openmpi/ompi/mca/btl/openib/btl_openib_component.c

/*
 * Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
 *                         University Research and Technology
 *                         Corporation.  All rights reserved.
 * Copyright (c) 2004-2005 The University of Tennessee and The University
 *                         of Tennessee Research Foundation.  All rights
 *                         reserved.
 * Copyright (c) 2004-2005 High Performance Computing Center Stuttgart, 
 *                         University of Stuttgart.  All rights reserved.
 * Copyright (c) 2004-2005 The Regents of the University of California.
 *                         All rights reserved.
 * Copyright (c) 2006      Cisco Systems, Inc.  All rights reserved.
 * $COPYRIGHT$
 * 
 * Additional copyrights may follow
 * 
 * $HEADER$
 */


#include "ompi_config.h"
#include "ompi/constants.h"
#include "opal/event/event.h"
#include "opal/util/if.h"
#include "opal/util/argv.h"
#include "opal/util/output.h"
#include "opal/util/show_help.h"
#include "ompi/proc/proc.h"
#include "ompi/mca/pml/pml.h"
#include "ompi/mca/btl/btl.h"
#include "opal/sys/timer.h"

#include "opal/mca/base/mca_base_param.h"
#include "orte/mca/errmgr/errmgr.h"
#include "orte/util/sys_info.h"
#include "ompi/mca/mpool/base/base.h" 
#include "ompi/mca/btl/base/base.h"
#include "btl_openib.h"
#include "btl_openib_frag.h"
#include "btl_openib_endpoint.h" 
#include "btl_openib_eager_rdma.h"
#include "btl_openib_proc.h"
#include "btl_openib_ini.h"
#include "btl_openib_mca.h"

#include "ompi/datatype/convertor.h" 
#include "ompi/mca/mpool/mpool.h" 
#include <sysfs/libsysfs.h>  
#include <infiniband/verbs.h> 
#include <errno.h> 
#include <string.h>   /* for strerror()*/ 

#include "ompi/mca/pml/base/pml_base_module_exchange.h"

/*
 * Local functions
 */
static int btl_openib_component_open(void);
static int btl_openib_component_close(void);
static int btl_openib_modex_send(void);
static void btl_openib_control(struct mca_btl_base_module_t* btl,
                               mca_btl_base_tag_t tag,
                               mca_btl_base_descriptor_t* descriptor,
                               void* cbdata);
static int init_one_port(opal_list_t *btl_list, mca_btl_openib_hca_t *hca,
                         uint8_t port_num, struct ibv_port_attr *ib_port_attr);
static int init_one_hca(opal_list_t *btl_list, struct ibv_device* ib_dev);
static mca_btl_base_module_t **btl_openib_component_init(
    int *num_btl_modules, bool enable_progress_threads,
    bool enable_mpi_threads);
static void merge_values(ompi_btl_openib_ini_values_t *target,
                         ompi_btl_openib_ini_values_t *src);
static int btl_openib_handle_incoming(mca_btl_openib_module_t *openib_btl,
                                         mca_btl_openib_endpoint_t *endpoint,
                                         mca_btl_openib_frag_t *frag, 
                                         size_t byte_len, const int prio);
static char* btl_openib_component_status_to_string(enum ibv_wc_status status);
static int btl_openib_component_progress(void);
static void btl_openib_frag_progress_pending(
         mca_btl_openib_module_t* openib_btl, mca_btl_base_endpoint_t *endpoint,
         int prio);


mca_btl_openib_component_t mca_btl_openib_component = {
    {
        /* First, the mca_base_component_t struct containing meta information
           about the component itself */

        {
            /* Indicate that we are a pml v1.0.0 component (which also implies a
               specific MCA version) */

            MCA_BTL_BASE_VERSION_1_0_1,

            "openib", /* MCA component name */
            OMPI_MAJOR_VERSION,  /* MCA component major version */
            OMPI_MINOR_VERSION,  /* MCA component minor version */
            OMPI_RELEASE_VERSION,  /* MCA component release version */
            btl_openib_component_open,  /* component open */
            btl_openib_component_close  /* component close */
        },

        /* Next the MCA v1.0.0 component meta data */

        {
            /* Whether the component is checkpointable or not */

            false
        },

        btl_openib_component_init,  
        btl_openib_component_progress,
    }
};


/*
 *  Called by MCA framework to open the component, registers
 *  component parameters.
 */

int btl_openib_component_open(void)
{
    int ret;

    /* initialize state */
    mca_btl_openib_component.ib_num_btls = 0;
    mca_btl_openib_component.openib_btls = NULL;
    
    /* initialize objects */ 
    OBJ_CONSTRUCT(&mca_btl_openib_component.ib_procs, opal_list_t);

    /* register IB component parameters */
    ret = btl_openib_register_mca_params();

    mca_btl_openib_component.max_send_size = 
        mca_btl_openib_module.super.btl_max_send_size; 
    mca_btl_openib_component.eager_limit = 
        mca_btl_openib_module.super.btl_eager_limit; 

    return ret;
}

/*
 * component cleanup - sanity checking of queue lengths
 */

static int btl_openib_component_close(void)
{
    ompi_btl_openib_ini_finalize();
    return OMPI_SUCCESS;
}


/*
 *  Register OPENIB  port information. The MCA framework
 *  will make this available to all peers.
 */

static int btl_openib_modex_send(void)
{
    int         rc, i;
    size_t      size;
    mca_btl_openib_port_info_t *ports = NULL;

    size = mca_btl_openib_component.ib_num_btls * sizeof (mca_btl_openib_port_info_t);
    if (size != 0) {
        ports = (mca_btl_openib_port_info_t *)malloc (size);
        if (NULL == ports) {
            BTL_ERROR(("Failed malloc: %s:%d\n", __FILE__, __LINE__));
            return OMPI_ERR_OUT_OF_RESOURCE;
        }

        for (i = 0; i < mca_btl_openib_component.ib_num_btls; i++) {
            mca_btl_openib_module_t *btl = &mca_btl_openib_component.openib_btls[i];
            ports[i] = btl->port_info;
        }
    }
    rc = mca_pml_base_modex_send (&mca_btl_openib_component.super.btl_version, ports, size);
    if (NULL != ports) {
        free (ports);
    }
    return rc;
}

/*
 * Callback function on control message.
 */

static void btl_openib_control(struct mca_btl_base_module_t* btl,
                               mca_btl_base_tag_t tag,
                               mca_btl_base_descriptor_t* descriptor,
                               void* cbdata)
{
    /* dont return credits used for control messages */
    mca_btl_openib_frag_t* frag = (mca_btl_openib_frag_t*)descriptor;
    mca_btl_openib_endpoint_t* endpoint = frag->endpoint;
    mca_btl_openib_control_header_t *ctl_hdr = frag->segment.seg_addr.pval;
    mca_btl_openib_eager_rdma_header_t *rdma_hdr;
    mca_btl_openib_rdma_credits_header_t *credits_hdr;

    if(frag->size == mca_btl_openib_component.eager_limit) {
	    /* if not sent via rdma */
        if(!MCA_BTL_OPENIB_RDMA_FRAG(frag) &&
                ctl_hdr->type == MCA_BTL_OPENIB_CONTROL_CREDITS) {
             OPAL_THREAD_ADD32(&endpoint->rd_credits[BTL_OPENIB_HP_QP], -1);
        }
    } else {
        OPAL_THREAD_ADD32(&endpoint->rd_credits[BTL_OPENIB_LP_QP], -1);
    }

    switch (ctl_hdr->type) {
    case MCA_BTL_OPENIB_CONTROL_CREDITS:
        credits_hdr = (mca_btl_openib_rdma_credits_header_t*)ctl_hdr;
        if(credits_hdr->rdma_credits)
            OPAL_THREAD_ADD32(&endpoint->eager_rdma_remote.tokens,
                    credits_hdr->rdma_credits);
       break;
    case MCA_BTL_OPENIB_CONTROL_RDMA:
       rdma_hdr = (mca_btl_openib_eager_rdma_header_t*)ctl_hdr;
       if (endpoint->eager_rdma_remote.base.pval) {
	       BTL_ERROR(("Got RDMA connect twise!"));
	       return;
       }
       endpoint->eager_rdma_remote.rkey =  rdma_hdr->rkey;
       endpoint->eager_rdma_remote.base.pval = rdma_hdr->rdma_start.pval;
       endpoint->eager_rdma_remote.tokens =
           mca_btl_openib_component.eager_rdma_num - 1;
       break;
    default:
       BTL_ERROR(("Unknown message type received by BTL"));
       break;
    }
}

static int init_one_port(opal_list_t *btl_list, mca_btl_openib_hca_t *hca,
                         uint8_t port_num, struct ibv_port_attr *ib_port_attr)
{
    uint16_t lid, i, lmc;
    mca_btl_openib_module_t *openib_btl;
    mca_btl_base_selected_module_t *ib_selected;

    lmc = (1 << ib_port_attr->lmc);

    if (0 != mca_btl_openib_component.max_lmc && 
        mca_btl_openib_component.max_lmc < lmc) {
        lmc = mca_btl_openib_component.max_lmc;
    }

    for(lid = ib_port_attr->lid;
            lid < ib_port_attr->lid + lmc; lid++){
        for(i = 0; i < mca_btl_openib_component.btls_per_lid; i++){
            openib_btl = malloc(sizeof(mca_btl_openib_module_t));
            if(NULL == openib_btl) {
                BTL_ERROR(("Failed malloc: %s:%d\n", __FILE__, __LINE__));
                return OMPI_ERR_OUT_OF_RESOURCE;
            }
            memcpy(openib_btl, &mca_btl_openib_module,
                    sizeof(mca_btl_openib_module));
            memcpy(&openib_btl->ib_port_attr, ib_port_attr,
                    sizeof(struct ibv_port_attr));
            ib_selected = OBJ_NEW(mca_btl_base_selected_module_t);
            ib_selected->btl_module = (mca_btl_base_module_t*) openib_btl;
            openib_btl->hca = hca;
            openib_btl->port_num = (uint8_t) port_num;
            openib_btl->lid = lid;
            openib_btl->src_path_bits = lid - ib_port_attr->lid;
            /* store the sm_lid for multi-nic support */
            openib_btl->port_info.subnet = ib_port_attr->sm_lid;
            openib_btl->port_info.mtu = hca->mtu;
            openib_btl->ib_reg[MCA_BTL_TAG_BTL].cbfunc = btl_openib_control;
            openib_btl->ib_reg[MCA_BTL_TAG_BTL].cbdata = NULL;
            opal_list_append(btl_list, (opal_list_item_t*) ib_selected);
            hca->btls++;
            ++mca_btl_openib_component.ib_num_btls;
            if (-1 != mca_btl_openib_component.ib_max_btls &&
                mca_btl_openib_component.ib_num_btls >=
                mca_btl_openib_component.ib_max_btls) {
                return OMPI_SUCCESS;
            }
        }
    }

    return OMPI_SUCCESS;
}

static int init_one_hca(opal_list_t *btl_list, struct ibv_device* ib_dev)
{
    struct mca_mpool_base_resources_t mpool_resources;
    mca_btl_openib_hca_t *hca;
    uint8_t i;
    int ret = -1;
    ompi_btl_openib_ini_values_t values, default_values;

    hca = malloc(sizeof(mca_btl_openib_hca_t));
    if(NULL == hca){
        BTL_ERROR(("Failed malloc: %s:%d\n", __FILE__, __LINE__));
        return OMPI_ERR_OUT_OF_RESOURCE;
    }
    
    hca->ib_dev = ib_dev;
    hca->ib_dev_context = ibv_open_device(ib_dev);
    hca->btls = 0;
    if(NULL == hca->ib_dev_context){ 
        BTL_ERROR(("error obtaining device context for %s errno says %s\n",
                    ibv_get_device_name(ib_dev), strerror(errno))); 
        goto free_hca;
    } 
       
    if(ibv_query_device(hca->ib_dev_context, &hca->ib_dev_attr)){ 
        BTL_ERROR(("error obtaining device attributes for %s errno says %s\n",
                    ibv_get_device_name(ib_dev), strerror(errno))); 
        goto close_hca;
    }

    /* Load in vendor/part-specific HCA parameters.  Note that even if
       we don't find values for this vendor/part, "values" will be set
       indicating that it does not have good values */
    ret = ompi_btl_openib_ini_query(hca->ib_dev_attr.vendor_id,
                                    hca->ib_dev_attr.vendor_part_id,
                                    &values);
    if (OMPI_SUCCESS != ret && OMPI_ERR_NOT_FOUND != ret) {
        /* If we get a serious error, propagate it upwards */
        goto close_hca;
    }
    if (OMPI_ERR_NOT_FOUND == ret) {
        /* If we didn't find a matching HCA in the INI files, output a
           warning that we're using default values (unless overridden
           that we don't want to see these warnings) */
        if (mca_btl_openib_component.warn_no_hca_params_found) {
            opal_show_help("help-mpi-btl-openib.txt",
                           "no hca params found", true,
                           orte_system_info.nodename,
                           hca->ib_dev_attr.vendor_id,
                           hca->ib_dev_attr.vendor_part_id);
        }
    }
    /* Note that even if we don't find default values, "values" will
       be set indicating that it does not have good values */
    ret = ompi_btl_openib_ini_query(0, 0, &default_values);
    if (OMPI_SUCCESS != ret && OMPI_ERR_NOT_FOUND != ret) {
        /* If we get a serious error, propagate it upwards */
        goto close_hca;
    }

    /* If we did find values for this HCA (or in the defaults
       section), handle them */
    merge_values(&values, &default_values);
    if (values.mtu_set) {
        switch (values.mtu) {
        case 256:
            hca->mtu = IBV_MTU_256;
            break;
        case 512:
            hca->mtu = IBV_MTU_512;
            break;
        case 1024:
            hca->mtu = IBV_MTU_1024;
            break;
        case 2048:
            hca->mtu = IBV_MTU_2048;
            break;
        case 4096:
            hca->mtu = IBV_MTU_4096;
            break;
        default:
            BTL_ERROR(("invalid MTU value specified in INI file (%d); ignored\n", values.mtu));
            hca->mtu = mca_btl_openib_component.ib_mtu;
            break;
        }
    } else {
        hca->mtu = mca_btl_openib_component.ib_mtu;
    }

    hca->ib_pd = ibv_alloc_pd(hca->ib_dev_context);
    if(NULL == hca->ib_pd){
        BTL_ERROR(("error allocating pd for %s errno says %s\n",
                    ibv_get_device_name(ib_dev), strerror(errno)));
        goto close_hca;
    }

    mpool_resources.ib_pd = hca->ib_pd;
    hca->mpool =
        mca_mpool_base_module_create(mca_btl_openib_component.ib_mpool_name,
                hca, &mpool_resources);
    if(NULL == hca->mpool){
         BTL_ERROR(("error creating IB memory pool for %s errno says %s\n",
                     ibv_get_device_name(ib_dev), strerror(errno)));
         goto dealloc_pd;
    }
   
    ret = OMPI_SUCCESS; 
    /* Note ports are 1 based hence j = 1 */
    for(i = 1; i <= hca->ib_dev_attr.phys_port_cnt; i++){
        struct ibv_port_attr ib_port_attr;

        if(ibv_query_port(hca->ib_dev_context, i, &ib_port_attr)){
            BTL_ERROR(("error getting port attributes for device %s "
                        "port number %d errno says %s",
                        ibv_get_device_name(ib_dev), i, strerror(errno)));
            break; 
        }

        if(IBV_PORT_ACTIVE == ib_port_attr.state){
            ret = init_one_port(btl_list, hca, i, &ib_port_attr);

            if (OMPI_SUCCESS != ret) {
                break;
            }
        }
    }

    if (hca->btls != 0)
        return ret;

    mca_mpool_base_module_destroy(hca->mpool);
dealloc_pd:
    ibv_dealloc_pd(hca->ib_pd);
close_hca:
    ibv_close_device(hca->ib_dev_context);
free_hca:
    free(hca);
    return ret;
}
/*
 *  IB component initialization:
 *  (1) read interface list from kernel and compare against component parameters
 *      then create a BTL instance for selected interfaces
 *  (2) setup IB listen socket for incoming connection attempts
 *  (3) register BTL parameters with the MCA
 */

static mca_btl_base_module_t** 
btl_openib_component_init(int *num_btl_modules, 
                          bool enable_progress_threads,
                          bool enable_mpi_threads)
{
    struct ibv_device **ib_devs; 
    mca_btl_base_module_t** btls;
    int i, ret, length, num_devs;
    opal_list_t btl_list; 
    mca_btl_openib_module_t * openib_btl; 
    mca_btl_base_selected_module_t* ib_selected; 
    opal_list_item_t* item; 
#if OMPI_MCA_BTL_OPENIB_HAVE_DEVICE_LIST == 0
    struct dlist *dev_list; 
    struct ibv_device* ib_dev; 
#endif
    unsigned short seedv[3];
    

    /* initialization */
    *num_btl_modules = 0;
    num_devs = 0; 

    /* openib BTL does not currently support progress threads, so
       disable the component if they were requested */
    if (enable_progress_threads) {
        mca_btl_base_error_no_nics("OpenIB", "HCA");
        mca_btl_openib_component.ib_num_btls = 0;
        btl_openib_modex_send();
        return NULL;
    }

    seedv[0] = orte_process_info.my_name->vpid;
    seedv[1] = opal_sys_timer_get_cycles();
    seedv[2] = opal_sys_timer_get_cycles();
    seed48(seedv);

    /* Read in INI files with HCA-specific parameters */
    if (OMPI_SUCCESS != (ret = ompi_btl_openib_ini_init())) {
        return NULL;
    }

#if OMPI_MCA_BTL_OPENIB_HAVE_DEVICE_LIST
    ib_devs = ibv_get_device_list(&num_devs);
#else 
    /* Determine the number of hca's available on the host */
    dev_list = ibv_get_devices(); 
    if (NULL == dev_list) {
        mca_btl_base_error_no_nics("OpenIB", "HCA");
        mca_btl_openib_component.ib_num_btls = 0;
        btl_openib_modex_send();
        return NULL;
    }
    dlist_start(dev_list); 

    dlist_for_each_data(dev_list, ib_dev, struct ibv_device)
        num_devs++; 
#endif

    if(0 == num_devs) { 
        mca_btl_base_error_no_nics("OpenIB", "HCA");
        btl_openib_modex_send();
        return NULL; 
    }
       
#if OMPI_MCA_BTL_OPENIB_HAVE_DEVICE_LIST == 0
    /* Allocate space for the ib devices */ 
    ib_devs = (struct ibv_device**) malloc(num_devs * sizeof(struct ibv_dev*));
    if(NULL == ib_devs) {
        BTL_ERROR(("Failed malloc: %s:%d\n", __FILE__, __LINE__));
        return NULL;
    }

    dlist_start(dev_list); 

    i = 0; 
    dlist_for_each_data(dev_list, ib_dev, struct ibv_device)
        ib_devs[i++] =  ib_dev; 
#endif
            
    /* We must loop through all the hca id's, get their handles and
       for each hca we query the number of ports on the hca and set up
       a distinct btl module for each hca port */ 

    OBJ_CONSTRUCT(&btl_list, opal_list_t); 
    OBJ_CONSTRUCT(&mca_btl_openib_component.ib_lock, opal_mutex_t);

    for (i = 0; i < num_devs &&
             (-1 == mca_btl_openib_component.ib_max_btls ||
              mca_btl_openib_component.ib_num_btls <
              mca_btl_openib_component.ib_max_btls); i++){
        if (OMPI_SUCCESS != (ret = init_one_hca(&btl_list, ib_devs[i]))) {
            break;
        }
    }

    if(ret != OMPI_SUCCESS) {
        opal_show_help("help-mpi-btl-openib.txt",
                "error in hca init", true, orte_system_info.nodename);
    }
       
    if(0 == mca_btl_openib_component.ib_num_btls) {
        opal_show_help("help-mpi-btl-openib.txt",
                "no active ports found", true, orte_system_info.nodename);
        return NULL;
    }

    /* Allocate space for btl modules */
    mca_btl_openib_component.openib_btls =
        malloc(sizeof(mca_btl_openib_module_t) *
                mca_btl_openib_component.ib_num_btls);
    
    if(NULL == mca_btl_openib_component.openib_btls) {
        BTL_ERROR(("Failed malloc: %s:%d\n", __FILE__, __LINE__));
        return NULL;
    }
    btls = malloc(mca_btl_openib_component.ib_num_btls *
            sizeof(struct mca_btl_openib_module_t*));
    if(NULL == btls) {
        BTL_ERROR(("Failed malloc: %s:%d\n", __FILE__, __LINE__));
        return NULL;
    }

    /* Copy the btl module structs into a contiguous array and fully
       initialize them */
    for(i = 0; i < mca_btl_openib_component.ib_num_btls; i++){
        item = opal_list_remove_first(&btl_list); 
        ib_selected = (mca_btl_base_selected_module_t*)item; 
        openib_btl = (mca_btl_openib_module_t*) ib_selected->btl_module; 
        memcpy(&(mca_btl_openib_component.openib_btls[i]), openib_btl,
                sizeof(mca_btl_openib_module_t)); 
        free(openib_btl); 
        OBJ_RELEASE(ib_selected); 

        openib_btl = &mca_btl_openib_component.openib_btls[i];
        openib_btl->rd_num = mca_btl_openib_component.rd_num +
            mca_btl_openib_component.rd_rsv;
        openib_btl->rd_low = mca_btl_openib_component.rd_low;
        openib_btl->num_peers = 0; 
        openib_btl->sd_tokens[BTL_OPENIB_HP_QP] =
            openib_btl->sd_tokens[BTL_OPENIB_LP_QP] = mca_btl_openib_component.srq_sd_max;

        /* Initialize module state */

        OBJ_CONSTRUCT(&openib_btl->pending_frags[BTL_OPENIB_HP_QP], opal_list_t);
        OBJ_CONSTRUCT(&openib_btl->pending_frags[BTL_OPENIB_LP_QP], opal_list_t);
            
        OBJ_CONSTRUCT(&openib_btl->ib_lock, opal_mutex_t); 
        OBJ_CONSTRUCT(&openib_btl->send_free_eager, ompi_free_list_t);
        OBJ_CONSTRUCT(&openib_btl->send_free_max, ompi_free_list_t);
        OBJ_CONSTRUCT(&openib_btl->send_free_frag, ompi_free_list_t);
        OBJ_CONSTRUCT(&openib_btl->send_free_control, ompi_free_list_t);
        
        OBJ_CONSTRUCT(&openib_btl->recv_free_eager, ompi_free_list_t);
        OBJ_CONSTRUCT(&openib_btl->recv_free_max, ompi_free_list_t);

        /* initialize the memory pool using the hca */ 
        openib_btl->super.btl_mpool = openib_btl->hca->mpool;

        /* Initialize pool of send fragments */ 
        length = sizeof(mca_btl_openib_frag_t) + 
            sizeof(mca_btl_openib_header_t) + 
            sizeof(mca_btl_openib_footer_t) + 
            openib_btl->super.btl_eager_limit;
	
        openib_btl->eager_rdma_frag_size = (length + mca_btl_openib_component.buffer_alignment) & ~(mca_btl_openib_component.buffer_alignment-1);
 
        ompi_free_list_init_ex(&openib_btl->send_free_eager,
                            length,
                            sizeof(mca_btl_openib_frag_t),
                            mca_btl_openib_component.buffer_alignment,
                            OBJ_CLASS(mca_btl_openib_send_frag_eager_t),
                            mca_btl_openib_component.ib_free_list_num,
                            mca_btl_openib_component.ib_free_list_max,
                            mca_btl_openib_component.ib_free_list_inc,
                            openib_btl->super.btl_mpool);
        
        ompi_free_list_init_ex(&openib_btl->recv_free_eager,
                            length, 
                            sizeof(mca_btl_openib_frag_t),
                            mca_btl_openib_component.buffer_alignment,
                            OBJ_CLASS(mca_btl_openib_recv_frag_eager_t),
                            mca_btl_openib_component.ib_free_list_num,
                            mca_btl_openib_component.ib_free_list_max,
                            mca_btl_openib_component.ib_free_list_inc,
                            openib_btl->super.btl_mpool);

        length = sizeof(mca_btl_openib_frag_t) + 
            sizeof(mca_btl_openib_header_t) + 
            openib_btl->super.btl_max_send_size;
        
        ompi_free_list_init_ex(&openib_btl->send_free_max,
                            length,
                            sizeof(mca_btl_openib_frag_t),
                            mca_btl_openib_component.buffer_alignment,
                            OBJ_CLASS(mca_btl_openib_send_frag_max_t),
                            mca_btl_openib_component.ib_free_list_num,
                            mca_btl_openib_component.ib_free_list_max,
                            mca_btl_openib_component.ib_free_list_inc,
                            openib_btl->super.btl_mpool);
                
        /* Initialize pool of receive fragments */
        ompi_free_list_init_ex(&openib_btl->recv_free_max, 
                             length, 
                             sizeof(mca_btl_openib_frag_t),
                             mca_btl_openib_component.buffer_alignment,
                             OBJ_CLASS (mca_btl_openib_recv_frag_max_t),
                             mca_btl_openib_component.ib_free_list_num,
                             mca_btl_openib_component.ib_free_list_max,
                             mca_btl_openib_component.ib_free_list_inc, 
                             openib_btl->super.btl_mpool);

        length = sizeof(mca_btl_openib_frag_t) +
            sizeof(mca_btl_openib_header_t) +
            sizeof(mca_btl_openib_footer_t) + 
            sizeof(mca_btl_openib_eager_rdma_header_t);

        ompi_free_list_init_ex(&openib_btl->send_free_control,
                            length,
                            sizeof(mca_btl_openib_frag_t),
                            mca_btl_openib_component.buffer_alignment,
                            OBJ_CLASS(mca_btl_openib_send_frag_control_t),
                            mca_btl_openib_component.ib_free_list_num,
                            -1,
                            mca_btl_openib_component.ib_free_list_inc,
                            openib_btl->super.btl_mpool);

        length = sizeof(mca_btl_openib_frag_t);

        ompi_free_list_init(&openib_btl->send_free_frag,
                            length, 
                            OBJ_CLASS(mca_btl_openib_send_frag_frag_t),
                            mca_btl_openib_component.ib_free_list_num,
                            mca_btl_openib_component.ib_free_list_max,
                            mca_btl_openib_component.ib_free_list_inc,
                            NULL);

        orte_pointer_array_init(&openib_btl->eager_rdma_buffers, 
                mca_btl_openib_component.max_eager_rdma,
                mca_btl_openib_component.max_eager_rdma, 
                0);
        openib_btl->eager_rdma_buffers_count = 0;
        OBJ_CONSTRUCT(&openib_btl->eager_rdma_lock, opal_mutex_t); 
        
        orte_pointer_array_init(&openib_btl->endpoints, 10, INT_MAX, 100);
        btls[i] = &openib_btl->super;
    }

    /* Post OOB receive to support dynamic connection setup */
    mca_btl_openib_post_recv();
    btl_openib_modex_send();

    *num_btl_modules = mca_btl_openib_component.ib_num_btls;
#if OMPI_MCA_BTL_OPENIB_HAVE_DEVICE_LIST
    ibv_free_device_list(ib_devs);
#else
    free(ib_devs);
#endif
    return btls;
}


static void merge_values(ompi_btl_openib_ini_values_t *target,
                         ompi_btl_openib_ini_values_t *src)
{
    if (!target->mtu_set && src->mtu_set) {
        target->mtu = src->mtu;
        target->mtu_set = true;
    }
}


static int btl_openib_handle_incoming(mca_btl_openib_module_t *openib_btl,
                                         mca_btl_openib_endpoint_t *endpoint,
                                         mca_btl_openib_frag_t *frag, 
                                         size_t byte_len, const int prio)
{
    ompi_free_list_t *free_list;

    if(BTL_OPENIB_HP_QP == prio)
        free_list = &openib_btl->recv_free_eager;
    else
        free_list = &openib_btl->recv_free_max;

    /* advance the segment address past the header and subtract from the
     * length..*/
    frag->segment.seg_len = byte_len - sizeof(mca_btl_openib_header_t);

    /* call registered callback */
    openib_btl->ib_reg[frag->hdr->tag].cbfunc(&openib_btl->super,
            frag->hdr->tag, &frag->base, 
            openib_btl->ib_reg[frag->hdr->tag].cbdata);

    if(BTL_OPENIB_IS_RDMA_CREDITS(frag->hdr->credits) &&
            BTL_OPENIB_CREDITS(frag->hdr->credits) > 0)
        OPAL_THREAD_ADD32(&endpoint->eager_rdma_remote.tokens,
            BTL_OPENIB_CREDITS(frag->hdr->credits));
    else
        if(!mca_btl_openib_component.use_srq && frag->hdr->credits > 0)
            OPAL_THREAD_ADD32(&endpoint->sd_tokens[prio],
                frag->hdr->credits);

    if (!MCA_BTL_OPENIB_RDMA_FRAG(frag)) {
        OMPI_FREE_LIST_RETURN(free_list, (ompi_free_list_item_t*) frag);
    } else {
        mca_btl_openib_frag_t *tf;
        OPAL_THREAD_LOCK(&endpoint->eager_rdma_local.lock);
        MCA_BTL_OPENIB_RDMA_MAKE_REMOTE(frag->ftr);
        while (endpoint->eager_rdma_local.tail !=
                endpoint->eager_rdma_local.head) {
            tf = MCA_BTL_OPENIB_GET_LOCAL_RDMA_FRAG(endpoint,
                    endpoint->eager_rdma_local.tail);
            if (MCA_BTL_OPENIB_RDMA_FRAG_LOCAL (tf))
                break;
            OPAL_THREAD_ADD32(&endpoint->eager_rdma_local.credits, 1);
            MCA_BTL_OPENIB_RDMA_NEXT_INDEX(endpoint->eager_rdma_local.tail);
         }
        OPAL_THREAD_UNLOCK(&endpoint->eager_rdma_local.lock);
    }
   
    if (!endpoint->eager_rdma_local.base.pval &&
            mca_btl_openib_component.use_eager_rdma &&
            BTL_OPENIB_HP_QP == prio &&
            openib_btl->eager_rdma_buffers_count <
            mca_btl_openib_component.max_eager_rdma &&
            OPAL_THREAD_ADD32(&endpoint->eager_recv_count, 1) ==
            mca_btl_openib_component.eager_rdma_threshold) {
        mca_btl_openib_endpoint_connect_eager_rdma(endpoint); 
    }

    /* repost receive descriptors if receive not by RDMA */
    if(!MCA_BTL_OPENIB_RDMA_FRAG(frag)) {
        if(mca_btl_openib_component.use_srq) {
            OPAL_THREAD_ADD32((int32_t*)&openib_btl->srd_posted[prio], -1);
            mca_btl_openib_post_srr(openib_btl, 0, prio);
        } else {
            OPAL_THREAD_ADD32((int32_t*)&endpoint->rd_posted[prio], -1);
            btl_openib_endpoint_post_rr(endpoint, 0, prio);
        }
    }

    /* nothing to progress for SRQ case */
    if(!mca_btl_openib_component.use_srq) {
        btl_openib_frag_progress_pending(openib_btl, endpoint, prio);
    }

    /* check to see if we need to return credits */
    if(btl_openib_check_send_credits(endpoint, prio)) {
        mca_btl_openib_endpoint_send_credits(endpoint, prio);
    }

    return OMPI_SUCCESS;
}

static char* btl_openib_component_status_to_string(enum ibv_wc_status status)
{ 
    switch(status) { 
    case IBV_WC_SUCCESS:
        return "SUCCESS"; 
        break;
    case IBV_WC_LOC_LEN_ERR:
        return "LOCAL LENGTH ERROR"; 
        break;
    case IBV_WC_LOC_QP_OP_ERR:
        return "LOCAL QP OPERATION ERROR";
        break;
    case IBV_WC_LOC_EEC_OP_ERR:
        return "LOCAL EEC OPERATION ERROR";
        break;
    case IBV_WC_LOC_PROT_ERR:
        return "LOCAL PROTOCOL ERROR";
        break;
    case IBV_WC_WR_FLUSH_ERR:
        return "WORK REQUEST FLUSHED ERROR";
        break;
    case IBV_WC_MW_BIND_ERR:
        return "MEMORY WINDOW BIND ERROR";
        break;
    case IBV_WC_BAD_RESP_ERR:
        return "BAD RESPONSE ERROR";
        break;
    case IBV_WC_LOC_ACCESS_ERR:
        return "LOCAL ACCESS ERROR";
        break;
    case IBV_WC_REM_INV_REQ_ERR:
        return "INVALID REQUEST ERROR";
        break;
    case IBV_WC_REM_ACCESS_ERR:
        return "REMOTE ACCESS ERROR";
        break;
    case IBV_WC_REM_OP_ERR:
        return "REMOTE OPERATION ERROR";
        break;
    case IBV_WC_RETRY_EXC_ERR:
        return "RETRY EXCEEDED ERROR";
        break;
    case IBV_WC_RNR_RETRY_EXC_ERR:
        return "RECEIVER NOT READY RETRY EXCEEEDED ERROR";
        break;
    case IBV_WC_LOC_RDD_VIOL_ERR:
        return "LOCAL RDD VIOLATION ERROR";
        break;
    case IBV_WC_REM_INV_RD_REQ_ERR:
        return "INVALID READ REQUEST ERROR";
        break;
    case IBV_WC_REM_ABORT_ERR:
        return "REMOTE ABORT ERROR";
        break;
    case IBV_WC_INV_EECN_ERR:
        return "INVALID EECN ERROR";
        break;
    case IBV_WC_INV_EEC_STATE_ERR:
        return "INVALID EEC STATE ERROR";
        break;
    case IBV_WC_FATAL_ERR: 
        return "FATAL ERROR";
        break;
    case IBV_WC_RESP_TIMEOUT_ERR:
        return "RESPONSE TIMEOUT ERROR";
        break;
    case IBV_WC_GENERAL_ERR:
        return "GENERAL ERROR";
        break;
    default:
        return "STATUS UNDEFINED";
        break;
    }
}


static inline int btl_openib_frag_progress_one(
        mca_btl_openib_module_t* openib_btl,
        mca_btl_openib_frag_t* frag)
{
    int res;

    switch(frag->wr_desc.sr_desc.opcode) {
        case IBV_WR_SEND:
            res = mca_btl_openib_endpoint_send(frag->endpoint, frag);
            break;
        case IBV_WR_RDMA_WRITE:
            res = mca_btl_openib_put((mca_btl_base_module_t*) openib_btl,
                    frag->endpoint,
                    (mca_btl_base_descriptor_t*) frag);
            break;
        case IBV_WR_RDMA_READ:
            res = mca_btl_openib_get((mca_btl_base_module_t *) openib_btl,
                    frag->endpoint,
                    (mca_btl_base_descriptor_t*) frag);
            break;
        default:
            res = OMPI_ERROR; 
            BTL_ERROR(("error in posting pending operation, "
                        "invalide opcode %d\n", frag->wr_desc.sr_desc.opcode));
            break;
    }

    return res;
}

#define BTL_OPENIB_TOKENS(E, P) ((E)->sd_tokens[(P)] + \
        (((P) == BTL_OPENIB_HP_QP)?(E)->eager_rdma_remote.tokens:0))
static void btl_openib_frag_progress_pending(
        mca_btl_openib_module_t* openib_btl, mca_btl_base_endpoint_t *endpoint,
        int prio)
{
    
    opal_list_item_t *frag_item;
    mca_btl_openib_frag_t* frag;

    /* check to see if we need to progress any pending desciptors */
    while(!opal_list_is_empty(&endpoint->pending_frags[prio]) &&
            endpoint->sd_wqe[prio] > 0 &&
            BTL_OPENIB_TOKENS(endpoint, prio) > 0) {
        OPAL_THREAD_LOCK(&endpoint->endpoint_lock);
        frag_item = opal_list_remove_first(&(endpoint->pending_frags[prio]));
        OPAL_THREAD_UNLOCK(&endpoint->endpoint_lock);
        if(NULL == (frag = (mca_btl_openib_frag_t *) frag_item))
            break;
        if(btl_openib_frag_progress_one(openib_btl, frag) ==
                OMPI_ERR_OUT_OF_RESOURCE)
            break;
    }

    if(!mca_btl_openib_component.use_srq)
        return;

    while(!opal_list_is_empty(&openib_btl->pending_frags[prio]) &&
            openib_btl->sd_tokens[prio] > 0) {
        /* dequeue resources due to global flow control */
        OPAL_THREAD_LOCK(&openib_btl->ib_lock);
        frag_item = opal_list_remove_first(&openib_btl->pending_frags[prio]);
        OPAL_THREAD_UNLOCK(&openib_btl->ib_lock);
        if(NULL == (frag = (mca_btl_openib_frag_t *) frag_item))
            break;
        if(btl_openib_frag_progress_one(openib_btl, frag) ==
                OMPI_ERR_OUT_OF_RESOURCE)
            break;
     }
}

/*
 *  IB component progress.
 */
static int btl_openib_component_progress(void)
{
    static char *qp_name[] = {"HP", "LP"};
    int i, j, c, qp;
    int count = 0,ne = 0, ret;
    mca_btl_openib_frag_t* frag; 
    mca_btl_openib_endpoint_t* endpoint; 
    struct ibv_wc wc; 
    mca_btl_openib_module_t* openib_btl;

    /* Poll for RDMA completions - if any succeed, we don't process the slower
     * queues.
     */
    for(i = 0; i < mca_btl_openib_component.ib_num_btls; i++) {
        mca_btl_openib_module_t* openib_btl = &mca_btl_openib_component.openib_btls[i];

        OPAL_THREAD_LOCK(&openib_btl->eager_rdma_lock);
        c = openib_btl->eager_rdma_buffers_count;
        OPAL_THREAD_UNLOCK(&openib_btl->eager_rdma_lock);

        for(j = 0; j < c; j++) {
            endpoint = 
                orte_pointer_array_get_item(openib_btl->eager_rdma_buffers, j);

            if(!endpoint) /* shouldn't happen */
                continue;

            OPAL_THREAD_LOCK(&endpoint->eager_rdma_local.lock);
            frag = MCA_BTL_OPENIB_GET_LOCAL_RDMA_FRAG (endpoint,
                    endpoint->eager_rdma_local.head);

            if (MCA_BTL_OPENIB_RDMA_FRAG_LOCAL (frag)) {
                uint32_t size = MCA_BTL_OPENIB_RDMA_FRAG_GET_SIZE(frag->ftr);
#if OMPI_ENABLE_DEBUG
                if (frag->ftr->seq != endpoint->eager_rdma_local.seq)
                    BTL_ERROR(("Eager RDMA wrong SEQ: received %d expected %d",
                                frag->ftr->seq, 
                                endpoint->eager_rdma_local.seq));
                endpoint->eager_rdma_local.seq++;
#endif
                MCA_BTL_OPENIB_RDMA_NEXT_INDEX(endpoint->eager_rdma_local.head);

                OPAL_THREAD_UNLOCK(&endpoint->eager_rdma_local.lock);
                frag->hdr = (mca_btl_openib_header_t*)(((char*)frag->ftr) - 
                        size + sizeof(mca_btl_openib_footer_t));
                frag->segment.seg_addr.pval = ((unsigned char* )frag->hdr) + 
                    sizeof(mca_btl_openib_header_t);

                ret = btl_openib_handle_incoming(openib_btl,
                        frag->endpoint, frag, 
                        size - sizeof(mca_btl_openib_footer_t),
                        BTL_OPENIB_HP_QP);
                if (ret != MPI_SUCCESS) { 
                    openib_btl->error_cb(&openib_btl->super, 
                                         MCA_BTL_ERROR_FLAGS_FATAL);
                    return 0;
                }
                count++;
            } else
                OPAL_THREAD_UNLOCK(&endpoint->eager_rdma_local.lock);
        }
    }
    if(count) return count;

    for(i = 0; i < mca_btl_openib_component.ib_num_btls; i++) {
        openib_btl = &mca_btl_openib_component.openib_btls[i];
        
        /* We have two completion queues, one for "high" priority and one for
         * "low". Check high priority before low priority */
        for(qp = 0; qp < 2; qp++) {
            ne = ibv_poll_cq(openib_btl->ib_cq[qp], 1, &wc);

            if(0 == ne)
                continue;

            if(ne < 0 || wc.status != IBV_WC_SUCCESS)
                goto error;

            frag = (mca_btl_openib_frag_t*) (unsigned long) wc.wr_id; 
            endpoint = frag->endpoint;
            /* Handle work completions */
            switch(wc.opcode) {
            case IBV_WC_RDMA_READ:
                assert(BTL_OPENIB_LP_QP == qp);
                OPAL_THREAD_ADD32(&frag->endpoint->get_tokens, 1);
                /* fall through */

            case IBV_WC_RDMA_WRITE:
                if(BTL_OPENIB_LP_QP == qp) {
                    /* process a completed write */
                    frag->base.des_cbfunc(&openib_btl->super, endpoint,
                            &frag->base, OMPI_SUCCESS);

                    /* return send wqe */
                    OPAL_THREAD_ADD32(&endpoint->sd_wqe[qp], 1);

                    /* check for pending frags */
                    btl_openib_frag_progress_pending(openib_btl, endpoint, qp);

                    count++;
                    break;
                }
                /* fall through for high prio QP */
            case IBV_WC_SEND:
                /* Process a completed send */
                frag->base.des_cbfunc(&openib_btl->super, endpoint, &frag->base,
                        OMPI_SUCCESS); 

                /* return send wqe */
                OPAL_THREAD_ADD32(&endpoint->sd_wqe[qp], 1);
                if(mca_btl_openib_component.use_srq)
                    OPAL_THREAD_ADD32(&openib_btl->sd_tokens[qp], 1);
                /* check to see if we need to progress any pending desciptors */
                btl_openib_frag_progress_pending(openib_btl, endpoint, qp);

                /* check to see if we need to return credits */
                if(btl_openib_check_send_credits(endpoint, qp)) {
                    mca_btl_openib_endpoint_send_credits(endpoint, qp);
                }

                count++;
                break;

            case IBV_WC_RECV: 
                if(wc.wc_flags & IBV_WC_WITH_IMM) {
                    endpoint = (mca_btl_openib_endpoint_t*)
                        orte_pointer_array_get_item(openib_btl->endpoints,
                                wc.imm_data);
                    frag->endpoint = endpoint;
                }
                /* Process a RECV */ 
                ret = btl_openib_handle_incoming(openib_btl, endpoint, frag,
                        wc.byte_len, qp);
                if (ret != OMPI_SUCCESS) { 
                    openib_btl->error_cb(&openib_btl->super,
                            MCA_BTL_ERROR_FLAGS_FATAL);
                    return 0;
                }
                count++; 
                break; 

            default:
                BTL_ERROR(("Unhandled work completion opcode is %d",
                            wc.opcode));
                openib_btl->error_cb(&openib_btl->super,
                        MCA_BTL_ERROR_FLAGS_FATAL);
                break;
            }
        }
    }
    return count;
error:
    if(ne < 0){ 
        BTL_ERROR(("error polling %s CQ with %d errno says %s\n",
                    qp_name[qp], ne, strerror(errno))); 
    } else {
        static int flush_err_printed[] = {0, 0};
        ompi_proc_t* remote_proc = NULL; 
        frag = (mca_btl_openib_frag_t*) (unsigned long) wc.wr_id; 
        if(frag) { 
            endpoint = (mca_btl_openib_endpoint_t*) frag->endpoint; 
            if(endpoint && 
               endpoint->endpoint_proc && 
               endpoint->endpoint_proc->proc_ompi) {
                remote_proc = endpoint->endpoint_proc->proc_ompi; 
            }
        }
        if(wc.status != IBV_WC_WR_FLUSH_ERR || !flush_err_printed[qp]++)
            BTL_PEER_ERROR(remote_proc, ("error polling %s CQ with status %s "
                        "status number %d for wr_id %llu opcode %d",
                        qp_name[qp],
                        btl_openib_component_status_to_string(wc.status), 
                       wc.status, wc.wr_id, wc.opcode)); 
        if(wc.status == IBV_WC_RETRY_EXC_ERR) { 
            opal_show_help("help-mpi-btl-openib.txt",
                    "btl_openib:retry-exceeded", true);
        }
    }
    openib_btl->error_cb(&openib_btl->super, MCA_BTL_ERROR_FLAGS_FATAL); 
    return count;
}