common/ofi: Added multi-NIC support to provider selection

Adds the capability to select a NIC based on hardware locality.
Creates a list of NICs that share the same cpuset as the process,
then selects the NIC based on the (local rank) % (number of NICs).
If no NICs are available that share the same cpuset, the selection process
will create a list of all available NICs and make a selection based on
(local rank) % (number of NICs)

Signed-off-by: Nikola Dancejic <dancejic@amazon.com>

ompi/mca/mtl/ofi/Makefile.am

@@ -78,6 +78,7 @@ mca_mtl_ofi_la_LDFLAGS = \
         $(opal_ofi_LDFLAGS) \
         -module -avoid-version
 mca_mtl_ofi_la_LIBADD = $(top_builddir)/ompi/lib@OMPI_LIBMPI_NAME@.la \
+        $(OPAL_TOP_BUILDDIR)/opal/mca/common/ofi/lib@OPAL_LIB_PREFIX@mca_common_ofi.la \
         $(opal_ofi_LIBS)
 
 noinst_LTLIBRARIES = $(component_noinst)

ompi/mca/mtl/ofi/mtl_ofi_component.c

@@ -16,6 +16,7 @@
 #include "mtl_ofi.h"
 #include "opal/util/argv.h"
 #include "opal/util/printf.h"
+#include "opal/mca/common/ofi/common_ofi.h"
 
 static int ompi_mtl_ofi_component_open(void);
 static int ompi_mtl_ofi_component_query(mca_base_module_t **module, int *priority);
@@ -371,6 +372,28 @@ select_ofi_provider(struct fi_info *providers,
                         __FILE__, __LINE__,
                         (prov ? prov->fabric_attr->prov_name : "none"));
 
+     /* The initial fi_getinfo() call will return a list of providers
+      * available for this process. once a provider is selected from the
+      * list, we will cycle through the remaining list to identify NICs
+      * serviced by this provider, and try to pick one on the same NUMA
+      * node as this process. If there are no NICs on the same NUMA node,
+      * we pick one in a manner which allows all ranks to make balanced
+      * use of available NICs on the system.
+      *
+      * Most providers give a separate fi_info object for each NIC,
+      * however some may have multiple info objects with different
+      * attributes for the same NIC. The initial provider attributes
+      * are used to ensure that all NICs we return provide the same
+      * capabilities as the inital one.
+      */
+    if (NULL != prov) {
+        prov = opal_mca_common_ofi_select_provider(prov, ompi_process_info.my_local_rank);
+        opal_output_verbose(1, ompi_mtl_base_framework.framework_output,
+                            "%s:%d: mtl:ofi:provider: %s\n",
+                            __FILE__, __LINE__,
+                            (prov ? prov->domain_attr->name : "none"));
+    }
+
     return prov;
 }
 

opal/mca/btl/ofi/Makefile.am

@@ -58,6 +58,7 @@ mca_btl_ofi_la_SOURCES = $(component_sources)
 mca_btl_ofi_la_LDFLAGS = -module -avoid-version \
                          $(opal_ofi_LDFLAGS)
 mca_btl_ofi_la_LIBADD = $(top_builddir)/opal/lib@OPAL_LIB_PREFIX@open-pal.la \
+    $(OPAL_TOP_BUILDDIR)/opal/mca/common/ofi/lib@OPAL_LIB_PREFIX@mca_common_ofi.la \
     $(opal_ofi_LIBS)
 
 noinst_LTLIBRARIES = $(lib)

opal/mca/btl/ofi/btl_ofi_component.c

@@ -30,6 +30,7 @@
 #include "opal/mca/btl/btl.h"
 #include "opal/mca/btl/base/base.h"
 #include "opal/mca/hwloc/base/base.h"
+#include "opal/mca/common/ofi/common_ofi.h"
 
 #include <string.h>
 
@@ -240,7 +241,7 @@ static mca_btl_base_module_t **mca_btl_ofi_component_init (int *num_btl_modules,
         return NULL;
     }
 
-    struct fi_info *info, *info_list;
+    struct fi_info *info, *info_list, *selected_info;
     struct fi_info hints = {0};
     struct fi_ep_attr ep_attr = {0};
     struct fi_rx_attr rx_attr = {0};
@@ -331,10 +332,27 @@ static mca_btl_base_module_t **mca_btl_ofi_component_init (int *num_btl_modules,
         rc = validate_info(info, required_caps);
         if (OPAL_SUCCESS == rc) {
             /* Device passed sanity check, let's make a module.
-             * We only pick the first device we found valid */
-            rc = mca_btl_ofi_init_device(info);
-            if (OPAL_SUCCESS == rc)
+             *
+             * The initial fi_getinfo() call will return a list of providers
+             * available for this process. once a provider is selected from the
+             * list, we will cycle through the remaining list to identify NICs
+             * serviced by this provider, and try to pick one on the same NUMA
+             * node as this process. If there are no NICs on the same NUMA node,
+             * we pick one in a manner which allows all ranks to make balanced
+             * use of available NICs on the system.
+             *
+             * Most providers give a separate fi_info object for each NIC,
+             * however some may have multiple info objects with different
+             * attributes for the same NIC. The initial provider attributes
+             * are used to ensure that all NICs we return provide the same
+             * capabilities as the inital one.
+             */
+            selected_info = opal_mca_common_ofi_select_provider(info, opal_process_info.my_local_rank);
+            rc = mca_btl_ofi_init_device(selected_info);
+            if (OPAL_SUCCESS == rc) {
+                info = selected_info;
                 break;
+            }
         }
         info = info->next;
     }

opal/mca/common/ofi/common_ofi.c

@@ -11,6 +11,7 @@
 
 #include "opal_config.h"
 #include "opal/constants.h"
+#include "opal/mca/hwloc/base/base.h"
 
 #include <errno.h>
 #include <unistd.h>
@@ -25,3 +26,258 @@ int mca_common_ofi_register_mca_variables(void)
         return OPAL_ERROR;
     }
 }
+
+/* check that the tx attributes match */
+static int
+check_tx_attr(struct fi_tx_attr *provider_info,
+              struct fi_tx_attr *provider)
+{
+    if (!(provider->msg_order & ~(provider_info->msg_order)) &&
+        !(provider->op_flags & ~(provider_info->op_flags)) &&
+        (provider->inject_size == provider_info->inject_size)) {
+        return 0;
+    } else {
+        return OPAL_ERROR;
+    }
+}
+
+/* check that the rx attributes match */
+static int
+check_rx_attr(struct fi_rx_attr *provider_info,
+              struct fi_rx_attr *provider)
+{
+    if (!(provider->msg_order & ~(provider_info->msg_order)) &&
+        !(provider->op_flags & ~(provider_info->op_flags))) {
+        return 0;
+    } else {
+        return OPAL_ERROR;
+    }
+}
+
+/* check that the ep attributes match */
+static int
+check_ep_attr(struct fi_ep_attr *provider_info,
+              struct fi_ep_attr *provider)
+{
+    if (!(provider->type & ~(provider_info->type)) &&
+        !(provider->mem_tag_format & ~(provider_info->mem_tag_format)) &&
+        (provider->max_msg_size == provider_info->max_msg_size) &&
+        (provider->tx_ctx_cnt == provider_info->tx_ctx_cnt) &&
+        (provider->rx_ctx_cnt == provider_info->rx_ctx_cnt)) {
+        return 0;
+    } else {
+        return OPAL_ERROR;
+    }
+}
+
+/* check that the provider attributes match */
+static int
+check_provider_attr(struct fi_info *provider_info,
+                    struct fi_info *provider)
+{
+    /* make sure both info are the same provider and provide the same attributes */
+    if (0 == strcmp(provider_info->fabric_attr->prov_name, provider->fabric_attr->prov_name) &&
+        !check_tx_attr(provider_info->tx_attr, provider->tx_attr) &&
+        !check_rx_attr(provider_info->rx_attr, provider->rx_attr) &&
+        !check_ep_attr(provider_info->ep_attr, provider->ep_attr) &&
+        !(provider_info->caps & ~(provider->caps)) &&
+        !(provider_info->mode & ~(provider->mode))) {
+        return 0;
+    } else {
+        return OPAL_ERROR;
+    }
+}
+
+/* Check if a process and a pci device share the same cpuset
+ *     @param (IN) pci              struct fi_pci_attr pci device attributes,
+ *                                  used to find hwloc object for device.
+ *
+ *     @param (IN) topology         hwloc_topology_t topology to get the cpusets
+ *                                  from
+ *
+ *     @param (OUT)                 returns true if cpusets match and false if
+ *                                  cpusets do not match or an error prevents comparison
+ *
+ *     Uses a pci device to find an ancestor that contains a cpuset, and
+ *     determines if it intersects with the cpuset that the process is bound to.
+ *     if the process is not bound, or if a cpuset is unavailable for whatever
+ *     reason, returns false. Otherwise, returns the result of
+ *     hwloc_cpuset_intersects()
+ */
+static bool
+compare_cpusets(hwloc_topology_t topology, struct fi_pci_attr pci)
+{
+    bool result = false;
+    int ret;
+    hwloc_bitmap_t proc_cpuset;
+    hwloc_obj_t obj = NULL;
+
+    /* Cannot find topology info if no topology is found */
+    if (NULL == topology) {
+        return false;
+    }
+
+    /* Allocate memory for proc_cpuset */
+    proc_cpuset = hwloc_bitmap_alloc();
+    if (NULL == proc_cpuset) {
+        return false;
+    }
+
+    /* Fill cpuset with the collection of cpu cores that the process runs on */
+    ret = hwloc_get_cpubind(topology, proc_cpuset, HWLOC_CPUBIND_PROCESS);
+    if (0 > ret) {
+        goto error;
+    }
+
+    /* Get the pci device from bdf */
+    obj = hwloc_get_pcidev_by_busid(topology, pci.domain_id, pci.bus_id,
+                                    pci.device_id, pci.function_id);
+    if (NULL == obj) {
+        goto error;
+    }
+
+    /* pcidev objects don't have cpusets so find the first non-io object above */
+    obj = hwloc_get_non_io_ancestor_obj(topology, obj);
+    if (NULL != obj) {
+        result = hwloc_bitmap_intersects(proc_cpuset, obj->cpuset);
+    }
+
+error:
+    hwloc_bitmap_free(proc_cpuset);
+    return result;
+}
+
+/* Count providers returns the number of providers present in an fi_info list
+ *     @param (IN) provider_list    struct fi_info* list of providers available
+ *
+ *     @param (OUT)                 int number of providers present in the list
+ *
+ *     returns 0 if the list is NULL
+ */
+static int
+count_providers(struct fi_info* provider_list)
+{
+    struct fi_info* dev = provider_list;
+    int num_provider = 0;
+
+    while (NULL != dev) {
+        num_provider++;
+        dev = dev->next;
+    }
+
+    return num_provider;
+}
+
+/* Selects a NIC based on hardware locality to process cpuset and device BDF.
+ *
+ *     @param provider_list (IN)    struct fi_info* An initially selected
+ *                                  provider NIC. The provider name and
+ *                                  attributes are used to restrict NIC
+ *                                  selection. This provider is returned if the
+ *                                  NIC selection fails.
+ *
+ *     @param local_index (IN)      int The local rank of the process. Used to
+ *                                  select one valid NIC if there is a case
+ *                                  where more than one can be selected. This
+ *                                  could occur when more than one provider
+ *                                  shares the same cpuset as the process.
+ *
+ *     @param provider (OUT)        struct fi_info* object with the selected
+ *                                  provider if the selection succeeds
+ *                                  if the selection fails, returns the fi_info
+ *                                  object that was initially provided.
+ *
+ * If there is more than one provider that shares the same cpuset, we use
+ * (local rank % number of valid providers that share the process cpuset)
+ * to select one of the local providers.
+ *
+ * Likewise, If no providers share the same cpuset as the process, we use
+ * (local rank % number of valid providers that share the process cpuset)
+ * to select one of the valid providers.
+ *
+ * Initializes opal_hwloc_topology to access hardware topology if not previously
+ * initialized
+ *
+ * If a provider does not provide a BDF, the locality can't be determined and it
+ * is treated as though it does not share the same cpuset as the process.
+ *
+ * All errors should be recoverable and will return the initially provided
+ * provider. However, if an error occurs this will no longer guarantee
+ * that the provider returned is local to the process or that the processes will
+ * balance across available NICs.
+ */
+struct fi_info*
+opal_mca_common_ofi_select_provider(struct fi_info *provider_list, int local_index)
+{
+    struct fi_info *provider = provider_list, *current_provider = provider_list;
+    struct fi_info **provider_table;
+    struct fi_pci_attr pci;
+    int ret;
+    unsigned int num_provider = 0, provider_limit = 0;
+    bool provider_found = false, cpusets_match = false;
+
+    /* Initialize opal_hwloc_topology if it is not already */
+    ret = opal_hwloc_base_get_topology();
+    if (0 > ret) {
+        /* Provider selection can continue but there is no guarantee of locality */
+        opal_output(1, "%s:%d:Failed to initialize topology\n", __FILE__, __LINE__);
+    }
+
+    provider_limit = count_providers(provider_list);
+
+    /* Allocate memory for provider table */
+    provider_table = calloc(provider_limit, sizeof(struct fi_info*));
+    if (NULL == provider_table) {
+        opal_output(1, "%s:%d:Failed to allocate memory for provider table\n", __FILE__, __LINE__);
+        return provider_list;
+    }
+
+    current_provider = provider;
+
+    /* Cycle through remaining fi_info objects, looking for alike providers */
+    while (NULL != current_provider) {
+        if (!check_provider_attr(provider, current_provider)) {
+            cpusets_match = false;
+            if (NULL != current_provider->nic) {
+                pci = current_provider->nic->bus_attr->attr.pci;
+                cpusets_match = compare_cpusets(opal_hwloc_topology, pci);
+            }
+
+            /* Reset the list if the cpusets match and no other provider was
+             * found on the same cpuset as the process.
+             */
+            if (cpusets_match && !provider_found) {
+                provider_found = true;
+                num_provider = 0;
+            }
+
+            /* Add the provider to the provider list if the cpusets match or if
+             * no other provider was found on the same cpuset as the process.
+             */
+            if (cpusets_match || !provider_found) {
+                provider_table[num_provider] = current_provider;
+                num_provider++;
+            }
+        }
+        current_provider = current_provider->next;
+    }
+
+    /* Select provider from local rank % number of providers */
+    if (num_provider > 0) {
+        provider = provider_table[local_index % num_provider];
+    }
+
+#if OPAL_DEBUG_ENABLE
+    if (NULL != provider->nic) {
+        pci = provider->nic->bus_attr->attr.pci;
+        cpusets_match = compare_cpusets(opal_hwloc_topology, pci);
+    }
+
+    opal_output(10, "local rank: %d device: %s cpusets match: %s\n",
+                local_index, provider->domain_attr->name, cpusets_match ? "true" : "false");
+#endif
+
+err_free_table:
+    free(provider_table);
+    return provider;
+}

opal/mca/common/ofi/common_ofi.h

@@ -16,4 +16,6 @@
 
 OPAL_DECLSPEC int mca_common_ofi_register_mca_variables(void);
 
+struct fi_info* opal_mca_common_ofi_select_provider(struct fi_info *provider_list, int rank);
+
 #endif /* OPAL_MCA_COMMON_OFI_H */