[PATCH v5] mm/damon: remove duplicate get_monitoring_region() definitions

[SeongJae Park <sj@kernel.org>]

From: Xin Hao <xhao@linux.alibaba.com>

In lru_sort.c and reclaim.c, they are all defining
get_monitoring_region() function, there is no need to define it
separately.

As 'get_monitoring_region()' is not a 'static' function anymore, we try
to use a prefix to distinguish with other functions, so there rename it
to 'damon_find_biggest_system_ram'.

Suggested-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Xin Hao <xhao@linux.alibaba.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: SeongJae Park <sj@kernel.org>
---
Changes from v4
(https://lore.kernel.org/damon/20220909024105.84831-1-xhao@linux.alibaba.com/)
- Fix trivial cosmetic nits (SeongJae Park)
- Move definition of the new struct to core.c (SeongJae Park)

 include/linux/damon.h |  2 ++
 mm/damon/core.c       | 40 ++++++++++++++++++++++++++++++++++++++++
 mm/damon/lru_sort.c   | 37 ++-----------------------------------
 mm/damon/reclaim.c    | 37 ++-----------------------------------
 4 files changed, 46 insertions(+), 70 deletions(-)

diff --git a/include/linux/damon.h b/include/linux/damon.h
index 90f20675da22..016b6c9c03d6 100644
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -549,6 +549,8 @@ static inline bool damon_target_has_pid(const struct damon_ctx *ctx)
 int damon_start(struct damon_ctx **ctxs, int nr_ctxs, bool exclusive);
 int damon_stop(struct damon_ctx **ctxs, int nr_ctxs);
 
+bool damon_find_biggest_system_ram(unsigned long *start, unsigned long *end);
+
 #endif	/* CONFIG_DAMON */
 
 #endif	/* _DAMON_H */
diff --git a/mm/damon/core.c b/mm/damon/core.c
index 6f6c9c9aca9d..325365939308 100644
--- a/mm/damon/core.c
+++ b/mm/damon/core.c
@@ -1239,4 +1239,44 @@ static int kdamond_fn(void *data)
 	return 0;
 }
 
+/*
+ * struct damon_system_ram_region - System RAM resource address region of
+ *				    [@start, @end).
+ * @start:	Start address of the region (inclusive).
+ * @end:	End address of the region (exclusive).
+ */
+struct damon_system_ram_region {
+	unsigned long start;
+	unsigned long end;
+};
+
+static int walk_system_ram(struct resource *res, void *arg)
+{
+	struct damon_system_ram_region *a = arg;
+
+	if (a->end - a->start < resource_size(res)) {
+		a->start = res->start;
+		a->end = res->end;
+	}
+	return 0;
+}
+
+/*
+ * Find biggest 'System RAM' resource and store its start and end address in
+ * @start and @end, respectively.  If no System RAM is found, returns false.
+ */
+bool damon_find_biggest_system_ram(unsigned long *start, unsigned long *end)
+
+{
+	struct damon_system_ram_region arg = {};
+
+	walk_system_ram_res(0, ULONG_MAX, &arg, walk_system_ram);
+	if (arg.end <= arg.start)
+		return false;
+
+	*start = arg.start;
+	*end = arg.end;
+	return true;
+}
+
 #include "core-test.h"
diff --git a/mm/damon/lru_sort.c b/mm/damon/lru_sort.c
index 0184ed4828b7..8415e18fcf0e 100644
--- a/mm/damon/lru_sort.c
+++ b/mm/damon/lru_sort.c
@@ -257,39 +257,6 @@ module_param(nr_cold_quota_exceeds, ulong, 0400);
 static struct damon_ctx *ctx;
 static struct damon_target *target;
 
-struct damon_lru_sort_ram_walk_arg {
-	unsigned long start;
-	unsigned long end;
-};
-
-static int walk_system_ram(struct resource *res, void *arg)
-{
-	struct damon_lru_sort_ram_walk_arg *a = arg;
-
-	if (a->end - a->start < resource_size(res)) {
-		a->start = res->start;
-		a->end = res->end;
-	}
-	return 0;
-}
-
-/*
- * Find biggest 'System RAM' resource and store its start and end address in
- * @start and @end, respectively.  If no System RAM is found, returns false.
- */
-static bool get_monitoring_region(unsigned long *start, unsigned long *end)
-{
-	struct damon_lru_sort_ram_walk_arg arg = {};
-
-	walk_system_ram_res(0, ULONG_MAX, &arg, walk_system_ram);
-	if (arg.end <= arg.start)
-		return false;
-
-	*start = arg.start;
-	*end = arg.end;
-	return true;
-}
-
 /* Create a DAMON-based operation scheme for hot memory regions */
 static struct damos *damon_lru_sort_new_hot_scheme(unsigned int hot_thres)
 {
@@ -414,8 +381,8 @@ static int damon_lru_sort_apply_parameters(void)
 	if (monitor_region_start > monitor_region_end)
 		return -EINVAL;
 	if (!monitor_region_start && !monitor_region_end &&
-			!get_monitoring_region(&monitor_region_start,
-				&monitor_region_end))
+	    !damon_find_biggest_system_ram(&monitor_region_start,
+					   &monitor_region_end))
 		return -EINVAL;
 	addr_range.start = monitor_region_start;
 	addr_range.end = monitor_region_end;
diff --git a/mm/damon/reclaim.c b/mm/damon/reclaim.c
index 5aeca0b9e88e..fe7bc0c55ecb 100644
--- a/mm/damon/reclaim.c
+++ b/mm/damon/reclaim.c
@@ -229,39 +229,6 @@ module_param(nr_quota_exceeds, ulong, 0400);
 static struct damon_ctx *ctx;
 static struct damon_target *target;
 
-struct damon_reclaim_ram_walk_arg {
-	unsigned long start;
-	unsigned long end;
-};
-
-static int walk_system_ram(struct resource *res, void *arg)
-{
-	struct damon_reclaim_ram_walk_arg *a = arg;
-
-	if (a->end - a->start < resource_size(res)) {
-		a->start = res->start;
-		a->end = res->end;
-	}
-	return 0;
-}
-
-/*
- * Find biggest 'System RAM' resource and store its start and end address in
- * @start and @end, respectively.  If no System RAM is found, returns false.
- */
-static bool get_monitoring_region(unsigned long *start, unsigned long *end)
-{
-	struct damon_reclaim_ram_walk_arg arg = {};
-
-	walk_system_ram_res(0, ULONG_MAX, &arg, walk_system_ram);
-	if (arg.end <= arg.start)
-		return false;
-
-	*start = arg.start;
-	*end = arg.end;
-	return true;
-}
-
 static struct damos *damon_reclaim_new_scheme(void)
 {
 	struct damos_access_pattern pattern = {
@@ -328,8 +295,8 @@ static int damon_reclaim_apply_parameters(void)
 	if (monitor_region_start > monitor_region_end)
 		return -EINVAL;
 	if (!monitor_region_start && !monitor_region_end &&
-			!get_monitoring_region(&monitor_region_start,
-				&monitor_region_end))
+	    !damon_find_biggest_system_ram(&monitor_region_start,
+					   &monitor_region_end))
 		return -EINVAL;
 	addr_range.start = monitor_region_start;
 	addr_range.end = monitor_region_end;
-- 
2.25.1