UCP/CORE: Cache reachable system devices (Direct NIC datapath).

src/ucp/core/ucp_context.c

@@ -1799,6 +1799,28 @@ static void ucp_fill_resources_reg_md_map_update(ucp_context_h context)
     }
 }
 
+static void ucp_fill_resources_reachable_sys_devs(ucp_context_h context)
+{
+    unsigned num_sys_devs;
+    ucp_md_index_t md_index;
+    ucp_tl_md_t *tl_md;
+    ucs_sys_device_t sys_dev, sys_dev_md;
+
+    num_sys_devs = ucs_topo_num_devices();
+    for (md_index = 0; md_index < context->num_mds; ++md_index) {
+        tl_md                     = &context->tl_mds[md_index];
+        tl_md->reachable_sys_devs = UCS_MASK(num_sys_devs);
+        for (sys_dev = 0; sys_dev < num_sys_devs; ++sys_dev) {
+            ucs_for_each_bit(sys_dev_md, tl_md->sys_dev_map) {
+                if (!ucs_topo_is_reachable(sys_dev_md, sys_dev)) {
+                    tl_md->reachable_sys_devs &= ~UCS_BIT(sys_dev);
+                    break;
+                }
+            }
+        }
+    }
+}
+
 static ucs_status_t ucp_fill_resources(ucp_context_h context,
                                        const ucp_config_t *config)
 {
@@ -1913,6 +1935,7 @@ static ucs_status_t ucp_fill_resources(ucp_context_h context,
     }
 
     ucp_fill_resources_reg_md_map_update(context);
+    ucp_fill_resources_reachable_sys_devs(context);
 
     /* If unified mode is enabled, initialize tl_bitmap to 0.
      * Then the worker will open all available transport resources and will

src/ucp/core/ucp_context.h

@@ -331,6 +331,12 @@ typedef struct ucp_tl_md {
      * Set of known system devices associated to the MD
      */
     ucp_sys_dev_map_t      sys_dev_map;
+
+    /**
+     * Set of system devices that can reach all system devices associated with
+     * the MD
+     */
+    ucp_sys_dev_map_t      reachable_sys_devs;
 } ucp_tl_md_t;
 
 

src/ucp/core/ucp_mm.c

@@ -524,28 +524,6 @@ static ucs_status_t ucp_memh_register_gva(ucp_context_h context, ucp_mem_h memh,
     return UCS_OK;
 }
 
-static int ucp_memh_sys_dev_reachable(ucs_sys_device_t mem_sys_dev,
-                                      ucp_sys_dev_map_t sys_dev_map)
-{
-    ucs_sys_device_t sys_dev;
-
-    if (mem_sys_dev == UCS_SYS_DEVICE_ID_UNKNOWN) {
-        return 1;
-    }
-
-    /*
-     * If at least one sys_dev is not reachable, do not register on it
-     * as we cannot know in advance which device is going to be used.
-     */
-    ucs_for_each_bit(sys_dev, sys_dev_map) {
-        if (!ucs_topo_is_reachable(sys_dev, mem_sys_dev)) {
-            return 0;
-        }
-    }
-
-    return 1;
-}
-
 static ucs_status_t
 ucp_memh_register_internal(ucp_context_h context, ucp_mem_h memh,
                            ucp_md_map_t md_map, unsigned uct_flags,
@@ -566,7 +544,6 @@ ucp_memh_register_internal(ucp_context_h context, ucp_mem_h memh,
     void *reg_address;
     size_t reg_length;
     size_t reg_align;
-    ucp_sys_dev_map_t sys_dev_map;
 
     if (gva_enable) {
         status = ucp_memh_register_gva(context, memh, md_map);
@@ -614,9 +591,8 @@ ucp_memh_register_internal(ucp_context_h context, ucp_mem_h memh,
 
             /* Exclude any unreachable MD from registration */
             ucs_for_each_bit(md_index, dmabuf_md_map) {
-                sys_dev_map = context->tl_mds[md_index].sys_dev_map;
-                if (!ucp_memh_sys_dev_reachable(mem_attr.sys_dev,
-                                                sys_dev_map)) {
+                if (!(context->tl_mds[md_index].reachable_sys_devs &
+                      UCS_BIT(mem_attr.sys_dev))) {
                     ucs_trace("md[%d] skipped: cannot reach mem_sys_dev=%u",
                               md_index, mem_attr.sys_dev);
                     reg_md_map &= ~UCS_BIT(md_index);