2023-05-08 13:03:01

by Yunsheng Lin

[permalink] [raw]
Subject: [PATCH RFC 2/2] net: remove __skb_frag_set_page()

The remaining users calling __skb_frag_set_page() with
page being NULL seems to doing defensive programming, as
shinfo->nr_frags is already decremented, so remove them.

Signed-off-by: Yunsheng Lin <[email protected]>
---
drivers/net/ethernet/broadcom/bnx2.c | 1 -
drivers/net/ethernet/broadcom/bnxt/bnxt.c | 1 -
include/linux/skbuff.h | 12 ------------
3 files changed, 14 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnx2.c b/drivers/net/ethernet/broadcom/bnx2.c
index 466e1d62bcf6..0d917a9699c5 100644
--- a/drivers/net/ethernet/broadcom/bnx2.c
+++ b/drivers/net/ethernet/broadcom/bnx2.c
@@ -2955,7 +2955,6 @@ bnx2_reuse_rx_skb_pages(struct bnx2 *bp, struct bnx2_rx_ring_info *rxr,
shinfo = skb_shinfo(skb);
shinfo->nr_frags--;
page = skb_frag_page(&shinfo->frags[shinfo->nr_frags]);
- __skb_frag_set_page(&shinfo->frags[shinfo->nr_frags], NULL);

cons_rx_pg->page = page;
dev_kfree_skb(skb);
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index efaff5018af8..f3f08660ec30 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -1105,7 +1105,6 @@ static u32 __bnxt_rx_agg_pages(struct bnxt *bp,
unsigned int nr_frags;

nr_frags = --shinfo->nr_frags;
- __skb_frag_set_page(&shinfo->frags[nr_frags], NULL);
cons_rx_buf->page = page;

/* Update prod since possibly some pages have been
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 0d1027ea81e0..a3c448757b4e 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -3491,18 +3491,6 @@ static inline void skb_frag_page_copy(skb_frag_t *fragto,
fragto->bv_page = fragfrom->bv_page;
}

-/**
- * __skb_frag_set_page - sets the page contained in a paged fragment
- * @frag: the paged fragment
- * @page: the page to set
- *
- * Sets the fragment @frag to contain @page.
- */
-static inline void __skb_frag_set_page(skb_frag_t *frag, struct page *page)
-{
- frag->bv_page = page;
-}
-
bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t prio);

/**
--
2.33.0


2023-05-08 14:45:12

by Simon Horman

[permalink] [raw]
Subject: Re: [PATCH RFC 2/2] net: remove __skb_frag_set_page()

On Mon, May 08, 2023 at 08:39:22PM +0800, Yunsheng Lin wrote:
> The remaining users calling __skb_frag_set_page() with
> page being NULL seems to doing defensive programming, as
> shinfo->nr_frags is already decremented, so remove them.
>
> Signed-off-by: Yunsheng Lin <[email protected]>

...

> diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
> index efaff5018af8..f3f08660ec30 100644
> --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
> +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
> @@ -1105,7 +1105,6 @@ static u32 __bnxt_rx_agg_pages(struct bnxt *bp,
> unsigned int nr_frags;
>
> nr_frags = --shinfo->nr_frags;

Hi Yunsheng,

nr_frags is now unused, other than being set on the line above.
Probably this local variable can be removed.

> - __skb_frag_set_page(&shinfo->frags[nr_frags], NULL);
> cons_rx_buf->page = page;
>

...

2023-05-09 00:54:51

by Yunsheng Lin

[permalink] [raw]
Subject: Re: [PATCH RFC 2/2] net: remove __skb_frag_set_page()

On 2023/5/8 22:31, Simon Horman wrote:
> On Mon, May 08, 2023 at 08:39:22PM +0800, Yunsheng Lin wrote:
>> The remaining users calling __skb_frag_set_page() with
>> page being NULL seems to doing defensive programming, as
>> shinfo->nr_frags is already decremented, so remove them.
>>
>> Signed-off-by: Yunsheng Lin <[email protected]>
>
> ...
>
>> diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
>> index efaff5018af8..f3f08660ec30 100644
>> --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
>> +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
>> @@ -1105,7 +1105,6 @@ static u32 __bnxt_rx_agg_pages(struct bnxt *bp,
>> unsigned int nr_frags;
>>
>> nr_frags = --shinfo->nr_frags;
>
> Hi Yunsheng,
>
> nr_frags is now unused, other than being set on the line above.
> Probably this local variable can be removed.

Yes, will remove that.
Thanks.