The struct of 'damon_lru_sort_ram_walk_arg' is the same with struct of
'damon_addr_range', so, there no need to redefine it, just use struct of
'damon_addr_range' instead.

Signed-off-by: Xin Hao <xhao@linux.alibaba.com>
---
 mm/damon/lru_sort.c | 34 +++++++++++++---------------------
 1 file changed, 13 insertions(+), 21 deletions(-)

diff --git a/mm/damon/lru_sort.c b/mm/damon/lru_sort.c
index ac50dca026f9..a3674532fa67 100644
--- a/mm/damon/lru_sort.c
+++ b/mm/damon/lru_sort.c
@@ -257,18 +257,13 @@ 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;
+	struct damon_addr_range *r = arg;

-	if (a->end - a->start < resource_size(res)) {
-		a->start = res->start;
-		a->end = res->end;
+	if (r->end - r->start < resource_size(res)) {
+		r->start = res->start;
+		r->end = res->end;
 	}
 	return 0;
 }
@@ -277,16 +272,12 @@ static int walk_system_ram(struct resource *res, void *arg)
  * 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)
+static bool get_monitoring_region(struct damon_addr_range *range)
 {
-	struct damon_lru_sort_ram_walk_arg arg = {};
-
-	walk_system_ram_res(0, ULONG_MAX, &arg, walk_system_ram);
-	if (arg.end <= arg.start)
+	walk_system_ram_res(0, ULONG_MAX, range, walk_system_ram);
+	if (range->end <= range->start)
 		return false;

-	*start = arg.start;
-	*end = arg.end;
 	return true;
 }

@@ -380,9 +371,12 @@ 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))
+	if (!monitor_region_end)
+		return -EINVAL;
+
+	addr_range.start = monitor_region_start;
+	addr_range.end = monitor_region_end;
+	if (!get_monitoring_region(&addr_range))
 		return -EINVAL;

 	err = damon_set_attrs(ctx, sample_interval, aggr_interval, 0,
@@ -408,8 +402,6 @@ static int damon_lru_sort_apply_parameters(void)
 		return -ENOMEM;
 	damon_add_scheme(ctx, scheme);

-	addr_range.start = monitor_region_start;
-	addr_range.end = monitor_region_end;
 	return damon_set_regions(target, &addr_range, 1);
 }

--
2.27.0

Hi Xin,

On Thu, 18 Aug 2022 18:57:32 +0800 Xin Hao <xhao@linux.alibaba.com> wrote:

> The struct of 'damon_lru_sort_ram_walk_arg' is the same with struct of
> 'damon_addr_range', so, there no need to redefine it, just use struct of
> 'damon_addr_range' instead.

Reducing code is always good, thanks.  However, I think the type of the 'start'
and 'end' fields of 'struct damon_addr_range' might be changed in a future.
It's very unlikely, though.  Also, we might add some more fields to the struct
in a future.  After all, the purpose of 'struct damon_addr_range' is not saving
the 'start' and 'end' fields of 'struct resource'.  I'd like to avoid making
any possible dependency here, sorry.


Thanks,
SJ

[...]

在 2022/8/19 上午1:23, SeongJae Park 写道:
> Hi Xin,
>
> On Thu, 18 Aug 2022 18:57:32 +0800 Xin Hao <xhao@linux.alibaba.com> wrote:
>
>> The struct of 'damon_lru_sort_ram_walk_arg' is the same with struct of
>> 'damon_addr_range', so, there no need to redefine it, just use struct of
>> 'damon_addr_range' instead.
> Reducing code is always good, thanks.  However, I think the type of the 'start'
> and 'end' fields of 'struct damon_addr_range' might be changed in a future.
OK,  get it.
> It's very unlikely, though.  Also, we might add some more fields to the struct
> in a future.  After all, the purpose of 'struct damon_addr_range' is not saving
> the 'start' and 'end' fields of 'struct resource'.  I'd like to avoid making
> any possible dependency here, sorry.
>
>
> Thanks,
> SJ
>
> [...]