Configurable heap memory release rate (#32589)

Expose config option for tcmalloc [memory background release rate](bf4db7e4c8/tcmalloc/malloc_extension.h (L637C15-L637C39), that eases tuning of tcmalloc in Envoy. Gperf tcmalloc is not yet supported in this change, as gperf tcmalloc memory release does not function the same way as tcmalloc does and introduced test flakiness.

Commit Message:
Additional Description:
Risk Level:
Testing: Unit tests
Docs Changes: API docs
Release Notes:
Platform Specific Features:

Signed-off-by: Kateryna Nezdolii <kateryna.nezdolii@gmail.com>
Signed-off-by: Kateryna Nezdolii <kateryna.nezdolii@docker.com>
Co-authored-by: Matt Klein <mattklein123@gmail.com>

Mirrored from https://github.com/envoyproxy/envoy @ 02dc6af0bd66af3105bb47919ee67102b6611feb

envoy/config/bootstrap/v3/bootstrap.proto

@@ -41,7 +41,7 @@ option (udpa.annotations.file_status).package_version_status = ACTIVE;
 // <config_overview_bootstrap>` for more detail.
 
 // Bootstrap :ref:`configuration overview <config_overview_bootstrap>`.
-// [#next-free-field: 41]
+// [#next-free-field: 42]
 message Bootstrap {
   option (udpa.annotations.versioning).previous_message_type =
       "envoy.config.bootstrap.v2.Bootstrap";
@@ -411,6 +411,10 @@ message Bootstrap {
 
   // Optional gRPC async manager config.
   GrpcAsyncClientManagerConfig grpc_async_client_manager_config = 40;
+
+  // Optional configuration for memory allocation manager.
+  // Memory releasing is only supported for `tcmalloc allocator <https://github.com/google/tcmalloc>`_.
+  MemoryAllocatorManager memory_allocator_manager = 41;
 }
 
 // Administration interface :ref:`operations documentation
@@ -734,3 +738,14 @@ message CustomInlineHeader {
   // The type of the header that is expected to be set as the inline header.
   InlineHeaderType inline_header_type = 2 [(validate.rules).enum = {defined_only: true}];
 }
+
+message MemoryAllocatorManager {
+  // Configures tcmalloc to perform background release of free memory in amount of bytes per ``memory_release_interval`` interval.
+  // If equals to ``0``, no memory release will occur. Defaults to ``0``.
+  uint64 bytes_to_release = 1;
+
+  // Interval in milliseconds for memory releasing. If specified, during every
+  // interval Envoy will try to release ``bytes_to_release`` of free memory back to operating system for reuse.
+  // Defaults to 1000 milliseconds.
+  google.protobuf.Duration memory_release_interval = 2;
+}