[PATCH v2 1/2] mm/damon/core: add 'struct kdamond' abstraction layer

From: Alex Rusuf
Date: Fri May 31 2024 - 08:25:35 EST


In current implementation kdamond tracks only 1
context, that is kdamond _is_ damon_ctx what makes
it very difficult to implement multiple contexts.

This patch adds another level of abstraction, that is
'struct kdamond' - structure which represents kdamond itself.
It holds references to all contexts organized in list.

Few fields like ->kdamond_started and ->kdamond_lock
(just ->lock for 'struct kdamond') also has been moved
to 'struct kdamond', because they have nothing to do
with the context itself, but with the whole kdamond
daemon.

Signed-off-by: Alex Rusuf <yorha.op@xxxxxxxxx>
---
include/linux/damon.h | 73 ++++++++---
mm/damon/core.c | 249 ++++++++++++++++++++++-------------
mm/damon/lru_sort.c | 31 +++--
mm/damon/modules-common.c | 36 +++--
mm/damon/modules-common.h | 3 +-
mm/damon/reclaim.c | 30 +++--
mm/damon/sysfs.c | 268 ++++++++++++++++++++++++--------------
7 files changed, 463 insertions(+), 227 deletions(-)

diff --git a/include/linux/damon.h b/include/linux/damon.h
index 886d07294..7cb9979a0 100644
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -568,29 +568,49 @@ struct damon_attrs {
unsigned long max_nr_regions;
};

+/**
+ * struct kdamond - Represents a background daemon that is responsible
+ * for executing each context.
+ *
+ * @lock: Kdamond's global lock, serializes accesses to any field.
+ * @self: Kernel thread which is actually being executed.
+ * @contexts: Head of contexts (&damon_ctx) list.
+ * @nr_ctxs: Number of contexts being monitored.
+ *
+ * Each DAMON's background daemon has this structure. Once
+ * configured, daemon can be started by calling damon_start().
+ *
+ * Monitoring can be explicitly stopped by calling damon_stop(). Once
+ * daemon is terminated @self is set to NULL, so users can know if
+ * monitoring is stopped by reading @self pointer. Access to @self
+ * must also be protected by @lock.
+ */
+struct kdamond {
+ struct mutex lock;
+ struct task_struct *self;
+ struct list_head contexts;
+ size_t nr_ctxs;
+
+/* private: */
+ /* for waiting until the execution of the kdamond_fn is started */
+ struct completion kdamond_started;
+};
+
/**
* struct damon_ctx - Represents a context for each monitoring. This is the
* main interface that allows users to set the attributes and get the results
* of the monitoring.
*
* @attrs: Monitoring attributes for accuracy/overhead control.
- * @kdamond: Kernel thread who does the monitoring.
- * @kdamond_lock: Mutex for the synchronizations with @kdamond.
+ * @kdamond: Back reference to daemon who is the owner of this context.
+ * @list: List head of siblings.
*
* For each monitoring context, one kernel thread for the monitoring is
* created. The pointer to the thread is stored in @kdamond.
*
* Once started, the monitoring thread runs until explicitly required to be
* terminated or every monitoring target is invalid. The validity of the
- * targets is checked via the &damon_operations.target_valid of @ops. The
- * termination can also be explicitly requested by calling damon_stop().
- * The thread sets @kdamond to NULL when it terminates. Therefore, users can
- * know whether the monitoring is ongoing or terminated by reading @kdamond.
- * Reads and writes to @kdamond from outside of the monitoring thread must
- * be protected by @kdamond_lock.
- *
- * Note that the monitoring thread protects only @kdamond via @kdamond_lock.
- * Accesses to other fields must be protected by themselves.
+ * targets is checked via the &damon_operations.target_valid of @ops.
*
* @ops: Set of monitoring operations for given use cases.
* @callback: Set of callbacks for monitoring events notifications.
@@ -614,12 +634,11 @@ struct damon_ctx {
* update
*/
unsigned long next_ops_update_sis;
- /* for waiting until the execution of the kdamond_fn is started */
- struct completion kdamond_started;
+ unsigned long sz_limit;

/* public: */
- struct task_struct *kdamond;
- struct mutex kdamond_lock;
+ struct kdamond *kdamond;
+ struct list_head list;

struct damon_operations ops;
struct damon_callback callback;
@@ -653,6 +672,15 @@ static inline unsigned long damon_sz_region(struct damon_region *r)
return r->ar.end - r->ar.start;
}

+static inline struct damon_target *damon_first_target(struct damon_ctx *ctx)
+{
+ return list_first_entry(&ctx->adaptive_targets, struct damon_target, list);
+}
+
+static inline struct damon_ctx *damon_first_ctx(struct kdamond *kdamond)
+{
+ return list_first_entry(&kdamond->contexts, struct damon_ctx, list);
+}

#define damon_for_each_region(r, t) \
list_for_each_entry(r, &t->regions_list, list)
@@ -675,6 +703,12 @@ static inline unsigned long damon_sz_region(struct damon_region *r)
#define damon_for_each_scheme_safe(s, next, ctx) \
list_for_each_entry_safe(s, next, &(ctx)->schemes, list)

+#define damon_for_each_context(c, kdamond) \
+ list_for_each_entry(c, &(kdamond)->contexts, list)
+
+#define damon_for_each_context_safe(c, next, kdamond) \
+ list_for_each_entry_safe(c, next, &(kdamond)->contexts, list)
+
#define damos_for_each_quota_goal(goal, quota) \
list_for_each_entry(goal, &quota->goals, list)

@@ -736,7 +770,12 @@ void damon_destroy_target(struct damon_target *t);
unsigned int damon_nr_regions(struct damon_target *t);

struct damon_ctx *damon_new_ctx(void);
+void damon_add_ctx(struct kdamond *kdamond, struct damon_ctx *ctx);
+struct kdamond *damon_new_kdamond(void);
void damon_destroy_ctx(struct damon_ctx *ctx);
+void damon_destroy_ctxs(struct kdamond *kdamond);
+void damon_destroy_kdamond(struct kdamond *kdamond);
+bool damon_kdamond_running(struct kdamond *kdamond);
int damon_set_attrs(struct damon_ctx *ctx, struct damon_attrs *attrs);
void damon_set_schemes(struct damon_ctx *ctx,
struct damos **schemes, ssize_t nr_schemes);
@@ -758,8 +797,8 @@ static inline unsigned int damon_max_nr_accesses(const struct damon_attrs *attrs
}


-int damon_start(struct damon_ctx **ctxs, int nr_ctxs, bool exclusive);
-int damon_stop(struct damon_ctx **ctxs, int nr_ctxs);
+int damon_start(struct kdamond *kdamond, bool exclusive);
+int damon_stop(struct kdamond *kdamond);

int damon_set_region_biggest_system_ram_default(struct damon_target *t,
unsigned long *start, unsigned long *end);
diff --git a/mm/damon/core.c b/mm/damon/core.c
index 6d503c1c1..cfc9c803d 100644
--- a/mm/damon/core.c
+++ b/mm/damon/core.c
@@ -24,7 +24,7 @@
#endif

static DEFINE_MUTEX(damon_lock);
-static int nr_running_ctxs;
+static int nr_running_kdamonds;
static bool running_exclusive_ctxs;

static DEFINE_MUTEX(damon_ops_lock);
@@ -488,8 +488,6 @@ struct damon_ctx *damon_new_ctx(void)
if (!ctx)
return NULL;

- init_completion(&ctx->kdamond_started);
-
ctx->attrs.sample_interval = 5 * 1000;
ctx->attrs.aggr_interval = 100 * 1000;
ctx->attrs.ops_update_interval = 60 * 1000 * 1000;
@@ -499,17 +497,41 @@ struct damon_ctx *damon_new_ctx(void)
ctx->next_aggregation_sis = 0;
ctx->next_ops_update_sis = 0;

- mutex_init(&ctx->kdamond_lock);
-
ctx->attrs.min_nr_regions = 10;
ctx->attrs.max_nr_regions = 1000;

INIT_LIST_HEAD(&ctx->adaptive_targets);
INIT_LIST_HEAD(&ctx->schemes);
+ INIT_LIST_HEAD(&ctx->list);

return ctx;
}

+/**
+ * Adds newly allocated and configured @ctx to @kdamond.
+ */
+void damon_add_ctx(struct kdamond *kdamond, struct damon_ctx *ctx)
+{
+ list_add_tail(&ctx->list, &kdamond->contexts);
+ ++kdamond->nr_ctxs;
+}
+
+struct kdamond *damon_new_kdamond(void)
+{
+ struct kdamond *kdamond;
+
+ kdamond = kzalloc(sizeof(*kdamond), GFP_KERNEL);
+ if (!kdamond)
+ return NULL;
+
+ init_completion(&kdamond->kdamond_started);
+ mutex_init(&kdamond->lock);
+
+ INIT_LIST_HEAD(&kdamond->contexts);
+
+ return kdamond;
+}
+
static void damon_destroy_targets(struct damon_ctx *ctx)
{
struct damon_target *t, *next_t;
@@ -523,6 +545,11 @@ static void damon_destroy_targets(struct damon_ctx *ctx)
damon_destroy_target(t);
}

+static inline void damon_del_ctx(struct damon_ctx *ctx)
+{
+ list_del(&ctx->list);
+}
+
void damon_destroy_ctx(struct damon_ctx *ctx)
{
struct damos *s, *next_s;
@@ -532,9 +559,27 @@ void damon_destroy_ctx(struct damon_ctx *ctx)
damon_for_each_scheme_safe(s, next_s, ctx)
damon_destroy_scheme(s);

+ damon_del_ctx(ctx);
kfree(ctx);
}

+void damon_destroy_ctxs(struct kdamond *kdamond)
+{
+ struct damon_ctx *c, *next;
+
+ damon_for_each_context_safe(c, next, kdamond) {
+ damon_destroy_ctx(c);
+ --kdamond->nr_ctxs;
+ }
+}
+
+void damon_destroy_kdamond(struct kdamond *kdamond)
+{
+ damon_destroy_ctxs(kdamond);
+ mutex_destroy(&kdamond->lock);
+ kfree(kdamond);
+}
+
static unsigned int damon_age_for_new_attrs(unsigned int age,
struct damon_attrs *old_attrs, struct damon_attrs *new_attrs)
{
@@ -667,13 +712,27 @@ void damon_set_schemes(struct damon_ctx *ctx, struct damos **schemes,
*/
int damon_nr_running_ctxs(void)
{
- int nr_ctxs;
+ int nr_kdamonds;

mutex_lock(&damon_lock);
- nr_ctxs = nr_running_ctxs;
+ nr_kdamonds = nr_running_kdamonds;
mutex_unlock(&damon_lock);

- return nr_ctxs;
+ return nr_kdamonds;
+}
+
+/**
+ * damon_kdamond_running() - Return true if kdamond is running
+ * false otherwise.
+ */
+bool damon_kdamond_running(struct kdamond *kdamond)
+{
+ bool running;
+
+ mutex_lock(&kdamond->lock);
+ running = kdamond->self != NULL;
+ mutex_unlock(&kdamond->lock);
+ return running;
}

/* Returns the size upper limit for each monitoring region */
@@ -700,38 +759,37 @@ static int kdamond_fn(void *data);

/*
* __damon_start() - Starts monitoring with given context.
- * @ctx: monitoring context
+ * @kdamond: daemon to be started
*
* This function should be called while damon_lock is hold.
*
* Return: 0 on success, negative error code otherwise.
*/
-static int __damon_start(struct damon_ctx *ctx)
+static int __damon_start(struct kdamond *kdamond)
{
int err = -EBUSY;

- mutex_lock(&ctx->kdamond_lock);
- if (!ctx->kdamond) {
+ mutex_lock(&kdamond->lock);
+ if (!kdamond->self) {
err = 0;
- reinit_completion(&ctx->kdamond_started);
- ctx->kdamond = kthread_run(kdamond_fn, ctx, "kdamond.%d",
- nr_running_ctxs);
- if (IS_ERR(ctx->kdamond)) {
- err = PTR_ERR(ctx->kdamond);
- ctx->kdamond = NULL;
+ reinit_completion(&kdamond->kdamond_started);
+ kdamond->self = kthread_run(kdamond_fn, kdamond, "kdamond.%d",
+ nr_running_kdamonds);
+ if (IS_ERR(kdamond->self)) {
+ err = PTR_ERR(kdamond->self);
+ kdamond->self = NULL;
} else {
- wait_for_completion(&ctx->kdamond_started);
+ wait_for_completion(&kdamond->kdamond_started);
}
}
- mutex_unlock(&ctx->kdamond_lock);
+ mutex_unlock(&kdamond->lock);

return err;
}

/**
* damon_start() - Starts the monitorings for a given group of contexts.
- * @ctxs: an array of the pointers for contexts to start monitoring
- * @nr_ctxs: size of @ctxs
+ * @kdamond: a daemon that contains list of monitoring contexts
* @exclusive: exclusiveness of this contexts group
*
* This function starts a group of monitoring threads for a group of monitoring
@@ -743,74 +801,59 @@ static int __damon_start(struct damon_ctx *ctx)
*
* Return: 0 on success, negative error code otherwise.
*/
-int damon_start(struct damon_ctx **ctxs, int nr_ctxs, bool exclusive)
+int damon_start(struct kdamond *kdamond, bool exclusive)
{
- int i;
int err = 0;

+ BUG_ON(!kdamond);
+ BUG_ON(!kdamond->nr_ctxs);
+
+ if (kdamond->nr_ctxs != 1)
+ return -EINVAL;
+
mutex_lock(&damon_lock);
- if ((exclusive && nr_running_ctxs) ||
+ if ((exclusive && nr_running_kdamonds) ||
(!exclusive && running_exclusive_ctxs)) {
mutex_unlock(&damon_lock);
return -EBUSY;
}

- for (i = 0; i < nr_ctxs; i++) {
- err = __damon_start(ctxs[i]);
- if (err)
- break;
- nr_running_ctxs++;
- }
- if (exclusive && nr_running_ctxs)
+ err = __damon_start(kdamond);
+ if (err)
+ return err;
+ nr_running_kdamonds++;
+
+ if (exclusive && nr_running_kdamonds)
running_exclusive_ctxs = true;
mutex_unlock(&damon_lock);

return err;
}

-/*
- * __damon_stop() - Stops monitoring of a given context.
- * @ctx: monitoring context
+/**
+ * damon_stop() - Stops the monitorings for a given group of contexts.
+ * @kdamond: a daemon (that contains list of monitoring contexts)
+ * to be stopped.
*
* Return: 0 on success, negative error code otherwise.
*/
-static int __damon_stop(struct damon_ctx *ctx)
+int damon_stop(struct kdamond *kdamond)
{
struct task_struct *tsk;

- mutex_lock(&ctx->kdamond_lock);
- tsk = ctx->kdamond;
+ mutex_lock(&kdamond->lock);
+ tsk = kdamond->self;
if (tsk) {
get_task_struct(tsk);
- mutex_unlock(&ctx->kdamond_lock);
+ mutex_unlock(&kdamond->lock);
kthread_stop_put(tsk);
return 0;
}
- mutex_unlock(&ctx->kdamond_lock);
+ mutex_unlock(&kdamond->lock);

return -EPERM;
}

-/**
- * damon_stop() - Stops the monitorings for a given group of contexts.
- * @ctxs: an array of the pointers for contexts to stop monitoring
- * @nr_ctxs: size of @ctxs
- *
- * Return: 0 on success, negative error code otherwise.
- */
-int damon_stop(struct damon_ctx **ctxs, int nr_ctxs)
-{
- int i, err = 0;
-
- for (i = 0; i < nr_ctxs; i++) {
- /* nr_running_ctxs is decremented in kdamond_fn */
- err = __damon_stop(ctxs[i]);
- if (err)
- break;
- }
- return err;
-}
-
/*
* Reset the aggregated monitoring results ('nr_accesses' of each region).
*/
@@ -1582,29 +1625,68 @@ static void kdamond_init_intervals_sis(struct damon_ctx *ctx)
}
}

+static bool kdamond_init_ctx(struct damon_ctx *ctx)
+{
+ if (ctx->ops.init)
+ ctx->ops.init(ctx);
+ if (ctx->callback.before_start && ctx->callback.before_start(ctx))
+ return false;
+
+ kdamond_init_intervals_sis(ctx);
+ ctx->sz_limit = damon_region_sz_limit(ctx);
+
+ return true;
+}
+
+static bool kdamond_init_ctxs(struct kdamond *kdamond)
+{
+ struct damon_ctx *c;
+
+ damon_for_each_context(c, kdamond)
+ if (!kdamond_init_ctx(c))
+ return false;
+ return true;
+}
+
+static void kdamond_finish_ctx(struct damon_ctx *ctx)
+{
+ struct damon_target *t;
+ struct damon_region *r, *next;
+
+ damon_for_each_target(t, ctx) {
+ damon_for_each_region_safe(r, next, t)
+ damon_destroy_region(r, t);
+ }
+
+ if (ctx->callback.before_terminate)
+ ctx->callback.before_terminate(ctx);
+ if (ctx->ops.cleanup)
+ ctx->ops.cleanup(ctx);
+}
+
+static void kdamond_finish_ctxs(struct kdamond *kdamond)
+{
+ struct damon_ctx *c;
+
+ damon_for_each_context(c, kdamond)
+ kdamond_finish_ctx(c);
+}
+
/*
* The monitoring daemon that runs as a kernel thread
*/
static int kdamond_fn(void *data)
{
- struct damon_ctx *ctx = data;
- struct damon_target *t;
- struct damon_region *r, *next;
+ struct kdamond *kdamond = data;
+ struct damon_ctx *ctx = damon_first_ctx(kdamond);
unsigned int max_nr_accesses = 0;
- unsigned long sz_limit = 0;

pr_debug("kdamond (%d) starts\n", current->pid);

- complete(&ctx->kdamond_started);
- kdamond_init_intervals_sis(ctx);
-
- if (ctx->ops.init)
- ctx->ops.init(ctx);
- if (ctx->callback.before_start && ctx->callback.before_start(ctx))
+ complete(&kdamond->kdamond_started);
+ if (!kdamond_init_ctxs(kdamond))
goto done;

- sz_limit = damon_region_sz_limit(ctx);
-
while (!kdamond_need_stop(ctx)) {
/*
* ctx->attrs and ctx->next_{aggregation,ops_update}_sis could
@@ -1616,6 +1698,7 @@ static int kdamond_fn(void *data)
unsigned long next_aggregation_sis = ctx->next_aggregation_sis;
unsigned long next_ops_update_sis = ctx->next_ops_update_sis;
unsigned long sample_interval = ctx->attrs.sample_interval;
+ unsigned long sz_limit = ctx->sz_limit;

if (kdamond_wait_activation(ctx))
break;
@@ -1666,28 +1749,20 @@ static int kdamond_fn(void *data)
sample_interval;
if (ctx->ops.update)
ctx->ops.update(ctx);
- sz_limit = damon_region_sz_limit(ctx);
+ ctx->sz_limit = damon_region_sz_limit(ctx);
}
}
done:
- damon_for_each_target(t, ctx) {
- damon_for_each_region_safe(r, next, t)
- damon_destroy_region(r, t);
- }
-
- if (ctx->callback.before_terminate)
- ctx->callback.before_terminate(ctx);
- if (ctx->ops.cleanup)
- ctx->ops.cleanup(ctx);
+ kdamond_finish_ctxs(kdamond);

pr_debug("kdamond (%d) finishes\n", current->pid);
- mutex_lock(&ctx->kdamond_lock);
- ctx->kdamond = NULL;
- mutex_unlock(&ctx->kdamond_lock);
+ mutex_lock(&kdamond->lock);
+ kdamond->self = NULL;
+ mutex_unlock(&kdamond->lock);

mutex_lock(&damon_lock);
- nr_running_ctxs--;
- if (!nr_running_ctxs && running_exclusive_ctxs)
+ nr_running_kdamonds--;
+ if (!nr_running_kdamonds && running_exclusive_ctxs)
running_exclusive_ctxs = false;
mutex_unlock(&damon_lock);

diff --git a/mm/damon/lru_sort.c b/mm/damon/lru_sort.c
index 3de2916a6..76c20098a 100644
--- a/mm/damon/lru_sort.c
+++ b/mm/damon/lru_sort.c
@@ -142,8 +142,18 @@ static struct damos_access_pattern damon_lru_sort_stub_pattern = {
.max_age_region = UINT_MAX,
};

-static struct damon_ctx *ctx;
-static struct damon_target *target;
+static struct kdamond *kdamond;
+
+static inline struct damon_ctx *damon_lru_sort_ctx(void)
+{
+ return damon_first_ctx(kdamond);
+}
+
+static inline struct damon_target *damon_lru_sort_target(void)
+{
+ return damon_first_target(
+ damon_lru_sort_ctx());
+}

static struct damos *damon_lru_sort_new_scheme(
struct damos_access_pattern *pattern, enum damos_action action)
@@ -201,6 +211,7 @@ static int damon_lru_sort_apply_parameters(void)
struct damos *scheme, *hot_scheme, *cold_scheme;
struct damos *old_hot_scheme = NULL, *old_cold_scheme = NULL;
unsigned int hot_thres, cold_thres;
+ struct damon_ctx *ctx = damon_lru_sort_ctx();
int err = 0;

err = damon_set_attrs(ctx, &damon_lru_sort_mon_attrs);
@@ -237,7 +248,8 @@ static int damon_lru_sort_apply_parameters(void)
damon_set_schemes(ctx, &hot_scheme, 1);
damon_add_scheme(ctx, cold_scheme);

- return damon_set_region_biggest_system_ram_default(target,
+ return damon_set_region_biggest_system_ram_default(
+ damon_lru_sort_target(),
&monitor_region_start,
&monitor_region_end);
}
@@ -247,7 +259,7 @@ static int damon_lru_sort_turn(bool on)
int err;

if (!on) {
- err = damon_stop(&ctx, 1);
+ err = damon_stop(kdamond);
if (!err)
kdamond_pid = -1;
return err;
@@ -257,10 +269,11 @@ static int damon_lru_sort_turn(bool on)
if (err)
return err;

- err = damon_start(&ctx, 1, true);
+ err = damon_start(kdamond, true);
if (err)
return err;
- kdamond_pid = ctx->kdamond->pid;
+
+ kdamond_pid = kdamond->self->pid;
return 0;
}

@@ -279,7 +292,7 @@ static int damon_lru_sort_enabled_store(const char *val,
return 0;

/* Called before init function. The function will handle this. */
- if (!ctx)
+ if (!kdamond)
goto set_param_out;

err = damon_lru_sort_turn(enable);
@@ -334,11 +347,13 @@ static int damon_lru_sort_after_wmarks_check(struct damon_ctx *c)

static int __init damon_lru_sort_init(void)
{
- int err = damon_modules_new_paddr_ctx_target(&ctx, &target);
+ struct damon_ctx *ctx;
+ int err = damon_modules_new_paddr_kdamond(&kdamond);

if (err)
return err;

+ ctx = damon_lru_sort_ctx();
ctx->callback.after_wmarks_check = damon_lru_sort_after_wmarks_check;
ctx->callback.after_aggregation = damon_lru_sort_after_aggregation;

diff --git a/mm/damon/modules-common.c b/mm/damon/modules-common.c
index 7cf96574c..436bb7948 100644
--- a/mm/damon/modules-common.c
+++ b/mm/damon/modules-common.c
@@ -9,13 +9,7 @@

#include "modules-common.h"

-/*
- * Allocate, set, and return a DAMON context for the physical address space.
- * @ctxp: Pointer to save the point to the newly created context
- * @targetp: Pointer to save the point to the newly created target
- */
-int damon_modules_new_paddr_ctx_target(struct damon_ctx **ctxp,
- struct damon_target **targetp)
+static int __damon_modules_new_paddr_kdamond(struct kdamond *kdamond)
{
struct damon_ctx *ctx;
struct damon_target *target;
@@ -34,9 +28,33 @@ int damon_modules_new_paddr_ctx_target(struct damon_ctx **ctxp,
damon_destroy_ctx(ctx);
return -ENOMEM;
}
+
damon_add_target(ctx, target);
+ damon_add_ctx(kdamond, ctx);
+
+ return 0;
+}
+
+/*
+ * Allocate, set, and return a DAMON daemon for the physical address space.
+ * @kdamondp: Pointer to save the point to the newly created kdamond
+ */
+int damon_modules_new_paddr_kdamond(struct kdamond **kdamondp)
+{
+ int err;
+ struct kdamond *kdamond;
+
+ kdamond = damon_new_kdamond();
+ if (!kdamond)
+ return -ENOMEM;
+
+ err = __damon_modules_new_paddr_kdamond(kdamond);
+ if (err) {
+ damon_destroy_kdamond(kdamond);
+ return err;
+ }
+ kdamond->nr_ctxs = 1;

- *ctxp = ctx;
- *targetp = target;
+ *kdamondp = kdamond;
return 0;
}
diff --git a/mm/damon/modules-common.h b/mm/damon/modules-common.h
index f49cdb417..5fc5b8ae3 100644
--- a/mm/damon/modules-common.h
+++ b/mm/damon/modules-common.h
@@ -45,5 +45,4 @@
module_param_named(nr_##qt_exceed_name, stat.qt_exceeds, ulong, \
0400);

-int damon_modules_new_paddr_ctx_target(struct damon_ctx **ctxp,
- struct damon_target **targetp);
+int damon_modules_new_paddr_kdamond(struct kdamond **kdamondp);
diff --git a/mm/damon/reclaim.c b/mm/damon/reclaim.c
index 9bd341d62..f6540ef1a 100644
--- a/mm/damon/reclaim.c
+++ b/mm/damon/reclaim.c
@@ -150,8 +150,18 @@ static struct damos_stat damon_reclaim_stat;
DEFINE_DAMON_MODULES_DAMOS_STATS_PARAMS(damon_reclaim_stat,
reclaim_tried_regions, reclaimed_regions, quota_exceeds);

-static struct damon_ctx *ctx;
-static struct damon_target *target;
+static struct kdamond *kdamond;
+
+static inline struct damon_ctx *damon_reclaim_ctx(void)
+{
+ return damon_first_ctx(kdamond);
+}
+
+static inline struct damon_target *damon_reclaim_target(void)
+{
+ return damon_first_target(
+ damon_reclaim_ctx());
+}

static struct damos *damon_reclaim_new_scheme(void)
{
@@ -197,6 +207,7 @@ static int damon_reclaim_apply_parameters(void)
struct damos *scheme, *old_scheme;
struct damos_quota_goal *goal;
struct damos_filter *filter;
+ struct damon_ctx *ctx = damon_reclaim_ctx();
int err = 0;

err = damon_set_attrs(ctx, &damon_reclaim_mon_attrs);
@@ -244,7 +255,8 @@ static int damon_reclaim_apply_parameters(void)
}
damon_set_schemes(ctx, &scheme, 1);

- return damon_set_region_biggest_system_ram_default(target,
+ return damon_set_region_biggest_system_ram_default(
+ damon_reclaim_target(),
&monitor_region_start,
&monitor_region_end);
}
@@ -254,7 +266,7 @@ static int damon_reclaim_turn(bool on)
int err;

if (!on) {
- err = damon_stop(&ctx, 1);
+ err = damon_stop(kdamond);
if (!err)
kdamond_pid = -1;
return err;
@@ -264,10 +276,10 @@ static int damon_reclaim_turn(bool on)
if (err)
return err;

- err = damon_start(&ctx, 1, true);
+ err = damon_start(kdamond, true);
if (err)
return err;
- kdamond_pid = ctx->kdamond->pid;
+ kdamond_pid = kdamond->self->pid;
return 0;
}

@@ -286,7 +298,7 @@ static int damon_reclaim_enabled_store(const char *val,
return 0;

/* Called before init function. The function will handle this. */
- if (!ctx)
+ if (!kdamond)
goto set_param_out;

err = damon_reclaim_turn(enable);
@@ -337,11 +349,13 @@ static int damon_reclaim_after_wmarks_check(struct damon_ctx *c)

static int __init damon_reclaim_init(void)
{
- int err = damon_modules_new_paddr_ctx_target(&ctx, &target);
+ struct damon_ctx *ctx;
+ int err = damon_modules_new_paddr_kdamond(&kdamond);

if (err)
return err;

+ ctx = damon_reclaim_ctx();
ctx->callback.after_wmarks_check = damon_reclaim_after_wmarks_check;
ctx->callback.after_aggregation = damon_reclaim_after_aggregation;

diff --git a/mm/damon/sysfs.c b/mm/damon/sysfs.c
index 6fee383bc..bfdb979e6 100644
--- a/mm/damon/sysfs.c
+++ b/mm/damon/sysfs.c
@@ -939,7 +939,7 @@ static const struct kobj_type damon_sysfs_contexts_ktype = {
struct damon_sysfs_kdamond {
struct kobject kobj;
struct damon_sysfs_contexts *contexts;
- struct damon_ctx *damon_ctx;
+ struct kdamond *kdamond;
};

static struct damon_sysfs_kdamond *damon_sysfs_kdamond_alloc(void)
@@ -974,16 +974,6 @@ static void damon_sysfs_kdamond_rm_dirs(struct damon_sysfs_kdamond *kdamond)
kobject_put(&kdamond->contexts->kobj);
}

-static bool damon_sysfs_ctx_running(struct damon_ctx *ctx)
-{
- bool running;
-
- mutex_lock(&ctx->kdamond_lock);
- running = ctx->kdamond != NULL;
- mutex_unlock(&ctx->kdamond_lock);
- return running;
-}
-
/*
* enum damon_sysfs_cmd - Commands for a specific kdamond.
*/
@@ -1065,15 +1055,15 @@ static struct damon_sysfs_cmd_request damon_sysfs_cmd_request;
static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
char *buf)
{
- struct damon_sysfs_kdamond *kdamond = container_of(kobj,
+ struct damon_sysfs_kdamond *sys_kdamond = container_of(kobj,
struct damon_sysfs_kdamond, kobj);
- struct damon_ctx *ctx = kdamond->damon_ctx;
+ struct kdamond *kdamond = sys_kdamond->kdamond;
bool running;

- if (!ctx)
+ if (!kdamond)
running = false;
else
- running = damon_sysfs_ctx_running(ctx);
+ running = damon_kdamond_running(kdamond);

return sysfs_emit(buf, "%s\n", running ?
damon_sysfs_cmd_strs[DAMON_SYSFS_CMD_ON] :
@@ -1242,13 +1232,15 @@ static bool damon_sysfs_schemes_regions_updating;
static void damon_sysfs_before_terminate(struct damon_ctx *ctx)
{
struct damon_target *t, *next;
- struct damon_sysfs_kdamond *kdamond;
+ struct damon_sysfs_kdamond *sys_kdamond;
+ struct kdamond *kdamond;
enum damon_sysfs_cmd cmd;

/* damon_sysfs_schemes_update_regions_stop() might not yet called */
- kdamond = damon_sysfs_cmd_request.kdamond;
+ kdamond = ctx->kdamond;
+ sys_kdamond = damon_sysfs_cmd_request.kdamond;
cmd = damon_sysfs_cmd_request.cmd;
- if (kdamond && ctx == kdamond->damon_ctx &&
+ if (sys_kdamond && kdamond == sys_kdamond->kdamond &&
(cmd == DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_REGIONS ||
cmd == DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_BYTES) &&
damon_sysfs_schemes_regions_updating) {
@@ -1260,12 +1252,12 @@ static void damon_sysfs_before_terminate(struct damon_ctx *ctx)
if (!damon_target_has_pid(ctx))
return;

- mutex_lock(&ctx->kdamond_lock);
+ mutex_lock(&kdamond->lock);
damon_for_each_target_safe(t, next, ctx) {
put_pid(t->pid);
damon_destroy_target(t);
}
- mutex_unlock(&ctx->kdamond_lock);
+ mutex_unlock(&kdamond->lock);
}

/*
@@ -1277,55 +1269,91 @@ static void damon_sysfs_before_terminate(struct damon_ctx *ctx)
* callbacks while holding ``damon_syfs_lock``, to safely access the DAMON
* contexts-internal data and DAMON sysfs variables.
*/
-static int damon_sysfs_upd_schemes_stats(struct damon_sysfs_kdamond *kdamond)
+static int damon_sysfs_upd_schemes_stats(struct damon_sysfs_kdamond *sys_kdamond)
{
- struct damon_ctx *ctx = kdamond->damon_ctx;
+ struct damon_ctx *c;
+ struct damon_sysfs_context **sysfs_ctxs;

- if (!ctx)
+ if (!sys_kdamond->kdamond)
return -EINVAL;
- damon_sysfs_schemes_update_stats(
- kdamond->contexts->contexts_arr[0]->schemes, ctx);
+
+ sysfs_ctxs = sys_kdamond->contexts->contexts_arr;
+ damon_for_each_context(c, sys_kdamond->kdamond) {
+ struct damon_sysfs_context *sysfs_ctx = *sysfs_ctxs;
+
+ damon_sysfs_schemes_update_stats(sysfs_ctx->schemes, c);
+ ++sysfs_ctxs;
+ }
return 0;
}

static int damon_sysfs_upd_schemes_regions_start(
- struct damon_sysfs_kdamond *kdamond, bool total_bytes_only)
+ struct damon_sysfs_kdamond *sys_kdamond, bool total_bytes_only)
{
- struct damon_ctx *ctx = kdamond->damon_ctx;
+ struct damon_ctx *c;
+ struct damon_sysfs_context **sysfs_ctxs;
+ int err;

- if (!ctx)
+ if (!sys_kdamond->kdamond)
return -EINVAL;
- return damon_sysfs_schemes_update_regions_start(
- kdamond->contexts->contexts_arr[0]->schemes, ctx,
- total_bytes_only);
+
+ sysfs_ctxs = sys_kdamond->contexts->contexts_arr;
+ damon_for_each_context(c, sys_kdamond->kdamond) {
+ struct damon_sysfs_context *sysfs_ctx = *sysfs_ctxs;
+
+ err = damon_sysfs_schemes_update_regions_start(sysfs_ctx->schemes, c,
+ total_bytes_only);
+ if (err)
+ return err;
+ ++sysfs_ctxs;
+ }
+ return 0;
}

static int damon_sysfs_upd_schemes_regions_stop(
- struct damon_sysfs_kdamond *kdamond)
+ struct damon_sysfs_kdamond *sys_kdamond)
{
- struct damon_ctx *ctx = kdamond->damon_ctx;
+ struct damon_ctx *c;
+ int err;

- if (!ctx)
+ if (!sys_kdamond->kdamond)
return -EINVAL;
- return damon_sysfs_schemes_update_regions_stop(ctx);
+
+ damon_for_each_context(c, sys_kdamond->kdamond) {
+ err = damon_sysfs_schemes_update_regions_stop(c);
+ if (err)
+ return err;
+ }
+ return 0;
}

static int damon_sysfs_clear_schemes_regions(
- struct damon_sysfs_kdamond *kdamond)
+ struct damon_sysfs_kdamond *sys_kdamond)
{
- struct damon_ctx *ctx = kdamond->damon_ctx;
+ struct damon_ctx *c;
+ struct damon_sysfs_context **sysfs_ctxs;
+ int err;

- if (!ctx)
+ if (!sys_kdamond->kdamond)
return -EINVAL;
- return damon_sysfs_schemes_clear_regions(
- kdamond->contexts->contexts_arr[0]->schemes, ctx);
+
+ sysfs_ctxs = sys_kdamond->contexts->contexts_arr;
+ damon_for_each_context(c, sys_kdamond->kdamond) {
+ struct damon_sysfs_context *sysfs_ctx = *sysfs_ctxs;
+
+ err = damon_sysfs_schemes_clear_regions(sysfs_ctx->schemes, c);
+ if (err)
+ return err;
+ ++sysfs_ctxs;
+ }
+ return 0;
}

static inline bool damon_sysfs_kdamond_running(
- struct damon_sysfs_kdamond *kdamond)
+ struct damon_sysfs_kdamond *sys_kdamond)
{
- return kdamond->damon_ctx &&
- damon_sysfs_ctx_running(kdamond->damon_ctx);
+ return sys_kdamond->kdamond &&
+ damon_kdamond_running(sys_kdamond->kdamond);
}

static int damon_sysfs_apply_inputs(struct damon_ctx *ctx,
@@ -1351,23 +1379,34 @@ static int damon_sysfs_apply_inputs(struct damon_ctx *ctx,
*
* If the sysfs input is wrong, the kdamond will be terminated.
*/
-static int damon_sysfs_commit_input(struct damon_sysfs_kdamond *kdamond)
+static int damon_sysfs_commit_input(struct damon_sysfs_kdamond *sys_kdamond)
{
- if (!damon_sysfs_kdamond_running(kdamond))
+ struct damon_ctx *c;
+ struct damon_sysfs_context *sysfs_ctx;
+ int err;
+
+ if (!damon_sysfs_kdamond_running(sys_kdamond))
return -EINVAL;
/* TODO: Support multiple contexts per kdamond */
- if (kdamond->contexts->nr != 1)
+ if (sys_kdamond->contexts->nr != 1)
return -EINVAL;

- return damon_sysfs_apply_inputs(kdamond->damon_ctx,
- kdamond->contexts->contexts_arr[0]);
+ sysfs_ctx = sys_kdamond->contexts->contexts_arr[0];
+ damon_for_each_context(c, sys_kdamond->kdamond) {
+ err = damon_sysfs_apply_inputs(c, sysfs_ctx);
+ if (err)
+ return err;
+ ++sysfs_ctx;
+ }
+ return 0;
}

static int damon_sysfs_commit_schemes_quota_goals(
struct damon_sysfs_kdamond *sysfs_kdamond)
{
- struct damon_ctx *ctx;
- struct damon_sysfs_context *sysfs_ctx;
+ struct damon_ctx *c;
+ struct damon_sysfs_context **sysfs_ctxs;
+ int err;

if (!damon_sysfs_kdamond_running(sysfs_kdamond))
return -EINVAL;
@@ -1375,9 +1414,16 @@ static int damon_sysfs_commit_schemes_quota_goals(
if (sysfs_kdamond->contexts->nr != 1)
return -EINVAL;

- ctx = sysfs_kdamond->damon_ctx;
- sysfs_ctx = sysfs_kdamond->contexts->contexts_arr[0];
- return damos_sysfs_set_quota_scores(sysfs_ctx->schemes, ctx);
+ sysfs_ctxs = sysfs_kdamond->contexts->contexts_arr;
+ damon_for_each_context(c, sysfs_kdamond->kdamond) {
+ struct damon_sysfs_context *sysfs_ctx = *sysfs_ctxs;
+
+ err = damos_sysfs_set_quota_scores(sysfs_ctx->schemes, c);
+ if (err)
+ return err;
+ ++sysfs_ctxs;
+ }
+ return 0;
}

/*
@@ -1391,14 +1437,21 @@ static int damon_sysfs_commit_schemes_quota_goals(
* DAMON contexts-internal data and DAMON sysfs variables.
*/
static int damon_sysfs_upd_schemes_effective_quotas(
- struct damon_sysfs_kdamond *kdamond)
+ struct damon_sysfs_kdamond *sys_kdamond)
{
- struct damon_ctx *ctx = kdamond->damon_ctx;
+ struct damon_ctx *c;
+ struct damon_sysfs_context **sysfs_ctxs;

- if (!ctx)
+ if (!sys_kdamond->kdamond)
return -EINVAL;
- damos_sysfs_update_effective_quotas(
- kdamond->contexts->contexts_arr[0]->schemes, ctx);
+
+ sysfs_ctxs = sys_kdamond->contexts->contexts_arr;
+ damon_for_each_context(c, sys_kdamond->kdamond) {
+ struct damon_sysfs_context *sysfs_ctx = *sysfs_ctxs;
+
+ damos_sysfs_update_effective_quotas(sysfs_ctx->schemes, c);
+ ++sysfs_ctxs;
+ }
return 0;
}

@@ -1415,7 +1468,7 @@ static int damon_sysfs_upd_schemes_effective_quotas(
static int damon_sysfs_cmd_request_callback(struct damon_ctx *c, bool active,
bool after_aggregation)
{
- struct damon_sysfs_kdamond *kdamond;
+ struct damon_sysfs_kdamond *sys_kdamond;
bool total_bytes_only = false;
int err = 0;

@@ -1423,27 +1476,27 @@ static int damon_sysfs_cmd_request_callback(struct damon_ctx *c, bool active,
if (!damon_sysfs_schemes_regions_updating &&
!mutex_trylock(&damon_sysfs_lock))
return 0;
- kdamond = damon_sysfs_cmd_request.kdamond;
- if (!kdamond || kdamond->damon_ctx != c)
+ sys_kdamond = damon_sysfs_cmd_request.kdamond;
+ if (!sys_kdamond || !c || sys_kdamond->kdamond != c->kdamond)
goto out;
switch (damon_sysfs_cmd_request.cmd) {
case DAMON_SYSFS_CMD_UPDATE_SCHEMES_STATS:
- err = damon_sysfs_upd_schemes_stats(kdamond);
+ err = damon_sysfs_upd_schemes_stats(sys_kdamond);
break;
case DAMON_SYSFS_CMD_COMMIT:
if (!after_aggregation)
goto out;
- err = damon_sysfs_commit_input(kdamond);
+ err = damon_sysfs_commit_input(sys_kdamond);
break;
case DAMON_SYSFS_CMD_COMMIT_SCHEMES_QUOTA_GOALS:
- err = damon_sysfs_commit_schemes_quota_goals(kdamond);
+ err = damon_sysfs_commit_schemes_quota_goals(sys_kdamond);
break;
case DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_BYTES:
total_bytes_only = true;
fallthrough;
case DAMON_SYSFS_CMD_UPDATE_SCHEMES_TRIED_REGIONS:
if (!damon_sysfs_schemes_regions_updating) {
- err = damon_sysfs_upd_schemes_regions_start(kdamond,
+ err = damon_sysfs_upd_schemes_regions_start(sys_kdamond,
total_bytes_only);
if (!err) {
damon_sysfs_schemes_regions_updating = true;
@@ -1458,15 +1511,15 @@ static int damon_sysfs_cmd_request_callback(struct damon_ctx *c, bool active,
*/
if (active && !damos_sysfs_regions_upd_done())
goto keep_lock_out;
- err = damon_sysfs_upd_schemes_regions_stop(kdamond);
+ err = damon_sysfs_upd_schemes_regions_stop(sys_kdamond);
damon_sysfs_schemes_regions_updating = false;
}
break;
case DAMON_SYSFS_CMD_CLEAR_SCHEMES_TRIED_REGIONS:
- err = damon_sysfs_clear_schemes_regions(kdamond);
+ err = damon_sysfs_clear_schemes_regions(sys_kdamond);
break;
case DAMON_SYSFS_CMD_UPDATE_SCHEMES_EFFECTIVE_QUOTAS:
- err = damon_sysfs_upd_schemes_effective_quotas(kdamond);
+ err = damon_sysfs_upd_schemes_effective_quotas(sys_kdamond);
break;
default:
break;
@@ -1529,40 +1582,63 @@ static struct damon_ctx *damon_sysfs_build_ctx(
return ctx;
}

-static int damon_sysfs_turn_damon_on(struct damon_sysfs_kdamond *kdamond)
+static struct kdamond *damon_sysfs_build_kdamond(
+ struct damon_sysfs_context **sys_ctx, size_t nr_ctxs)
{
struct damon_ctx *ctx;
+ struct kdamond *kdamond;
+
+ kdamond = damon_new_kdamond();
+ if (!kdamond)
+ return ERR_PTR(-ENOMEM);
+
+ for (size_t i = 0; i < nr_ctxs; ++i) {
+ ctx = damon_sysfs_build_ctx(sys_ctx[i]);
+ if (IS_ERR(ctx)) {
+ damon_destroy_kdamond(kdamond);
+ return ERR_PTR(PTR_ERR(ctx));
+ }
+ ctx->kdamond = kdamond;
+ damon_add_ctx(kdamond, ctx);
+ }
+ return kdamond;
+}
+
+static int damon_sysfs_turn_damon_on(struct damon_sysfs_kdamond *sys_kdamond)
+{
+ struct kdamond *kdamond;
int err;

- if (damon_sysfs_kdamond_running(kdamond))
+ if (damon_sysfs_kdamond_running(sys_kdamond))
return -EBUSY;
- if (damon_sysfs_cmd_request.kdamond == kdamond)
+ if (damon_sysfs_cmd_request.kdamond == sys_kdamond)
return -EBUSY;
/* TODO: support multiple contexts per kdamond */
- if (kdamond->contexts->nr != 1)
+ if (sys_kdamond->contexts->nr != 1)
return -EINVAL;

- if (kdamond->damon_ctx)
- damon_destroy_ctx(kdamond->damon_ctx);
- kdamond->damon_ctx = NULL;
+ if (sys_kdamond->kdamond)
+ damon_destroy_kdamond(sys_kdamond->kdamond);
+ sys_kdamond->kdamond = NULL;

- ctx = damon_sysfs_build_ctx(kdamond->contexts->contexts_arr[0]);
- if (IS_ERR(ctx))
- return PTR_ERR(ctx);
- err = damon_start(&ctx, 1, false);
+ kdamond = damon_sysfs_build_kdamond(sys_kdamond->contexts->contexts_arr,
+ sys_kdamond->contexts->nr);
+ if (IS_ERR(kdamond))
+ return PTR_ERR(kdamond);
+ err = damon_start(kdamond, false);
if (err) {
- damon_destroy_ctx(ctx);
+ damon_destroy_kdamond(kdamond);
return err;
}
- kdamond->damon_ctx = ctx;
+ sys_kdamond->kdamond = kdamond;
return err;
}

-static int damon_sysfs_turn_damon_off(struct damon_sysfs_kdamond *kdamond)
+static int damon_sysfs_turn_damon_off(struct damon_sysfs_kdamond *sys_kdamond)
{
- if (!kdamond->damon_ctx)
+ if (!sys_kdamond->kdamond)
return -EINVAL;
- return damon_stop(&kdamond->damon_ctx, 1);
+ return damon_stop(sys_kdamond->kdamond);
/*
* To allow users show final monitoring results of already turned-off
* DAMON, we free kdamond->damon_ctx in next
@@ -1654,21 +1730,21 @@ static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
static ssize_t pid_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
- struct damon_sysfs_kdamond *kdamond = container_of(kobj,
+ struct damon_sysfs_kdamond *sys_kdamond = container_of(kobj,
struct damon_sysfs_kdamond, kobj);
- struct damon_ctx *ctx;
+ struct kdamond *kdamond;
int pid = -1;

if (!mutex_trylock(&damon_sysfs_lock))
return -EBUSY;
- ctx = kdamond->damon_ctx;
- if (!ctx)
+ kdamond = sys_kdamond->kdamond;
+ if (!kdamond)
goto out;

- mutex_lock(&ctx->kdamond_lock);
- if (ctx->kdamond)
- pid = ctx->kdamond->pid;
- mutex_unlock(&ctx->kdamond_lock);
+ mutex_lock(&kdamond->lock);
+ if (kdamond->self)
+ pid = kdamond->self->pid;
+ mutex_unlock(&kdamond->lock);
out:
mutex_unlock(&damon_sysfs_lock);
return sysfs_emit(buf, "%d\n", pid);
@@ -1676,12 +1752,12 @@ static ssize_t pid_show(struct kobject *kobj,

static void damon_sysfs_kdamond_release(struct kobject *kobj)
{
- struct damon_sysfs_kdamond *kdamond = container_of(kobj,
+ struct damon_sysfs_kdamond *sys_kdamond = container_of(kobj,
struct damon_sysfs_kdamond, kobj);

- if (kdamond->damon_ctx)
- damon_destroy_ctx(kdamond->damon_ctx);
- kfree(kdamond);
+ if (sys_kdamond->kdamond)
+ damon_destroy_kdamond(sys_kdamond->kdamond);
+ kfree(sys_kdamond);
}

static struct kobj_attribute damon_sysfs_kdamond_state_attr =
--
2.42.0