2021-11-15 09:02:23

by Yajun Deng

Subject: [PATCH net-next] skbuff: Add helper function for head_frag and pfmemalloc

This series of build_skb() has the same code, add skb_set_head_frag_pfmemalloc()
for it, at the same time, in-line skb_propagate_pfmemalloc().

Signed-off-by: Yajun Deng <[email protected]>
---
include/linux/skbuff.h | 19 ++++++++++++-------
net/core/skbuff.c | 19 +++++--------------
2 files changed, 17 insertions(+), 21 deletions(-)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 0bd6520329f6..3e26b80bde29 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -3007,15 +3007,20 @@ static inline bool dev_page_is_reusable(const struct page *page)
}

/**
- * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page
- * @page: The page that was allocated from skb_alloc_page
- * @skb: The skb that may need pfmemalloc set
+ * skb_set_head_frag_pfmemalloc - Set head_frag and pfmemalloc
+ * @skb: The skb that may need head_frag and pfmemalloc set
+ * @data: data buffer provided by caller
+ * @frag_size: size of data, or 0 if head was kmalloced
*/
-static inline void skb_propagate_pfmemalloc(const struct page *page,
- struct sk_buff *skb)
+static inline void skb_set_head_frag_pfmemalloc(struct sk_buff *skb, void *data,
+ unsigned int frag_size)
{
- if (page_is_pfmemalloc(page))
- skb->pfmemalloc = true;
+
+ if (likely(skb) && frag_size) {
+ skb->head_frag = 1;
+ if (page_is_pfmemalloc(virt_to_head_page(data)))
+ skb->pfmemalloc = 1;
+ }
}

/**
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 67a9188d8a49..7b3d2bf746ae 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -255,11 +255,8 @@ struct sk_buff *build_skb(void *data, unsigned int frag_size)
{
struct sk_buff *skb = __build_skb(data, frag_size);

- if (skb && frag_size) {
- skb->head_frag = 1;
- if (page_is_pfmemalloc(virt_to_head_page(data)))
- skb->pfmemalloc = 1;
- }
+ skb_set_head_frag_pfmemalloc(skb, data, frag_size);
+
return skb;
}
EXPORT_SYMBOL(build_skb);
@@ -278,11 +275,8 @@ struct sk_buff *build_skb_around(struct sk_buff *skb,

__build_skb_around(skb, data, frag_size);

- if (frag_size) {
- skb->head_frag = 1;
- if (page_is_pfmemalloc(virt_to_head_page(data)))
- skb->pfmemalloc = 1;
- }
+ skb_set_head_frag_pfmemalloc(skb, data, frag_size);
+
return skb;
}
EXPORT_SYMBOL(build_skb_around);
@@ -325,10 +319,7 @@ struct sk_buff *napi_build_skb(void *data, unsigned int frag_size)
{
struct sk_buff *skb = __napi_build_skb(data, frag_size);

- if (likely(skb) && frag_size) {
- skb->head_frag = 1;
- skb_propagate_pfmemalloc(virt_to_head_page(data), skb);
- }
+ skb_set_head_frag_pfmemalloc(skb, data, frag_size);

return skb;
}
--
2.32.0

2021-11-15 12:27:59

by Alexander Lobakin

Subject: Re: [PATCH net-next] skbuff: Add helper function for head_frag and pfmemalloc

From: Yajun Deng <[email protected]>
Date: Mon, 15 Nov 2021 16:57:08 +0800

> This series of build_skb() has the same code, add skb_set_head_frag_pfmemalloc()
> for it, at the same time, in-line skb_propagate_pfmemalloc().
>
> Signed-off-by: Yajun Deng <[email protected]>
> ---
> include/linux/skbuff.h | 19 ++++++++++++-------
> net/core/skbuff.c | 19 +++++--------------
> 2 files changed, 17 insertions(+), 21 deletions(-)

build_skb(), build_skb_around() and napi_build_skb() are 3-liners,
and all of their code is here in linux/skbuff.h. Would it make
sense to make them static inlines, and export their "__"
counterparts instead?

Thanks,
Al