On 2024/7/2 23:52, Alexander H Duyck wrote:
> On Tue, 2024-06-25 at 21:52 +0800, Yunsheng Lin wrote:
>> introduce the skb_copy_to_va_nocache() helper to avoid
>> calling virt_to_page() and skb_copy_to_page_nocache().
>>
>> CC: Alexander Duyck <alexander.duyck@gmail.com>
>> Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
>> ---
>> include/net/sock.h | 15 +++++++++++++++
>> 1 file changed, 15 insertions(+)
>>
>> diff --git a/include/net/sock.h b/include/net/sock.h
>> index cce23ac4d514..7ad235465485 100644
>> --- a/include/net/sock.h
>> +++ b/include/net/sock.h
>> @@ -2201,6 +2201,21 @@ static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *fro
>> return 0;
>> }
>>
>> +static inline int skb_copy_to_va_nocache(struct sock *sk, struct iov_iter *from,
>> + struct sk_buff *skb, char *va, int copy)
>> +{
>> + int err;
>> +
>> + err = skb_do_copy_data_nocache(sk, skb, from, va, copy, skb->len);
>> + if (err)
>> + return err;
>> +
>> + skb_len_add(skb, copy);
>> + sk_wmem_queued_add(sk, copy);
>> + sk_mem_charge(sk, copy);
>> + return 0;
>> +}
>> +
>> /**
>> * sk_wmem_alloc_get - returns write allocations
>> * @sk: socket
>
> One minor nit. Rather than duplicate skb_copy_to_page_nocache you would
> be better served to implement this one before it, and then just update
> skb_copy_to_page_nocache to be:
> return skb_copy_to_va_nocache(sk, from, skb,
> page_address(page) + off, copy);
>
> We can save ourselves at least a few lines of code that way and it
> creates one spot to do any changes.
Looking at more closely, it seems we may be able to just rename
skb_copy_to_page_nocache() to skb_copy_to_va_nocache() as there
is no caller for skb_copy_to_page_nocache() after this patchset.
>
> .
>