Index: compiler-rt/lib/fuzzer/FuzzerDriver.cpp
===================================================================
--- compiler-rt/lib/fuzzer/FuzzerDriver.cpp
+++ compiler-rt/lib/fuzzer/FuzzerDriver.cpp
@@ -867,7 +867,7 @@
   }
 
   if (Flags.fork)
-    FuzzWithFork(F->GetMD().GetRand(), Options, Args, *Inputs, Flags.fork);
+    FuzzWithFork(F->GetMD().GetRand(), Options, Args, *Inputs, Flags.fork, Flags.NumCorpuses);
 
   if (Flags.merge)
     Merge(F, Options, Args, *Inputs, Flags.merge_control_file);
Index: compiler-rt/lib/fuzzer/FuzzerFlags.def
===================================================================
--- compiler-rt/lib/fuzzer/FuzzerFlags.def
+++ compiler-rt/lib/fuzzer/FuzzerFlags.def
@@ -56,6 +56,7 @@
 FUZZER_FLAG_INT(max_total_time, 0, "If positive, indicates the maximal total "
                                    "time in seconds to run the fuzzer.")
 FUZZER_FLAG_INT(help, 0, "Print help.")
+FUZZER_FLAG_INT(NumCorpuses, 1, "Divide the corpus into N parts according to size.")
 FUZZER_FLAG_INT(fork, 0, "Experimental mode where fuzzing happens "
                 "in a subprocess")
 FUZZER_FLAG_INT(ignore_timeouts, 1, "Ignore timeouts in fork mode")
Index: compiler-rt/lib/fuzzer/FuzzerFork.h
===================================================================
--- compiler-rt/lib/fuzzer/FuzzerFork.h
+++ compiler-rt/lib/fuzzer/FuzzerFork.h
@@ -18,7 +18,7 @@
 namespace fuzzer {
 void FuzzWithFork(Random &Rand, const FuzzingOptions &Options,
                   const Vector<std::string> &Args,
-                  const Vector<std::string> &CorpusDirs, int NumJobs);
+                  const Vector<std::string> &CorpusDirs, int NumJobs, int NumCorpuses);
 } // namespace fuzzer
 
 #endif // LLVM_FUZZER_FORK_H
Index: compiler-rt/lib/fuzzer/FuzzerFork.cpp
===================================================================
--- compiler-rt/lib/fuzzer/FuzzerFork.cpp
+++ compiler-rt/lib/fuzzer/FuzzerFork.cpp
@@ -114,7 +114,7 @@
         .count();
   }
 
-  FuzzJob *CreateNewJob(size_t JobId) {
+  FuzzJob *CreateNewJob(size_t JobId, int NumCorpuses) {
     Command Cmd(Args);
     Cmd.removeFlag("fork");
     Cmd.removeFlag("runs");
@@ -135,11 +135,23 @@
     std::string Seeds;
     if (size_t CorpusSubsetSize =
             std::min(Files.size(), (size_t)sqrt(Files.size() + 2))) {
+      size_t AverageSize = Files.size()/NumCorpuses +1;
       auto Time1 = std::chrono::system_clock::now();
+      size_t StartIndex = ((JobId-1)%NumCorpuses) *  AverageSize;
+      printf("\n Job %d Choose Corpus  %d ",JobId,(JobId)%NumCorpuses);
       for (size_t i = 0; i < CorpusSubsetSize; i++) {
-        auto &SF = Files[Rand->SkewTowardsLast(Files.size())];
-        Seeds += (Seeds.empty() ? "" : ",") + SF;
-        CollectDFT(SF);
+        size_t j = Rand->SkewTowardsLast(AverageSize);
+        size_t m = j + StartIndex;
+        if (m < Files.size()) {
+                auto &SF = Files[m];
+                Seeds += (Seeds.empty() ? "" : ",") + SF;
+                CollectDFT(SF);
+        }
+        else  {
+                auto &SF = Files[Rand->SkewTowardsLast(Files.size())];
+                Seeds += (Seeds.empty() ? "" : ",") + SF;
+                CollectDFT(SF);
+        }
       }
       auto Time2 = std::chrono::system_clock::now();
       auto DftTimeInSeconds = duration_cast<seconds>(Time2 - Time1).count();
@@ -284,7 +296,7 @@
 // This is just a skeleton of an experimental -fork=1 feature.
 void FuzzWithFork(Random &Rand, const FuzzingOptions &Options,
                   const Vector<std::string> &Args,
-                  const Vector<std::string> &CorpusDirs, int NumJobs) {
+                  const Vector<std::string> &CorpusDirs, int NumJobs, int NumCorpuses) {
   Printf("INFO: -fork=%d: fuzzing in separate process(s)\n", NumJobs);
 
   GlobalEnv Env;
@@ -341,8 +353,9 @@
   Vector<std::thread> Threads;
   for (int t = 0; t < NumJobs; t++) {
     Threads.push_back(std::thread(WorkerThread, &FuzzQ, &MergeQ));
-    FuzzQ.Push(Env.CreateNewJob(JobId++));
+    FuzzQ.Push(Env.CreateNewJob(JobId++, NumCorpuses));
   }
+  //printf("\n 创建%d个jobs\n",NumJobs);
 
   while (true) {
     std::unique_ptr<FuzzJob> Job(MergeQ.Pop());
@@ -399,7 +412,7 @@
       break;
     }
 
-    FuzzQ.Push(Env.CreateNewJob(JobId++));
+    FuzzQ.Push(Env.CreateNewJob(JobId++, NumCorpuses));
   }
 
   for (auto &T : Threads)