4 files changed, 12 insertions, 2 deletions
diff --git a/lld/ELF/Config.h b/lld/ELF/Config.h
index 273b756c0a5..aeaa0f9f52c 100644
--- a/lld/ELF/Config.h
+++ b/lld/ELF/Config.h
@@ -74,6 +74,7 @@ struct Configuration {
   bool Static = false;
   bool StripAll;
   bool SysvHash = true;
+  bool Threads;
   bool Verbose;
   bool ZExecStack;
   bool ZNodelete;
diff --git a/lld/ELF/Driver.cpp b/lld/ELF/Driver.cpp
index 8fff516946a..064938abaaa 100644
--- a/lld/ELF/Driver.cpp
+++ b/lld/ELF/Driver.cpp
@@ -239,6 +239,7 @@ void LinkerDriver::readConfigs(opt::InputArgList &Args) {
   Config->SaveTemps = Args.hasArg(OPT_save_temps);
   Config->Shared = Args.hasArg(OPT_shared);
   Config->StripAll = Args.hasArg(OPT_strip_all);
+  Config->Threads = Args.hasArg(OPT_threads);
   Config->Verbose = Args.hasArg(OPT_verbose);
 
   Config->DynamicLinker = getString(Args, OPT_dynamic_linker);
diff --git a/lld/ELF/Options.td b/lld/ELF/Options.td
index 24e984119c4..c11cb9469f2 100644
--- a/lld/ELF/Options.td
+++ b/lld/ELF/Options.td
@@ -118,6 +118,8 @@ def strip_all : Flag<["--"], "strip-all">,
 def sysroot : Joined<["--"], "sysroot=">,
   HelpText<"Set the system root">;
 
+def threads : Joined<["--"], "threads">;
+
 def undefined : Joined<["--"], "undefined=">,
   HelpText<"Force undefined symbol during linking">;
 
diff --git a/lld/ELF/OutputSections.cpp b/lld/ELF/OutputSections.cpp
index 79705664b50..d9c0d160b4b 100644
--- a/lld/ELF/OutputSections.cpp
+++ b/lld/ELF/OutputSections.cpp
@@ -12,6 +12,7 @@
 #include "LinkerScript.h"
 #include "SymbolTable.h"
 #include "Target.h"
+#include "lld/Core/Parallel.h"
 #include "llvm/Support/Dwarf.h"
 #include "llvm/Support/MathExtras.h"
 #include <map>
@@ -929,8 +930,13 @@ template <class ELFT> void OutputSection<ELFT>::writeTo(uint8_t *Buf) {
   ArrayRef<uint8_t> Filler = Script->getFiller(this->Name);
   if (!Filler.empty())
     fill(Buf, this->getSize(), Filler);
-  for (InputSection<ELFT> *C : Sections)
-    C->writeTo(Buf);
+  if (Config->Threads) {
+    parallel_for_each(Sections.begin(), Sections.end(),
+                      [=](InputSection<ELFT> *C) { C->writeTo(Buf); });
+  } else {
+    for (InputSection<ELFT> *C : Sections)
+      C->writeTo(Buf);
+  }
 }
 
 template <class ELFT>