Merge branch 'akpm' (patches from Andrew)

Merge misc updates from Andrew Morton:
 "146 patches.

  Subsystems affected by this patch series: kthread, ia64, scripts,
  ntfs, squashfs, ocfs2, vfs, and mm (slab-generic, slab, kmemleak,
  dax, kasan, debug, pagecache, gup, shmem, frontswap, memremap,
  memcg, selftests, pagemap, dma, vmalloc, memory-failure, hugetlb,
  userfaultfd, vmscan, mempolicy, oom-kill, hugetlbfs, migration, thp,
  ksm, page-poison, percpu, rmap, zswap, zram, cleanups, hmm, and
  damon)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (146 commits)
  mm/damon: hide kernel pointer from tracepoint event
  mm/damon/vaddr: hide kernel pointer from damon_va_three_regions() failure log
  mm/damon/vaddr: use pr_debug() for damon_va_three_regions() failure logging
  mm/damon/dbgfs: remove an unnecessary variable
  mm/damon: move the implementation of damon_insert_region to damon.h
  mm/damon: add access checking for hugetlb pages
  Docs/admin-guide/mm/damon/usage: update for schemes statistics
  mm/damon/dbgfs: support all DAMOS stats
  Docs/admin-guide/mm/damon/reclaim: document statistics parameters
  mm/damon/reclaim: provide reclamation statistics
  mm/damon/schemes: account how many times quota limit has exceeded
  mm/damon/schemes: account scheme actions that successfully applied
  mm/damon: remove a mistakenly added comment for a future feature
  Docs/admin-guide/mm/damon/usage: update for kdamond_pid and (mk|rm)_contexts
  Docs/admin-guide/mm/damon/usage: mention tracepoint at the beginning
  Docs/admin-guide/mm/damon/usage: remove redundant information
  Docs/admin-guide/mm/damon/usage: update for scheme quotas and watermarks
  mm/damon: convert macro functions to static inline functions
  mm/damon: modify damon_rand() macro to static inline function
  mm/damon: move damon_rand() definition into damon.h
  ...

1 files changed, 53 insertions, 36 deletions

diff --git a/include/linux/damon.h b/include/linux/damon.h
index b4d4be3cc987..5e1e3a128b77 100644
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -11,12 +11,19 @@
 #include <linux/mutex.h>
 #include <linux/time64.h>
 #include <linux/types.h>
+#include <linux/random.h>
 
 /* Minimal region size.  Every damon_region is aligned by this. */
 #define DAMON_MIN_REGION	PAGE_SIZE
 /* Max priority score for DAMON-based operation schemes */
 #define DAMOS_MAX_SCORE		(99)
 
+/* Get a random number in [l, r) */
+static inline unsigned long damon_rand(unsigned long l, unsigned long r)
+{
+	return l + prandom_u32_max(r - l);
+}
+
 /**
  * struct damon_addr_range - Represents an address region of [@start, @end).
  * @start:	Start address of the region (inclusive).
@@ -186,6 +193,22 @@ struct damos_watermarks {
 };
 
 /**
+ * struct damos_stat - Statistics on a given scheme.
+ * @nr_tried:	Total number of regions that the scheme is tried to be applied.
+ * @sz_tried:	Total size of regions that the scheme is tried to be applied.
+ * @nr_applied:	Total number of regions that the scheme is applied.
+ * @sz_applied:	Total size of regions that the scheme is applied.
+ * @qt_exceeds: Total number of times the quota of the scheme has exceeded.
+ */
+struct damos_stat {
+	unsigned long nr_tried;
+	unsigned long sz_tried;
+	unsigned long nr_applied;
+	unsigned long sz_applied;
+	unsigned long qt_exceeds;
+};
+
+/**
  * struct damos - Represents a Data Access Monitoring-based Operation Scheme.
  * @min_sz_region:	Minimum size of target regions.
  * @max_sz_region:	Maximum size of target regions.
@@ -196,8 +219,7 @@ struct damos_watermarks {
  * @action:		&damo_action to be applied to the target regions.
  * @quota:		Control the aggressiveness of this scheme.
  * @wmarks:		Watermarks for automated (in)activation of this scheme.
- * @stat_count:		Total number of regions that this scheme is applied.
- * @stat_sz:		Total size of regions that this scheme is applied.
+ * @stat:		Statistics of this scheme.
  * @list:		List head for siblings.
  *
  * For each aggregation interval, DAMON finds regions which fit in the
@@ -228,8 +250,7 @@ struct damos {
 	enum damos_action action;
 	struct damos_quota quota;
 	struct damos_watermarks wmarks;
-	unsigned long stat_count;
-	unsigned long stat_sz;
+	struct damos_stat stat;
 	struct list_head list;
 };
 
@@ -274,7 +295,8 @@ struct damon_ctx;
  * as an integer in [0, &DAMOS_MAX_SCORE].
  * @apply_scheme is called from @kdamond when a region for user provided
  * DAMON-based operation scheme is found.  It should apply the scheme's action
- * to the region.  This is not used for &DAMON_ARBITRARY_TARGET case.
+ * to the region and return bytes of the region that the action is successfully
+ * applied.
  * @target_valid should check whether the target is still valid for the
  * monitoring.
  * @cleanup is called from @kdamond just before its termination.
@@ -288,8 +310,9 @@ struct damon_primitive {
 	int (*get_scheme_score)(struct damon_ctx *context,
 			struct damon_target *t, struct damon_region *r,
 			struct damos *scheme);
-	int (*apply_scheme)(struct damon_ctx *context, struct damon_target *t,
-			struct damon_region *r, struct damos *scheme);
+	unsigned long (*apply_scheme)(struct damon_ctx *context,
+			struct damon_target *t, struct damon_region *r,
+			struct damos *scheme);
 	bool (*target_valid)(void *target);
 	void (*cleanup)(struct damon_ctx *context);
 };
@@ -392,14 +415,20 @@ struct damon_ctx {
 	struct list_head schemes;
 };
 
-#define damon_next_region(r) \
-	(container_of(r->list.next, struct damon_region, list))
+static inline struct damon_region *damon_next_region(struct damon_region *r)
+{
+	return container_of(r->list.next, struct damon_region, list);
+}
 
-#define damon_prev_region(r) \
-	(container_of(r->list.prev, struct damon_region, list))
+static inline struct damon_region *damon_prev_region(struct damon_region *r)
+{
+	return container_of(r->list.prev, struct damon_region, list);
+}
 
-#define damon_last_region(t) \
-	(list_last_entry(&t->regions_list, struct damon_region, list))
+static inline struct damon_region *damon_last_region(struct damon_target *t)
+{
+	return list_last_entry(&t->regions_list, struct damon_region, list);
+}
 
 #define damon_for_each_region(r, t) \
 	list_for_each_entry(r, &t->regions_list, list)
@@ -422,9 +451,18 @@ struct damon_ctx {
 #ifdef CONFIG_DAMON
 
 struct damon_region *damon_new_region(unsigned long start, unsigned long end);
-inline void damon_insert_region(struct damon_region *r,
+
+/*
+ * Add a region between two other regions
+ */
+static inline void damon_insert_region(struct damon_region *r,
 		struct damon_region *prev, struct damon_region *next,
-		struct damon_target *t);
+		struct damon_target *t)
+{
+	__list_add(&r->list, &prev->list, &next->list);
+	t->nr_regions++;
+}
+
 void damon_add_region(struct damon_region *r, struct damon_target *t);
 void damon_destroy_region(struct damon_region *r, struct damon_target *t);
 
@@ -461,34 +499,13 @@ int damon_stop(struct damon_ctx **ctxs, int nr_ctxs);
 #endif	/* CONFIG_DAMON */
 
 #ifdef CONFIG_DAMON_VADDR
-
-/* Monitoring primitives for virtual memory address spaces */
-void damon_va_init(struct damon_ctx *ctx);
-void damon_va_update(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(void *t);
-void damon_va_cleanup(struct damon_ctx *ctx);
-int damon_va_apply_scheme(struct damon_ctx *context, struct damon_target *t,
-		struct damon_region *r, struct damos *scheme);
-int damon_va_scheme_score(struct damon_ctx *context, struct damon_target *t,
-		struct damon_region *r, struct damos *scheme);
 void damon_va_set_primitives(struct damon_ctx *ctx);
-
 #endif	/* CONFIG_DAMON_VADDR */
 
 #ifdef CONFIG_DAMON_PADDR
-
-/* Monitoring primitives for the physical memory address space */
-void damon_pa_prepare_access_checks(struct damon_ctx *ctx);
-unsigned int damon_pa_check_accesses(struct damon_ctx *ctx);
 bool damon_pa_target_valid(void *t);
-int damon_pa_apply_scheme(struct damon_ctx *context, struct damon_target *t,
-		struct damon_region *r, struct damos *scheme);
-int damon_pa_scheme_score(struct damon_ctx *context, struct damon_target *t,
-		struct damon_region *r, struct damos *scheme);
 void damon_pa_set_primitives(struct damon_ctx *ctx);
-
 #endif	/* CONFIG_DAMON_PADDR */
 
 #endif	/* _DAMON_H */