* [PATCH] mm/workingset.c: avoid unnecessary max_nodes estimation in count_shadow_nodes()
@ 2021-01-23 7:38 Miaohe Lin
2021-01-26 16:24 ` Vlastimil Babka
0 siblings, 1 reply; 2+ messages in thread
From: Miaohe Lin @ 2021-01-23 7:38 UTC (permalink / raw)
To: akpm; +Cc: linux-mm, linux-kernel, linmiaohe
If list_lru_shrink_count is 0, we always return SHRINK_EMPTY regardless of
the value of max_nodes. So we can return early if nodes == 0 to save some
cpu cycles of approximating a reasonable limit for the nodes.
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
---
mm/workingset.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/mm/workingset.c b/mm/workingset.c
index 10e96de945b3..7db8f3dad13c 100644
--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -461,6 +461,8 @@ static unsigned long count_shadow_nodes(struct shrinker *shrinker,
unsigned long pages;
nodes = list_lru_shrink_count(&shadow_nodes, sc);
+ if (!nodes)
+ return SHRINK_EMPTY;
/*
* Approximate a reasonable limit for the nodes
@@ -503,9 +505,6 @@ static unsigned long count_shadow_nodes(struct shrinker *shrinker,
max_nodes = pages >> (XA_CHUNK_SHIFT - 3);
- if (!nodes)
- return SHRINK_EMPTY;
-
if (nodes <= max_nodes)
return 0;
return nodes - max_nodes;
--
2.19.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] mm/workingset.c: avoid unnecessary max_nodes estimation in count_shadow_nodes()
2021-01-23 7:38 [PATCH] mm/workingset.c: avoid unnecessary max_nodes estimation in count_shadow_nodes() Miaohe Lin
@ 2021-01-26 16:24 ` Vlastimil Babka
0 siblings, 0 replies; 2+ messages in thread
From: Vlastimil Babka @ 2021-01-26 16:24 UTC (permalink / raw)
To: Miaohe Lin, akpm; +Cc: linux-mm, linux-kernel
On 1/23/21 8:38 AM, Miaohe Lin wrote:
> If list_lru_shrink_count is 0, we always return SHRINK_EMPTY regardless of
> the value of max_nodes. So we can return early if nodes == 0 to save some
> cpu cycles of approximating a reasonable limit for the nodes.
>
> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
> ---
> mm/workingset.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/mm/workingset.c b/mm/workingset.c
> index 10e96de945b3..7db8f3dad13c 100644
> --- a/mm/workingset.c
> +++ b/mm/workingset.c
> @@ -461,6 +461,8 @@ static unsigned long count_shadow_nodes(struct shrinker *shrinker,
> unsigned long pages;
>
> nodes = list_lru_shrink_count(&shadow_nodes, sc);
> + if (!nodes)
> + return SHRINK_EMPTY;
>
> /*
> * Approximate a reasonable limit for the nodes
> @@ -503,9 +505,6 @@ static unsigned long count_shadow_nodes(struct shrinker *shrinker,
>
> max_nodes = pages >> (XA_CHUNK_SHIFT - 3);
>
> - if (!nodes)
> - return SHRINK_EMPTY;
> -
> if (nodes <= max_nodes)
> return 0;
> return nodes - max_nodes;
>
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2021-01-26 16:25 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-01-23 7:38 [PATCH] mm/workingset.c: avoid unnecessary max_nodes estimation in count_shadow_nodes() Miaohe Lin
2021-01-26 16:24 ` Vlastimil Babka
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).