[PATCH V3] mm/damon: Remove duplicate get_monitoring_region() definitions

[PATCH V3] mm/damon: Remove duplicate get_monitoring_region() definitions

[Xin Hao]

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

BTW, this patch removes two struct 'damon_lru_sort_ram_walk_arg' and
'damon_reclaim_ram_walk_arg', though the two structs are removed, if we
want to add more fields to these structs for other purposes later, it will
not too late for us to use them again.
For example:
    struct damon_reclaim_ram_walk_arg {
	struct damon_addr_range raw_walk;
	xxx  A;
	xxx  B;
    }
    struct damon_lru_sort_ram_walk_arg {
	struct damon_addr_range raw_walk;
	xxx  A;
	xxx  B;
    }

Signed-off-by: Xin Hao <xhao@linux.alibaba.com>
---
 include/linux/damon.h |  1 +
 mm/damon/core.c       | 28 ++++++++++++++++++++++++++++
 mm/damon/lru_sort.c   | 37 ++-----------------------------------
 mm/damon/reclaim.c    | 37 ++-----------------------------------
 4 files changed, 33 insertions(+), 70 deletions(-)

diff --git a/include/linux/damon.h b/include/linux/damon.h
index 7b1f4a488230..f27b92e5afc2 100644
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -500,6 +500,7 @@ void damon_add_region(struct damon_region *r, struct damon_target *t);
 void damon_destroy_region(struct damon_region *r, struct damon_target *t);
 int damon_set_regions(struct damon_target *t, struct damon_addr_range *ranges,
 		unsigned int nr_ranges);
+bool damon_get_sram_monitoring_region(unsigned long *start, unsigned long *end);

 struct damos *damon_new_scheme(
 		unsigned long min_sz_region, unsigned long max_sz_region,
diff --git a/mm/damon/core.c b/mm/damon/core.c
index 7d25dc582fe3..05a2d1b9d03d 100644
--- a/mm/damon/core.c
+++ b/mm/damon/core.c
@@ -276,6 +276,34 @@ struct damos *damon_new_scheme(
 	return scheme;
 }

+static inline int walk_system_ram(struct resource *res, void *arg)
+{
+	struct damon_addr_range *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_get_sram_monitoring_region(unsigned long *start, unsigned long *end)
+{
+	struct damon_addr_range 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;
+}
+
 void damon_add_scheme(struct damon_ctx *ctx, struct damos *s)
 {
 	list_add_tail(&s->list, &ctx->schemes);
diff --git a/mm/damon/lru_sort.c b/mm/damon/lru_sort.c
index 9de6f00a71c5..cbe7e865dc74 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)
 {
@@ -404,8 +371,8 @@ 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_get_sram_monitoring_region(&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 a7faf51b4bd4..484bb802d249 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_watermarks wmarks = {
@@ -323,8 +290,8 @@ 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_get_sram_monitoring_region(&monitor_region_start,
+					      &monitor_region_end))
 		return -EINVAL;
 	addr_range.start = monitor_region_start;
 	addr_range.end = monitor_region_end;
--
2.31.0

Re: [PATCH V3] mm/damon: Remove duplicate get_monitoring_region() definitions

[SeongJae Park]

Hi Xin,


Thanks for your efforts!  But, please answer to some more comments below.

> In lru_sort.c and reclaim.c, they are all defining get_monitoring_region()
> function, there is no need to define it separately.
> 
> BTW, this patch removes two struct 'damon_lru_sort_ram_walk_arg' and
> 'damon_reclaim_ram_walk_arg', though the two structs are removed, if we
> want to add more fields to these structs for other purposes later, it will
> not too late for us to use them again.
> For example:
>     struct damon_reclaim_ram_walk_arg {
> 	struct damon_addr_range raw_walk;
> 	xxx  A;
> 	xxx  B;
>     }
>     struct damon_lru_sort_ram_walk_arg {
> 	struct damon_addr_range raw_walk;
> 	xxx  A;
> 	xxx  B;
>     }

Sorry, seems I didn't make my words clear enough.  What I'm concerning[1] is,
any possible future change to 'struct damon_addr_range', not to
'struct damon_{reclaim,lru_sort}_ram_walk_arg'.

Also, after all, as mentioned before, the purpose of 'struct damon_addr_range'
is not saving the 'start' and 'end' fields of 'struct resource'.  Let's use
different types for different purposes to avoid any unneeded dependencies.

[1] https://lore.kernel.org/damon/20220907172712.61006-1-sj@kernel.org/

> 
> Signed-off-by: Xin Hao <xhao@linux.alibaba.com>
> ---
>  include/linux/damon.h |  1 +
>  mm/damon/core.c       | 28 ++++++++++++++++++++++++++++
>  mm/damon/lru_sort.c   | 37 ++-----------------------------------
>  mm/damon/reclaim.c    | 37 ++-----------------------------------
>  4 files changed, 33 insertions(+), 70 deletions(-)
> 
> diff --git a/include/linux/damon.h b/include/linux/damon.h
> index 7b1f4a488230..f27b92e5afc2 100644
> --- a/include/linux/damon.h
> +++ b/include/linux/damon.h
> @@ -500,6 +500,7 @@ void damon_add_region(struct damon_region *r, struct damon_target *t);
>  void damon_destroy_region(struct damon_region *r, struct damon_target *t);
>  int damon_set_regions(struct damon_target *t, struct damon_addr_range *ranges,
>  		unsigned int nr_ranges);
> +bool damon_get_sram_monitoring_region(unsigned long *start, unsigned long *end);
> 
>  struct damos *damon_new_scheme(
>  		unsigned long min_sz_region, unsigned long max_sz_region,
> diff --git a/mm/damon/core.c b/mm/damon/core.c
> index 7d25dc582fe3..05a2d1b9d03d 100644
> --- a/mm/damon/core.c
> +++ b/mm/damon/core.c
> @@ -276,6 +276,34 @@ struct damos *damon_new_scheme(
>  	return scheme;
>  }
> 
> +static inline int walk_system_ram(struct resource *res, void *arg)

We will pass pointer to this function.  I guess 'inline' makes no sense?

> +{
> +	struct damon_addr_range *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_get_sram_monitoring_region(unsigned long *start, unsigned long *end)

We should avoid too verbose name, so 'sram' looks nice, but it might be able to
be more clear to let readers know what it does.  For an example, how about
'damon_find_biggest_system_ram()'?

Below parts all look good.


Thanks,
SJ

[...]

Re: [PATCH V3] mm/damon: Remove duplicate get_monitoring_region() definitions

[haoxin]

在 2022/9/9 上午2:19, SeongJae Park 写道:
> Hi Xin,
>
>
> Thanks for your efforts!  But, please answer to some more comments below.
>
>> In lru_sort.c and reclaim.c, they are all defining get_monitoring_region()
>> function, there is no need to define it separately.
>>
>> BTW, this patch removes two struct 'damon_lru_sort_ram_walk_arg' and
>> 'damon_reclaim_ram_walk_arg', though the two structs are removed, if we
>> want to add more fields to these structs for other purposes later, it will
>> not too late for us to use them again.
>> For example:
>>      struct damon_reclaim_ram_walk_arg {
>> 	struct damon_addr_range raw_walk;
>> 	xxx  A;
>> 	xxx  B;
>>      }
>>      struct damon_lru_sort_ram_walk_arg {
>> 	struct damon_addr_range raw_walk;
>> 	xxx  A;
>> 	xxx  B;
>>      }
> Sorry, seems I didn't make my words clear enough.  What I'm concerning[1] is,
> any possible future change to 'struct damon_addr_range', not to
> 'struct damon_{reclaim,lru_sort}_ram_walk_arg'.
>
> Also, after all, as mentioned before, the purpose of 'struct damon_addr_range'
> is not saving the 'start' and 'end' fields of 'struct resource'.  Let's use
> different types for different purposes to avoid any unneeded dependencies.
Ok， i will define another struct.
>
> [1] https://lore.kernel.org/damon/20220907172712.61006-1-sj@kernel.org/
>
>> Signed-off-by: Xin Hao <xhao@linux.alibaba.com>
>> ---
>>   include/linux/damon.h |  1 +
>>   mm/damon/core.c       | 28 ++++++++++++++++++++++++++++
>>   mm/damon/lru_sort.c   | 37 ++-----------------------------------
>>   mm/damon/reclaim.c    | 37 ++-----------------------------------
>>   4 files changed, 33 insertions(+), 70 deletions(-)
>>
>> diff --git a/include/linux/damon.h b/include/linux/damon.h
>> index 7b1f4a488230..f27b92e5afc2 100644
>> --- a/include/linux/damon.h
>> +++ b/include/linux/damon.h
>> @@ -500,6 +500,7 @@ void damon_add_region(struct damon_region *r, struct damon_target *t);
>>   void damon_destroy_region(struct damon_region *r, struct damon_target *t);
>>   int damon_set_regions(struct damon_target *t, struct damon_addr_range *ranges,
>>   		unsigned int nr_ranges);
>> +bool damon_get_sram_monitoring_region(unsigned long *start, unsigned long *end);
>>
>>   struct damos *damon_new_scheme(
>>   		unsigned long min_sz_region, unsigned long max_sz_region,
>> diff --git a/mm/damon/core.c b/mm/damon/core.c
>> index 7d25dc582fe3..05a2d1b9d03d 100644
>> --- a/mm/damon/core.c
>> +++ b/mm/damon/core.c
>> @@ -276,6 +276,34 @@ struct damos *damon_new_scheme(
>>   	return scheme;
>>   }
>>
>> +static inline int walk_system_ram(struct resource *res, void *arg)
> We will pass pointer to this function.  I guess 'inline' makes no sense?
  Ok, i will remove it.
>> +{
>> +	struct damon_addr_range *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_get_sram_monitoring_region(unsigned long *start, unsigned long *end)
> We should avoid too verbose name, so 'sram' looks nice, but it might be able to
> be more clear to let readers know what it does.  For an example, how about
> 'damon_find_biggest_system_ram()'?
Ok.
>
> Below parts all look good.
>
>
> Thanks,
> SJ
>
> [...]