Commit bdcb3b2e authored by Eisenhauer, Greg's avatar Eisenhauer, Greg
Browse files

better CXI Slingshot error message

parent 1fcd3b03

source/adios2/toolkit/sst/dp/rdma_dp.c

+78 −0
Original line number Diff line number Diff line
@@ -1260,6 +1260,43 @@ static int get_cxi_auth_key_from_writer(struct cxi_auth_key *key, attr_list Writ 
    key->vni = (uint16_t)vni;

    return EXIT_SUCCESS;

}



/*

 * Returns 1 if `writer_vni` appears in the comma-separated SLINGSHOT_VNIS env

 * value (e.g. "4576,4530"), 0 otherwise.  If SLINGSHOT_VNIS is unset, returns 0.

 */

static int writer_vni_in_local_env(uint16_t writer_vni)

{

    char const *vni_env_str = getenv("SLINGSHOT_VNIS");

    if (!vni_env_str)

    {

        return 0;

    }

    char const *p = vni_env_str;

    while (*p)

    {

        char *end = NULL;

        long v = strtol(p, &end, 10);

        if (end == p)

        {

            break;

        }

        if ((uint16_t)v == writer_vni)

        {

            return 1;

        }

        p = end;

        if (*p == ',')

        {

            ++p;

        }

        else

        {

            break;

        }

    }

    return 0;

}

#endif



typedef enum
@@ -1465,6 +1502,24 @@ static DP_RS_Stream RdmaInitReader(CP_Services Svcs, void *CP_Stream, void **Rea 
    {

        Svcs->verbose(CP_Stream, DPSummaryVerbose, "Reader found CXI auth key: %d %d\n",

                      tagged_key.key.vni, tagged_key.key.svc_id);

        if (Stream->Rank == 0 && !writer_vni_in_local_env(tagged_key.key.vni))

        {

            char const *local_vnis = getenv("SLINGSHOT_VNIS");

            Svcs->verbose(CP_Stream, DPCriticalVerbose,

                          "WARNING: SST RDMA DataPlane: writer's CXI VNI %u is not "

                          "present in this process's SLINGSHOT_VNIS=\"%s\".  "

                          "The kernel CXI driver will refuse to open a fabric with "

                          "a VNI not allocated to this job, so libfabric fi_getinfo() "

                          "is expected to fail with -61 (No data available) and the "

                          "reader open will not complete.  On HPE Cray EX systems "

                          "(Perlmutter, Frontier) Slingshot VNIs are per-allocation "

                          "and there is no supported mechanism to share a VNI across "

                          "two independent Slurm jobs.  Launch writer and reader in "

                          "the same Slurm allocation: as multiple srun steps in one "

                          "job, as a single MPMD srun (writer : reader), or as a "

                          "Slurm heterogeneous job.\n",

                          (unsigned)tagged_key.key.vni, local_vnis ? local_vnis : "(unset)");

        }

        Stream->Fabric->cxi_auth_key = calloc(1, sizeof(struct cxi_auth_key));

        memcpy(Stream->Fabric->cxi_auth_key, &tagged_key.key, sizeof(struct cxi_auth_key));

    }
@@ -2570,6 +2625,29 @@ static int RdmaGetPriority(CP_Services Svcs, void *CP_Stream, struct _SstParams 


    char const *vni_env_str = getenv("SLINGSHOT_VNIS");



#ifdef SST_HAVE_CRAY_CXI

    if (!vni_env_str)

    {

        static int warned_no_vni = 0;

        if (!warned_no_vni)

        {

            warned_no_vni = 1;

            Svcs->verbose(

                CP_Stream, DPCriticalVerbose,

                "WARNING: SST RDMA DataPlane: this build supports Cray CXI/Slingshot, but "

                "SLINGSHOT_VNIS is not set in this process's environment.  On HPE Cray EX "

                "systems (Perlmutter, Frontier) Slingshot VNIs are allocated by the launcher; "

                "if you intended to use RDMA, ensure the job was launched via "

                "'srun --network=...vni...' (e.g. job_vni,single_node_vni) rather than directly "

                "on a login node or without the --network flag.  Declining RDMA DP priority; "

                "SST will fall back to another DataPlane (typically evpath/sockets), which on "

                "this machine will not use Slingshot RDMA.\n");

        }

        fi_freeinfo(hints);

        return -1;

    }

#endif



    uint32_t fi_version;

    if (vni_env_str)

    {