[android, core] pin core threads to logical CPUs 0-3 (#3121)

this basically allows the threads to exist in these logical CPUs, undisturbed, and without trashing each other's cache
this could improve performance, very tricky thing to pull off correctly, but again, this is mostly an experiment
will mainly benefit: Linux, Android, FreeBSD, Windows (not ARM)
Additionally, this means no context trashing :)

Signed-off-by: lizzie <lizzie@eden-emu.dev>

Co-authored-by: Caio Oliveira <caiooliveirafarias0@gmail.com>
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/3121
Reviewed-by: DraVee <dravee@eden-emu.dev>
Reviewed-by: MaranBr <maranbr@eden-emu.dev>
Co-authored-by: lizzie <lizzie@eden-emu.dev>
Co-committed-by: lizzie <lizzie@eden-emu.dev>

1 files changed, 11 insertions, 12 deletions

diff --git a/src/core/cpu_manager.cpp b/src/core/cpu_manager.cpp
index 1a80fcfaa4..10fdcdf8a2 100644
--- a/src/core/cpu_manager.cpp
+++ b/src/core/cpu_manager.cpp
@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 // SPDX-FileCopyrightText: Copyright 2018 yuzu Emulator Project
@@ -7,6 +7,7 @@
 #include "common/fiber.h"
 #include "common/scope_exit.h"
 #include "common/thread.h"
+#include "common/settings.h"
 #include "core/core.h"
 #include "core/core_timing.h"
 #include "core/cpu_manager.h"
@@ -25,11 +26,8 @@ CpuManager::~CpuManager() = default;
 void CpuManager::Initialize() {
     num_cores = is_multicore ? Core::Hardware::NUM_CPU_CORES : 1;
     gpu_barrier = std::make_unique<Common::Barrier>(num_cores + 1);
-
-    for (std::size_t core = 0; core < num_cores; core++) {
-        core_data[core].host_thread =
-            std::jthread([this, core](std::stop_token token) { RunThread(token, core); });
-    }
+    for (std::size_t core = 0; core < num_cores; core++)
+        core_data[core].host_thread = std::jthread([this, core](std::stop_token token) { RunThread(token, core); });
 }
 
 void CpuManager::Shutdown() {
@@ -188,14 +186,15 @@ void CpuManager::ShutdownThread() {
 void CpuManager::RunThread(std::stop_token token, std::size_t core) {
     /// Initialization
     system.RegisterCoreThread(core);
-    std::string name;
-    if (is_multicore) {
-        name = "CPUCore_" + std::to_string(core);
-    } else {
-        name = "CPUThread";
-    }
+    std::string name = is_multicore ? ("CPUCore_" + std::to_string(core)) : std::string{"CPUThread"};
     Common::SetCurrentThreadName(name.c_str());
     Common::SetCurrentThreadPriority(Common::ThreadPriority::Critical);
+#ifdef __ANDROID__
+    // Aimed specifically for Snapdragon 8 Elite devices
+    // This kills performance on desktop, but boosts perf for UMA devices
+    // like the S8E. Mediatek and Mali likely won't suffer.
+    Common::PinCurrentThreadToPerformanceCore(core);
+#endif
     auto& data = core_data[core];
     data.host_context = Common::Fiber::ThreadToFiber();