Updated PR#196 to use a common hash function

src/include/utils.h

@@ -11,7 +11,7 @@
 #include <stdint.h>
 
 ncclResult_t getHostName(char* hostname, int maxlen, const char delim);
-uint64_t getnHash(const char* string, int n);
+uint64_t getHash(const char* string, int n);
 uint64_t getHostHash();
 uint64_t getPidHash();
 

src/init.cc

@@ -691,8 +691,8 @@ static ncclResult_t initTransportsRank(struct ncclComm* comm, ncclUniqueId* comm
 
   int rank = comm->rank;
   int nranks = comm->nRanks;
-  uint64_t commHash = getnHash(commId->internal, NCCL_UNIQUE_ID_BYTES);
-  TRACE(NCCL_INIT, "comm %p, commHash %lu, rank %d nranks %d - BEGIN", comm, commHash, rank, nranks);
+  uint64_t commHash = getHash(commId->internal, NCCL_UNIQUE_ID_BYTES);
+  TRACE(NCCL_INIT, "comm %p, commHash %lx, rank %d nranks %d - BEGIN", comm, commHash, rank, nranks);
   NCCLCHECK(bootstrapInit(commId, rank, nranks, &comm->bootstrap));
 
   // AllGather1 - begin

src/misc/utils.cc

@@ -87,18 +87,9 @@ void ncclDebugLog(ncclDebugLogLevel level, unsigned long flags, const char *file
   }
 }
 
-uint64_t getHash(const char* string) {
+uint64_t getHash(const char* string, int n) {
   // Based on DJB2, result = result * 33 + char
   uint64_t result = 5381;
-  for (int c = 0; string[c] != '\0'; c++) {
-    result = ((result << 5) + result) + string[c];
-  }
-  return result;
-}
-
-uint64_t getnHash(const char* string, int n) {
-  // Based on DJB2, result = result * 33 + char
-  uint64_t result = 9527;
   for (int c = 0; c < n; c++) {
     result = ((result << 5) + result) + string[c];
   }
@@ -129,7 +120,7 @@ uint64_t getHostHash(void) {
   uname[offset]='\0';
   TRACE(NCCL_INIT,"unique hostname '%s'", uname);
 
-  return getHash(uname);
+  return getHash(uname, strlen(uname));
 }
 
 /* Generate a hash of the unique identifying string for this process
@@ -149,7 +140,7 @@ uint64_t getPidHash(void) {
   pname[plen+len]='\0';
   TRACE(NCCL_INIT,"unique PID '%s'", pname);
 
-  return getHash(pname);
+  return getHash(pname, strlen(pname));
 }
 
 int parseStringList(const char* string, struct netIf* ifList, int maxList) {