Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754179Ab0KHHmH (ORCPT ); Mon, 8 Nov 2010 02:42:07 -0500 Received: from mga03.intel.com ([143.182.124.21]:26506 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753803Ab0KHHmE (ORCPT ); Mon, 8 Nov 2010 02:42:04 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.58,313,1286175600"; d="scan'208";a="345803486" From: xiaohui.xin@intel.com To: eric.dumazet@gmail.com, netdev@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, mst@redhat.com, mingo@elte.hu, davem@davemloft.net, herbert@gondor.hengli.com.au, jdike@linux.intel.com Cc: Xin Xiaohui Subject: Re:[PATCH v14 06/17] Use callback to deal with skb_release_data() specially. Date: Mon, 8 Nov 2010 16:03:50 +0800 Message-Id: <1289203430-5935-1-git-send-email-xiaohui.xin@intel.com> X-Mailer: git-send-email 1.7.3 In-Reply-To: <1288861663.2659.47.camel@edumazet-laptop> References: <1288861663.2659.47.camel@edumazet-laptop> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2285 Lines: 83 From: Xin Xiaohui >> Hmm, I suggest you read the comment two lines above. >> >> If destructor_arg is now cleared each time we allocate a new skb, then, >> please move it before dataref in shinfo structure, so that the following >> memset() does the job efficiently... > > >Something like : > >diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h >index e6ba898..2dca504 100644 >--- a/include/linux/skbuff.h >+++ b/include/linux/skbuff.h >@@ -195,6 +195,9 @@ struct skb_shared_info { > __be32 ip6_frag_id; > __u8 tx_flags; > struct sk_buff *frag_list; >+ /* Intermediate layers must ensure that destructor_arg >+ * remains valid until skb destructor */ >+ void *destructor_arg; > struct skb_shared_hwtstamps hwtstamps; > > /* >@@ -202,9 +205,6 @@ struct skb_shared_info { > */ > atomic_t dataref; > >- /* Intermediate layers must ensure that destructor_arg >- * remains valid until skb destructor */ >- void * destructor_arg; > /* must be last field, see pskb_expand_head() */ > skb_frag_t frags[MAX_SKB_FRAGS]; > }; > > Will that affect the cache line? Or, we can move the line to clear destructor_arg to the end of __alloc_skb(). It looks like as the following, which one do you prefer? Thanks Xiaohui --- net/core/skbuff.c | 8 ++++++++ 1 files changed, 8 insertions(+), 0 deletions(-) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index c83b421..df852f2 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -224,6 +224,7 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask, child->fclone = SKB_FCLONE_UNAVAILABLE; } + shinfo->destructor_arg = NULL; out: return skb; nodata: @@ -343,6 +344,13 @@ static void skb_release_data(struct sk_buff *skb) if (skb_has_frags(skb)) skb_drop_fraglist(skb); + if (skb->dev && dev_is_mpassthru(skb->dev)) { + struct skb_ext_page *ext_page = + skb_shinfo(skb)->destructor_arg; + if (ext_page && ext_page->dtor) + ext_page->dtor(ext_page); + } + kfree(skb->head); } } -- 1.7.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/