Improve robustness of PCI detection

Fallback to default values when class/speed is unknown.

2 files changed, 5 insertions, 6 deletions

diff --git a/src/graph/topo.cc b/src/graph/topo.cc
index 5cd8d4e..3767ba9 100644
--- a/src/graph/topo.cc
+++ b/src/graph/topo.cc
@@ -303,8 +303,8 @@ ncclResult_t ncclTopoAddGpu(struct ncclXmlNode* xmlGpu, struct ncclTopoSystem* s
   return ncclSuccess;
 }
 
-struct kvDict kvDictPciClass[] = { { "0x060400", PCI }, { "0x068000", NVS }, { "0x068001", CPU }, { "0x03", GPU }, { "0x02", NIC }, { NULL, 0 } };
-struct kvDict kvDictPciGen[] = { { "2.5 GT/s", 15 }, { "5 GT/s", 30 }, { "8 GT/s", 60 }, { "16 GT/s", 120 }, { NULL, 0 } }; // x100 Mbps per lane
+struct kvDict kvDictPciClass[] = { { "0x060400", PCI }, { "0x068000", NVS }, { "0x068001", CPU }, { "0x03", GPU }, { "0x02", NIC }, { NULL, PCI /* Default fallback value */ } };
+struct kvDict kvDictPciGen[] = { { "2.5 GT/s", 15 }, { "5 GT/s", 30 }, { "8 GT/s", 60 }, { "16 GT/s", 120 }, { NULL, 60 /* Default fallback */ } }; // x100 Mbps per lane
 ncclResult_t ncclTopoAddPci(struct ncclXmlNode* xmlPci, struct ncclTopoSystem* system, struct ncclTopoNode* parent) {
   const char* str;
 
@@ -356,8 +356,6 @@ ncclResult_t ncclTopoAddPci(struct ncclXmlNode* xmlPci, struct ncclTopoSystem* s
 
     // Manage cases where speed was not indicated in /sys
     if (width == 0) width = 16;
-    if (strlen(str) == 0 || strcasecmp(str, "Unknown speed") == 0) str = "8 GT/s";
-
     NCCLCHECK(kvConvertToInt(str, &speed, kvDictPciGen)); // Values in 100Mbps, per lane (we want GB/s in the end)
 
     NCCLCHECK(ncclTopoConnectNodes(node, parent, LINK_PCI, width*speed/80.0));
diff --git a/src/graph/xml.h b/src/graph/xml.h
index fa04527..22e016f 100644
--- a/src/graph/xml.h
+++ b/src/graph/xml.h
@@ -218,8 +218,9 @@ static ncclResult_t kvConvertToInt(const char* str, int* value, struct kvDict* d
     }
     d++;
   }
-  WARN("KV Convert to int : could not find value of '%s' in dictionary", str);
-  return ncclInternalError;
+  INFO(NCCL_GRAPH, "KV Convert to int : could not find value of '%s' in dictionary, falling back to %d", str, d->value);
+  *value = d->value;
+  return ncclSuccess;
 }
 static ncclResult_t kvConvertToStr(int value, const char** str, struct kvDict* dict) {
   struct kvDict* d = dict;