Allow more parallelism when low on memory but not on ramdisk

Author: MihaZupan

Runner/JobBase.cs

@@ -615,6 +615,8 @@ protected int GetRemainingSystemMemoryGB()
         return (int)(memory.AvailablePhysical / 1024 / 1024 / 1024);
     }
 
+    protected static bool OnRamDisk => Environment.CurrentDirectory.StartsWith("/ramdisk", StringComparison.Ordinal);
+
     protected async Task ChangeWorkingDirectoryToRamOrFastestDiskAsync(bool allowRamDisk = true)
     {
         string? newLocation = await ChangeWorkingDirectoryToRamOrFastestDiskAsyncCore(allowRamDisk);

Runner/Jobs/NuGetExtraAssembliesJob.cs

@@ -120,7 +120,8 @@ private async Task ProcessApprovedPackagesAsync(List<(string Id, string Version,
         string diffOutputDir = "nuget-diff-temp";
         Directory.CreateDirectory(diffOutputDir);
 
-        int parallelism = Math.Min(Math.Min(Environment.ProcessorCount, GetRemainingSystemMemoryGB() / 3), approvedPackages.Count);
+        int memoryParallelism = OnRamDisk ? GetRemainingSystemMemoryGB() / 3 : GetRemainingSystemMemoryGB() * 2;
+        int parallelism = Math.Min(Math.Min(Environment.ProcessorCount, memoryParallelism), approvedPackages.Count);
         parallelism = Math.Max(parallelism, 1);
         var packageQueue = new Queue<(string Id, string Version, string PkgDir, string Dll, Dictionary<string, string> Deps)>(approvedPackages);