Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933131Ab0FEKLS (ORCPT ); Sat, 5 Jun 2010 06:11:18 -0400 Received: from mga01.intel.com ([192.55.52.88]:65455 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932872Ab0FEKHG (ORCPT ); Sat, 5 Jun 2010 06:07:06 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.53,366,1272870000"; d="scan'208";a="804988053" From: xiaohui.xin@intel.com To: 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: [RFC PATCH v7 09/19] Ignore room skb_reserve() when device is using external buffer. Date: Sat, 5 Jun 2010 18:14:48 +0800 Message-Id: <1275732899-5423-9-git-send-email-xiaohui.xin@intel.com> X-Mailer: git-send-email 1.5.4.4 In-Reply-To: <1275732899-5423-8-git-send-email-xiaohui.xin@intel.com> References: <1275732899-5423-1-git-send-email-xiaohui.xin@intel.com> <1275732899-5423-2-git-send-email-xiaohui.xin@intel.com> <1275732899-5423-3-git-send-email-xiaohui.xin@intel.com> <1275732899-5423-4-git-send-email-xiaohui.xin@intel.com> <1275732899-5423-5-git-send-email-xiaohui.xin@intel.com> <1275732899-5423-6-git-send-email-xiaohui.xin@intel.com> <1275732899-5423-7-git-send-email-xiaohui.xin@intel.com> <1275732899-5423-8-git-send-email-xiaohui.xin@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1424 Lines: 41 From: Xin Xiaohui Make the skb->data and skb->head from external buffer to be consistent, we ignore the room reserved by driver for kernel skb. Signed-off-by: Xin Xiaohui Signed-off-by: Zhao Yu Reviewed-by: Jeff Dike --- include/linux/skbuff.h | 9 +++++++++ 1 files changed, 9 insertions(+), 0 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 5ff8c27..193b259 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -1200,6 +1200,15 @@ static inline int skb_tailroom(const struct sk_buff *skb) */ static inline void skb_reserve(struct sk_buff *skb, int len) { + /* Since skb_reserve() is only for an empty buffer, + * and when the skb is getting external buffer, we cannot + * retain the external buffer has the same reserved space + * in the header which kernel allocatd skb has, so have to + * ignore this. And we have recorded the external buffer + * info in the destructor_arg field, so use it as indicator. + */ + if (skb_shinfo(skb)->destructor_arg) + return; skb->data += len; skb->tail += len; } -- 1.5.4.4 -- 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/