diff --git a/llvm/include/llvm/Analysis/InlineAdvisor.h b/llvm/include/llvm/Analysis/InlineAdvisor.h
--- a/llvm/include/llvm/Analysis/InlineAdvisor.h
+++ b/llvm/include/llvm/Analysis/InlineAdvisor.h
@@ -199,7 +199,7 @@
 /// inlining should not be attempted.
 Optional<InlineCost>
 shouldInline(CallBase &CB, function_ref<InlineCost(CallBase &CB)> GetInlineCost,
-             OptimizationRemarkEmitter &ORE);
+             OptimizationRemarkEmitter &ORE, bool EnableDeferral);
 
 /// Emit ORE message.
 void emitInlinedInto(OptimizationRemarkEmitter &ORE, DebugLoc DLoc,
diff --git a/llvm/include/llvm/Analysis/InlineCost.h b/llvm/include/llvm/Analysis/InlineCost.h
--- a/llvm/include/llvm/Analysis/InlineCost.h
+++ b/llvm/include/llvm/Analysis/InlineCost.h
@@ -182,6 +182,9 @@
 
   /// Compute inline cost even when the cost has exceeded the threshold.
   Optional<bool> ComputeFullInlineCost;
+
+  /// Indicate whether we should allow inline deferral.
+  Optional<bool> EnableDeferral = true;
 };
 
 /// Generate the parameters to tune the inline cost analysis based only on the
diff --git a/llvm/lib/Analysis/InlineAdvisor.cpp b/llvm/lib/Analysis/InlineAdvisor.cpp
--- a/llvm/lib/Analysis/InlineAdvisor.cpp
+++ b/llvm/lib/Analysis/InlineAdvisor.cpp
@@ -118,7 +118,9 @@
     return getInlineCost(CB, Params, CalleeTTI, GetAssumptionCache, GetTLI,
                          GetBFI, PSI, RemarksEnabled ? &ORE : nullptr);
   };
-  auto OIC = llvm::shouldInline(CB, GetInlineCost, ORE);
+  auto OIC = llvm::shouldInline(CB, GetInlineCost, ORE,
+                                Params.EnableDeferral.hasValue() &&
+                                    Params.EnableDeferral.getValue());
   return std::make_unique<DefaultInlineAdvice>(this, CB, OIC, ORE);
 }
 
@@ -298,7 +300,7 @@
 Optional<InlineCost>
 llvm::shouldInline(CallBase &CB,
                    function_ref<InlineCost(CallBase &CB)> GetInlineCost,
-                   OptimizationRemarkEmitter &ORE) {
+                   OptimizationRemarkEmitter &ORE, bool EnableDeferral) {
   using namespace ore;
 
   InlineCost IC = GetInlineCost(CB);
@@ -335,7 +337,8 @@
   }
 
   int TotalSecondaryCost = 0;
-  if (shouldBeDeferred(Caller, IC, TotalSecondaryCost, GetInlineCost)) {
+  if (EnableDeferral &&
+      shouldBeDeferred(Caller, IC, TotalSecondaryCost, GetInlineCost)) {
     LLVM_DEBUG(dbgs() << "    NOT Inlining: " << CB
                       << " Cost = " << IC.getCost()
                       << ", outer Cost = " << TotalSecondaryCost << '\n');
diff --git a/llvm/lib/Analysis/InlineCost.cpp b/llvm/lib/Analysis/InlineCost.cpp
--- a/llvm/lib/Analysis/InlineCost.cpp
+++ b/llvm/lib/Analysis/InlineCost.cpp
@@ -2250,7 +2250,8 @@
                                /*HotCallSiteThreshold*/ {},
                                /*LocallyHotCallSiteThreshold*/ {},
                                /*ColdCallSiteThreshold*/ {},
-                               /* ComputeFullInlineCost*/ true};
+                               /*ComputeFullInlineCost*/ true,
+                               /*EnableDeferral*/ true};
 
   InlineCostCallAnalyzer CA(*Call.getCalledFunction(), Call, Params, CalleeTTI,
                             GetAssumptionCache, GetBFI, PSI, ORE, true,
diff --git a/llvm/lib/Passes/PassBuilder.cpp b/llvm/lib/Passes/PassBuilder.cpp
--- a/llvm/lib/Passes/PassBuilder.cpp
+++ b/llvm/lib/Passes/PassBuilder.cpp
@@ -254,6 +254,12 @@
     "enable-npm-call-graph-profile", cl::init(true), cl::Hidden,
     cl::desc("Enable call graph profile pass for the new PM (default = on)"));
 
+/// Flag to enable inline deferral during PGO.
+static cl::opt<bool>
+    EnablePGOInlineDeferral("enable-npm-pgo-inline-deferral", cl::init(true),
+                            cl::Hidden,
+                            cl::desc("Enable inline deferral during PGO"));
+
 PipelineTuningOptions::PipelineTuningOptions() {
   LoopInterleaving = true;
   LoopVectorization = true;
@@ -712,6 +718,9 @@
       PGOOpt->Action == PGOOptions::SampleUse)
     IP.HotCallSiteThreshold = 0;
 
+  if (PGOOpt)
+    IP.EnableDeferral = EnablePGOInlineDeferral;
+
   ModuleInlinerWrapperPass MIWP(IP, DebugLogging, UseInlineAdvisor,
                                 MaxDevirtIterations);
 
diff --git a/llvm/lib/Transforms/IPO/Inliner.cpp b/llvm/lib/Transforms/IPO/Inliner.cpp
--- a/llvm/lib/Transforms/IPO/Inliner.cpp
+++ b/llvm/lib/Transforms/IPO/Inliner.cpp
@@ -438,7 +438,7 @@
       // just become a regular analysis dependency.
       OptimizationRemarkEmitter ORE(Caller);
 
-      auto OIC = shouldInline(CB, GetInlineCost, ORE);
+      auto OIC = shouldInline(CB, GetInlineCost, ORE, true);
       // If the policy determines that we should inline this function,
       // delete the call instead.
       if (!OIC)