Re: [dpdk-dev] [PATCH v2 2/2] mbuf: assign valid bit values for some RX and TX flags

["Ananyev, Konstantin" <konstantin.ananyev@intel.com>]

> -----Original Message-----
> From: Zhang, Helin
> Sent: Saturday, December 06, 2014 1:08 AM
> To: Ananyev, Konstantin; dev@dpdk.org
> Cc: Cao, Waterman; Cao, Min; Wu, Jingjing; Liu, Jijiang; olivier.matz@6wind.com
> Subject: RE: [PATCH v2 2/2] mbuf: assign valid bit values for some RX and TX flags
> 
> 
> 
> > -----Original Message-----
> > From: Zhang, Helin
> > Sent: Saturday, December 6, 2014 8:40 AM
> > To: Ananyev, Konstantin; dev@dpdk.org
> > Cc: Cao, Waterman; Cao, Min; Wu, Jingjing; Liu, Jijiang;
> > olivier.matz@6wind.com
> > Subject: RE: [PATCH v2 2/2] mbuf: assign valid bit values for some RX and TX
> > flags
> >
> > OK. I will send out another patch according to your comments. Thanks a lot!
> >
> > Regards,
> > Helin
> >
> > > -----Original Message-----
> > > From: Ananyev, Konstantin
> > > Sent: Friday, December 5, 2014 6:50 PM
> > > To: Zhang, Helin; dev@dpdk.org
> > > Cc: Cao, Waterman; Cao, Min; Wu, Jingjing; Liu, Jijiang;
> > > olivier.matz@6wind.com
> > > Subject: RE: [PATCH v2 2/2] mbuf: assign valid bit values for some RX
> > > and TX flags
> > >
> > > Hi Helin,
> > >
> > > > -----Original Message-----
> > > > From: Zhang, Helin
> > > > Sent: Friday, December 05, 2014 1:46 AM
> > > > To: dev@dpdk.org
> > > > Cc: Cao, Waterman; Cao, Min; Wu, Jingjing; Liu, Jijiang; Ananyev,
> > > > Konstantin; olivier.matz@6wind.com; Zhang, Helin
> > > > Subject: [PATCH v2 2/2] mbuf: assign valid bit values for some RX
> > > > and TX flags
> > > >
> > > > Before redefining mbuf structure, there was lack of free bits in
> > > > 'ol_flags' (32 bits in total) for new RX or TX flags. So it tried to
> > > > reuse existant bits as most as possible, or even assigning 0 to some
> > > > of bit flags. After new mbuf structure defined, there are quite a
> > > > lot of free bits. So those newly added bit flags should be assigned
> > > > with correct and valid bit values, and getting their names should be
> > > > enabled as well. Note that 'RECIP' should be removed, as nowhere
> > > > will use it.
> > > >
> > > > Signed-off-by: Helin Zhang <helin.zhang@intel.com>
> > > > ---
> > > >  lib/librte_mbuf/rte_mbuf.c |  9 ++++-----
> > > > lib/librte_mbuf/rte_mbuf.h
> > > > | 19 +++++++++----------
> > > >  2 files changed, 13 insertions(+), 15 deletions(-)
> > > >
> > > > v2 changes:
> > > > * Removed error flag of 'ECIPE' processing only in mbuf. All other error flags
> > > >   were added back.
> > > > * Assigned error flags with correct and valid values, as their previous values
> > > >   were invalid.
> > > > * Enabled getting all error flag names.
> > > >
> > > > diff --git a/lib/librte_mbuf/rte_mbuf.c b/lib/librte_mbuf/rte_mbuf.c
> > > > index 87c2963..3ce7c8d 100644
> > > > --- a/lib/librte_mbuf/rte_mbuf.c
> > > > +++ b/lib/librte_mbuf/rte_mbuf.c
> > > > @@ -210,11 +210,10 @@ const char *rte_get_rx_ol_flag_name(uint64_t
> > > mask)
> > > >  	case PKT_RX_FDIR: return "PKT_RX_FDIR";
> > > >  	case PKT_RX_L4_CKSUM_BAD: return "PKT_RX_L4_CKSUM_BAD";
> > > >  	case PKT_RX_IP_CKSUM_BAD: return "PKT_RX_IP_CKSUM_BAD";
> > > > -	/* case PKT_RX_EIP_CKSUM_BAD: return "PKT_RX_EIP_CKSUM_BAD"; */
> > > > -	/* case PKT_RX_OVERSIZE: return "PKT_RX_OVERSIZE"; */
> > > > -	/* case PKT_RX_HBUF_OVERFLOW: return "PKT_RX_HBUF_OVERFLOW";
> > > */
> > > > -	/* case PKT_RX_RECIP_ERR: return "PKT_RX_RECIP_ERR"; */
> > > > -	/* case PKT_RX_MAC_ERR: return "PKT_RX_MAC_ERR"; */
> > > > +	case PKT_RX_EIP_CKSUM_BAD: return "PKT_RX_EIP_CKSUM_BAD";
> > > > +	case PKT_RX_OVERSIZE: return "PKT_RX_OVERSIZE";
> > > > +	case PKT_RX_HBUF_OVERFLOW: return
> > "PKT_RX_HBUF_OVERFLOW";
> > > > +	case PKT_RX_MAC_ERR: return "PKT_RX_MAC_ERR";
> > > >  	case PKT_RX_IPV4_HDR: return "PKT_RX_IPV4_HDR";
> > > >  	case PKT_RX_IPV4_HDR_EXT: return "PKT_RX_IPV4_HDR_EXT";
> > > >  	case PKT_RX_IPV6_HDR: return "PKT_RX_IPV6_HDR"; diff --git
> > > > a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h index
> > > > 2e5fce5..c9591c0 100644
> > > > --- a/lib/librte_mbuf/rte_mbuf.h
> > > > +++ b/lib/librte_mbuf/rte_mbuf.h
> > > > @@ -84,11 +84,6 @@ extern "C" {
> > > >  #define PKT_RX_FDIR          (1ULL << 2)  /**< RX packet with FDIR
> > > match indicate. */
> > > >  #define PKT_RX_L4_CKSUM_BAD  (1ULL << 3)  /**< L4 cksum of RX pkt.
> > > is
> > > > not OK. */  #define PKT_RX_IP_CKSUM_BAD  (1ULL << 4)  /**< IP cksum
> > > of
> > > > RX pkt. is not OK. */ -#define PKT_RX_EIP_CKSUM_BAD (0ULL << 0)
> > > > /**<
> > > External IP header checksum error. */
> > > > -#define PKT_RX_OVERSIZE      (0ULL << 0)  /**< Num of desc of an RX
> > > pkt oversize. */
> > > > -#define PKT_RX_HBUF_OVERFLOW (0ULL << 0)  /**< Header buffer
> > > overflow. */
> > > > -#define PKT_RX_RECIP_ERR     (0ULL << 0)  /**< Hardware processing
> > > error. */
> > > > -#define PKT_RX_MAC_ERR       (0ULL << 0)  /**< MAC error. */
> > > >  #define PKT_RX_IPV4_HDR      (1ULL << 5)  /**< RX packet with IPv4
> > > header. */
> > > >  #define PKT_RX_IPV4_HDR_EXT  (1ULL << 6)  /**< RX packet with
> > > extended IPv4 header. */
> > > >  #define PKT_RX_IPV6_HDR      (1ULL << 7)  /**< RX packet with IPv6
> > > header. */
> > > > @@ -99,6 +94,10 @@ extern "C" {
> > > >  #define PKT_RX_TUNNEL_IPV6_HDR (1ULL << 12) /**< RX tunnel packet
> > > with IPv6 header. */
> > > >  #define PKT_RX_FDIR_ID       (1ULL << 13) /**< FD id reported if FDIR
> > > match. */
> > > >  #define PKT_RX_FDIR_FLX      (1ULL << 14) /**< Flexible bytes
> > reported
> > > if FDIR match. */
> > > > +#define PKT_RX_EIP_CKSUM_BAD (1ULL << 15)  /**< External IP header
> > > checksum error. */
> > > > +#define PKT_RX_OVERSIZE      (1ULL << 16)  /**< Num of desc of an
> > RX
> > > pkt oversize. */
> > > > +#define PKT_RX_HBUF_OVERFLOW (1ULL << 17)  /**< Header buffer
> > > overflow. */
> > > > +#define PKT_RX_MAC_ERR       (1ULL << 18)  /**< MAC error. */
> > > >  /* add new RX flags here */
> > >
> > > I still think there is no point to have several flags to indicate HW
> > > error for the packet.
> > > As I suggested before we can collapse 3 of them (OVERSIZE,
> > > HBUF_OVERFLOW,
> > > MAC_ERR) into one.
> > > As I remember, Oliver even suggested to drop such packets.
> > > As was said above - if is not a whole packet SW can't do much with it anyway.
> > > The only thing such bad packets can probably be used for - some sort
> > > of debugging.
> > > So we probably can combine both things:
> > > - in normal operation just drop such packet
> > > - if PMD_DEBUG_RX is enabled, then write a log record, set RX_HW_ERR
> > > and deliver a packet to the upper layer.
> I still do not want to drop the bad packet here, as it may affect vector processing.
> At least it should be investigated how much impact on vector RX. I prefer to let
> up-layer software do that.

But right now, i40e doesn't have any vector RX support.
You probably meant implications with scatter RX, no?
Another thing - if you HW can't receive packets normally, then something really wrong is going on.
In such situation, you probably wouldn't worry about your RX performance anyway :) 
But I suppose it is a good first step, let's just collapse 3 error flags into one for now.
Then  we can decide should we drop such packets or not. 
Konstantin

> 
> > >
> > > >
> > > >  /* add new TX flags here */
> > > > @@ -141,13 +140,13 @@ extern "C" {
> > > >  #define PKT_TX_IP_CKSUM      (1ULL << 54) /**< IP cksum of TX pkt.
> > > computed by NIC. */
> > > >  #define PKT_TX_IPV4_CSUM     PKT_TX_IP_CKSUM /**< Alias of
> > > PKT_TX_IP_CKSUM. */
> > > >
> > > > -/** Tell the NIC it's an IPv4 packet. Required for L4 checksum offload or
> > TSO.
> > > */
> > > > -#define PKT_TX_IPV4          PKT_RX_IPV4_HDR
> > > > +/** Tell the NIC it's an IPv4 packet. */
> > > > +#define PKT_TX_IPV4          (1ULL << 55) /**< TX packet is a IPV4
> > > packet. */
> > > >
> > > > -/** Tell the NIC it's an IPv6 packet. Required for L4 checksum offload or
> > TSO.
> > > */
> > > > -#define PKT_TX_IPV6          PKT_RX_IPV6_HDR
> > > > +/** Tell the NIC it's an IPv6 packet. */
> > > > +#define PKT_TX_IPV6          (1ULL << 56) /**< TX packet is a IPV6
> > > packet. */
> > > >
> > > > -#define PKT_TX_VLAN_PKT      (1ULL << 55) /**< TX packet is a 802.1q
> > > VLAN packet. */
> > > > +#define PKT_TX_VLAN_PKT      (1ULL << 57) /**< TX packet is a VLAN
> > > packet. */
> > >
> > > I don't think these changes should be part of that patch.
> > > They violate another patch that Frank sent before.
> > >
> > > Konstantin
> > >
> > > >
> > > >  /* Use final bit of flags to indicate a control mbuf */
> > > >  #define CTRL_MBUF_FLAG       (1ULL << 63) /**< Mbuf contains
> > control
> > > data */
> > > > --
> > > > 1.9.3