diff --git a/scripts/core/INTRO.rst b/scripts/core/INTRO.rst
index 448e3569e2..898d4ce5f3 100644
--- a/scripts/core/INTRO.rst
+++ b/scripts/core/INTRO.rst
@@ -396,6 +396,14 @@ Specific environment variables can be set to control the behavior of unified run
 
     See the Layers_ section for details of the layers currently included in the runtime.
 
+.. envvar:: UR_LOADER_PRELOAD_FILTER
+
+    If set, the loader will read `ONEAPI_DEVICE_SELECTOR` before loading the UR Adapters to determine which backends should be loaded.
+
+    .. note::
+
+    This environment variable is default enabled on Linux, but default disabled on Windows.
+
 Service identifiers
 ---------------------
 
diff --git a/source/adapters/level_zero/context.cpp b/source/adapters/level_zero/context.cpp
index 22adfa96ed..041f088d04 100644
--- a/source/adapters/level_zero/context.cpp
+++ b/source/adapters/level_zero/context.cpp
@@ -769,9 +769,11 @@ ur_result_t ur_context_handle_t_::getAvailableCommandList(
         CommandList =
             Queue->CommandListMap
                 .emplace(ZeCommandList,
-                         ur_command_list_info_t(ZeFence, true, false,
-                                                ZeCommandQueue, ZeQueueDesc,
-                                                Queue->useCompletionBatching()))
+                         ur_command_list_info_t(
+                             ZeFence, true, false, ZeCommandQueue, ZeQueueDesc,
+                             Queue->useCompletionBatching(), true,
+                             ZeCommandListIt->second.InOrderList,
+                             ZeCommandListIt->second.IsImmediate))
                 .first;
       }
       ZeCommandListCache.erase(ZeCommandListIt);
diff --git a/source/loader/CMakeLists.txt b/source/loader/CMakeLists.txt
index 5b5cfea201..3d533a8f3d 100644
--- a/source/loader/CMakeLists.txt
+++ b/source/loader/CMakeLists.txt
@@ -165,6 +165,26 @@ if(UR_ENABLE_SANITIZER)
         )
         target_include_directories(ur_loader PRIVATE ${LLVM_INCLUDE_DIRS})
         target_link_libraries(ur_loader PRIVATE LLVMSupport LLVMSymbolize)
+        # In in-tree build, if LLVM is built with libc++, we also need to build
+        # symbolizer.cpp with libc++ abi and link libc++ in.
+        if(NOT UR_STANDALONE_BUILD AND LLVM_LIBCXX_USED)
+            execute_process(
+                COMMAND ${CMAKE_CXX_COMPILER} --print-file-name=libc++.a
+                OUTPUT_VARIABLE LIBCXX_PATH
+                OUTPUT_STRIP_TRAILING_WHITESPACE)
+            execute_process(
+                COMMAND ${CMAKE_CXX_COMPILER} --print-file-name=libc++abi.a
+                OUTPUT_VARIABLE LIBCXX_ABI_PATH
+                OUTPUT_STRIP_TRAILING_WHITESPACE)
+            set_property(SOURCE
+                ${CMAKE_CURRENT_SOURCE_DIR}/layers/sanitizer/linux/symbolizer.cpp
+                APPEND_STRING PROPERTY COMPILE_FLAGS
+                " -stdlib=libc++ ")
+            if(NOT EXISTS ${LIBCXX_PATH} OR NOT EXISTS ${LIBCXX_ABI_PATH})
+                message(FATAL_ERROR "libc++ is required but can't find the libraries")
+            endif()
+            target_link_libraries(ur_loader PRIVATE ${LIBCXX_PATH} ${LIBCXX_ABI_PATH})
+        endif()
     endif()
 
     target_include_directories(ur_loader PRIVATE
diff --git a/source/loader/layers/sanitizer/linux/symbolizer.cpp b/source/loader/layers/sanitizer/linux/symbolizer.cpp
index 5dd120e1f0..bcc90738f2 100644
--- a/source/loader/layers/sanitizer/linux/symbolizer.cpp
+++ b/source/loader/layers/sanitizer/linux/symbolizer.cpp
@@ -31,8 +31,9 @@ llvm::symbolize::PrinterConfig GetPrinterConfig() {
 
 extern "C" {
 
-bool SymbolizeCode(const std::string ModuleName, uint64_t ModuleOffset,
-                   std::string &Result) {
+void SymbolizeCode(const char *ModuleName, uint64_t ModuleOffset,
+                   char *ResultString, size_t ResultSize, size_t *RetSize) {
+    std::string Result;
     llvm::raw_string_ostream OS(Result);
     llvm::symbolize::Request Request{ModuleName, ModuleOffset};
     llvm::symbolize::PrinterConfig Config =
@@ -51,10 +52,16 @@ bool SymbolizeCode(const std::string ModuleName, uint64_t ModuleOffset,
         {ModuleOffset, llvm::object::SectionedAddress::UndefSection});
 
     if (!ResOrErr) {
-        return false;
+        return;
     }
     Printer->print(Request, *ResOrErr);
     ur_sanitizer_layer::GetSymbolizer()->pruneCache();
-    return true;
+    if (RetSize) {
+        *RetSize = Result.size() + 1;
+    }
+    if (ResultString) {
+        std::strncpy(ResultString, Result.c_str(), ResultSize);
+        ResultString[ResultSize - 1] = '\0';
+    }
 }
 }
diff --git a/source/loader/layers/sanitizer/stacktrace.cpp b/source/loader/layers/sanitizer/stacktrace.cpp
index e33fcf0416..38bef94811 100644
--- a/source/loader/layers/sanitizer/stacktrace.cpp
+++ b/source/loader/layers/sanitizer/stacktrace.cpp
@@ -15,9 +15,10 @@
 
 extern "C" {
 
-__attribute__((weak)) bool SymbolizeCode(const std::string ModuleName,
+__attribute__((weak)) void SymbolizeCode(const char *ModuleName,
                                          uint64_t ModuleOffset,
-                                         std::string &Result);
+                                         char *ResultString, size_t ResultSize,
+                                         size_t *RetSize);
 }
 
 namespace ur_sanitizer_layer {
@@ -49,7 +50,7 @@ void ParseBacktraceInfo(BacktraceInfo BI, std::string &ModuleName,
 // Parse symbolizer output in the following formats:
 //   <function_name>
 //   <file_name>:<line_number>[:<column_number>]
-SourceInfo ParseSymbolizerOutput(std::string Output) {
+SourceInfo ParseSymbolizerOutput(const std::string &Output) {
     SourceInfo Info;
     // Parse function name
     size_t End = Output.find_first_of('\n');
@@ -98,8 +99,14 @@ void StackTrace::print() const {
             std::string ModuleName;
             uptr Offset;
             ParseBacktraceInfo(BI, ModuleName, Offset);
-            if (SymbolizeCode(ModuleName, Offset, Result)) {
-                SourceInfo SrcInfo = ParseSymbolizerOutput(std::move(Result));
+            size_t ResultSize = 0;
+            SymbolizeCode(ModuleName.c_str(), Offset, nullptr, 0, &ResultSize);
+            if (ResultSize) {
+                std::vector<char> ResultVector(ResultSize);
+                SymbolizeCode(ModuleName.c_str(), Offset, ResultVector.data(),
+                              ResultSize, nullptr);
+                std::string Result((char *)ResultVector.data());
+                SourceInfo SrcInfo = ParseSymbolizerOutput(Result);
                 if (SrcInfo.file != "??") {
                     getContext()->logger.always(" #{} in {} {}:{}:{}", index,
                                                 SrcInfo.function, SrcInfo.file,
@@ -109,10 +116,10 @@ void StackTrace::print() const {
                                                 SrcInfo.function, ModuleName,
                                                 (void *)Offset);
                 }
-                continue;
             }
+        } else {
+            getContext()->logger.always("  #{} {}", index, BI);
         }
-        getContext()->logger.always("  #{} {}", index, BI);
         ++index;
     }
     getContext()->logger.always("");
diff --git a/source/loader/ur_adapter_registry.hpp b/source/loader/ur_adapter_registry.hpp
index 25cd9a9fff..ff07eca100 100644
--- a/source/loader/ur_adapter_registry.hpp
+++ b/source/loader/ur_adapter_registry.hpp
@@ -152,10 +152,123 @@ class AdapterRegistry {
         return paths.empty() ? std::nullopt : std::optional(paths);
     }
 
+    ur_result_t readPreFilterODS(std::string platformBackendName) {
+        // TODO: Refactor this to the common code such that both the prefilter and urDeviceGetSelected use the same functionality.
+        bool acceptLibrary = true;
+        std::optional<EnvVarMap> odsEnvMap;
+        try {
+            odsEnvMap = getenv_to_map("ONEAPI_DEVICE_SELECTOR", false);
+
+        } catch (...) {
+            // If the selector is malformed, then we ignore selector and return success.
+            logger::error("ERROR: missing backend, format of filter = "
+                          "'[!]backend:filterStrings'");
+            return UR_RESULT_SUCCESS;
+        }
+        logger::debug(
+            "getenv_to_map parsed env var and {} a map",
+            (odsEnvMap.has_value() ? "produced" : "failed to produce"));
+
+        // if the ODS env var is not set at all, then pretend it was set to the default
+        using EnvVarMap = std::map<std::string, std::vector<std::string>>;
+        EnvVarMap mapODS =
+            odsEnvMap.has_value() ? odsEnvMap.value() : EnvVarMap{{"*", {"*"}}};
+        for (auto &termPair : mapODS) {
+            std::string backend = termPair.first;
+            // TODO: Figure out how to process all ODS errors rather than returning
+            // on the first error.
+            if (backend.empty()) {
+                // FIXME: never true because getenv_to_map rejects this case
+                // malformed term: missing backend -- output ERROR, then continue
+                logger::error("ERROR: missing backend, format of filter = "
+                              "'[!]backend:filterStrings'");
+                continue;
+            }
+            logger::debug("ONEAPI_DEVICE_SELECTOR Pre-Filter with backend '{}' "
+                          "and platform library name '{}'",
+                          backend, platformBackendName);
+            enum FilterType {
+                AcceptFilter,
+                DiscardFilter,
+            } termType =
+                (backend.front() != '!') ? AcceptFilter : DiscardFilter;
+            logger::debug(
+                "termType is {}",
+                (termType != AcceptFilter ? "DiscardFilter" : "AcceptFilter"));
+            if (termType != AcceptFilter) {
+                logger::debug("DEBUG: backend was '{}'", backend);
+                backend.erase(backend.cbegin());
+                logger::debug("DEBUG: backend now '{}'", backend);
+            }
+
+            // Verify that the backend string is valid, otherwise ignore the backend.
+            if ((strcmp(backend.c_str(), "*") != 0) &&
+                (strcmp(backend.c_str(), "level_zero") != 0) &&
+                (strcmp(backend.c_str(), "opencl") != 0) &&
+                (strcmp(backend.c_str(), "cuda") != 0) &&
+                (strcmp(backend.c_str(), "hip") != 0)) {
+                logger::debug("ONEAPI_DEVICE_SELECTOR Pre-Filter with illegal "
+                              "backend '{}' ",
+                              backend);
+                continue;
+            }
+
+            // case-insensitive comparison by converting both tolower
+            std::transform(platformBackendName.begin(),
+                           platformBackendName.end(),
+                           platformBackendName.begin(),
+                           [](unsigned char c) { return std::tolower(c); });
+            std::transform(backend.begin(), backend.end(), backend.begin(),
+                           [](unsigned char c) { return std::tolower(c); });
+            std::size_t nameFound = platformBackendName.find(backend);
+
+            bool backendFound = nameFound != std::string::npos;
+            if (termType == AcceptFilter) {
+                if (backend.front() != '*' && !backendFound) {
+                    logger::debug(
+                        "The ONEAPI_DEVICE_SELECTOR backend name '{}' was not "
+                        "found in the platform library name '{}'",
+                        backend, platformBackendName);
+                    acceptLibrary = false;
+                    continue;
+                } else if (backend.front() == '*' || backendFound) {
+                    return UR_RESULT_SUCCESS;
+                }
+            } else {
+                if (backendFound || backend.front() == '*') {
+                    acceptLibrary = false;
+                    logger::debug(
+                        "The ONEAPI_DEVICE_SELECTOR backend name for discard "
+                        "'{}' was found in the platform library name '{}'",
+                        backend, platformBackendName);
+                    continue;
+                }
+            }
+        }
+        if (acceptLibrary) {
+            return UR_RESULT_SUCCESS;
+        }
+        return UR_RESULT_ERROR_INVALID_VALUE;
+    }
+
     void discoverKnownAdapters() {
         auto searchPathsEnvOpt = getEnvAdapterSearchPaths();
         auto loaderLibPathOpt = getLoaderLibPath();
+#if defined(_WIN32)
+        bool loaderPreFilter = getenv_tobool("UR_LOADER_PRELOAD_FILTER", false);
+#else
+        bool loaderPreFilter = getenv_tobool("UR_LOADER_PRELOAD_FILTER", true);
+#endif
         for (const auto &adapterName : knownAdapterNames) {
+
+            if (loaderPreFilter) {
+                if (readPreFilterODS(adapterName) != UR_RESULT_SUCCESS) {
+                    logger::debug("The adapter '{}' was removed based on the "
+                                  "pre-filter from ONEAPI_DEVICE_SELECTOR.",
+                                  adapterName);
+                    continue;
+                }
+            }
             std::vector<fs::path> loadPaths;
 
             // Adapter search order:
diff --git a/test/loader/adapter_registry/CMakeLists.txt b/test/loader/adapter_registry/CMakeLists.txt
index 2778ad5c40..6d80430e6c 100644
--- a/test/loader/adapter_registry/CMakeLists.txt
+++ b/test/loader/adapter_registry/CMakeLists.txt
@@ -51,3 +51,7 @@ add_adapter_reg_search_test(search-order
     SEARCH_PATH ${TEST_SEARCH_PATH}
     ENVS "TEST_ADAPTER_SEARCH_PATH=\"${TEST_SEARCH_PATH}\"" "TEST_CUR_SEARCH_PATH=\"${TEST_BIN_PATH}\""
     SOURCES search_order.cpp)
+
+add_adapter_reg_search_test(prefilter
+    SEARCH_PATH ""
+    SOURCES prefilter.cpp)
diff --git a/test/loader/adapter_registry/fixtures.hpp b/test/loader/adapter_registry/fixtures.hpp
index 79a831d40f..da5c963e8a 100644
--- a/test/loader/adapter_registry/fixtures.hpp
+++ b/test/loader/adapter_registry/fixtures.hpp
@@ -74,5 +74,49 @@ struct adapterRegSearchTest : ::testing::Test {
         }
     }
 };
+#ifndef _WIN32
+struct adapterPreFilterTest : ::testing::Test {
+    ur_loader::AdapterRegistry *registry;
+    const fs::path levelzeroLibName =
+        MAKE_LIBRARY_NAME("ur_adapter_level_zero", "0");
+    std::function<bool(const fs::path &)> islevelzeroLibName =
+        [this](const fs::path &path) { return path == levelzeroLibName; };
+
+    std::function<bool(const std::vector<fs::path> &)> haslevelzeroLibName =
+        [this](const std::vector<fs::path> &paths) {
+            return std::any_of(paths.cbegin(), paths.cend(),
+                               islevelzeroLibName);
+        };
+
+    const fs::path openclLibName = MAKE_LIBRARY_NAME("ur_adapter_opencl", "0");
+    std::function<bool(const fs::path &)> isOpenclLibName =
+        [this](const fs::path &path) { return path == openclLibName; };
+
+    std::function<bool(const std::vector<fs::path> &)> hasOpenclLibName =
+        [this](const std::vector<fs::path> &paths) {
+            return std::any_of(paths.cbegin(), paths.cend(), isOpenclLibName);
+        };
+
+    const fs::path cudaLibName = MAKE_LIBRARY_NAME("ur_adapter_cuda", "0");
+    std::function<bool(const fs::path &)> isCudaLibName =
+        [this](const fs::path &path) { return path == cudaLibName; };
+
+    std::function<bool(const std::vector<fs::path> &)> hasCudaLibName =
+        [this](const std::vector<fs::path> &paths) {
+            return std::any_of(paths.cbegin(), paths.cend(), isCudaLibName);
+        };
+
+    void SetUp(std::string filter) {
+        try {
+            setenv("ONEAPI_DEVICE_SELECTOR", filter.c_str(), 1);
+            registry = new ur_loader::AdapterRegistry;
+        } catch (const std::invalid_argument &e) {
+            FAIL() << e.what();
+        }
+    }
+    void SetUp() override {}
+    void TearDown() override { delete registry; }
+};
+#endif
 
 #endif // UR_ADAPTER_REG_TEST_HELPERS_H
diff --git a/test/loader/adapter_registry/prefilter.cpp b/test/loader/adapter_registry/prefilter.cpp
new file mode 100644
index 0000000000..1d2b095da3
--- /dev/null
+++ b/test/loader/adapter_registry/prefilter.cpp
@@ -0,0 +1,140 @@
+// Copyright (C) 2024 Intel Corporation
+// Part of the Unified-Runtime Project, under the Apache License v2.0 with LLVM Exceptions.
+// See LICENSE.TXT
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+#include "fixtures.hpp"
+
+#ifndef _WIN32
+
+TEST_F(adapterPreFilterTest, testPrefilterAcceptFilterSingleBackend) {
+    SetUp("level_zero:*");
+    auto levelZeroExists =
+        std::any_of(registry->cbegin(), registry->cend(), haslevelzeroLibName);
+    EXPECT_TRUE(levelZeroExists);
+    auto openclExists =
+        std::any_of(registry->cbegin(), registry->cend(), hasOpenclLibName);
+    EXPECT_FALSE(openclExists);
+    auto cudaExists =
+        std::any_of(registry->cbegin(), registry->cend(), hasCudaLibName);
+    EXPECT_FALSE(cudaExists);
+}
+
+TEST_F(adapterPreFilterTest, testPrefilterAcceptFilterMultipleBackends) {
+    SetUp("level_zero:*;opencl:*");
+    auto levelZeroExists =
+        std::any_of(registry->cbegin(), registry->cend(), haslevelzeroLibName);
+    EXPECT_TRUE(levelZeroExists);
+    auto openclExists =
+        std::any_of(registry->cbegin(), registry->cend(), hasOpenclLibName);
+    EXPECT_TRUE(openclExists);
+    auto cudaExists =
+        std::any_of(registry->cbegin(), registry->cend(), hasCudaLibName);
+    EXPECT_FALSE(cudaExists);
+}
+
+TEST_F(adapterPreFilterTest, testPrefilterDiscardFilterSingleBackend) {
+    SetUp("!level_zero:*");
+    auto levelZeroExists =
+        std::any_of(registry->cbegin(), registry->cend(), haslevelzeroLibName);
+    EXPECT_FALSE(levelZeroExists);
+    auto openclExists =
+        std::any_of(registry->cbegin(), registry->cend(), hasOpenclLibName);
+    EXPECT_TRUE(openclExists);
+    auto cudaExists =
+        std::any_of(registry->cbegin(), registry->cend(), hasCudaLibName);
+    EXPECT_TRUE(cudaExists);
+}
+
+TEST_F(adapterPreFilterTest, testPrefilterDiscardFilterMultipleBackends) {
+    SetUp("!level_zero:*;!cuda:*");
+    auto levelZeroExists =
+        std::any_of(registry->cbegin(), registry->cend(), haslevelzeroLibName);
+    EXPECT_FALSE(levelZeroExists);
+    auto openclExists =
+        std::any_of(registry->cbegin(), registry->cend(), hasOpenclLibName);
+    EXPECT_TRUE(openclExists);
+    auto cudaExists =
+        std::any_of(registry->cbegin(), registry->cend(), hasCudaLibName);
+    EXPECT_FALSE(cudaExists);
+}
+
+TEST_F(adapterPreFilterTest, testPrefilterAcceptAndDiscardFilter) {
+    SetUp("!cuda:*;level_zero:*");
+    auto levelZeroExists =
+        std::any_of(registry->cbegin(), registry->cend(), haslevelzeroLibName);
+    EXPECT_TRUE(levelZeroExists);
+    auto openclExists =
+        std::any_of(registry->cbegin(), registry->cend(), hasOpenclLibName);
+    EXPECT_FALSE(openclExists);
+    auto cudaExists =
+        std::any_of(registry->cbegin(), registry->cend(), hasCudaLibName);
+    EXPECT_FALSE(cudaExists);
+}
+
+TEST_F(adapterPreFilterTest, testPrefilterDiscardFilterAll) {
+    SetUp("*");
+    auto levelZeroExists =
+        std::any_of(registry->cbegin(), registry->cend(), haslevelzeroLibName);
+    EXPECT_TRUE(levelZeroExists);
+    auto openclExists =
+        std::any_of(registry->cbegin(), registry->cend(), hasOpenclLibName);
+    EXPECT_TRUE(openclExists);
+    auto cudaExists =
+        std::any_of(registry->cbegin(), registry->cend(), hasCudaLibName);
+    EXPECT_TRUE(cudaExists);
+}
+
+TEST_F(adapterPreFilterTest, testPrefilterWithInvalidMissingBackend) {
+    SetUp(":garbage");
+    auto levelZeroExists =
+        std::any_of(registry->cbegin(), registry->cend(), haslevelzeroLibName);
+    EXPECT_TRUE(levelZeroExists);
+    auto openclExists =
+        std::any_of(registry->cbegin(), registry->cend(), hasOpenclLibName);
+    EXPECT_TRUE(openclExists);
+    auto cudaExists =
+        std::any_of(registry->cbegin(), registry->cend(), hasCudaLibName);
+    EXPECT_TRUE(cudaExists);
+}
+
+TEST_F(adapterPreFilterTest, testPrefilterWithInvalidBackend) {
+    SetUp("garbage:0");
+    auto levelZeroExists =
+        std::any_of(registry->cbegin(), registry->cend(), haslevelzeroLibName);
+    EXPECT_TRUE(levelZeroExists);
+    auto openclExists =
+        std::any_of(registry->cbegin(), registry->cend(), hasOpenclLibName);
+    EXPECT_TRUE(openclExists);
+    auto cudaExists =
+        std::any_of(registry->cbegin(), registry->cend(), hasCudaLibName);
+    EXPECT_TRUE(cudaExists);
+}
+
+TEST_F(adapterPreFilterTest, testPrefilterWithNotAllAndAcceptFilter) {
+    SetUp("!*;level_zero");
+    auto levelZeroExists =
+        std::any_of(registry->cbegin(), registry->cend(), haslevelzeroLibName);
+    EXPECT_TRUE(levelZeroExists);
+    auto openclExists =
+        std::any_of(registry->cbegin(), registry->cend(), hasOpenclLibName);
+    EXPECT_FALSE(openclExists);
+    auto cudaExists =
+        std::any_of(registry->cbegin(), registry->cend(), hasCudaLibName);
+    EXPECT_FALSE(cudaExists);
+}
+
+TEST_F(adapterPreFilterTest, testPrefilterWithNotAllFilter) {
+    SetUp("!*");
+    auto levelZeroExists =
+        std::any_of(registry->cbegin(), registry->cend(), haslevelzeroLibName);
+    EXPECT_FALSE(levelZeroExists);
+    auto openclExists =
+        std::any_of(registry->cbegin(), registry->cend(), hasOpenclLibName);
+    EXPECT_FALSE(openclExists);
+    auto cudaExists =
+        std::any_of(registry->cbegin(), registry->cend(), hasCudaLibName);
+    EXPECT_FALSE(cudaExists);
+}
+
+#endif