[ofw] [PATCH 3/3] Mlx4 (checksum): improving the mechanism of csum offload

Smith, Stan stan.smith at intel.com
Thu Sep 4 12:54:52 PDT 2008


Please see inline comments.

Thanks.

Tzachi Dar wrote:
> See bellow.
>
> Thanks
> Tzachi
>
>> -----Original Message-----
>> From: Smith, Stan [mailto:stan.smith at intel.com]
>> Sent: Thursday, September 04, 2008 10:16 PM
>> To: Alex Naslednikov; Tzachi Dar; ofw at lists.openfabrics.org
>> Subject: RE: [ofw] [PATCH 3/3] Mlx4 (checksum): improving the
>> mechanism of csum offload
>>
>> Hello Alex,
>>
>> Some questions:
>>
>> 1) Am I correct in understanding that ipoib offload is turned 'on'
>> by default?
>>
> The mode that is turned on by default, is "do checksum in HW if HW
> supports it, or by SW if HW doesn't support that". Probably the best
> mode for everyone.
>
>> 2) For debug/testing purposes, how does one turn ipoib
>> offload 'off' or 'on'?
>
> I have once sent such a script, I'll try to find it or send a new one.
>

Should this script be part of IPoIB offload documentation?

>
>>
>> 3) In the patch for ipoib_port.c, when making the call
>>     query_ca(p_port->ib_mgr.h_ca, NULL, &attr_size );
>>    I do not see attr_size initialized, hence it could be a very
>>    large integer (stack garbage). The garbage value could pass the
>>    1st call to get the attr size, then the following
>> cl_malloc(attr_size) call could fail
>> due to the very large integer.
>>    Do you agree?
>
> In the function mlnx_query_ca there is the following code:
>         // resource sufficience check
>         if (NULL == p_ca_attr || *p_byte_count < required_size) {
>                 *p_byte_count = required_size;
>                 status = IB_INSUFFICIENT_MEMORY;
>                 if ( p_ca_attr != NULL) {
>                         HCA_PRINT (TRACE_LEVEL_ERROR,HCA_DBG_SHIM,
>                                 ("Failed *p_byte_count (%d) <
> required_size (%d)\n", *p_byte_count, required_size ));
>                 }
>                 goto err_insuff_mem;
>         }
> Since p_ca_attr== NULL there shouldn't be a problem, the value is
> ignored.

OK, situation covered.

Thanks.

>
>
>>
>> Please notify the list when the patches are applied and committed to
>> svn.
>>
>> Thanks,
>>
>> Stan.
>>
>>
>> Alex Naslednikov wrote:
>>> This is cumulative patch that fixes all open issues shown the last
>>> week: SGE wrong calculation LSO messages in log files
>>> Fixes in ipoib csum offload mechanism
>>> Adding 3 states for CSUM offload : disabled, enabled if supported
>>> by HW and bypass (see inline)
>>>
>>> Signed-off by: xalex (Alexander Naslednikov)
>>> Index:
>> D:/Windows/MLNX_WINOF_CSUM_ARBEL/ulp/ipoib/kernel/ipoib_port.c
>>> ===================================================================
>>> --- D:/Windows/MLNX_WINOF_CSUM_ARBEL/ulp/ipoib/kernel/ipoib_port.c
>>> (revision 3106) +++
>>> D:/Windows/MLNX_WINOF_CSUM_ARBEL/ulp/ipoib/kernel/ipoib_port.c
>>>         (revision 3107) @@ -825,6 +825,8 @@ uint64_t
>>>         vaddr; net32_t                         rkey;
>>>         ib_qp_attr_t            qp_attr;
>>> +       ib_ca_attr_t *          p_ca_attr;
>>> +       uint32_t                        attr_size;
>>>
>>>         IPOIB_ENTER( IPOIB_DBG_INIT );
>>>
>>> @@ -889,7 +891,7 @@
>>>
>> p_port->p_adapter->p_ifc->get_err_str( status
>>> )) );
>>>                 return status;
>>>         }
>>> -
>>> +
>>>         /* Allocate the QP. */
>>>         cl_memclr( &qp_create, sizeof(qp_create) );
>>>         qp_create.qp_type = IB_QPT_UNRELIABLE_DGRM; @@ -897,8
>>>         +899,47 @@ qp_create.rq_sge = 2;   /* To support buffers
>>>         spanning pages. */ qp_create.h_rq_cq =
>>>         p_port->ib_mgr.h_recv_cq; qp_create.sq_depth =
>>> p_port->p_adapter->params.sq_depth;
>>> -       //TODO: Figure out the right number of SGE entries for
>>> sends.
>>> -       qp_create.sq_sge = MAX_SEND_SGE;
>>> +
>>> +       //Figure out the right number of SGE entries for sends.
>>> +       /* Get the size of the CA attribute structure. */
>>> +       status = p_port->p_adapter->p_ifc->query_ca(
>>> p_port->ib_mgr.h_ca, NULL, &attr_size );
>>> +       if( status != IB_INSUFFICIENT_MEMORY )
>>> +       {
>>> +               IPOIB_PRINT_EXIT( TRACE_LEVEL_ERROR,
>>> IPOIB_DBG_ERROR, +                       ("ib_query_ca failed with
>>> status %s.\n", p_port->p_adapter->p_ifc->get_err_str(status)) );
>>> +               return status;
>>> +       }
>>> +
>>> +       /* Allocate enough space to store the attribute structure.
>>> */ +       p_ca_attr = cl_malloc( attr_size );
>>> +       if( !p_ca_attr )
>>> +       {
>>> +               IPOIB_PRINT_EXIT( TRACE_LEVEL_ERROR,
>>> IPOIB_DBG_ERROR, +                       ("cl_malloc failed to
>>> allocate p_ca_attr!\n") ); +               return
>>> IB_INSUFFICIENT_RESOURCES; +       } +
>>> +       /* Query the CA attributes. */
>>> +       status =
>>> p_port->p_adapter->p_ifc->query_ca(p_port->ib_mgr.h_ca, p_ca_attr,
>>> &attr_size ); +       if( status != IB_SUCCESS )
>>> +       {
>>> +               cl_free( p_ca_attr );
>>> +
>>> +               IPOIB_PRINT_EXIT( TRACE_LEVEL_ERROR,
>>> IPOIB_DBG_ERROR, +                       ("ib_query_ca failed with
>>> status %s.\n", p_port->p_adapter->p_ifc->get_err_str(status)) );
>>> +               return status;
>>> +       }
>>> +#define UD_QP_USED_SGE 3
>>> +       qp_create.sq_sge = MAX_SEND_SGE < p_ca_attr->max_sges ?
>>> MAX_SEND_SGE  : (p_ca_attr->max_sges - UD_QP_USED_SGE);
>>> +       if (!p_ca_attr->ipoib_csum) {
>>> +               //checksum is not supported by device
>>> +               //user must specify BYPASS to explicitly cancel
>>> checksum calculation +               if
>>> (p_port->p_adapter->params.send_chksum_offload == CSUM_ENABLED) +
>> p_port->p_adapter->params.send_chksum_offload
>>> = CSUM_DISABLED;
>>> +               if (p_port->p_adapter->params.recv_chksum_offload
>>> == CSUM_ENABLED) +
>> p_port->p_adapter->params.recv_chksum_offload
>>> = CSUM_DISABLED;
>>> +       }
>>> +
>>>         qp_create.h_sq_cq = p_port->ib_mgr.h_send_cq;
>>>         qp_create.sq_signaled = TRUE;
>>>         status = p_port->p_adapter->p_ifc->create_qp( @@ -1937,7
>>> +1978,7 @@
>>>
>>>                 }
>>>                 /* Successful completion.  Get the receive
>>> information. */ -               p_desc->ndis_csum.Value = (ULONG)
>>> p_wc->csum_ok; +               p_desc->ndis_csum.Value = (ULONG)
>>>                 p_wc->recv.ud.csum_ok; cl_perf_start( GetRecvEndpts
>>>                 ); __recv_get_endpts( p_port, p_desc, p_wc, &p_src,
>>>                 &p_dst ); cl_perf_stop( &p_port->p_adapter->perf,
>>>                         GetRecvEndpts ); @@ -2580,10 +2621,22 @@
>>>                 ("__buf_mgr_get_ndis_pkt failed\n") ); return
>>>         IB_INSUFFICIENT_RESOURCES; }
>>> -
>>> +       if (p_port->p_adapter->params.recv_chksum_offload !=
>>>         CSUM_BYPASS) { /* Get the checksums directly from packet
>>> information. */
>>> -       NDIS_PER_PACKET_INFO_FROM_PACKET( *pp_packet,
>>> TcpIpChecksumPacketInfo ) =
>>> -               (PVOID) (uintn_t) (p_desc->ndis_csum.Value);
>>> +       /* In this case, no one of cheksum's cat get false value */
>>> +       /* If hardware checksum failed or wasn't calculated, NDIS
>>> will recalculate it again */ +
>>> NDIS_PER_PACKET_INFO_FROM_PACKET( *pp_packet,
>>> TcpIpChecksumPacketInfo ) = +                       (PVOID)
>>> (uintn_t) (p_desc->ndis_csum.Value); +       } else { +
>>> NDIS_TCP_IP_CHECKSUM_PACKET_INFO        chksum; +               /*
>>> Flag the checksums as having been calculated. */ +
>>> chksum.Value = 0; +
>> chksum.Receive.NdisPacketTcpChecksumSucceeded = TRUE;
>>> +
>> chksum.Receive.NdisPacketUdpChecksumSucceeded = TRUE;
>>> +               chksum.Receive.NdisPacketIpChecksumSucceeded = TRUE;
>>> +               NDIS_PER_PACKET_INFO_FROM_PACKET( *pp_packet,
>>> TcpIpChecksumPacketInfo ) = +
>>> (void*)(uintn_t)chksum.Value; +       }
>>>         ipoib_inc_recv_stat( p_port->p_adapter, type, p_desc->len );
>>>
>>>         IPOIB_EXIT( IPOIB_DBG_RECV );
>>> @@ -3833,9 +3886,9 @@
>>>                 p_desc->wr.dgrm.ud.hlen = lso_header_size;
>>>                 // Tell NDIS how much we will send.
>>>                 PktExt->NdisPacketInfo[TcpLargeSendPacketInfo] =
>>> UlongToPtr(PacketLength); -               p_desc->wr.send_opt |=
>>> (IB_SEND_OPT_TX_IP_CSUM | IB_SEND_OPT_TX_TCP_UDP_CSUM); +
>>> p_desc->wr.send_opt |= (IB_SEND_OPT_TX_IP_CSUM |
>>>                 IB_SEND_OPT_TX_TCP_UDP_CSUM) |
>>> IB_SEND_OPT_SIGNALED; __send_gen(p_port, p_desc, IndexOfData); -
>>> p_desc->wr.wr_type = ( WR_LSO | IB_SEND_OPT_SIGNALED); +
>>>         p_desc->wr.wr_type = WR_LSO; } else {
>>>
>>>                 /* Setup the first local data segment (used for the
>>> IPoIB header). */ Index:
>>> D:/Windows/MLNX_WINOF_CSUM_ARBEL/ulp/ipoib/kernel/ipoib_adapter.h
>>> ===================================================================
>>> ---
>> D:/Windows/MLNX_WINOF_CSUM_ARBEL/ulp/ipoib/kernel/ipoib_adapter.h
>>> (revision 3106) +++
>>> D:/Windows/MLNX_WINOF_CSUM_ARBEL/ulp/ipoib/kernel/ipoib_adapter.h
>>> (revision 3107) @@ -60,15 +60,15 @@
>>>  /*
>>>   * Macros
>>>   */
>>> +typedef enum {CSUM_DISABLED = 0, CSUM_ENABLED, CSUM_BYPASS}
>>> tCsumTypeEn;
>>>
>>> -
>>>  typedef struct _ipoib_params
>>>  {
>>>         int32_t         rq_depth;
>>>         int32_t         rq_low_watermark;
>>>         int32_t         sq_depth;
>>> -       boolean_t       send_chksum_offload;
>>> -       boolean_t       recv_chksum_offload;
>>> +       int32_t         send_chksum_offload;  //is actually of type
>>> tCsumTypeEn +       int32_t         recv_chksum_offload; //is
>>>         actually of type tCsumTypeEn uint32_t        sa_timeout;
>>>         uint32_t        sa_retry_cnt;
>>>         uint32_t        recv_pool_ratio;
>>> @@ -91,12 +91,11 @@
>>>  *              Number of send WQEs to allocate.
>>>  *
>>>  *      send_chksum_offload
>>> -*              Flag to indicate whether to offload send checksums.
>>> This will make it
>>> -*              so that IPoIB packets should never be forwarded out
>>> of the IB subnet
>>> -*              without recalculating the checksum. -*
>>>  *      recv_chksum_offload
>>> -*              Flag to indicate whether to offload recv checksums.
>>> +*              Flags to indicate whether to offload send/recv
>>> checksums. +*              0 - No hardware cheksum
>>> +*              1 - Try to offload if the device support it
>>> +*              2 - Always report success (checksum bypass)  *
>>>  *      wsdp_enabled
>>>  *              Flag to indicate whether WSDP is enabled for an
>>> adapter adapter. Index:
>>> D:/Windows/MLNX_WINOF_CSUM_ARBEL/ulp/ipoib/kernel/ipoib_driver.c
>>> ===================================================================
>>> ---
>>> D:/Windows/MLNX_WINOF_CSUM_ARBEL/ulp/ipoib/kernel/ipoib_driver.c
>>> (revision 3106) +++
>>>
>>> D:/Windows/MLNX_WINOF_CSUM_ARBEL/ulp/ipoib/kernel/ipoib_driver.c
>>> (revision 3107) @@ -150,8 +150,8 @@ {NDIS_STRING_CONST("RqDepth"),
>>> 1,
>>> IPOIB_OFFSET(rq_depth),              IPOIB_SIZE(rq_depth), 512,
>>>         128,    1024}, {NDIS_STRING_CONST("RqLowWatermark"),   0,
>>> IPOIB_OFFSET(rq_low_watermark),      IPOIB_SIZE(rq_low_watermark),
>>>         4, 2,      8}, {NDIS_STRING_CONST("SqDepth"),          1,
>>> IPOIB_OFFSET(sq_depth),              IPOIB_SIZE(sq_depth), 512,
>>> 128,    1024}, -       {NDIS_STRING_CONST("SendChksum"),       1,
>>> IPOIB_OFFSET(send_chksum_offload),
>>> IPOIB_SIZE(send_chksum_offload),0, 0,      1},
>>> -       {NDIS_STRING_CONST("RecvChksum"),       1,
>>> IPOIB_OFFSET(recv_chksum_offload),
>>> IPOIB_SIZE(recv_chksum_offload),0, 0,      1},
>>> +       {NDIS_STRING_CONST("SendChksum"),       1,
>>> IPOIB_OFFSET(send_chksum_offload),
>>>
>> IPOIB_SIZE(send_chksum_offload),CSUM_ENABLED,CSUM_DISABLED,CSUM_BYPASS
>>> },
>>> +       {NDIS_STRING_CONST("RecvChksum"),       1,
>>> IPOIB_OFFSET(recv_chksum_offload),
>>>
>> IPOIB_SIZE(recv_chksum_offload),CSUM_ENABLED,CSUM_DISABLED,CSU
>> M_BYPASS},
>>>         {NDIS_STRING_CONST("SaTimeout"),        1,
>>> IPOIB_OFFSET(sa_timeout),            IPOIB_SIZE(sa_timeout),
>>> 1000,       250,    UINT_MAX},
>>>         {NDIS_STRING_CONST("SaRetries"),        1,
>>> IPOIB_OFFSET(sa_retry_cnt),          IPOIB_SIZE(sa_retry_cnt), 10,
>>>         1,      UINT_MAX}, {NDIS_STRING_CONST("RecvRatio"),
>>> 1, IPOIB_OFFSET(recv_pool_ratio),
>>> IPOIB_SIZE(recv_pool_ratio), 1, 1,      10}, @@ -1450,28 +1450,20 @@
>>>         p_offload_task->TaskBufferLength =
>>> sizeof(NDIS_TASK_TCP_IP_CHECKSUM);
>>>         p_offload_chksum =
>>>
>>> (NDIS_TASK_TCP_IP_CHECKSUM*)p_offload_task->TaskBuffer; - +
>>>         p_offload_chksum->V4Transmit.IpOptionsSupported =
>>> -               p_adapter->params.send_chksum_offload;
>>>         p_offload_chksum->V4Transmit.TcpOptionsSupported =
>>> -               p_adapter->params.send_chksum_offload;
>>>         p_offload_chksum->V4Transmit.TcpChecksum =
>>> -               p_adapter->params.send_chksum_offload;
>>>         p_offload_chksum->V4Transmit.UdpChecksum =
>>> -               p_adapter->params.send_chksum_offload;
>>>         p_offload_chksum->V4Transmit.IpChecksum =
>>> -               p_adapter->params.send_chksum_offload;
>>> +               !!(p_adapter->params.send_chksum_offload);
>>>
>>>         p_offload_chksum->V4Receive.IpOptionsSupported =
>>> -               p_adapter->params.recv_chksum_offload;
>>>         p_offload_chksum->V4Receive.TcpOptionsSupported =
>>> -               p_adapter->params.recv_chksum_offload;
>>>         p_offload_chksum->V4Receive.TcpChecksum =
>>> -                       p_adapter->params.recv_chksum_offload;
>>>         p_offload_chksum->V4Receive.UdpChecksum =
>>> -               p_adapter->params.recv_chksum_offload;
>>>         p_offload_chksum->V4Receive.IpChecksum =
>>> -               p_adapter->params.recv_chksum_offload;
>>> +               !!(p_adapter->params.recv_chksum_offload);
>>>
>>>         p_offload_chksum->V6Transmit.IpOptionsSupported = FALSE;
>>>         p_offload_chksum->V6Transmit.TcpOptionsSupported = FALSE;
>>> Index:
>> D:/Windows/MLNX_WINOF_CSUM_ARBEL/ulp/ipoib/kernel/netipoib.inx
>>> ===================================================================
>>> --- D:/Windows/MLNX_WINOF_CSUM_ARBEL/ulp/ipoib/kernel/netipoib.inx
>>> (revision 3106) +++
>>> D:/Windows/MLNX_WINOF_CSUM_ARBEL/ulp/ipoib/kernel/netipoib.inx
>>> (revision 3107) @@ -95,18 +95,28 @@
>>>
>>>  HKR, Ndi\Params\SendChksum,            ParamDesc,      0, "Send
>>>  Checksum Offload" HKR, Ndi\Params\SendChksum,            Type,
>>> 0, "enum" -HKR, Ndi\Params\SendChksum,            Default,
>>> 0, "0" +HKR, Ndi\Params\SendChksum,            Default,        0,
>>>  "1" HKR, Ndi\Params\SendChksum,            Optional,       0, "0"
>>>  HKR, Ndi\Params\SendChksum\enum,       "0",    0, "Disabled"
>>> -HKR, Ndi\Params\SendChksum\enum,       "1",    0, "Enabled"
>>> +HKR, Ndi\Params\SendChksum\enum,       "1",    0, "Enabled (if
>>> supported by HW)" +HKR, Ndi\Params\SendChksum\enum,       "2",
>>> 0, "Bypass"
>>>
>>>  HKR, Ndi\Params\RecvChksum,            ParamDesc,      0, "Recv
>>>  Checksum Offload" HKR, Ndi\Params\RecvChksum,            Type,
>>> 0, "enum" -HKR, Ndi\Params\RecvChksum,            Default,
>>> 0, "0" +HKR, Ndi\Params\RecvChksum,            Default,        0,
>>>  "1" HKR, Ndi\Params\RecvChksum,            Optional,       0, "0"
>>>  HKR, Ndi\Params\RecvChksum\enum,       "0",    0, "Disabled"
>>> -HKR, Ndi\Params\RecvChksum\enum,       "1",    0, "Enabled"
>>> +HKR, Ndi\Params\RecvChksum\enum,       "1",    0, "Enabled (if
>>> supported by HW)" +HKR, Ndi\Params\RecvChksum\enum,       "2",
>>> 0, "Bypass"
>>>
>>> +HKR, Ndi\Params\lso,           ParamDesc,      0, "Large Send
>>> Offload" +HKR, Ndi\Params\lso,           Type,           0, "enum"
>>> +HKR, Ndi\Params\lso,           Default,        0, "0"
>>> +HKR, Ndi\Params\lso,           Optional,       0, "0"
>>> +HKR, Ndi\Params\lso\enum,      "0",    0, "Disabled"
>>> +HKR, Ndi\Params\lso\enum,      "1",    0, "Enabled" +
>>> +
>>>  HKR, Ndi\Params\SaTimeout,             ParamDesc,      0, "SA
>>>  Query Timeout (ms)" HKR, Ndi\Params\SaTimeout,             Type,
>>>  0, "dword" HKR, Ndi\Params\SaTimeout,             Default,
>>> 0, "1000" Index:
>>> D:/Windows/MLNX_WINOF_CSUM_ARBEL/hw/mlx4/kernel/bus/ib/cq.c
>>> ===================================================================
>>> --- D:/Windows/MLNX_WINOF_CSUM_ARBEL/hw/mlx4/kernel/bus/ib/cq.c
>>> (revision 3106) +++
>>>
>>> D:/Windows/MLNX_WINOF_CSUM_ARBEL/hw/mlx4/kernel/bus/ib/cq.c
>>>                 (revision 3107) @@ -498,7 +498,7 @@
>>> wc->recv.ud.path_bits           = (u8)(cqe->g_mlpath_rqpn & 0x7f);
>>>                 wc->recv.ud.recv_opt            |=
>>> cqe->g_mlpath_rqpn & 0x080 ? IB_RECV_OPT_GRH_VALID : 0;
>>> wc->recv.ud.pkey_index  = (u16)(be32_to_cpu(cqe->immed_rss_invalid)
>>> & 0x7f); -               wc->csum_ok =
>>> mlx4_ib_ipoib_csum_ok(cqe->ipoib_status,cqe->checksum); +
>>>         wc->recv.ud.csum_ok =
>>> mlx4_ib_ipoib_csum_ok(cqe->ipoib_status,cqe->checksum);         }
>>> if (!is_send && cqe->rlid == 0){
>>>
>> MLX4_PRINT(TRACE_LEVEL_INFORMATION,MLX4_DBG_CQ,("found
>>> rlid == 0 \n "));
>>> _______________________________________________
>>> ofw mailing list
>>> ofw at lists.openfabrics.org
>>> http://lists.openfabrics.org/cgi-bin/mailman/listinfo/ofw




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