From 8a571d88d8d7a3280cc0f85c20d0ba8fe7919128 Mon Sep 17 00:00:00 2001
From: Lin Huang <lin.huang@eosnetwork.com>
Date: Fri, 8 Sep 2023 09:17:33 -0400
Subject: [PATCH 1/2] Increase maximum allowed number of read-only threads to
 128

---
 plugins/producer_plugin/producer_plugin.cpp |  4 +---
 tests/CMakeLists.txt                        |  4 ++--
 tests/read_only_trx_test.py                 | 12 +++++++-----
 3 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/plugins/producer_plugin/producer_plugin.cpp b/plugins/producer_plugin/producer_plugin.cpp
index c8db42b9fe..dbebf6dff6 100644
--- a/plugins/producer_plugin/producer_plugin.cpp
+++ b/plugins/producer_plugin/producer_plugin.cpp
@@ -617,9 +617,7 @@ class producer_plugin_impl : public std::enable_shared_from_this<producer_plugin
    };
 
    uint32_t _ro_thread_pool_size{0};
-   // Due to uncertainty to get total virtual memory size on a 5-level paging system for eos-vm-oc and
-   // possible memory exhuastion for large number of contract usage for non-eos-vm-oc, set a hard limit
-   static constexpr uint32_t         _ro_max_threads_allowed{8};
+   static constexpr uint32_t         _ro_max_threads_allowed{128};
    named_thread_pool<struct read>    _ro_thread_pool;
    fc::microseconds                  _ro_write_window_time_us{200000};
    fc::microseconds                  _ro_read_window_time_us{60000};
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 71147aaa34..233824062b 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -133,9 +133,9 @@ add_test(NAME compute_transaction_test COMMAND tests/compute_transaction_test.py
 set_property(TEST compute_transaction_test PROPERTY LABELS nonparallelizable_tests)
 add_test(NAME read-only-trx-basic-test COMMAND tests/read_only_trx_test.py -v -p 2 -n 3 --read-only-threads 0 ${UNSHARE} WORKING_DIRECTORY ${CMAKE_BINARY_DIR})
 set_property(TEST read-only-trx-basic-test PROPERTY LABELS nonparallelizable_tests)
-add_test(NAME read-only-trx-parallel-test COMMAND tests/read_only_trx_test.py -v -p 2 -n 3 --read-only-threads 6 --num-test-runs 3 ${UNSHARE} WORKING_DIRECTORY ${CMAKE_BINARY_DIR})
+add_test(NAME read-only-trx-parallel-test COMMAND tests/read_only_trx_test.py -v -p 2 -n 3 --read-only-threads 128 --num-test-runs 3 ${UNSHARE} WORKING_DIRECTORY ${CMAKE_BINARY_DIR})
 set_property(TEST read-only-trx-parallel-test PROPERTY LABELS nonparallelizable_tests)
-add_test(NAME read-only-trx-parallel-eos-vm-oc-test COMMAND tests/read_only_trx_test.py -v -p 2 -n 3 --eos-vm-oc-enable all --read-only-threads 6 --num-test-runs 3 ${UNSHARE} WORKING_DIRECTORY ${CMAKE_BINARY_DIR})
+add_test(NAME read-only-trx-parallel-eos-vm-oc-test COMMAND tests/read_only_trx_test.py -v -p 2 -n 3 --eos-vm-oc-enable all --read-only-threads 128 --num-test-runs 3 ${UNSHARE} WORKING_DIRECTORY ${CMAKE_BINARY_DIR})
 set_property(TEST read-only-trx-parallel-eos-vm-oc-test PROPERTY LABELS nonparallelizable_tests)
 add_test(NAME read-only-trx-parallel-no-oc-test COMMAND tests/read_only_trx_test.py -v -p 2 -n 3 --eos-vm-oc-enable none --read-only-threads 6 --num-test-runs 2 ${UNSHARE} WORKING_DIRECTORY ${CMAKE_BINARY_DIR})
 set_property(TEST read-only-trx-parallel-no-oc-test PROPERTY LABELS nonparallelizable_tests)
diff --git a/tests/read_only_trx_test.py b/tests/read_only_trx_test.py
index 661c3fded8..91f92a8a0b 100755
--- a/tests/read_only_trx_test.py
+++ b/tests/read_only_trx_test.py
@@ -148,12 +148,14 @@ def verifyOcVirtualMemory():
             pageSize = os.sysconf("SC_PAGESIZE")
             actualVmSize = vmPages * pageSize
 
-            # When OC tierup is enabled, virtual memory used by IC is around
+            # In OC tierup a memory slice is 8GB;
+            # The main thread uses 529 slices; each read-only thread uses 11 slices.
+            # Total virtual memory is around:
             # 529 slices * 8GB (for main thread) + numReadOnlyThreads * 11 slices * 8GB
-            # This test verifies virtual memory taken by one read-only thread
-            # is not in the order of 1TB.
-            otherGB = 1000 # add 1TB for virtual memory used by others
-            expectedVmSize = ((529 * 8) + (args.read_only_threads * 88) + otherGB) * 1024 * 1024 * 1024
+            # This test verifies virtual memory does not grow by the number
+            # of read-only thread in the order of TB.
+            memoryByOthersGB = 1000 # add 1TB for virtual memory used by others
+            expectedVmSize = ((529 * 8) + (args.read_only_threads * 88) + memoryByOthersGB) * 1024 * 1024 * 1024
             Utils.Print(f"pid: {apiNode.pid}, actualVmSize: {actualVmSize}, expectedVmSize: {expectedVmSize}")
             assert(actualVmSize < expectedVmSize)
     except FileNotFoundError:

From 920f325d039c053bddd7ddbac3ed55f151b6d2a1 Mon Sep 17 00:00:00 2001
From: Lin Huang <lin.huang@eosnetwork.com>
Date: Fri, 8 Sep 2023 11:02:30 -0400
Subject: [PATCH 2/2] Add comments explaining why max supported number of
 read-only threads can be increased

---
 plugins/producer_plugin/producer_plugin.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/plugins/producer_plugin/producer_plugin.cpp b/plugins/producer_plugin/producer_plugin.cpp
index dbebf6dff6..bffdf69e4d 100644
--- a/plugins/producer_plugin/producer_plugin.cpp
+++ b/plugins/producer_plugin/producer_plugin.cpp
@@ -617,6 +617,12 @@ class producer_plugin_impl : public std::enable_shared_from_this<producer_plugin
    };
 
    uint32_t _ro_thread_pool_size{0};
+   // In EOS VM OC tierup, 10 pages (11 slices) virtual memory is reserved for
+   // each read-only thread and 528 pages (529 slices) for the main-thread memory.
+   // With maximum 128 read-only threads, virtual memory required by OC is
+   // 15TB (OC's main thread uses 4TB VM (by 529 slices) and the read-only
+   // threads use 11TB (128 * 11 * 8GB)). It is about 11.7% of total VM space
+   // in a 64-bit Linux machine (about 128TB).
    static constexpr uint32_t         _ro_max_threads_allowed{128};
    named_thread_pool<struct read>    _ro_thread_pool;
    fc::microseconds                  _ro_write_window_time_us{200000};