock. */

static struct damon_sysfs_cmd_request damon_sysfs_cmd_request;



static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,

		char *buf)

{
@@ -1555,8 +1536,6 @@ static int damon_sysfs_turn_damon_on(struct damon_sysfs_kdamond *kdamond) 


	if (damon_sysfs_kdamond_running(kdamond))

		return -EBUSY;

	if (damon_sysfs_cmd_request.kdamond == kdamond)

		return -EBUSY;

	/* TODO: support multiple contexts per kdamond */

	if (kdamond->contexts->nr != 1)

		return -EINVAL;
@@ -1796,8 +1775,7 @@ static bool damon_sysfs_kdamonds_busy(struct damon_sysfs_kdamond **kdamonds, 
	int i;



	for (i = 0; i < nr_kdamonds; i++) {

		if (damon_sysfs_kdamond_running(kdamonds[i]) ||

		    damon_sysfs_cmd_request.kdamond == kdamonds[i])

		if (damon_sysfs_kdamond_running(kdamonds[i]))

			return true;

	}