From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH 1/3] add netdev_alloc_skb Date: Fri, 28 Jul 2006 10:46:28 +0200 Message-ID: <20060728084628.GA27892@lst.de> References: <20060728070851.GB25174@lst.de> <20060728.012424.70217564.davem@davemloft.net> <20060728082712.GA27366@lst.de> <20060728.012832.99202035.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: hch@lst.de, netdev@vger.kernel.org Return-path: Received: from verein.lst.de ([213.95.11.210]:30892 "EHLO mail.lst.de") by vger.kernel.org with ESMTP id S1751796AbWG1Iq6 (ORCPT ); Fri, 28 Jul 2006 04:46:58 -0400 To: David Miller Content-Disposition: inline In-Reply-To: <20060728.012832.99202035.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Fri, Jul 28, 2006 at 01:28:32AM -0700, David Miller wrote: > From: Christoph Hellwig > Date: Fri, 28 Jul 2006 10:27:12 +0200 > > > We need a fixup patch for the existing wrong comments on dev_alloc_skb > > anyway - but if you prefer to respin the netdev_alloc_skb and have > > another patch to fixup the original comments I can do that aswell. > > I intend to, for everyone's convenience, put the addition of > netdev_alloc_skb() into 2.6.18. Here is the requested fixed up version: Index: linux-2.6/include/linux/skbuff.h =================================================================== --- linux-2.6.orig/include/linux/skbuff.h 2006-07-26 13:27:07.000000000 +0200 +++ linux-2.6/include/linux/skbuff.h 2006-07-28 10:41:00.000000000 +0200 @@ -1104,6 +1104,28 @@ return __dev_alloc_skb(length, GFP_ATOMIC); } +extern struct sk_buff *__netdev_alloc_skb(struct net_device *dev, + unsigned int length, gfp_t gfp_mask); + +/** + * netdev_alloc_skb - allocate an skbuff for rx on a specific device + * @dev: network device to receive on + * @length: length to allocate + * + * Allocate a new &sk_buff and assign it a usage count of one. The + * buffer has unspecified headroom built in. Users should allocate + * the headroom they think they need without accounting for the + * built in space. The built in space is used for optimisations. + * + * %NULL is returned if there is no free memory. Although this function + * allocates memory it can be called from an interrupt. + */ +static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev, + unsigned int length) +{ + return __netdev_alloc_skb(dev, length, GFP_ATOMIC); +} + /** * skb_cow - copy header of skb when it is required * @skb: buffer to cow Index: linux-2.6/net/core/skbuff.c =================================================================== --- linux-2.6.orig/net/core/skbuff.c 2006-07-26 13:27:07.000000000 +0200 +++ linux-2.6/net/core/skbuff.c 2006-07-28 10:41:09.000000000 +0200 @@ -256,6 +256,29 @@ goto out; } +/** + * __netdev_alloc_skb - allocate an skbuff for rx on a specific device + * @dev: network device to receive on + * @length: length to allocate + * @gfp_mask: get_free_pages mask, passed to alloc_skb + * + * Allocate a new &sk_buff and assign it a usage count of one. The + * buffer has unspecified headroom built in. Users should allocate + * the headroom they think they need without accounting for the + * built in space. The built in space is used for optimisations. + * + * %NULL is returned if there is no free memory. + */ +struct sk_buff *__netdev_alloc_skb(struct net_device *dev, + unsigned int length, gfp_t gfp_mask) +{ + struct sk_buff *skb; + + skb = alloc_skb(length + NET_SKB_PAD, gfp_mask); + if (likely(skb)) + skb_reserve(skb, NET_SKB_PAD); + return skb; +} static void skb_drop_list(struct sk_buff **listp) { @@ -2042,6 +2065,7 @@ EXPORT_SYMBOL(kfree_skb); EXPORT_SYMBOL(__pskb_pull_tail); EXPORT_SYMBOL(__alloc_skb); +EXPORT_SYMBOL(__netdev_alloc_skb); EXPORT_SYMBOL(pskb_copy); EXPORT_SYMBOL(pskb_expand_head); EXPORT_SYMBOL(skb_checksum);