Remove experimental_local_memory_estimate flag.

The logic under this flag is incorrect. We have estimation like:

```remainingFreeRAM = TotalFreeRAM - TotalAvailableForBlazeRAM``` ,

but this doesn't make sense, and covers to zero in many cases.

RELNOTES[INC]: Flag --experimental_local_memory_estimate removed.

PiperOrigin-RevId: 458228240
Change-Id: I8b9b05a9b994cbc8170b1a44d0367a7742270a0d

Author: Googler

src/main/java/com/google/devtools/build/lib/actions/ResourceManager.java

@@ -21,8 +21,6 @@
 import com.google.devtools.build.lib.concurrent.ThreadSafety.ThreadSafe;
 import com.google.devtools.build.lib.profiler.AutoProfiler;
 import com.google.devtools.build.lib.profiler.ProfilerTask;
-import com.google.devtools.build.lib.unix.ProcMeminfoParser;
-import com.google.devtools.build.lib.util.OS;
 import com.google.devtools.build.lib.util.Pair;
 import com.google.devtools.build.lib.worker.Worker;
 import com.google.devtools.build.lib.worker.WorkerKey;
@@ -178,9 +176,6 @@ public static ResourceManager instance() {
   // Used local test count. Corresponds to the local test count definition in the ResourceSet class.
   private int usedLocalTestCount;
 
-  // Determines if local memory estimates are used.
-  private boolean localMemoryEstimate = false;
-
   /** If set, local-only actions are given priority over dynamically run actions. */
   private boolean prioritizeLocalActions;
 
@@ -231,14 +226,6 @@ public synchronized void setAvailableResources(ResourceSet resources) {
             staticResources.getLocalTestCount());
   }
 
-  /**
-   * If set to true, then resource acquisition will query the currently available memory, rather
-   * than counting it against the fixed maximum size.
-   */
-  public void setUseLocalMemoryEstimate(boolean value) {
-    localMemoryEstimate = value;
-  }
-
   /** Sets worker pool for taking the workers. Must be called before requesting the workers. */
   public void setWorkerPool(WorkerPool workerPool) {
     this.workerPool = workerPool;
@@ -475,23 +462,6 @@ private boolean areResourcesAvailable(ResourceSet resources) {
 
     double remainingRam = availableRam - usedRam;
 
-    if (localMemoryEstimate && OS.getCurrent() == OS.LINUX) {
-      try {
-        ProcMeminfoParser memInfo = new ProcMeminfoParser();
-        double totalFreeRam = memInfo.getFreeRamKb() / 1024.0;
-        double reserveMemory = staticResources.getMemoryMb();
-        remainingRam = totalFreeRam - reserveMemory;
-      } catch (IOException e) {
-        // If we get an error trying to determine the currently free system memory for any reason,
-        // just continue on.  It is not terribly clear what could cause this, aside from an
-        // unexpected ABI breakage in the linux kernel or an OS-level misconfiguration such as not
-        // having permissions to read /proc/meminfo.
-        //
-        // remainingRam is initialized to a value that results in behavior as if localMemoryEstimate
-        // was disabled.
-      }
-    }
-
     WorkerKey workerKey = resources.getWorkerKey();
     int availableWorkers = 0;
     int activeWorkers = 0;

src/main/java/com/google/devtools/build/lib/bazel/rules/BazelRulesModule.java

@@ -434,6 +434,15 @@ public static final class BazelBuildGraveyardOptions extends BuildGraveyardOptio
         metadataTags = {OptionMetadataTag.INCOMPATIBLE_CHANGE},
         help = "No-op")
     public boolean dontUseJavaSourceInfoProvider;
+
+    @Option(
+        name = "experimental_local_memory_estimate",
+        defaultValue = "false",
+        documentationCategory = OptionDocumentationCategory.UNDOCUMENTED,
+        metadataTags = {OptionMetadataTag.DEPRECATED},
+        effectTags = {OptionEffectTag.NO_OP},
+        help = "No-op.")
+    public boolean localMemoryEstimate;
   }
 
   /**

src/main/java/com/google/devtools/build/lib/buildtool/ExecutionTool.java

@@ -930,7 +930,6 @@ private Builder createBuilder(
   public static void configureResourceManager(ResourceManager resourceMgr, BuildRequest request) {
     ExecutionOptions options = request.getOptions(ExecutionOptions.class);
     resourceMgr.setPrioritizeLocalActions(options.prioritizeLocalActions);
-    resourceMgr.setUseLocalMemoryEstimate(options.localMemoryEstimate);
     resourceMgr.setAvailableResources(
         ResourceSet.create(
             options.localRamResources,

src/main/java/com/google/devtools/build/lib/exec/ExecutionOptions.java

@@ -325,21 +325,6 @@ public boolean shouldMaterializeParamFiles() {
       converter = RamResourceConverter.class)
   public float localRamResources;
 
-  @Option(
-    name = "experimental_local_memory_estimate",
-    defaultValue = "false",
-    documentationCategory = OptionDocumentationCategory.UNCATEGORIZED,
-    effectTags = {OptionEffectTag.UNKNOWN},
-    help =
-        "Estimate the actual memory available online. "
-            + "By default, Blaze assumes most actions use a fixed amount of memory, and counts "
-            + "that against the total available system memory, regardless of how much memory is "
-            + "actually available.  This option enables online estimation of how much memory is "
-            + "available at any given time, and thus does not require accurate estimation of how "
-            + "much memory a given action will take."
-  )
-  public boolean localMemoryEstimate;
-
   @Option(
       name = "local_test_jobs",
       defaultValue = "auto",