2021-10-21 03:44:10

by Wangshaobo (bobo)

Subject: [PATCH] mm/page_alloc: use clamp() to simplify code

This patch uses clamp() to simplify code in init_per_zone_wmark_min().

Signed-off-by: Wang ShaoBo <[email protected]>
---
mm/page_alloc.c | 12 ++++--------
1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index b37435c274cf..d0449212a824 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -8460,16 +8460,12 @@ int __meminit init_per_zone_wmark_min(void)
lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16);

- if (new_min_free_kbytes > user_min_free_kbytes) {
- min_free_kbytes = new_min_free_kbytes;
- if (min_free_kbytes < 128)
- min_free_kbytes = 128;
- if (min_free_kbytes > 262144)
- min_free_kbytes = 262144;
- } else {
+ if (new_min_free_kbytes > user_min_free_kbytes)
+ min_free_kbytes = clamp(new_min_free_kbytes, 128, 262144);
+ else
pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
new_min_free_kbytes, user_min_free_kbytes);
- }
+
setup_per_zone_wmarks();
refresh_zone_stat_thresholds();
setup_per_zone_lowmem_reserve();
--
2.25.1

2021-10-21 08:53:09

by David Hildenbrand

Subject: Re: [PATCH] mm/page_alloc: use clamp() to simplify code

On 21.10.21 05:48, Wang ShaoBo wrote:
> This patch uses clamp() to simplify code in init_per_zone_wmark_min().
>
> Signed-off-by: Wang ShaoBo <[email protected]>
> ---
> mm/page_alloc.c | 12 ++++--------
> 1 file changed, 4 insertions(+), 8 deletions(-)
>
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index b37435c274cf..d0449212a824 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -8460,16 +8460,12 @@ int __meminit init_per_zone_wmark_min(void)
> lowmem_kbytes = nr_free_buffer_pages() * (PAGE_SIZE >> 10);
> new_min_free_kbytes = int_sqrt(lowmem_kbytes * 16);
>
> - if (new_min_free_kbytes > user_min_free_kbytes) {
> - min_free_kbytes = new_min_free_kbytes;
> - if (min_free_kbytes < 128)
> - min_free_kbytes = 128;
> - if (min_free_kbytes > 262144)
> - min_free_kbytes = 262144;
> - } else {
> + if (new_min_free_kbytes > user_min_free_kbytes)
> + min_free_kbytes = clamp(new_min_free_kbytes, 128, 262144);
> + else
> pr_warn("min_free_kbytes is not updated to %d because user defined value %d is preferred\n",
> new_min_free_kbytes, user_min_free_kbytes);
> - }
> +
> setup_per_zone_wmarks();
> refresh_zone_stat_thresholds();
> setup_per_zone_lowmem_reserve();
>

Reviewed-by: David Hildenbrand <[email protected]>

--
Thanks,

David / dhildenb