Introduce Data Access MONitor (DAMON)

new file mode 100644
index 000000000000..183e0edd7f43
@@ -0,0 +1,95 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * DAMON api
+ *
+ * Author: SeongJae Park <[email protected]>
+ */
+
+#ifndef _DAMON_H_
+#define _DAMON_H_
+
+#include <linux/types.h>
+
+/**
+ * struct damon_addr_range - Represents an address region of [@start, @end).
+ * @start:	Start address of the region (inclusive).
+ * @end:	End address of the region (exclusive).
+ */
+struct damon_addr_range {
+	unsigned long start;
+	unsigned long end;
+};
+
+/**
+ * struct damon_region - Represents a monitoring target region.
+ * @ar:			The address range of the region.
+ * @nr_accesses:	Access frequency of this region.
+ * @list:		List head for siblings.
+ */
+struct damon_region {
+	struct damon_addr_range ar;
+	unsigned int nr_accesses;
+	struct list_head list;
+};
+
+/**
+ * struct damon_target - Represents a monitoring target.
+ * @id:			Unique identifier for this target.
+ * @regions_list:	Head of the monitoring target regions of this target.
+ * @list:		List head for siblings.
+ *
+ * Each monitoring context could have multiple targets.  For example, a context
+ * for virtual memory address spaces could have multiple target processes.  The
+ * @id of each target should be unique among the targets of the context.  For
+ * example, in the virtual address monitoring context, it could be a pidfd or
+ * an address of an mm_struct.
+ */
+struct damon_target {
+	unsigned long id;
+	struct list_head regions_list;
+	struct list_head list;
+};
+
+/**
+ * struct damon_ctx - Represents a context for each monitoring.
+ * @targets_list:	Head of monitoring targets (&damon_target) list.
+ */
+struct damon_ctx {
+	struct list_head targets_list;	/* 'damon_target' objects */
+};
+
+#define damon_next_region(r) \
+	(container_of(r->list.next, struct damon_region, list))
+
+#define damon_prev_region(r) \
+	(container_of(r->list.prev, struct damon_region, list))
+
+#define damon_for_each_region(r, t) \
+	list_for_each_entry(r, &t->regions_list, list)
+
+#define damon_for_each_region_safe(r, next, t) \
+	list_for_each_entry_safe(r, next, &t->regions_list, list)
+
+#define damon_for_each_target(t, ctx) \
+	list_for_each_entry(t, &(ctx)->targets_list, list)
+
+#define damon_for_each_target_safe(t, next, ctx) \
+	list_for_each_entry_safe(t, next, &(ctx)->targets_list, list)
+
+#ifdef CONFIG_DAMON
+
+struct damon_region *damon_new_region(unsigned long start, unsigned long end);
+inline void damon_insert_region(struct damon_region *r,
+		struct damon_region *prev, struct damon_region *next);
+void damon_add_region(struct damon_region *r, struct damon_target *t);
+void damon_destroy_region(struct damon_region *r);
+
+struct damon_target *damon_new_target(unsigned long id);
+void damon_add_target(struct damon_ctx *ctx, struct damon_target *t);
+void damon_free_target(struct damon_target *t);
+void damon_destroy_target(struct damon_target *t);
+unsigned int damon_nr_regions(struct damon_target *t);
+
+#endif	/* CONFIG_DAMON */
+
+#endif

121 lines not on this page · raw message

index 183e0edd7f43..1f7b095646c2 100644
@@ -8,6 +8,8 @@
 #ifndef _DAMON_H_
 #define _DAMON_H_
 
+#include <linux/mutex.h>
+#include <linux/time64.h>
 #include <linux/types.h>
 
 /**

@@ -23,11 +25,13 @@ struct damon_addr_range {
 /**
  * struct damon_region - Represents a monitoring target region.
  * @ar:			The address range of the region.
+ * @sampling_addr:	Address of the sample for the next access check.
  * @nr_accesses:	Access frequency of this region.
  * @list:		List head for siblings.
  */
 struct damon_region {
 	struct damon_addr_range ar;
+	unsigned long sampling_addr;
 	unsigned int nr_accesses;
 	struct list_head list;
 };

@@ -50,12 +54,130 @@ struct damon_target {
 	struct list_head list;
 };
 
+struct damon_ctx;
+
 /**
- * struct damon_ctx - Represents a context for each monitoring.
+ * struct damon_primitive	Monitoring primitives for given use cases.
+ *
+ * @init_target_regions:	Constructs initial monitoring target regions.
+ * @prepare_access_checks:	Prepares next access check of target regions.
+ * @check_accesses:		Checks the access of target regions.
+ * @target_valid:		Determine if the target is valid.
+ * @cleanup:			Cleans up the context.
+ *
+ * DAMON can be extended for various address spaces and usages.  For this,
+ * users should register the low level primitives for their target address
+ * space and usecase via the &damon_ctx.primitive.  Then, the monitoring thread
+ * calls @init_target_regions before starting the monitoring and
+ * @prepare_access_checks, @check_accesses, and @target_valid for each
+ * @sample_interval.
+ *
+ * @init_target_regions should construct proper monitoring target regions and
+ * link those to the DAMON context struct.
+ * @prepare_access_checks should manipulate the monitoring regions to be
+ * prepare for the next access check.
+ * @check_accesses should check the accesses to each region that made after the
+ * last preparation and update the `->nr_accesses` of each region.  It should
+ * also return max &damon_region.nr_accesses that made as a result of its
+ * update.
+ * @target_valid should check whether the target is still valid for the
+ * monitoring.
+ * @cleanup is called from @kdamond just before its termination.  After this
+ * call, only @kdamond_lock and @kdamond will be touched.
+ */
+struct damon_primitive {
+	void (*init_target_regions)(struct damon_ctx *context);
+	void (*prepare_access_checks)(struct damon_ctx *context);
+	unsigned int (*check_accesses)(struct damon_ctx *context);
+	bool (*target_valid)(struct damon_target *target);
+	void (*cleanup)(struct damon_ctx *context);
+};
+
+/*
+ * struct damon_callback	Monitoring events notification callbacks.
+ *
+ * @before_start:	Called before starting the monitoring.
+ * @after_sampling:	Called after each sampling.
+ * @after_aggregation:	Called after each aggregation.
+ * @before_terminate:	Called before terminating the monitoring.
+ * @private:		User private data.
+ *
+ * The monitoring thread (&damon_ctx->kdamond) calls @before_start and
+ * @before_terminate just before starting the monitoring and just before
+ * finishing the monitoring.  Therefore, those are good places for installing
+ * and cleaning @private.
+ *
+ * The monitoring thread calls @after_sampling and @after_aggregation for each
+ * of the sampling intervals and aggregation intervals, respectively.
+ * Therefore, users can safely access the monitoring results via
+ * &damon_ctx.targets_list without additional protection of
+ * damon_ctx.kdamond_lock.  For the reason, users are recommended to use these
+ * callback for the accesses to the results.
+ *
+ * If any callback returns non-zero, monitoring stops.
+ */
+struct damon_callback {
+	void *private;
+
+	int (*before_start)(struct damon_ctx *context);
+	int (*after_sampling)(struct damon_ctx *context);
+	int (*after_aggregation)(struct damon_ctx *context);
+	int (*before_terminate)(struct damon_ctx *context);
+};
+
+/**
+ * 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.
+ *
+ * @sample_interval:		The time between access samplings.
+ * @aggr_interval:		The time between monitor results aggregations.
+ * @nr_regions:			The number of monitoring regions.
+ *
+ * For each @sample_interval, DAMON checks whether each region is accessed or
+ * not.  It aggregates and keeps the access information (number of accesses to
+ * each region) for @aggr_interval time.  All time intervals are in
+ * micro-seconds.
+ *
+ * @kdamond:		Kernel thread who does the monitoring.
+ * @kdamond_stop:	Notifies whether kdamond should stop.
+ * @kdamond_lock:	Mutex for the synchronizations with @kdamond.
+ *
+ * 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 @target_valid callback.  The termination can also
+ * be explicitly requested by writing non-zero to @kdamond_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 and @kdamond_stop from outside of the monitoring thread
+ * must be protected by @kdamond_lock.
+ *
+ * Note that the monitoring thread protects only @kdamond and @kdamond_stop via
+ * @kdamond_lock.  Accesses to other fields must be protected by themselves.
+ *
  * @targets_list:	Head of monitoring targets (&damon_target) list.
+ *
+ * @primitive:	Set of monitoring primitives for given use cases.
+ * @callback:	Set of callbacks for monitoring events notifications.
  */
 struct damon_ctx {
+	unsigned long sample_interval;
+	unsigned long aggr_interval;
+	unsigned long nr_regions;
+
+	struct timespec64 last_aggregation;
+
+	struct task_struct *kdamond;
+	bool kdamond_stop;
+	struct mutex kdamond_lock;
+
 	struct list_head targets_list;	/* 'damon_target' objects */
+
+	struct damon_primitive primitive;
+	struct damon_callback callback;
 };
 
 #define damon_next_region(r) \

@@ -90,6 +212,15 @@ void damon_free_target(struct damon_target *t);
 void damon_destroy_target(struct damon_target *t);
 unsigned int damon_nr_regions(struct damon_target *t);
 
+int damon_set_targets(struct damon_ctx *ctx,
+		unsigned long *ids, ssize_t nr_ids);
+int damon_set_attrs(struct damon_ctx *ctx, unsigned long sample_int,
+		unsigned long aggr_int, unsigned long nr_reg);
+
+int damon_nr_running_ctxs(void);
+int damon_start(struct damon_ctx **ctxs, int nr_ctxs);
+int damon_stop(struct damon_ctx **ctxs, int nr_ctxs);
+
 #endif	/* CONFIG_DAMON */
 
 #endif

348 lines not on this page · raw message

index 1f7b095646c2..0797bdfbfc24 100644
@@ -132,7 +132,8 @@ struct damon_callback {
  *
  * @sample_interval:		The time between access samplings.
  * @aggr_interval:		The time between monitor results aggregations.
- * @nr_regions:			The number of monitoring regions.
+ * @min_nr_regions:		The minimum number of monitoring regions.
+ * @max_nr_regions:		The maximum number of monitoring regions.
  *
  * For each @sample_interval, DAMON checks whether each region is accessed or
  * not.  It aggregates and keeps the access information (number of accesses to

@@ -166,7 +167,8 @@ struct damon_callback {
 struct damon_ctx {
 	unsigned long sample_interval;
 	unsigned long aggr_interval;
-	unsigned long nr_regions;
+	unsigned long min_nr_regions;
+	unsigned long max_nr_regions;
 
 	struct timespec64 last_aggregation;
 

@@ -214,8 +216,9 @@ unsigned int damon_nr_regions(struct damon_target *t);
 
 int damon_set_targets(struct damon_ctx *ctx,
 		unsigned long *ids, ssize_t nr_ids);
-int damon_set_attrs(struct damon_ctx *ctx, unsigned long sample_int,
-		unsigned long aggr_int, unsigned long nr_reg);
+int damon_set_attrs(struct damon_ctx *ctx,
+		unsigned long sample_int, unsigned long aggr_int,
+		unsigned long min_nr_reg, unsigned long max_nr_reg);
 
 int damon_nr_running_ctxs(void);
 int damon_start(struct damon_ctx **ctxs, int nr_ctxs);

258 lines not on this page · raw message

index 0797bdfbfc24..53107182bbed 100644
@@ -60,6 +60,7 @@ struct damon_ctx;
  * struct damon_primitive	Monitoring primitives for given use cases.
  *
  * @init_target_regions:	Constructs initial monitoring target regions.
+ * @update_target_regions:	Updates monitoring target regions.
  * @prepare_access_checks:	Prepares next access check of target regions.
  * @check_accesses:		Checks the access of target regions.
  * @target_valid:		Determine if the target is valid.

@@ -68,12 +69,17 @@ struct damon_ctx;
  * DAMON can be extended for various address spaces and usages.  For this,
  * users should register the low level primitives for their target address
  * space and usecase via the &damon_ctx.primitive.  Then, the monitoring thread
- * calls @init_target_regions before starting the monitoring and
+ * calls @init_target_regions before starting the monitoring,
+ * @update_target_regions for each @regions_update_interval, and
  * @prepare_access_checks, @check_accesses, and @target_valid for each
  * @sample_interval.
+
  *
  * @init_target_regions should construct proper monitoring target regions and
  * link those to the DAMON context struct.
+ * @update_target_regions should update the monitoring target regions for
+ * current status.
+
  * @prepare_access_checks should manipulate the monitoring regions to be
  * prepare for the next access check.
  * @check_accesses should check the accesses to each region that made after the

@@ -87,6 +93,7 @@ struct damon_ctx;
  */
 struct damon_primitive {
 	void (*init_target_regions)(struct damon_ctx *context);
+	void (*update_target_regions)(struct damon_ctx *context);
 	void (*prepare_access_checks)(struct damon_ctx *context);
 	unsigned int (*check_accesses)(struct damon_ctx *context);
 	bool (*target_valid)(struct damon_target *target);

@@ -132,13 +139,15 @@ struct damon_callback {
  *
  * @sample_interval:		The time between access samplings.
  * @aggr_interval:		The time between monitor results aggregations.
+ * @regions_update_interval:	The time between monitor regions updates.
  * @min_nr_regions:		The minimum number of monitoring regions.
  * @max_nr_regions:		The maximum number of monitoring regions.
  *
  * For each @sample_interval, DAMON checks whether each region is accessed or
  * not.  It aggregates and keeps the access information (number of accesses to
- * each region) for @aggr_interval time.  All time intervals are in
- * micro-seconds.
+ * each region) for @aggr_interval time.  DAMON also checks whether the target
+ * memory regions need update (e.g., by ``mmap()`` calls from the application,
+ * @regions_update_interval.  All time intervals are in micro-seconds.
  *
  * @kdamond:		Kernel thread who does the monitoring.
  * @kdamond_stop:	Notifies whether kdamond should stop.

@@ -167,10 +176,12 @@ struct damon_callback {
 struct damon_ctx {
 	unsigned long sample_interval;
 	unsigned long aggr_interval;
+	unsigned long regions_update_interval;
 	unsigned long min_nr_regions;
 	unsigned long max_nr_regions;
 
 	struct timespec64 last_aggregation;
+	struct timespec64 last_regions_update;
 
 	struct task_struct *kdamond;
 	bool kdamond_stop;

@@ -216,8 +227,8 @@ unsigned int damon_nr_regions(struct damon_target *t);
 
 int damon_set_targets(struct damon_ctx *ctx,
 		unsigned long *ids, ssize_t nr_ids);
-int damon_set_attrs(struct damon_ctx *ctx,
-		unsigned long sample_int, unsigned long aggr_int,
+int damon_set_attrs(struct damon_ctx *ctx, unsigned long sample_int,
+		unsigned long aggr_int, unsigned long regions_update_int,
 		unsigned long min_nr_reg, unsigned long max_nr_reg);
 
 int damon_nr_running_ctxs(void);

index ed364b42721d..36428327e848 100644
@@ -167,6 +167,7 @@ int damon_set_targets(struct damon_ctx *ctx,
  * damon_set_attrs() - Set attributes for the monitoring.
  * @ctx:		monitoring context
  * @sample_int:		time interval between samplings
+ * @regions_update_int:	time interval between target regions update
  * @aggr_int:		time interval between aggregations
  * @min_nr_reg:		minimal number of regions
  * @max_nr_reg:		maximum number of regions

@@ -176,8 +177,8 @@ int damon_set_targets(struct damon_ctx *ctx,
  *
  * Return: 0 on success, negative error code otherwise.
  */
-int damon_set_attrs(struct damon_ctx *ctx,
-		    unsigned long sample_int, unsigned long aggr_int,
+int damon_set_attrs(struct damon_ctx *ctx, unsigned long sample_int,
+		    unsigned long aggr_int, unsigned long regions_update_int,
 		    unsigned long min_nr_reg, unsigned long max_nr_reg)
 {
 	if (min_nr_reg < 3) {

@@ -193,6 +194,7 @@ int damon_set_attrs(struct damon_ctx *ctx,
 
 	ctx->sample_interval = sample_int;
 	ctx->aggr_interval = aggr_int;
+	ctx->regions_update_interval = regions_update_int;
 	ctx->min_nr_regions = min_nr_reg;
 	ctx->max_nr_regions = max_nr_reg;
 

@@ -529,6 +531,17 @@ static void kdamond_split_regions(struct damon_ctx *ctx)
 	last_nr_regions = nr_regions;
 }
 
+/*
+ * Check whether it is time to check and apply the target monitoring regions
+ *
+ * Returns true if it is.
+ */
+static bool kdamond_need_update_regions(struct damon_ctx *ctx)
+{
+	return damon_check_reset_time_interval(&ctx->last_regions_update,
+			ctx->regions_update_interval);
+}
+
 /*
  * Check whether current monitoring should be stopped
  *

@@ -612,6 +625,11 @@ static int kdamond_fn(void *data)
 			kdamond_reset_aggregated(ctx);
 			kdamond_split_regions(ctx);
 		}
+
+		if (kdamond_need_update_regions(ctx)) {
+			kdamond_call_prmt(ctx, update_target_regions);
+			sz_limit = damon_region_sz_limit(ctx);
+		}
 	}
 	damon_for_each_target(t, ctx) {
 		damon_for_each_region_safe(r, next, t)

index 6be1aa559b1e..7736d290bb61 100644
@@ -132,7 +132,7 @@ enum pageflags {
 #ifdef CONFIG_MEMORY_FAILURE
 	PG_hwpoison,		/* hardware poisoned page. Don't touch */
 #endif
-#if defined(CONFIG_IDLE_PAGE_TRACKING) && defined(CONFIG_64BIT)
+#if defined(CONFIG_PAGE_IDLE_FLAG) && defined(CONFIG_64BIT)
 	PG_young,
 	PG_idle,
 #endif

@@ -432,7 +432,7 @@ static inline bool set_hwpoison_free_buddy_page(struct page *page)
 #define __PG_HWPOISON 0
 #endif
 
-#if defined(CONFIG_IDLE_PAGE_TRACKING) && defined(CONFIG_64BIT)
+#if defined(CONFIG_PAGE_IDLE_FLAG) && defined(CONFIG_64BIT)
 TESTPAGEFLAG(Young, young, PF_ANY)
 SETPAGEFLAG(Young, young, PF_ANY)
 TESTCLEARFLAG(Young, young, PF_ANY)

index cfce186f0c4e..c9cbc9756011 100644
@@ -19,7 +19,7 @@ struct page_ext_operations {
 enum page_ext_flags {
 	PAGE_EXT_OWNER,
 	PAGE_EXT_OWNER_ALLOCATED,
-#if defined(CONFIG_IDLE_PAGE_TRACKING) && !defined(CONFIG_64BIT)
+#if defined(CONFIG_PAGE_IDLE_FLAG) && !defined(CONFIG_64BIT)
 	PAGE_EXT_YOUNG,
 	PAGE_EXT_IDLE,
 #endif

index 1e894d34bdce..d8a6aecf99cb 100644
@@ -6,7 +6,7 @@
 #include <linux/page-flags.h>
 #include <linux/page_ext.h>
 
-#ifdef CONFIG_IDLE_PAGE_TRACKING
+#ifdef CONFIG_PAGE_IDLE_FLAG
 
 #ifdef CONFIG_64BIT
 static inline bool page_is_young(struct page *page)

@@ -106,7 +106,7 @@ static inline void clear_page_idle(struct page *page)
 }
 #endif /* CONFIG_64BIT */
 
-#else /* !CONFIG_IDLE_PAGE_TRACKING */
+#else /* !CONFIG_PAGE_IDLE_FLAG */
 
 static inline bool page_is_young(struct page *page)
 {

@@ -135,6 +135,6 @@ static inline void clear_page_idle(struct page *page)
 {
 }
 
-#endif /* CONFIG_IDLE_PAGE_TRACKING */
+#endif /* CONFIG_PAGE_IDLE_FLAG */
 
 #endif /* _LINUX_MM_PAGE_IDLE_H */

index 5fb752034386..4d182c32071b 100644
@@ -73,7 +73,7 @@
 #define IF_HAVE_PG_HWPOISON(flag,string)
 #endif
 
-#if defined(CONFIG_IDLE_PAGE_TRACKING) && defined(CONFIG_64BIT)
+#if defined(CONFIG_PAGE_IDLE_FLAG) && defined(CONFIG_64BIT)
 #define IF_HAVE_PG_IDLE(flag,string) ,{1UL << flag, string}
 #else
 #define IF_HAVE_PG_IDLE(flag,string)

index a3616f7a0e9e..f9a6ff65ac0a 100644
@@ -58,11 +58,21 @@
  * can utilize this callback to initialize the state of it correctly.
  */
 
+#if defined(CONFIG_PAGE_IDLE_FLAG) && !defined(CONFIG_64BIT)
+static bool need_page_idle(void)
+{
+	return true;
+}
+struct page_ext_operations page_idle_ops = {
+	.need = need_page_idle,
+};
+#endif
+
 static struct page_ext_operations *page_ext_ops[] = {
 #ifdef CONFIG_PAGE_OWNER
 	&page_owner_ops,
 #endif
-#if defined(CONFIG_IDLE_PAGE_TRACKING) && !defined(CONFIG_64BIT)
+#if defined(CONFIG_PAGE_IDLE_FLAG) && !defined(CONFIG_64BIT)
 	&page_idle_ops,
 #endif
 };

index 057c61df12db..144fb4ed961d 100644
@@ -211,16 +211,6 @@ static const struct attribute_group page_idle_attr_group = {
 	.name = "page_idle",
 };
 
-#ifndef CONFIG_64BIT
-static bool need_page_idle(void)
-{
-	return true;
-}
-struct page_ext_operations page_idle_ops = {
-	.need = need_page_idle,
-};
-#endif
-
 static int __init page_idle_init(void)
 {
 	int err;

index 53107182bbed..86d2a10e9073 100644
@@ -237,4 +237,18 @@ int damon_stop(struct damon_ctx **ctxs, int nr_ctxs);
 
 #endif	/* CONFIG_DAMON */
 
+#ifdef CONFIG_DAMON_PRIMITIVES
+
+/* Reference callback implementations for virtual memory */
+void damon_va_init_regions(struct damon_ctx *ctx);
+void damon_va_update_regions(struct damon_ctx *ctx);
+void damon_va_prepare_access_checks(struct damon_ctx *ctx);
+unsigned int damon_va_check_accesses(struct damon_ctx *ctx);
+bool damon_va_target_valid(struct damon_target *t);
+void damon_va_cleanup(struct damon_ctx *ctx);
+void damon_va_set_primitives(struct damon_ctx *ctx);
+
+#endif	/* CONFIG_DAMON_PRIMITIVES */
+
+
 #endif

582 lines not on this page · raw message

index 144fb4ed961d..0aa45f848570 100644
@@ -16,6 +16,8 @@
 #define BITMAP_CHUNK_SIZE	sizeof(u64)
 #define BITMAP_CHUNK_BITS	(BITMAP_CHUNK_SIZE * BITS_PER_BYTE)
 
+static DEFINE_MUTEX(page_idle_lock);
+
 /*
  * Idle page tracking only considers user memory pages, for other types of
  * pages the idle flag is always unset and an attempt to set it is silently

@@ -169,6 +171,9 @@ static ssize_t page_idle_bitmap_write(struct file *file, struct kobject *kobj,
 	unsigned long pfn, end_pfn;
 	int bit;
 
+	if (!mutex_is_locked(&page_idle_lock))
+		return -EPERM;
+
 	if (pos % BITMAP_CHUNK_SIZE || count % BITMAP_CHUNK_SIZE)
 		return -EINVAL;
 

@@ -197,17 +202,52 @@ static ssize_t page_idle_bitmap_write(struct file *file, struct kobject *kobj,
 	return (char *)in - buf;
 }
 
+static ssize_t page_idle_lock_show(struct kobject *kobj,
+		struct kobj_attribute *attr, char *buf)
+{
+	return sprintf(buf, "%d\n", mutex_is_locked(&page_idle_lock));
+}
+
+static ssize_t page_idle_lock_store(struct kobject *kobj,
+		struct kobj_attribute *attr, const char *buf, size_t count)
+{
+	bool do_lock;
+	int ret;
+
+	ret = kstrtobool(buf, &do_lock);
+	if (ret < 0)
+		return ret;
+
+	if (do_lock) {
+		if (!mutex_trylock(&page_idle_lock))
+			return -EBUSY;
+	} else {
+		mutex_unlock(&page_idle_lock);
+	}
+
+	return count;
+}
+
 static struct bin_attribute page_idle_bitmap_attr =
 		__BIN_ATTR(bitmap, 0600,
 			   page_idle_bitmap_read, page_idle_bitmap_write, 0);
 
+static struct kobj_attribute page_idle_lock_attr =
+		__ATTR(lock, 0600, page_idle_lock_show, page_idle_lock_store);
+
 static struct bin_attribute *page_idle_bin_attrs[] = {
 	&page_idle_bitmap_attr,
 	NULL,
 };
 
+static struct attribute *page_idle_lock_attrs[] = {
+	&page_idle_lock_attr.attr,
+	NULL,
+};
+
 static const struct attribute_group page_idle_attr_group = {
 	.bin_attrs = page_idle_bin_attrs,
+	.attrs = page_idle_lock_attrs,
 	.name = "page_idle",
 };
 

index d8a6aecf99cb..bcbb965b566c 100644
@@ -8,6 +8,8 @@
 
 #ifdef CONFIG_PAGE_IDLE_FLAG
 
+extern struct mutex page_idle_lock;
+
 #ifdef CONFIG_64BIT
 static inline bool page_is_young(struct page *page)
 {

index 6c8cb66866ac..9f33677e4807 100644
@@ -15,6 +15,10 @@
 #include <linux/sched/mm.h>
 #include <linux/slab.h>
 
+#ifndef CONFIG_IDLE_PAGE_TRACKING
+DEFINE_MUTEX(page_idle_lock);
+#endif
+
 /* Minimal region size.  Every damon_region is aligned by this. */
 #define MIN_REGION PAGE_SIZE
 

@@ -552,6 +556,9 @@ bool damon_va_target_valid(struct damon_target *t)
 {
 	struct task_struct *task;
 
+	if (!mutex_is_locked(&page_idle_lock))
+		return false;
+
 	task = damon_get_task_struct(t);
 	if (task) {
 		put_task_struct(task);

index 0aa45f848570..958dcc18f6cd 100644
@@ -16,7 +16,7 @@
 #define BITMAP_CHUNK_SIZE	sizeof(u64)
 #define BITMAP_CHUNK_BITS	(BITMAP_CHUNK_SIZE * BITS_PER_BYTE)
 
-static DEFINE_MUTEX(page_idle_lock);
+DEFINE_MUTEX(page_idle_lock);
 
 /*
  * Idle page tracking only considers user memory pages, for other types of

new file mode 100644
index 000000000000..2f422f4f1fb9
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM damon
+
+#if !defined(_TRACE_DAMON_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_DAMON_H
+
+#include <linux/damon.h>
+#include <linux/types.h>
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(damon_aggregated,
+
+	TP_PROTO(struct damon_target *t, struct damon_region *r,
+		unsigned int nr_regions),
+
+	TP_ARGS(t, r, nr_regions),
+
+	TP_STRUCT__entry(
+		__field(unsigned long, target_id)
+		__field(unsigned int, nr_regions)
+		__field(unsigned long, start)
+		__field(unsigned long, end)
+		__field(unsigned int, nr_accesses)
+	),
+
+	TP_fast_assign(
+		__entry->target_id = t->id;
+		__entry->nr_regions = nr_regions;
+		__entry->start = r->ar.start;
+		__entry->end = r->ar.end;
+		__entry->nr_accesses = r->nr_accesses;
+	),
+
+	TP_printk("target_id=%lu nr_regions=%u %lu-%lu: %u",
+			__entry->target_id, __entry->nr_regions,
+			__entry->start, __entry->end, __entry->nr_accesses)
+);
+
+#endif /* _TRACE_DAMON_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>

index 36428327e848..d7957d8ff530 100644
@@ -13,6 +13,9 @@
 #include <linux/random.h>
 #include <linux/slab.h>
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/damon.h>
+
 /* Minimal region size.  Every damon_region is aligned by this. */
 #define MIN_REGION PAGE_SIZE
 

@@ -386,8 +389,10 @@ static void kdamond_reset_aggregated(struct damon_ctx *c)
 	damon_for_each_target(t, c) {
 		struct damon_region *r;
 
-		damon_for_each_region(r, t)
+		damon_for_each_region(r, t) {
+			trace_damon_aggregated(t, r, damon_nr_regions(t));
 			r->nr_accesses = 0;
+		}
 	}
 }
 

index 86d2a10e9073..e46d30b4e96e 100644
@@ -225,6 +225,8 @@ void damon_free_target(struct damon_target *t);
 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_destroy_ctx(struct damon_ctx *ctx);
 int damon_set_targets(struct damon_ctx *ctx,
 		unsigned long *ids, ssize_t nr_ids);
 int damon_set_attrs(struct damon_ctx *ctx, unsigned long sample_int,

60 lines not on this page · raw message

424 lines not on this page · raw message

index 27cf8b96ab56..c4401762fc16 100644
@@ -15,6 +15,17 @@
 #include <linux/page_idle.h>
 #include <linux/slab.h>
 
+#define MIN_RECORD_BUFFER_LEN	1024
+#define MAX_RECORD_BUFFER_LEN	(4 * 1024 * 1024)
+#define MAX_RFILE_PATH_LEN	256
+
+struct dbgfs_recorder {
+	unsigned char *rbuf;
+	unsigned int rbuf_len;
+	unsigned int rbuf_offset;
+	char *rfile_path;
+};
+
 static struct damon_ctx **dbgfs_ctxs;
 static int dbgfs_nr_ctxs = 1;
 static int dbgfs_nr_terminated_ctxs;

@@ -99,6 +110,116 @@ static ssize_t dbgfs_attrs_write(struct file *file,
 	return ret;
 }
 
+static ssize_t dbgfs_record_read(struct file *file,
+		char __user *buf, size_t count, loff_t *ppos)
+{
+	struct damon_ctx *ctx = file->private_data;
+	struct dbgfs_recorder *rec = ctx->callback.private;
+	char record_buf[20 + MAX_RFILE_PATH_LEN];
+	int ret;
+
+	mutex_lock(&ctx->kdamond_lock);
+	ret = scnprintf(record_buf, ARRAY_SIZE(record_buf), "%u %s\n",
+			rec->rbuf_len, rec->rfile_path);
+	mutex_unlock(&ctx->kdamond_lock);
+	return simple_read_from_buffer(buf, count, ppos, record_buf, ret);
+}
+
+/*
+ * dbgfs_set_recording() - Set attributes for the recording.
+ * @ctx:	target kdamond context
+ * @rbuf_len:	length of the result buffer
+ * @rfile_path:	path to the monitor result files
+ *
+ * Setting 'rbuf_len' 0 disables recording.
+ *
+ * This function should not be called while the kdamond is running.
+ *
+ * Return: 0 on success, negative error code otherwise.
+ */
+static int dbgfs_set_recording(struct damon_ctx *ctx,
+			unsigned int rbuf_len, char *rfile_path)
+{
+	struct dbgfs_recorder *recorder;
+	size_t rfile_path_len;
+
+	if (rbuf_len && (rbuf_len > MAX_RECORD_BUFFER_LEN ||
+			rbuf_len < MIN_RECORD_BUFFER_LEN)) {
+		pr_err("result buffer size (%u) is out of [%d,%d]\n",
+				rbuf_len, MIN_RECORD_BUFFER_LEN,
+				MAX_RECORD_BUFFER_LEN);
+		return -EINVAL;
+	}
+	rfile_path_len = strnlen(rfile_path, MAX_RFILE_PATH_LEN);
+	if (rfile_path_len >= MAX_RFILE_PATH_LEN) {
+		pr_err("too long (>%d) result file path %s\n",
+				MAX_RFILE_PATH_LEN, rfile_path);
+		return -EINVAL;
+	}
+
+	recorder = ctx->callback.private;
+	if (!recorder) {
+		recorder = kzalloc(sizeof(*recorder), GFP_KERNEL);
+		if (!recorder)
+			return -ENOMEM;
+		ctx->callback.private = recorder;
+	}
+
+	recorder->rbuf_len = rbuf_len;
+	kfree(recorder->rbuf);
+	recorder->rbuf = NULL;
+	kfree(recorder->rfile_path);
+	recorder->rfile_path = NULL;
+
+	if (rbuf_len) {
+		recorder->rbuf = kvmalloc(rbuf_len, GFP_KERNEL);
+		if (!recorder->rbuf)
+			return -ENOMEM;
+	}
+	recorder->rfile_path = kmalloc(rfile_path_len + 1, GFP_KERNEL);
+	if (!recorder->rfile_path)
+		return -ENOMEM;
+	strncpy(recorder->rfile_path, rfile_path, rfile_path_len + 1);
+
+	return 0;
+}
+
+static ssize_t dbgfs_record_write(struct file *file,
+		const char __user *buf, size_t count, loff_t *ppos)
+{
+	struct damon_ctx *ctx = file->private_data;
+	char *kbuf;
+	unsigned int rbuf_len;
+	char rfile_path[MAX_RFILE_PATH_LEN];
+	ssize_t ret = count;
+	int err;
+
+	kbuf = user_input_str(buf, count, ppos);
+	if (IS_ERR(kbuf))
+		return PTR_ERR(kbuf);
+
+	if (sscanf(kbuf, "%u %s",
+				&rbuf_len, rfile_path) != 2) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	mutex_lock(&ctx->kdamond_lock);
+	if (ctx->kdamond) {
+		ret = -EBUSY;
+		goto unlock_out;
+	}
+
+	err = dbgfs_set_recording(ctx, rbuf_len, rfile_path);
+	if (err)
+		ret = err;
+unlock_out:
+	mutex_unlock(&ctx->kdamond_lock);
+out:
+	kfree(kbuf);
+	return ret;
+}
+
 #define targetid_is_pid(ctx)	\
 	(ctx->primitive.target_valid == damon_va_target_valid)
 

@@ -262,6 +383,13 @@ static const struct file_operations attrs_fops = {
 	.write = dbgfs_attrs_write,
 };
 
+static const struct file_operations record_fops = {
+	.owner = THIS_MODULE,
+	.open = damon_dbgfs_open,
+	.read = dbgfs_record_read,
+	.write = dbgfs_record_write,
+};
+
 static const struct file_operations target_ids_fops = {
 	.owner = THIS_MODULE,
 	.open = damon_dbgfs_open,

@@ -271,8 +399,9 @@ static const struct file_operations target_ids_fops = {
 
 static int dbgfs_fill_ctx_dir(struct dentry *dir, struct damon_ctx *ctx)
 {
-	const char * const file_names[] = {"attrs", "target_ids"};
-	const struct file_operations *fops[] = {&attrs_fops, &target_ids_fops};
+	const char * const file_names[] = {"attrs", "record", "target_ids"};
+	const struct file_operations *fops[] = {&attrs_fops, &record_fops,
+		&target_ids_fops};
 	int i;
 
 	for (i = 0; i < ARRAY_SIZE(file_names); i++) {

@@ -286,6 +415,120 @@ static int dbgfs_fill_ctx_dir(struct dentry *dir, struct damon_ctx *ctx)
 	return 0;
 }
 
+/*
+ * Flush the content in the result buffer to the result file
+ */
+static void dbgfs_flush_rbuffer(struct dbgfs_recorder *rec)
+{
+	ssize_t sz;
+	loff_t pos = 0;
+	struct file *rfile;
+
+	if (!rec->rbuf_offset)
+		return;
+
+	rfile = filp_open(rec->rfile_path,
+			O_CREAT | O_RDWR | O_APPEND | O_LARGEFILE, 0644);
+	if (IS_ERR(rfile)) {
+		pr_err("Cannot open the result file %s\n",
+				rec->rfile_path);
+		return;
+	}
+
+	while (rec->rbuf_offset) {
+		sz = kernel_write(rfile, rec->rbuf, rec->rbuf_offset, &pos);
+		if (sz < 0)
+			break;
+		rec->rbuf_offset -= sz;
+	}
+	filp_close(rfile, NULL);
+}
+
+/*
+ * Write a data into the result buffer
+ */
+static void dbgfs_write_rbuf(struct damon_ctx *ctx, void *data, ssize_t size)
+{
+	struct dbgfs_recorder *rec = ctx->callback.private;
+
+	if (!rec->rbuf_len || !rec->rbuf || !rec->rfile_path)
+		return;
+	if (rec->rbuf_offset + size > rec->rbuf_len)
+		dbgfs_flush_rbuffer(ctx->callback.private);
+	if (rec->rbuf_offset + size > rec->rbuf_len) {
+		pr_warn("%s: flush failed, or wrong size given(%u, %zu)\n",
+				__func__, rec->rbuf_offset, size);
+		return;
+	}
+
+	memcpy(&rec->rbuf[rec->rbuf_offset], data, size);
+	rec->rbuf_offset += size;
+}
+
+static void dbgfs_write_record_header(struct damon_ctx *ctx)
+{
+	int recfmt_ver = 2;
+
+	dbgfs_write_rbuf(ctx, "damon_recfmt_ver", 16);
+	dbgfs_write_rbuf(ctx, &recfmt_ver, sizeof(recfmt_ver));
+}
+
+static unsigned int nr_damon_targets(struct damon_ctx *ctx)
+{
+	struct damon_target *t;
+	unsigned int nr_targets = 0;
+
+	damon_for_each_target(t, ctx)
+		nr_targets++;
+
+	return nr_targets;
+}
+
+static int dbgfs_before_start(struct damon_ctx *ctx)
+{
+	dbgfs_write_record_header(ctx);
+	return 0;
+}
+
+/*
+ * Store the aggregated monitoring results to the result buffer
+ *
+ * The format for the result buffer is as below:
+ *
+ *   <time> <number of targets> <array of target infos>
+ *
+ *   target info: <id> <number of regions> <array of region infos>
+ *   region info: <start address> <end address> <nr_accesses>
+ */
+static int dbgfs_after_aggregation(struct damon_ctx *c)
+{
+	struct damon_target *t;
+	struct timespec64 now;
+	unsigned int nr;
+
+	ktime_get_coarse_ts64(&now);
+
+	dbgfs_write_rbuf(c, &now, sizeof(now));
+	nr = nr_damon_targets(c);
+	dbgfs_write_rbuf(c, &nr, sizeof(nr));
+
+	damon_for_each_target(t, c) {
+		struct damon_region *r;
+
+		dbgfs_write_rbuf(c, &t->id, sizeof(t->id));
+		nr = damon_nr_regions(t);
+		dbgfs_write_rbuf(c, &nr, sizeof(nr));
+		damon_for_each_region(r, t) {
+			dbgfs_write_rbuf(c, &r->ar.start, sizeof(r->ar.start));
+			dbgfs_write_rbuf(c, &r->ar.end, sizeof(r->ar.end));
+			dbgfs_write_rbuf(c, &r->nr_accesses,
+					sizeof(r->nr_accesses));
+		}
+	}
+
+	return 0;
+}
+
 static void dbgfs_unlock_page_idle_lock(void)
 {
 	mutex_lock(&damon_dbgfs_lock);

@@ -298,6 +541,7 @@ static void dbgfs_unlock_page_idle_lock(void)
 
 static int dbgfs_before_terminate(struct damon_ctx *ctx)
 {
+	dbgfs_flush_rbuffer(ctx->callback.private);
 	dbgfs_unlock_page_idle_lock();
 	return 0;
 }

@@ -310,7 +554,14 @@ static struct damon_ctx *dbgfs_new_ctx(void)
 	if (!ctx)
 		return NULL;
 
+	if (dbgfs_set_recording(ctx, 0, "none")) {
+		damon_destroy_ctx(ctx);
+		return NULL;
+	}
+
 	damon_va_set_primitives(ctx);
+	ctx->callback.before_start = dbgfs_before_start;
+	ctx->callback.after_aggregation = dbgfs_after_aggregation;
 	ctx->callback.before_terminate = dbgfs_before_terminate;
 	return ctx;
 }

index c4401762fc16..a0956618ec2d 100644
@@ -369,6 +369,32 @@ static ssize_t dbgfs_target_ids_write(struct file *file,
 	return ret;
 }
 
+static ssize_t dbgfs_kdamond_pid_read(struct file *file,
+		char __user *buf, size_t count, loff_t *ppos)
+{
+	struct damon_ctx *ctx = file->private_data;
+	char *kbuf;
+	ssize_t len;
+
+	kbuf = kmalloc(count, GFP_KERNEL);
+	if (!kbuf)
+		return -ENOMEM;
+
+	mutex_lock(&ctx->kdamond_lock);
+	if (ctx->kdamond)
+		len = scnprintf(kbuf, count, "%d\n", ctx->kdamond->pid);
+	else
+		len = scnprintf(kbuf, count, "none\n");
+	mutex_unlock(&ctx->kdamond_lock);
+	if (!len)
+		goto out;
+	len = simple_read_from_buffer(buf, count, ppos, kbuf, len);
+
+out:
+	kfree(kbuf);
+	return len;
+}
+
 static int damon_dbgfs_open(struct inode *inode, struct file *file)
 {
 	file->private_data = inode->i_private;

@@ -397,11 +423,18 @@ static const struct file_operations target_ids_fops = {
 	.write = dbgfs_target_ids_write,
 };
 
+static const struct file_operations kdamond_pid_fops = {
+	.owner = THIS_MODULE,
+	.open = damon_dbgfs_open,
+	.read = dbgfs_kdamond_pid_read,
+};
+
 static int dbgfs_fill_ctx_dir(struct dentry *dir, struct damon_ctx *ctx)
 {
-	const char * const file_names[] = {"attrs", "record", "target_ids"};
+	const char * const file_names[] = {"attrs", "record", "target_ids",
+		"kdamond_pid"};
 	const struct file_operations *fops[] = {&attrs_fops, &record_fops,
-		&target_ids_fops};
+		&target_ids_fops}, &kdamond_pid_fops;
 	int i;
 
 	for (i = 0; i < ARRAY_SIZE(file_names); i++) {

index a0956618ec2d..908fa395bdfb 100644
@@ -434,7 +434,7 @@ static int dbgfs_fill_ctx_dir(struct dentry *dir, struct damon_ctx *ctx)
 	const char * const file_names[] = {"attrs", "record", "target_ids",
 		"kdamond_pid"};
 	const struct file_operations *fops[] = {&attrs_fops, &record_fops,
-		&target_ids_fops}, &kdamond_pid_fops;
+		&target_ids_fops, &kdamond_pid_fops};
 	int i;
 
 	for (i = 0; i < ARRAY_SIZE(file_names); i++) {

@@ -506,6 +506,13 @@ static void dbgfs_write_record_header(struct damon_ctx *ctx)
 	dbgfs_write_rbuf(ctx, &recfmt_ver, sizeof(recfmt_ver));
 }
 
+static void dbgfs_free_recorder(struct dbgfs_recorder *recorder)
+{
+	kfree(recorder->rbuf);
+	kfree(recorder->rfile_path);
+	kfree(recorder);
+}
+
 static unsigned int nr_damon_targets(struct damon_ctx *ctx)
 {
 	struct damon_target *t;

@@ -599,6 +606,195 @@ static struct damon_ctx *dbgfs_new_ctx(void)
 	return ctx;
 }
 
+static void dbgfs_destroy_ctx(struct damon_ctx *ctx)
+{
+	dbgfs_free_recorder(ctx->callback.private);
+	damon_destroy_ctx(ctx);
+}
+
+/*
+ * Make a context of @name and create a debugfs directory for it.
+ *
+ * This function should be called while holding damon_dbgfs_lock.
+ *
+ * Returns 0 on success, negative error code otherwise.
+ */
+static int dbgfs_mk_context(char *name)
+{
+	struct dentry *root, **new_dirs, *new_dir;
+	struct damon_ctx **new_ctxs, *new_ctx;
+	int err;
+
+	if (damon_nr_running_ctxs())
+		return -EBUSY;
+
+	new_ctxs = krealloc(dbgfs_ctxs, sizeof(*dbgfs_ctxs) *
+			(dbgfs_nr_ctxs + 1), GFP_KERNEL);
+	if (!new_ctxs)
+		return -ENOMEM;
+
+	new_dirs = krealloc(dbgfs_dirs, sizeof(*dbgfs_dirs) *
+			(dbgfs_nr_ctxs + 1), GFP_KERNEL);
+	if (!new_dirs) {
+		kfree(new_ctxs);
+		return -ENOMEM;
+	}
+
+	dbgfs_ctxs = new_ctxs;
+	dbgfs_dirs = new_dirs;
+
+	root = dbgfs_dirs[0];
+	if (!root)
+		return -ENOENT;
+
+	new_dir = debugfs_create_dir(name, root);
+	if (IS_ERR(new_dir))
+		return PTR_ERR(new_dir);
+	dbgfs_dirs[dbgfs_nr_ctxs] = new_dir;
+
+	new_ctx = dbgfs_new_ctx();
+	if (!new_ctx) {
+		debugfs_remove(new_dir);
+		dbgfs_dirs[dbgfs_nr_ctxs] = NULL;
+		return -ENOMEM;
+	}
+	dbgfs_ctxs[dbgfs_nr_ctxs] = new_ctx;
+
+	err = dbgfs_fill_ctx_dir(dbgfs_dirs[dbgfs_nr_ctxs],
+			dbgfs_ctxs[dbgfs_nr_ctxs]);
+	if (err)
+		return err;
+
+	dbgfs_nr_ctxs++;
+	return 0;
+}
+
+static ssize_t dbgfs_mk_context_write(struct file *file,
+		const char __user *buf, size_t count, loff_t *ppos)
+{
+	char *kbuf;
+	char *ctx_name;
+	ssize_t ret = count;
+	int err;
+
+	kbuf = user_input_str(buf, count, ppos);
+	if (IS_ERR(kbuf))
+		return PTR_ERR(kbuf);
+	ctx_name = kmalloc(count + 1, GFP_KERNEL);
+	if (!ctx_name) {
+		kfree(kbuf);
+		return -ENOMEM;
+	}
+
+	/* Trim white space */
+	if (sscanf(kbuf, "%s", ctx_name) != 1) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	mutex_lock(&damon_dbgfs_lock);
+	err = dbgfs_mk_context(ctx_name);
+	if (err)
+		ret = err;
+	mutex_unlock(&damon_dbgfs_lock);
+
+out:
+	kfree(kbuf);
+	kfree(ctx_name);
+	return ret;
+}
+
+/*
+ * Remove a context of @name and its debugfs directory.
+ *
+ * This function should be called while holding damon_dbgfs_lock.
+ *
+ * Return 0 on success, negative error code otherwise.
+ */
+static int dbgfs_rm_context(char *name)
+{
+	struct dentry *root, *dir, **new_dirs;
+	struct damon_ctx **new_ctxs;
+	int i, j;
+
+	if (damon_nr_running_ctxs())
+		return -EBUSY;
+
+	root = dbgfs_dirs[0];
+	if (!root)
+		return -ENOENT;
+
+	dir = debugfs_lookup(name, root);
+	if (!dir)
+		return -ENOENT;
+
+	new_dirs = kmalloc_array(dbgfs_nr_ctxs - 1, sizeof(*dbgfs_dirs),
+			GFP_KERNEL);
+	if (!new_dirs)
+		return -ENOMEM;
+
+	new_ctxs = kmalloc_array(dbgfs_nr_ctxs - 1, sizeof(*dbgfs_ctxs),
+			GFP_KERNEL);
+	if (!new_ctxs) {
+		kfree(new_dirs);
+		return -ENOMEM;
+	}
+
+	for (i = 0, j = 0; i < dbgfs_nr_ctxs; i++) {
+		if (dbgfs_dirs[i] == dir) {
+			debugfs_remove(dbgfs_dirs[i]);
+			dbgfs_destroy_ctx(dbgfs_ctxs[i]);
+			continue;
+		}
+		new_dirs[j] = dbgfs_dirs[i];
+		new_ctxs[j++] = dbgfs_ctxs[i];
+	}
+
+	kfree(dbgfs_dirs);
+	kfree(dbgfs_ctxs);
+
+	dbgfs_dirs = new_dirs;
+	dbgfs_ctxs = new_ctxs;
+	dbgfs_nr_ctxs--;
+
+	return 0;
+}
+
+static ssize_t dbgfs_rm_context_write(struct file *file,
+		const char __user *buf, size_t count, loff_t *ppos)
+{
+	char *kbuf;
+	ssize_t ret = count;
+	int err;
+	char *ctx_name;
+
+	kbuf = user_input_str(buf, count, ppos);
+	if (IS_ERR(kbuf))
+		return PTR_ERR(kbuf);
+	ctx_name = kmalloc(count + 1, GFP_KERNEL);
+	if (!ctx_name) {
+		kfree(kbuf);
+		return -ENOMEM;
+	}
+
+	/* Trim white space */
+	if (sscanf(kbuf, "%s", ctx_name) != 1) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	mutex_lock(&damon_dbgfs_lock);
+	err = dbgfs_rm_context(ctx_name);
+	if (err)
+		ret = err;
+	mutex_unlock(&damon_dbgfs_lock);
+
+out:
+	kfree(kbuf);
+	kfree(ctx_name);
+	return ret;
+}
+
 static ssize_t dbgfs_monitor_on_read(struct file *file,
 		char __user *buf, size_t count, loff_t *ppos)
 {

@@ -651,6 +847,16 @@ static ssize_t dbgfs_monitor_on_write(struct file *file,
 	return ret;
 }
 
+static const struct file_operations mk_contexts_fops = {
+	.owner = THIS_MODULE,
+	.write = dbgfs_mk_context_write,
+};
+
+static const struct file_operations rm_contexts_fops = {
+	.owner = THIS_MODULE,
+	.write = dbgfs_rm_context_write,
+};
+
 static const struct file_operations monitor_on_fops = {
 	.owner = THIS_MODULE,
 	.read = dbgfs_monitor_on_read,

@@ -660,8 +866,10 @@ static const struct file_operations monitor_on_fops = {
 static int __init __damon_dbgfs_init(void)
 {
 	struct dentry *dbgfs_root;
-	const char * const file_names[] = {"monitor_on"};
-	const struct file_operations *fops[] = {&monitor_on_fops};
+	const char * const file_names[] = {"mk_contexts", "rm_contexts",
+		"monitor_on"};
+	const struct file_operations *fops[] = {&mk_contexts_fops,
+		&rm_contexts_fops, &monitor_on_fops};
 	int i;
 
 	dbgfs_root = debugfs_create_dir("damon", NULL);

253 lines not on this page · raw message

index 47baf859d7d9..7c547e1022af 100644
@@ -17,7 +17,11 @@
 #include <trace/events/damon.h>
 
 /* Minimal region size.  Every damon_region is aligned by this. */
+#ifndef CONFIG_DAMON_KUNIT_TEST
 #define MIN_REGION PAGE_SIZE
+#else
+#define MIN_REGION 1
+#endif
 
 /*
  * Functions and macros for DAMON data structures

@@ -703,3 +707,5 @@ static int kdamond_fn(void *data)
 
 	do_exit(0);
 }
+
+#include "core-test.h"

209 lines not on this page · raw message

index 908fa395bdfb..df807ffb283e 100644
@@ -914,3 +914,5 @@ static int __init damon_dbgfs_init(void)
 }
 
 module_init(damon_dbgfs_init);
+
+#include "dbgfs-test.h"

328 lines not on this page · raw message

index 9f33677e4807..b03200965b6d 100644
@@ -20,7 +20,11 @@ DEFINE_MUTEX(page_idle_lock);
 #endif
 
 /* Minimal region size.  Every damon_region is aligned by this. */
+#ifndef CONFIG_DAMON_PRIMITIVES_KUNIT_TEST
 #define MIN_REGION PAGE_SIZE
+#else
+#define MIN_REGION 1
+#endif
 
 /* Get a random number in [l, r) */
 #define damon_rand(l, r) (l + prandom_u32_max(r - l))

@@ -587,3 +591,5 @@ void damon_va_set_primitives(struct damon_ctx *ctx)
 	ctx->primitive.target_valid = damon_va_target_valid;
 	ctx->primitive.cleanup = damon_va_cleanup;
 }
+
+#include "primitives-test.h"