From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vijay Subramanian Subject: [PATCH V2 net-next] net: Cleanup skb cloning by adding SKB_FCLONE_FREE Date: Thu, 2 Oct 2014 10:00:43 -0700 Message-ID: <1412269243-5583-1-git-send-email-subramanian.vijay@gmail.com> Cc: davem@davemloft.net, edumazet@google.com, Vijay Subramanian To: netdev@vger.kernel.org Return-path: Received: from mail-pa0-f53.google.com ([209.85.220.53]:54364 "EHLO mail-pa0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751834AbaJBRA5 (ORCPT ); Thu, 2 Oct 2014 13:00:57 -0400 Received: by mail-pa0-f53.google.com with SMTP id kq14so2895223pab.40 for ; Thu, 02 Oct 2014 10:00:56 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: SKB_FCLONE_UNAVAILABLE has overloaded meaning depending on type of skb. 1: If skb is allocated from head_cache, it indicates fclone is not available. 2: If skb is a companion fclone skb (allocated from fclone_cache), it indicates it is available to be used. To avoid confusion for case 2 above, this patch replaces SKB_FCLONE_UNAVAILABLE with SKB_FCLONE_FREE where appropriate. For fclone companion skbs, this indicates it is free for use. SKB_FCLONE_UNAVAILABLE will now simply indicate skb is from head_cache and cannot / will not have a companion fclone. Signed-off-by: Vijay Subramanian --- V1-->V2: Comment all states include/linux/skbuff.h | 7 ++++--- net/core/skbuff.c | 8 ++++---- 2 files changed, 8 insertions(+), 7 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 7c5036d..3a5ec76 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -339,9 +339,10 @@ struct skb_shared_info { enum { - SKB_FCLONE_UNAVAILABLE, - SKB_FCLONE_ORIG, - SKB_FCLONE_CLONE, + SKB_FCLONE_UNAVAILABLE, /* skb has no fclone (from head_cache) */ + SKB_FCLONE_ORIG, /* orig skb (from fclone_cache) */ + SKB_FCLONE_CLONE, /* companion fclone skb (from fclone_cache) */ + SKB_FCLONE_FREE, /* this companion fclone skb is available */ }; enum { diff --git a/net/core/skbuff.c b/net/core/skbuff.c index f77e648..6f4e359 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -265,7 +265,7 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask, skb->fclone = SKB_FCLONE_ORIG; atomic_set(&fclones->fclone_ref, 1); - fclones->skb2.fclone = SKB_FCLONE_UNAVAILABLE; + fclones->skb2.fclone = SKB_FCLONE_FREE; fclones->skb2.pfmemalloc = pfmemalloc; } out: @@ -542,7 +542,7 @@ static void kfree_skbmem(struct sk_buff *skb) fclones = container_of(skb, struct sk_buff_fclones, skb2); /* Warning : We must perform the atomic_dec_and_test() before - * setting skb->fclone back to SKB_FCLONE_UNAVAILABLE, otherwise + * setting skb->fclone back to SKB_FCLONE_FREE, otherwise * skb_clone() could set clone_ref to 2 before our decrement. * Anyway, if we are going to free the structure, no need to * rewrite skb->fclone. @@ -553,7 +553,7 @@ static void kfree_skbmem(struct sk_buff *skb) /* The clone portion is available for * fast-cloning again. */ - skb->fclone = SKB_FCLONE_UNAVAILABLE; + skb->fclone = SKB_FCLONE_FREE; } break; } @@ -874,7 +874,7 @@ struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t gfp_mask) return NULL; if (skb->fclone == SKB_FCLONE_ORIG && - n->fclone == SKB_FCLONE_UNAVAILABLE) { + n->fclone == SKB_FCLONE_FREE) { n->fclone = SKB_FCLONE_CLONE; /* As our fastclone was free, clone_ref must be 1 at this point. * We could use atomic_inc() here, but it is faster -- 1.9.1