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[PATCH 3/5] mm/damon/core: receive addr_unit on damon_set_region_biggest_system_ram_default()

SeongJae Park posted 5 patches 3 weeks, 6 days ago
[PATCH 3/5] mm/damon/core: receive addr_unit on damon_set_region_biggest_system_ram_default()
Posted by SeongJae Park 3 weeks, 6 days ago 
damon_find_biggest_system_ram() was not supporting addr_unit in the
past.  Hence, its caller, damon_set_region_biggest_system_ram_default(),
was also not supporting addr_unit.  The previous commit has updated the
inner function to support addr_unit.  There is no more reason to not
support addr_unit on damon_set_region_biggest_system_ram_default().
Rather, it makes unnecessary inconsistency on support of addr_unit.
Update it to receive addr_unit and handle it inside.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 include/linux/damon.h | 1 +
 mm/damon/core.c       | 7 ++++---
 mm/damon/lru_sort.c   | 1 +
 mm/damon/reclaim.c    | 1 +
 mm/damon/stat.c       | 2 +-
 5 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/include/linux/damon.h b/include/linux/damon.h
index 1130c2f9a92f4..3a441fbca170d 100644
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -988,6 +988,7 @@ int damos_walk(struct damon_ctx *ctx, struct damos_walk_control *control);
 
 int damon_set_region_biggest_system_ram_default(struct damon_target *t,
 				unsigned long *start, unsigned long *end,
+				unsigned long addr_unit,
 				unsigned long min_region_sz);
 
 #endif	/* CONFIG_DAMON */
diff --git a/mm/damon/core.c b/mm/damon/core.c
index aee61bf991baa..d4f86c20b4f48 100644
--- a/mm/damon/core.c
+++ b/mm/damon/core.c
@@ -3103,6 +3103,7 @@ static bool damon_find_biggest_system_ram(unsigned long *start,
  * @t:		The monitoring target to set the region.
  * @start:	The pointer to the start address of the region.
  * @end:	The pointer to the end address of the region.
+ * @addr_unit:	The address unit for the damon_ctx of @t.
  * @min_region_sz:	Minimum region size.
  *
  * This function sets the region of @t as requested by @start and @end.  If the
@@ -3115,7 +3116,7 @@ static bool damon_find_biggest_system_ram(unsigned long *start,
  */
 int damon_set_region_biggest_system_ram_default(struct damon_target *t,
 			unsigned long *start, unsigned long *end,
-			unsigned long min_region_sz)
+			unsigned long addr_unit, unsigned long min_region_sz)
 {
 	struct damon_addr_range addr_range;
 
@@ -3123,12 +3124,12 @@ int damon_set_region_biggest_system_ram_default(struct damon_target *t,
 		return -EINVAL;
 
 	if (!*start && !*end &&
-		!damon_find_biggest_system_ram(start, end, 1))
+			!damon_find_biggest_system_ram(start, end, addr_unit))
 		return -EINVAL;
 
 	addr_range.start = *start;
 	addr_range.end = *end;
-	return damon_set_regions(t, &addr_range, 1, min_region_sz);
+	return damon_set_regions(t, &addr_range, addr_unit, min_region_sz);
 }
 
 /*
diff --git a/mm/damon/lru_sort.c b/mm/damon/lru_sort.c
index 7bc5c0b2aea3e..133ea17e258df 100644
--- a/mm/damon/lru_sort.c
+++ b/mm/damon/lru_sort.c
@@ -345,6 +345,7 @@ static int damon_lru_sort_apply_parameters(void)
 	err = damon_set_region_biggest_system_ram_default(param_target,
 					&monitor_region_start,
 					&monitor_region_end,
+					param_ctx->addr_unit,
 					param_ctx->min_region_sz);
 	if (err)
 		goto out;
diff --git a/mm/damon/reclaim.c b/mm/damon/reclaim.c
index 43d76f5bed449..01f2f6cdbcdfe 100644
--- a/mm/damon/reclaim.c
+++ b/mm/damon/reclaim.c
@@ -251,6 +251,7 @@ static int damon_reclaim_apply_parameters(void)
 	err = damon_set_region_biggest_system_ram_default(param_target,
 					&monitor_region_start,
 					&monitor_region_end,
+					param_ctx->addr_unit,
 					param_ctx->min_region_sz);
 	if (err)
 		goto out;
diff --git a/mm/damon/stat.c b/mm/damon/stat.c
index 25fb44ccf99d0..f9a2028483b05 100644
--- a/mm/damon/stat.c
+++ b/mm/damon/stat.c
@@ -181,7 +181,7 @@ static struct damon_ctx *damon_stat_build_ctx(void)
 		goto free_out;
 	damon_add_target(ctx, target);
 	if (damon_set_region_biggest_system_ram_default(target, &start, &end,
-							ctx->min_region_sz))
+				ctx->addr_unit, ctx->min_region_sz))
 		goto free_out;
 	return ctx;
 free_out:
-- 
2.47.3
Re: [PATCH 3/5] mm/damon/core: receive addr_unit on damon_set_region_biggest_system_ram_default()
Posted by SeongJae Park 3 weeks, 4 days ago 
On Tue, 10 Mar 2026 22:29:24 -0700 SeongJae Park <sj@kernel.org> wrote:

> damon_find_biggest_system_ram() was not supporting addr_unit in the
> past.  Hence, its caller, damon_set_region_biggest_system_ram_default(),
> was also not supporting addr_unit.  The previous commit has updated the
> inner function to support addr_unit.  There is no more reason to not
> support addr_unit on damon_set_region_biggest_system_ram_default().
> Rather, it makes unnecessary inconsistency on support of addr_unit.
> Update it to receive addr_unit and handle it inside.
> 
> Signed-off-by: SeongJae Park <sj@kernel.org>
> ---
>  include/linux/damon.h | 1 +
>  mm/damon/core.c       | 7 ++++---
>  mm/damon/lru_sort.c   | 1 +
>  mm/damon/reclaim.c    | 1 +
>  mm/damon/stat.c       | 2 +-
>  5 files changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/include/linux/damon.h b/include/linux/damon.h
> index 1130c2f9a92f4..3a441fbca170d 100644
> --- a/include/linux/damon.h
> +++ b/include/linux/damon.h
> @@ -988,6 +988,7 @@ int damos_walk(struct damon_ctx *ctx, struct damos_walk_control *control);
>  
>  int damon_set_region_biggest_system_ram_default(struct damon_target *t,
>  				unsigned long *start, unsigned long *end,
> +				unsigned long addr_unit,
>  				unsigned long min_region_sz);
>  
>  #endif	/* CONFIG_DAMON */
> diff --git a/mm/damon/core.c b/mm/damon/core.c
> index aee61bf991baa..d4f86c20b4f48 100644
[...]
> --- a/mm/damon/core.c
> +++ b/mm/damon/core.c
[...]
> @@ -3123,12 +3124,12 @@ int damon_set_region_biggest_system_ram_default(struct damon_target *t,
>  		return -EINVAL;
>  
>  	if (!*start && !*end &&
> -		!damon_find_biggest_system_ram(start, end, 1))
> +			!damon_find_biggest_system_ram(start, end, addr_unit))
>  		return -EINVAL;
>  
>  	addr_range.start = *start;
>  	addr_range.end = *end;
> -	return damon_set_regions(t, &addr_range, 1, min_region_sz);
> +	return damon_set_regions(t, &addr_range, addr_unit, min_region_sz);

The above line is unnecessarily and wrongly changing the third argument.  It is
the number of ranges that passed by the second argument, never meant to be the
addr_unit.

A similar bug [1] was found by an AI review, and I found this patch also has a
similar bug.

Andrew, could you please add below attaching fixup?

[1] https://lore.kernel.org/20260313234026.48872-1-sj@kernel.org


Thanks,
SJ

[...]
=== >8 ===
From 0d00bb5ca76502aef4a6a97b0855e33435147269 Mon Sep 17 00:00:00 2001
From: SeongJae Park <sj@kernel.org>
Date: Fri, 13 Mar 2026 16:49:08 -0700
Subject: [PATCH] mm/damon/core: fix wrong damon_set_regions() argument

The third argument is the length of the second parameter.  But addr_unit
is wrongly being passed.  Fix it.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 mm/damon/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/damon/core.c b/mm/damon/core.c
index d4f86c20b4f48..f9854aedc42d1 100644
--- a/mm/damon/core.c
+++ b/mm/damon/core.c
@@ -3129,7 +3129,7 @@ int damon_set_region_biggest_system_ram_default(struct damon_target *t,
 
 	addr_range.start = *start;
 	addr_range.end = *end;
-	return damon_set_regions(t, &addr_range, addr_unit, min_region_sz);
+	return damon_set_regions(t, &addr_range, 1, min_region_sz);
 }
 
 /*
-- 
2.47.3

Patchew 2.1-devel-ea86937

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