From ba2d420d839f0cf54e60feb8df2f4cf7165ed955 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Michal=20Strehovsk=C3=BD?=
 <MichalStrehovsky@users.noreply.github.com>
Date: Thu, 9 Mar 2023 11:41:27 +0900
Subject: [PATCH 1/5] Try reducing memory pressure during object writing

---
 .../Compiler/DependencyAnalysis/ObjectWriter.cs    | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/ObjectWriter.cs b/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/ObjectWriter.cs
index b42db28d6f2445..cd3ca61f27a5ec 100644
--- a/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/ObjectWriter.cs
+++ b/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/ObjectWriter.cs
@@ -1150,7 +1150,13 @@ public static void EmitObject(string objectFilePath, IReadOnlyCollection<Depende
                 }
 
                 if (logger.IsVerbose)
-                    logger.LogMessage($"Finalizing output to '{objectFilePath}'...");
+                    logger.LogMessage($"Emitting debug information");
+
+                // Native side of the object writer is going to do more native memory allocations.
+                // Free up as much memory as possible.
+                GC.Collect();
+                GC.WaitForPendingFinalizers();
+                GC.Collect();
 
                 objectWriter.EmitDebugModuleInfo();
 
@@ -1158,6 +1164,9 @@ public static void EmitObject(string objectFilePath, IReadOnlyCollection<Depende
             }
             finally
             {
+                if (logger.IsVerbose)
+                    logger.LogMessage($"Finalizing output to '{objectFilePath}'...");
+            
                 objectWriter.Dispose();
 
                 if (!succeeded)
@@ -1173,6 +1182,9 @@ public static void EmitObject(string objectFilePath, IReadOnlyCollection<Depende
                     }
                 }
             }
+            
+            if (logger.IsVerbose)
+                logger.LogMessage($"Done writing object file");
         }
 
         [DllImport(NativeObjectWriterFileName)]

From 0038b534fe723aa4a68332c4bce8eeb1172304fe Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Michal=20Strehovsk=C3=BD?=
 <MichalStrehovsky@users.noreply.github.com>
Date: Thu, 9 Mar 2023 11:49:42 +0900
Subject: [PATCH 2/5] Update ObjectWriter.cs

---
 .../Compiler/DependencyAnalysis/ObjectWriter.cs              | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/ObjectWriter.cs b/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/ObjectWriter.cs
index cd3ca61f27a5ec..58a6eb4131f86b 100644
--- a/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/ObjectWriter.cs
+++ b/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/ObjectWriter.cs
@@ -1153,7 +1153,10 @@ public static void EmitObject(string objectFilePath, IReadOnlyCollection<Depende
                     logger.LogMessage($"Emitting debug information");
 
                 // Native side of the object writer is going to do more native memory allocations.
-                // Free up as much memory as possible.
+                // Free up as much memory as possible so that we don't get OOM killed.
+                // This is potentially a waste of time. We're about to end the process and let the
+                // OS "garbage collect" the entire address space.
+                // https://github.com/dotnet/runtime/issues/83180
                 GC.Collect();
                 GC.WaitForPendingFinalizers();
                 GC.Collect();

From 13bc6041c3683c85aa4ff476f482188199f9ec21 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Michal=20Strehovsk=C3=BD?=
 <MichalStrehovsky@users.noreply.github.com>
Date: Thu, 9 Mar 2023 12:08:39 +0900
Subject: [PATCH 3/5] Apply suggestions from code review

Co-authored-by: Jan Kotas <jkotas@microsoft.com>
---
 .../Compiler/DependencyAnalysis/ObjectWriter.cs             | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/ObjectWriter.cs b/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/ObjectWriter.cs
index 58a6eb4131f86b..a91fc47f55d0c0 100644
--- a/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/ObjectWriter.cs
+++ b/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/ObjectWriter.cs
@@ -1157,9 +1157,7 @@ public static void EmitObject(string objectFilePath, IReadOnlyCollection<Depende
                 // This is potentially a waste of time. We're about to end the process and let the
                 // OS "garbage collect" the entire address space.
                 // https://github.com/dotnet/runtime/issues/83180
-                GC.Collect();
-                GC.WaitForPendingFinalizers();
-                GC.Collect();
+                GC.Collect(GC.MaxGeneration, GCCollectionMode.Aggressive););
 
                 objectWriter.EmitDebugModuleInfo();
 
@@ -1169,7 +1167,6 @@ public static void EmitObject(string objectFilePath, IReadOnlyCollection<Depende
             {
                 if (logger.IsVerbose)
                     logger.LogMessage($"Finalizing output to '{objectFilePath}'...");
-            
                 objectWriter.Dispose();
 
                 if (!succeeded)
@@ -1185,7 +1182,6 @@ public static void EmitObject(string objectFilePath, IReadOnlyCollection<Depende
                     }
                 }
             }
-            
             if (logger.IsVerbose)
                 logger.LogMessage($"Done writing object file");
         }

From 42bc053139f042c8980b20c8796e894ff8a95575 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Michal=20Strehovsk=C3=BD?=
 <MichalStrehovsky@users.noreply.github.com>
Date: Thu, 9 Mar 2023 12:14:07 +0900
Subject: [PATCH 4/5] Update ObjectWriter.cs

---
 .../Compiler/DependencyAnalysis/ObjectWriter.cs             | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/ObjectWriter.cs b/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/ObjectWriter.cs
index a91fc47f55d0c0..963e093397012e 100644
--- a/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/ObjectWriter.cs
+++ b/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/ObjectWriter.cs
@@ -1157,7 +1157,9 @@ public static void EmitObject(string objectFilePath, IReadOnlyCollection<Depende
                 // This is potentially a waste of time. We're about to end the process and let the
                 // OS "garbage collect" the entire address space.
                 // https://github.com/dotnet/runtime/issues/83180
-                GC.Collect(GC.MaxGeneration, GCCollectionMode.Aggressive););
+                var gcMemoryInfo = GC.GetGCMemoryInfo();
+                if (gcMemoryInfo.TotalCommittedBytes > gcMemoryInfo.TotalAvailableMemoryBytes / 2)
+                    GC.Collect(GC.MaxGeneration, GCCollectionMode.Aggressive));
 
                 objectWriter.EmitDebugModuleInfo();
 
@@ -1167,6 +1169,7 @@ public static void EmitObject(string objectFilePath, IReadOnlyCollection<Depende
             {
                 if (logger.IsVerbose)
                     logger.LogMessage($"Finalizing output to '{objectFilePath}'...");
+
                 objectWriter.Dispose();
 
                 if (!succeeded)
@@ -1182,6 +1185,7 @@ public static void EmitObject(string objectFilePath, IReadOnlyCollection<Depende
                     }
                 }
             }
+
             if (logger.IsVerbose)
                 logger.LogMessage($"Done writing object file");
         }

From 7ba41c0c86194455578b346d016afcedc32cc56a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Michal=20Strehovsk=C3=BD?=
 <MichalStrehovsky@users.noreply.github.com>
Date: Thu, 9 Mar 2023 12:36:54 +0900
Subject: [PATCH 5/5] Update ObjectWriter.cs

---
 .../Compiler/DependencyAnalysis/ObjectWriter.cs           | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/ObjectWriter.cs b/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/ObjectWriter.cs
index 963e093397012e..c5e164c8d914ac 100644
--- a/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/ObjectWriter.cs
+++ b/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/ObjectWriter.cs
@@ -1156,10 +1156,14 @@ public static void EmitObject(string objectFilePath, IReadOnlyCollection<Depende
                 // Free up as much memory as possible so that we don't get OOM killed.
                 // This is potentially a waste of time. We're about to end the process and let the
                 // OS "garbage collect" the entire address space.
-                // https://github.com/dotnet/runtime/issues/83180
                 var gcMemoryInfo = GC.GetGCMemoryInfo();
                 if (gcMemoryInfo.TotalCommittedBytes > gcMemoryInfo.TotalAvailableMemoryBytes / 2)
-                    GC.Collect(GC.MaxGeneration, GCCollectionMode.Aggressive));
+                {
+                    if (logger.IsVerbose)
+                        logger.LogMessage($"Freeing up memory");
+
+                    GC.Collect(GC.MaxGeneration, GCCollectionMode.Aggressive);
+                }
 
                 objectWriter.EmitDebugModuleInfo();