[ofw] [Patch][IPoIB_NDIS6_CM] Datapath improvement

Smith, Stan stan.smith at intel.com
Wed Dec 8 18:23:36 PST 2010


Hello,
  What is the 'uint64_t  phys_addr;' about? I find no references to phys_addr in the recv descriptor?

ipoib_prealloc_hdr_t.phys_addr is not 8-byte aligned, hence will cause IA64 alignment problems.

The ipoib_prealloc_hdr_t definition is why many people dislike C++ due to obscure data hiding......

typedef struct _ipoib_hdr
{
 net16_t   type;
 net16_t   resv;

} PACK_SUFFIX ipoib_hdr_t;
typedef struct _ipoib_prealloc_hdr:public ipoib_hdr_t
{
 uint64_t phys_addr;

} PACK_SUFFIX ipoib_prealloc_hdr_t;

Why not define a C struct which contains the ipoib_hdr_t and the 64-bit phys_addr, which is infinitely more clear than C++ approach?
Not to mention correctly aligned for IA64.
BTW, ipoib_prealloc_hdr_t does not need to be 'packed'. Perhaps this would fix the C++ definition alignment problem?

typedef struct _ipoib_prealloc_hdr
{
    uint64_t phys_addr;
    ipoib_hdt_t    h;
}  ipoib_prealloc_hdr_t;
It would be good to include some performance information as to how effective this patch is?
I agree this patch is the correct performance enhancement, how much performance improvement did you find?

I found a 30 MB/sec decrease in bandwidth at 64KB MTU using ttcp -D, while at 2044 MTU the CM performance is equal to UD?
Adding cl_get_physaddr() back into the send data path, restores the lost 30MB/s bandwidth?
You are on the right track with removing cl_get_physaddr() from the send data path, although I need to understand what's up with the BW drop.
Under investigation.

stan.


________________________________
From: ofw-bounces at lists.openfabrics.org [mailto:ofw-bounces at lists.openfabrics.org] On Behalf Of Alex Naslednikov
Sent: Wednesday, December 01, 2010 2:28 AM
To: ofw at lists.openfabrics.org
Subject: [ofw] [Patch][IPoIB_NDIS6_CM] Datapath improvement

This patch removes calls to MmGetPhysAddr from datapath
Tested with SdpConnect.exe on Win2008x64 vs. R2, with and w\o LSO, with the following data sizes:
65536, 655360, 512000, 519317 (bytes)
In addition, it passed several regression runs
Signed-off by: Alexander Naslednikov (xalex at mellanox.co.il)

Index: ulp/ipoib_NDIS6_CM/kernel/ipoib_port.cpp
===================================================================
--- ulp/ipoib_NDIS6_CM/kernel/ipoib_port.cpp                (revision 3007)
+++ ulp/ipoib_NDIS6_CM/kernel/ipoib_port.cpp             (working copy)
@@ -111,7 +111,8 @@
 ******************************************************************************/
 static void
 __port_construct(
-              IN                                                           ipoib_port_t* const                                        p_port );
+             IN                                                           ipoib_port_t* const                                        p_port,
+             IN                                                           int32_t                                                                                  alloc_size);

 static ib_api_status_t
 __port_init(
@@ -638,6 +639,7 @@

                CL_ASSERT( !p_adapter->p_port );

+             // Allocate PORT object along with "send queue depth" - 1 IPoIB headers
                p_port = (ipoib_port_t *) cl_zalloc( sizeof(ipoib_port_t) +
                                (sizeof(ipoib_prealloc_hdr_t) * (p_adapter->params.sq_depth - 1)) );
                if( !p_port )
@@ -652,7 +654,7 @@
                gp_ipoib_port = p_port;
 #endif

-              __port_construct( p_port );
+             __port_construct( p_port, p_adapter->params.sq_depth -1 );

                status = __port_init( p_port, p_adapter, p_pnp_rec );
                if( status != IB_SUCCESS )
@@ -689,7 +691,8 @@

 static void
 __port_construct(
-              IN                                                           ipoib_port_t* const                                        p_port )
+             IN                                                           ipoib_port_t* const                                        p_port,
+             IN                                                           int32_t                                                                                  alloc_size)
 {
                IPOIB_ENTER( IPOIB_DBG_INIT );

@@ -710,6 +713,12 @@

                KeInitializeEvent( &p_port->sa_event, NotificationEvent, TRUE );
                KeInitializeEvent( &p_port->leave_mcast_event, NotificationEvent, TRUE );
+
+             for ( int i = 0; i < alloc_size; ++i )
+             {
+                             p_port->hdr[i].phys_addr = cl_get_physaddr( &p_port->hdr[i] );
+                             p_port->hdr[i].resv = 0;
+             }

                IPOIB_EXIT( IPOIB_DBG_INIT );
 }
@@ -5278,9 +5287,7 @@
                ASSERT( hdr_idx < s_buf->p_port->p_adapter->params.sq_depth );

                /* Set up IPoIB Header */
-              s_buf->p_port->hdr[hdr_idx].type = p_eth_hdr->type;
-              s_buf->p_port->hdr[hdr_idx].resv = 0;
-
+             s_buf->p_port->hdr[hdr_idx].type = p_eth_hdr->type;

                //Init send buffer to 0
                s_buf->p_send_buf = NULL;
@@ -5309,8 +5316,7 @@
                                cl_perf_start( SendMgrFilter );

                                /* Put first DS to be IPoIB Header */
-                              p_desc->send_wr[0].local_ds[0].vaddr =
-                                                                                                                              cl_get_physaddr( &s_buf->p_port->hdr[hdr_idx] );
+                             p_desc->send_wr[0].local_ds[0].vaddr = s_buf->p_port->hdr[hdr_idx].phys_addr;
                                p_desc->send_wr[0].local_ds[0].length = sizeof(ipoib_hdr_t);
                                p_desc->send_wr[0].local_ds[0].lkey = s_buf->p_port->ib_mgr.lkey;

Index: ulp/ipoib_NDIS6_CM/kernel/ipoib_port.h
===================================================================
--- ulp/ipoib_NDIS6_CM/kernel/ipoib_port.h     (revision 2999)
+++ ulp/ipoib_NDIS6_CM/kernel/ipoib_port.h  (working copy)
@@ -168,6 +168,12 @@
 *            resv
 *                            Reserved portion of IPoIB header.
 *********/
+
+typedef struct _ipoib_prealloc_hdr:public ipoib_hdr_t
+{
+             uint64_t               phys_addr;
+} PACK_SUFFIX ipoib_prealloc_hdr_t;
+
 static const uint32_t      EthHeaderOffset                             = sizeof(eth_hdr_t);

 //We reuse eth header to put there IPoIB header for LSO Net Buffers.
@@ -369,6 +375,7 @@
                NDIS_TCP_IP_CHECKSUM_PACKET_INFO            ndis_csum;
 #if IPOIB_INLINE_RECV
                recv_buf_t                                         buf;
+             uint64_t                                               phys_addr;
 #else
                recv_buf_t                                         *p_buf;
 #endif
@@ -626,7 +633,7 @@
                ib_net16_t                                                          base_lid;
                LONG                                                                    n_no_progress;
                PIO_WORKITEM                                               pPoWorkItem;
-              ipoib_hdr_t                                                        hdr[1];  /* Must be last! */
+             ipoib_prealloc_hdr_t     hdr[1];  /* Must be last! */

 }             ipoib_port_t;
 #pragma warning(default:4324)

Alexander (XaleX) Naslednikov
SW Networking Team
Mellanox Technologies

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