mm/damon: rename damon_primitives to damon_operations

Patch series "Allow DAMON user code independent of monitoring primitives".

In-kernel DAMON user code is required to configure the monitoring context
(struct damon_ctx) with proper monitoring primitives (struct
damon_primitive).  This makes the user code dependent to all supporting
monitoring primitives.  For example, DAMON debugfs interface depends on
both DAMON_VADDR and DAMON_PADDR, though some users have interest in only
one use case.  As more monitoring primitives are introduced, the problem
will be bigger.

To minimize such unnecessary dependency, this patchset makes monitoring
primitives can be registered by the implemnting code and later dynamically
searched and selected by the user code.

In addition to that, this patchset renames monitoring primitives to
monitoring operations, which is more easy to intuitively understand what
it means and how it would be structed.

This patch (of 8):

DAMON has a set of callback functions called monitoring primitives and let
it can be configured with various implementations for easy extension for
different address spaces and usages.  However, the word 'primitive' is not
so explicit.  Meanwhile, many other structs resembles similar purpose
calls themselves 'operations'.  To make the code easier to be understood,
this commit renames 'damon_primitives' to 'damon_operations' before it is
too late to rename.

Link: https://lkml.kernel.org/r/20220215184603.1479-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20220215184603.1479-2-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Xin Hao <xhao@linux.alibaba.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

11 files changed, 72 insertions, 71 deletions

diff --git a/mm/damon/Kconfig b/mm/damon/Kconfig
index 5bcf05851ad0..01bad77ad7ae 100644
--- a/mm/damon/Kconfig
+++ b/mm/damon/Kconfig
@@ -25,27 +25,27 @@ config DAMON_KUNIT_TEST
 	  If unsure, say N.
 
 config DAMON_VADDR
-	bool "Data access monitoring primitives for virtual address spaces"
+	bool "Data access monitoring operations for virtual address spaces"
 	depends on DAMON && MMU
 	select PAGE_IDLE_FLAG
 	help
-	  This builds the default data access monitoring primitives for DAMON
+	  This builds the default data access monitoring operations for DAMON
 	  that work for virtual address spaces.
 
 config DAMON_PADDR
-	bool "Data access monitoring primitives for the physical address space"
+	bool "Data access monitoring operations for the physical address space"
 	depends on DAMON && MMU
 	select PAGE_IDLE_FLAG
 	help
-	  This builds the default data access monitoring primitives for DAMON
+	  This builds the default data access monitoring operations for DAMON
 	  that works for the physical address space.
 
 config DAMON_VADDR_KUNIT_TEST
-	bool "Test for DAMON primitives" if !KUNIT_ALL_TESTS
+	bool "Test for DAMON operations" if !KUNIT_ALL_TESTS
 	depends on DAMON_VADDR && KUNIT=y
 	default KUNIT_ALL_TESTS
 	help
-	  This builds the DAMON virtual addresses primitives Kunit test suite.
+	  This builds the DAMON virtual addresses operations Kunit test suite.
 
 	  For more information on KUnit and unit tests in general, please refer
 	  to the KUnit documentation.
diff --git a/mm/damon/Makefile b/mm/damon/Makefile
index f7d5ac377a2b..03931472991a 100644
--- a/mm/damon/Makefile
+++ b/mm/damon/Makefile
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 
 obj-$(CONFIG_DAMON)		:= core.o
-obj-$(CONFIG_DAMON_VADDR)	+= prmtv-common.o vaddr.o
-obj-$(CONFIG_DAMON_PADDR)	+= prmtv-common.o paddr.o
+obj-$(CONFIG_DAMON_VADDR)	+= ops-common.o vaddr.o
+obj-$(CONFIG_DAMON_PADDR)	+= ops-common.o paddr.o
 obj-$(CONFIG_DAMON_DBGFS)	+= dbgfs.o
 obj-$(CONFIG_DAMON_RECLAIM)	+= reclaim.o
diff --git a/mm/damon/core.c b/mm/damon/core.c
index bf495236d741..be93fb1c3473 100644
--- a/mm/damon/core.c
+++ b/mm/damon/core.c
@@ -204,10 +204,10 @@ struct damon_ctx *damon_new_ctx(void)
 
 	ctx->sample_interval = 5 * 1000;
 	ctx->aggr_interval = 100 * 1000;
-	ctx->primitive_update_interval = 60 * 1000 * 1000;
+	ctx->ops_update_interval = 60 * 1000 * 1000;
 
 	ktime_get_coarse_ts64(&ctx->last_aggregation);
-	ctx->last_primitive_update = ctx->last_aggregation;
+	ctx->last_ops_update = ctx->last_aggregation;
 
 	mutex_init(&ctx->kdamond_lock);
 
@@ -224,8 +224,8 @@ static void damon_destroy_targets(struct damon_ctx *ctx)
 {
 	struct damon_target *t, *next_t;
 
-	if (ctx->primitive.cleanup) {
-		ctx->primitive.cleanup(ctx);
+	if (ctx->ops.cleanup) {
+		ctx->ops.cleanup(ctx);
 		return;
 	}
 
@@ -250,7 +250,7 @@ void damon_destroy_ctx(struct damon_ctx *ctx)
  * @ctx:		monitoring context
  * @sample_int:		time interval between samplings
  * @aggr_int:		time interval between aggregations
- * @primitive_upd_int:	time interval between monitoring primitive updates
+ * @ops_upd_int:	time interval between monitoring operations updates
  * @min_nr_reg:		minimal number of regions
  * @max_nr_reg:		maximum number of regions
  *
@@ -260,7 +260,7 @@ void damon_destroy_ctx(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, unsigned long primitive_upd_int,
+		    unsigned long aggr_int, unsigned long ops_upd_int,
 		    unsigned long min_nr_reg, unsigned long max_nr_reg)
 {
 	if (min_nr_reg < 3)
@@ -270,7 +270,7 @@ int damon_set_attrs(struct damon_ctx *ctx, unsigned long sample_int,
 
 	ctx->sample_interval = sample_int;
 	ctx->aggr_interval = aggr_int;
-	ctx->primitive_update_interval = primitive_upd_int;
+	ctx->ops_update_interval = ops_upd_int;
 	ctx->min_nr_regions = min_nr_reg;
 	ctx->max_nr_regions = max_nr_reg;
 
@@ -516,10 +516,10 @@ static bool damos_valid_target(struct damon_ctx *c, struct damon_target *t,
 {
 	bool ret = __damos_valid_target(r, s);
 
-	if (!ret || !s->quota.esz || !c->primitive.get_scheme_score)
+	if (!ret || !s->quota.esz || !c->ops.get_scheme_score)
 		return ret;
 
-	return c->primitive.get_scheme_score(c, t, r, s) >= s->quota.min_score;
+	return c->ops.get_scheme_score(c, t, r, s) >= s->quota.min_score;
 }
 
 static void damon_do_apply_schemes(struct damon_ctx *c,
@@ -576,7 +576,7 @@ static void damon_do_apply_schemes(struct damon_ctx *c,
 			continue;
 
 		/* Apply the scheme */
-		if (c->primitive.apply_scheme) {
+		if (c->ops.apply_scheme) {
 			if (quota->esz &&
 					quota->charged_sz + sz > quota->esz) {
 				sz = ALIGN_DOWN(quota->esz - quota->charged_sz,
@@ -586,7 +586,7 @@ static void damon_do_apply_schemes(struct damon_ctx *c,
 				damon_split_region_at(c, t, r, sz);
 			}
 			ktime_get_coarse_ts64(&begin);
-			sz_applied = c->primitive.apply_scheme(c, t, r, s);
+			sz_applied = c->ops.apply_scheme(c, t, r, s);
 			ktime_get_coarse_ts64(&end);
 			quota->total_charged_ns += timespec64_to_ns(&end) -
 				timespec64_to_ns(&begin);
@@ -660,7 +660,7 @@ static void kdamond_apply_schemes(struct damon_ctx *c)
 			damos_set_effective_quota(quota);
 		}
 
-		if (!c->primitive.get_scheme_score)
+		if (!c->ops.get_scheme_score)
 			continue;
 
 		/* Fill up the score histogram */
@@ -669,7 +669,7 @@ static void kdamond_apply_schemes(struct damon_ctx *c)
 			damon_for_each_region(r, t) {
 				if (!__damos_valid_target(r, s))
 					continue;
-				score = c->primitive.get_scheme_score(
+				score = c->ops.get_scheme_score(
 						c, t, r, s);
 				quota->histogram[score] +=
 					r->ar.end - r->ar.start;
@@ -848,14 +848,15 @@ static void kdamond_split_regions(struct damon_ctx *ctx)
 }
 
 /*
- * Check whether it is time to check and apply the target monitoring regions
+ * Check whether it is time to check and apply the operations-related data
+ * structures.
  *
  * Returns true if it is.
  */
-static bool kdamond_need_update_primitive(struct damon_ctx *ctx)
+static bool kdamond_need_update_operations(struct damon_ctx *ctx)
 {
-	return damon_check_reset_time_interval(&ctx->last_primitive_update,
-			ctx->primitive_update_interval);
+	return damon_check_reset_time_interval(&ctx->last_ops_update,
+			ctx->ops_update_interval);
 }
 
 /*
@@ -873,11 +874,11 @@ static bool kdamond_need_stop(struct damon_ctx *ctx)
 	if (kthread_should_stop())
 		return true;
 
-	if (!ctx->primitive.target_valid)
+	if (!ctx->ops.target_valid)
 		return false;
 
 	damon_for_each_target(t, ctx) {
-		if (ctx->primitive.target_valid(t))
+		if (ctx->ops.target_valid(t))
 			return false;
 	}
 
@@ -976,8 +977,8 @@ static int kdamond_fn(void *data)
 
 	pr_debug("kdamond (%d) starts\n", current->pid);
 
-	if (ctx->primitive.init)
-		ctx->primitive.init(ctx);
+	if (ctx->ops.init)
+		ctx->ops.init(ctx);
 	if (ctx->callback.before_start && ctx->callback.before_start(ctx))
 		done = true;
 
@@ -987,16 +988,16 @@ static int kdamond_fn(void *data)
 		if (kdamond_wait_activation(ctx))
 			continue;
 
-		if (ctx->primitive.prepare_access_checks)
-			ctx->primitive.prepare_access_checks(ctx);
+		if (ctx->ops.prepare_access_checks)
+			ctx->ops.prepare_access_checks(ctx);
 		if (ctx->callback.after_sampling &&
 				ctx->callback.after_sampling(ctx))
 			done = true;
 
 		kdamond_usleep(ctx->sample_interval);
 
-		if (ctx->primitive.check_accesses)
-			max_nr_accesses = ctx->primitive.check_accesses(ctx);
+		if (ctx->ops.check_accesses)
+			max_nr_accesses = ctx->ops.check_accesses(ctx);
 
 		if (kdamond_aggregate_interval_passed(ctx)) {
 			kdamond_merge_regions(ctx,
@@ -1008,13 +1009,13 @@ static int kdamond_fn(void *data)
 			kdamond_apply_schemes(ctx);
 			kdamond_reset_aggregated(ctx);
 			kdamond_split_regions(ctx);
-			if (ctx->primitive.reset_aggregated)
-				ctx->primitive.reset_aggregated(ctx);
+			if (ctx->ops.reset_aggregated)
+				ctx->ops.reset_aggregated(ctx);
 		}
 
-		if (kdamond_need_update_primitive(ctx)) {
-			if (ctx->primitive.update)
-				ctx->primitive.update(ctx);
+		if (kdamond_need_update_operations(ctx)) {
+			if (ctx->ops.update)
+				ctx->ops.update(ctx);
 			sz_limit = damon_region_sz_limit(ctx);
 		}
 	}
@@ -1025,8 +1026,8 @@ static int kdamond_fn(void *data)
 
 	if (ctx->callback.before_terminate)
 		ctx->callback.before_terminate(ctx);
-	if (ctx->primitive.cleanup)
-		ctx->primitive.cleanup(ctx);
+	if (ctx->ops.cleanup)
+		ctx->ops.cleanup(ctx);
 
 	pr_debug("kdamond (%d) finishes\n", current->pid);
 	mutex_lock(&ctx->kdamond_lock);
diff --git a/mm/damon/dbgfs-test.h b/mm/damon/dbgfs-test.h
index 0d3a14c00acf..8f7f32595055 100644
--- a/mm/damon/dbgfs-test.h
+++ b/mm/damon/dbgfs-test.h
@@ -74,7 +74,7 @@ static void damon_dbgfs_test_set_targets(struct kunit *test)
 	char buf[64];
 
 	/* Make DAMON consider target has no pid */
-	ctx->primitive = (struct damon_primitive){};
+	ctx->ops = (struct damon_operations){};
 
 	dbgfs_set_targets(ctx, 0, NULL);
 	sprint_target_ids(ctx, buf, 64);
diff --git a/mm/damon/dbgfs.c b/mm/damon/dbgfs.c
index 78ff645433c6..719278a8cc5e 100644
--- a/mm/damon/dbgfs.c
+++ b/mm/damon/dbgfs.c
@@ -56,7 +56,7 @@ static ssize_t dbgfs_attrs_read(struct file *file,
 	mutex_lock(&ctx->kdamond_lock);
 	ret = scnprintf(kbuf, ARRAY_SIZE(kbuf), "%lu %lu %lu %lu %lu\n",
 			ctx->sample_interval, ctx->aggr_interval,
-			ctx->primitive_update_interval, ctx->min_nr_regions,
+			ctx->ops_update_interval, ctx->min_nr_regions,
 			ctx->max_nr_regions);
 	mutex_unlock(&ctx->kdamond_lock);
 
@@ -277,7 +277,7 @@ out:
 
 static inline bool target_has_pid(const struct damon_ctx *ctx)
 {
-	return ctx->primitive.target_valid == damon_va_target_valid;
+	return ctx->ops.target_valid == damon_va_target_valid;
 }
 
 static ssize_t sprint_target_ids(struct damon_ctx *ctx, char *buf, ssize_t len)
@@ -477,9 +477,9 @@ static ssize_t dbgfs_target_ids_write(struct file *file,
 
 	/* Configure the context for the address space type */
 	if (id_is_pid)
-		damon_va_set_primitives(ctx);
+		damon_va_set_operations(ctx);
 	else
-		damon_pa_set_primitives(ctx);
+		damon_pa_set_operations(ctx);
 
 	ret = dbgfs_set_targets(ctx, nr_targets, target_pids);
 	if (!ret)
@@ -735,7 +735,7 @@ static struct damon_ctx *dbgfs_new_ctx(void)
 	if (!ctx)
 		return NULL;
 
-	damon_va_set_primitives(ctx);
+	damon_va_set_operations(ctx);
 	ctx->callback.before_terminate = dbgfs_before_terminate;
 	return ctx;
 }
diff --git a/mm/damon/prmtv-common.c b/mm/damon/ops-common.c
index 92a04f5831d6..e346cc10d143 100644
--- a/mm/damon/prmtv-common.c
+++ b/mm/damon/ops-common.c
@@ -10,7 +10,7 @@
 #include <linux/pagemap.h>
 #include <linux/rmap.h>
 
-#include "prmtv-common.h"
+#include "ops-common.h"
 
 /*
  * Get an online page for a pfn if it's in the LRU list.  Otherwise, returns
diff --git a/mm/damon/prmtv-common.h b/mm/damon/ops-common.h
index e790cb5f8fe0..e790cb5f8fe0 100644
--- a/mm/damon/prmtv-common.h
+++ b/mm/damon/ops-common.h
diff --git a/mm/damon/paddr.c b/mm/damon/paddr.c
index 5e8244f65a1a..9f0abd0369bc 100644
--- a/mm/damon/paddr.c
+++ b/mm/damon/paddr.c
@@ -14,7 +14,7 @@
 #include <linux/swap.h>
 
 #include "../internal.h"
-#include "prmtv-common.h"
+#include "ops-common.h"
 
 static bool __damon_pa_mkold(struct page *page, struct vm_area_struct *vma,
 		unsigned long addr, void *arg)
@@ -261,15 +261,15 @@ static int damon_pa_scheme_score(struct damon_ctx *context,
 	return DAMOS_MAX_SCORE;
 }
 
-void damon_pa_set_primitives(struct damon_ctx *ctx)
+void damon_pa_set_operations(struct damon_ctx *ctx)
 {
-	ctx->primitive.init = NULL;
-	ctx->primitive.update = NULL;
-	ctx->primitive.prepare_access_checks = damon_pa_prepare_access_checks;
-	ctx->primitive.check_accesses = damon_pa_check_accesses;
-	ctx->primitive.reset_aggregated = NULL;
-	ctx->primitive.target_valid = damon_pa_target_valid;
-	ctx->primitive.cleanup = NULL;
-	ctx->primitive.apply_scheme = damon_pa_apply_scheme;
-	ctx->primitive.get_scheme_score = damon_pa_scheme_score;
+	ctx->ops.init = NULL;
+	ctx->ops.update = NULL;
+	ctx->ops.prepare_access_checks = damon_pa_prepare_access_checks;
+	ctx->ops.check_accesses = damon_pa_check_accesses;
+	ctx->ops.reset_aggregated = NULL;
+	ctx->ops.target_valid = damon_pa_target_valid;
+	ctx->ops.cleanup = NULL;
+	ctx->ops.apply_scheme = damon_pa_apply_scheme;
+	ctx->ops.get_scheme_score = damon_pa_scheme_score;
 }
diff --git a/mm/damon/reclaim.c b/mm/damon/reclaim.c
index 29da37192e4a..3c93095c793c 100644
--- a/mm/damon/reclaim.c
+++ b/mm/damon/reclaim.c
@@ -384,7 +384,7 @@ static int __init damon_reclaim_init(void)
 	if (!ctx)
 		return -ENOMEM;
 
-	damon_pa_set_primitives(ctx);
+	damon_pa_set_operations(ctx);
 	ctx->callback.after_aggregation = damon_reclaim_after_aggregation;
 
 	target = damon_new_target();
diff --git a/mm/damon/vaddr-test.h b/mm/damon/vaddr-test.h
index f0d0ba591792..1a55bb6c36c3 100644
--- a/mm/damon/vaddr-test.h
+++ b/mm/damon/vaddr-test.h
@@ -314,7 +314,7 @@ static struct kunit_case damon_test_cases[] = {
 };
 
 static struct kunit_suite damon_test_suite = {
-	.name = "damon-primitives",
+	.name = "damon-operations",
 	.test_cases = damon_test_cases,
 };
 kunit_test_suite(damon_test_suite);
diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c
index 6d3454dd3204..c0eb32025f9b 100644
--- a/mm/damon/vaddr.c
+++ b/mm/damon/vaddr.c
@@ -15,7 +15,7 @@
 #include <linux/pagewalk.h>
 #include <linux/sched/mm.h>
 
-#include "prmtv-common.h"
+#include "ops-common.h"
 
 #ifdef CONFIG_DAMON_VADDR_KUNIT_TEST
 #undef DAMON_MIN_REGION
@@ -739,17 +739,17 @@ static int damon_va_scheme_score(struct damon_ctx *context,
 	return DAMOS_MAX_SCORE;
 }
 
-void damon_va_set_primitives(struct damon_ctx *ctx)
+void damon_va_set_operations(struct damon_ctx *ctx)
 {
-	ctx->primitive.init = damon_va_init;
-	ctx->primitive.update = damon_va_update;
-	ctx->primitive.prepare_access_checks = damon_va_prepare_access_checks;
-	ctx->primitive.check_accesses = damon_va_check_accesses;
-	ctx->primitive.reset_aggregated = NULL;
-	ctx->primitive.target_valid = damon_va_target_valid;
-	ctx->primitive.cleanup = NULL;
-	ctx->primitive.apply_scheme = damon_va_apply_scheme;
-	ctx->primitive.get_scheme_score = damon_va_scheme_score;
+	ctx->ops.init = damon_va_init;
+	ctx->ops.update = damon_va_update;
+	ctx->ops.prepare_access_checks = damon_va_prepare_access_checks;
+	ctx->ops.check_accesses = damon_va_check_accesses;
+	ctx->ops.reset_aggregated = NULL;
+	ctx->ops.target_valid = damon_va_target_valid;
+	ctx->ops.cleanup = NULL;
+	ctx->ops.apply_scheme = damon_va_apply_scheme;
+	ctx->ops.get_scheme_score = damon_va_scheme_score;
 }
 
 #include "vaddr-test.h"