diff options
Diffstat (limited to 'net/core/skbuff.c')
| -rw-r--r-- | net/core/skbuff.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index b45cd1494243..84151cf40aeb 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -4931,3 +4931,31 @@ struct sk_buff *pskb_extract(struct sk_buff *skb, int off, return clone; } EXPORT_SYMBOL(pskb_extract); + +/** + * skb_condense - try to get rid of fragments/frag_list if possible + * @skb: buffer + * + * Can be used to save memory before skb is added to a busy queue. + * If packet has bytes in frags and enough tail room in skb->head, + * pull all of them, so that we can free the frags right now and adjust + * truesize. + * Notes: + * We do not reallocate skb->head thus can not fail. + * Caller must re-evaluate skb->truesize if needed. + */ +void skb_condense(struct sk_buff *skb) +{ + if (!skb->data_len || + skb->data_len > skb->end - skb->tail || + skb_cloned(skb)) + return; + + /* Nice, we can free page frag(s) right now */ + __pskb_pull_tail(skb, skb->data_len); + + /* Now adjust skb->truesize, since __pskb_pull_tail() does + * not do this. + */ + skb->truesize = SKB_TRUESIZE(skb_end_offset(skb)); +} |