From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp.tuxdriver.com (charlotte.tuxdriver.com [70.61.120.58]) by dpdk.org (Postfix) with ESMTP id 271181F7 for ; Wed, 1 Oct 2014 13:08:12 +0200 (CEST) Received: from [2001:470:8:a08:9833:6894:f2b2:43a] (helo=localhost) by smtp.tuxdriver.com with esmtpsa (TLSv1:AES128-SHA:128) (Exim 4.63) (envelope-from ) id 1XZHri-0007RW-FX; Wed, 01 Oct 2014 07:14:55 -0400 Date: Wed, 1 Oct 2014 07:14:37 -0400 From: Neil Horman To: Bruce Richardson Message-ID: <20141001111437.GE21151@hmsreliant.think-freely.org> References: <1412090762-18852-1-git-send-email-bruce.richardson@intel.com> <20140930170632.GJ2193@hmsreliant.think-freely.org> <20141001084721.GD1204@BRICHA3-MOBL> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20141001084721.GD1204@BRICHA3-MOBL> User-Agent: Mutt/1.5.23 (2014-03-12) X-Spam-Score: -2.9 (--) X-Spam-Status: No Cc: dev@dpdk.org Subject: Re: [dpdk-dev] [PATCH RFC] mbuf: Adjust TX flags to start at bit 32 X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 01 Oct 2014 11:08:12 -0000 On Wed, Oct 01, 2014 at 09:47:21AM +0100, Bruce Richardson wrote: > On Tue, Sep 30, 2014 at 01:06:32PM -0400, Neil Horman wrote: > > On Tue, Sep 30, 2014 at 04:26:02PM +0100, Bruce Richardson wrote: > > > This patch takes the existing TX flags defined for the mbuf and shifts > > > each uniquely defined one left so that additional RX flags can be > > > defined without having RX and TX flags mixed together. > > > > > > Signed-off-by: Bruce Richardson > > > --- > > > lib/librte_mbuf/rte_mbuf.h | 26 +++++++++++++------------- > > > 1 file changed, 13 insertions(+), 13 deletions(-) > > > > > > diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h > > > index 1c6e115..c9fc4ec 100644 > > > --- a/lib/librte_mbuf/rte_mbuf.h > > > +++ b/lib/librte_mbuf/rte_mbuf.h > > > @@ -86,26 +86,26 @@ extern "C" { > > > #define PKT_RX_IEEE1588_PTP 0x0200 /**< RX IEEE1588 L2 Ethernet PT Packet. */ > > > #define PKT_RX_IEEE1588_TMST 0x0400 /**< RX IEEE1588 L2/L4 timestamped packet.*/ > > > > > > -#define PKT_TX_VLAN_PKT 0x0800 /**< TX packet is a 802.1q VLAN packet. */ > > > -#define PKT_TX_IP_CKSUM 0x1000 /**< IP cksum of TX pkt. computed by NIC. */ > > > -#define PKT_TX_IPV4_CSUM 0x1000 /**< Alias of PKT_TX_IP_CKSUM. */ > > > -#define PKT_TX_IPV4 PKT_RX_IPV4_HDR /**< IPv4 with no IP checksum offload. */ > > > -#define PKT_TX_IPV6 PKT_RX_IPV6_HDR /**< IPv6 packet */ > > > +#define PKT_TX_VLAN_PKT (0x0001 << 32) /**< TX packet is a 802.1q VLAN packet. */ > > > +#define PKT_TX_IP_CKSUM (0x0002 << 32) /**< IP cksum of TX pkt. computed by NIC. */ > > > +#define PKT_TX_IPV4_CSUM PKT_TX_IP_CKSUM /**< Alias of PKT_TX_IP_CKSUM. */ > > > +#define PKT_TX_IPV4 PKT_RX_IPV4_HDR /**< IPv4 with no IP checksum offload. */ > > > +#define PKT_TX_IPV6 PKT_RX_IPV6_HDR /**< IPv6 packet */ > > > > > > /* > > > - * Bit 14~13 used for L4 packet type with checksum enabled. > > > + * Bit 35~34 used for L4 packet type with checksum enabled. > > > * 00: Reserved > > > * 01: TCP checksum > > > * 10: SCTP checksum > > > * 11: UDP checksum > > > */ > > > -#define PKT_TX_L4_MASK 0x6000 /**< Mask bits for L4 checksum offload request. */ > > > -#define PKT_TX_L4_NO_CKSUM 0x0000 /**< Disable L4 cksum of TX pkt. */ > > > -#define PKT_TX_TCP_CKSUM 0x2000 /**< TCP cksum of TX pkt. computed by NIC. */ > > > -#define PKT_TX_SCTP_CKSUM 0x4000 /**< SCTP cksum of TX pkt. computed by NIC. */ > > > -#define PKT_TX_UDP_CKSUM 0x6000 /**< UDP cksum of TX pkt. computed by NIC. */ > > > -/* Bit 15 */ > > > -#define PKT_TX_IEEE1588_TMST 0x8000 /**< TX IEEE1588 packet to timestamp. */ > > > +#define PKT_TX_L4_NO_CKSUM (0x0000 << 32) /**< Disable L4 cksum of TX pkt. */ > > > +#define PKT_TX_TCP_CKSUM (0x0004 << 32) /**< TCP cksum of TX pkt. computed by NIC. */ > > > +#define PKT_TX_SCTP_CKSUM (0x0008 << 32) /**< SCTP cksum of TX pkt. computed by NIC. */ > > > +#define PKT_TX_UDP_CKSUM (0x000C << 32) /**< UDP cksum of TX pkt. computed by NIC. */ > > > +#define PKT_TX_L4_MASK (0x000C << 32) /**< Mask for L4 cksum offload request. */ > > > +/* Bit 36 */ > > > +#define PKT_TX_IEEE1588_TMST (0x0010 << 32) /**< TX IEEE1588 packet to timestamp. */ > > > > > > /* Use final bit of flags to indicate a control mbuf */ > > > #define CTRL_MBUF_FLAG (1ULL << 63) > > > -- > > > 1.9.3 > > > > > > > > > > I'm not opposed to the patch at all, but I would like to point out that this is > > the sort of change that breaks ABI very easily (which is fine right now given > > the mbuf changes already staged for the release, but still something to be aware > > of). As such, are there advantages to this patch (other than the niceness of > > human readability)? > > > > If we're going to reshuffle these flags now, it might be nice to start tx flags > > at the most significant bit and count back, and start rx flags at the least > > significant bit and count up. That would ensure that we don't reserve flags for > > a direction without need. > > > > Best > > Neil > > > Good idea, though currently the most significant bit is being used as a flag > to indicate a control mbuf. My thinking is that we may potentially need > other flags that are not just for RX or TX, and to have those at the end. > However, given that that is likely to be the exception case, perhaps we > could reserve the last byte for non-RX/TX flags and then implement the > scheme you suggest. What do you think? > Sure, seems reasonable Neil > /Bruce >