System: Check host page size on startup

src/util/platform_misc.h

@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: 2019-2022 Connor McLaughlin <stenzek@gmail.com>
+// SPDX-FileCopyrightText: 2019-2024 Connor McLaughlin <stenzek@gmail.com>
 // SPDX-License-Identifier: (GPL-3.0 OR CC-BY-NC-ND-4.0)
 
 #include "window_info.h"
@@ -9,6 +9,12 @@ namespace PlatformMisc {
 void SuspendScreensaver();
 void ResumeScreensaver();
 
+/// Returns the size of pages for the current host.
+size_t GetRuntimePageSize();
+
+/// Returns the size of a cache line for the current host.
+size_t GetRuntimeCacheLineSize();
+
 /// Abstracts platform-specific code for asynchronously playing a sound.
 /// On Windows, this will use PlaySound(). On Linux, it will shell out to aplay. On MacOS, it uses NSSound.
 bool PlaySoundAsync(const char* path);

src/util/platform_misc_mac.mm

@@ -1,17 +1,19 @@
-// SPDX-FileCopyrightText: 2019-2022 Connor McLaughlin <stenzek@gmail.com>
+// SPDX-FileCopyrightText: 2019-2024 Connor McLaughlin <stenzek@gmail.com>
 // SPDX-License-Identifier: (GPL-3.0 OR CC-BY-NC-ND-4.0)
 
+#include "metal_layer.h"
 #include "platform_misc.h"
 #include "window_info.h"
-#include "metal_layer.h"
 
 #include "common/log.h"
 #include "common/small_string.h"
 
-#include <IOKit/pwr_mgt/IOPMLib.h>
 #include <Cocoa/Cocoa.h>
+#include <IOKit/pwr_mgt/IOPMLib.h>
 #include <QuartzCore/QuartzCore.h>
 #include <cinttypes>
+#include <optional>
+#include <sys/sysctl.h>
 #include <vector>
 
 Log_SetChannel(PlatformMisc);
@@ -50,11 +52,11 @@ void PlatformMisc::SuspendScreensaver()
 {
   if (s_screensaver_suspended)
 
-  if (!SetScreensaverInhibitMacOS(true))
-  {
-    Log_ErrorPrintf("Failed to suspend screensaver.");
-    return;
-  }
+    if (!SetScreensaverInhibitMacOS(true))
+    {
+      Log_ErrorPrintf("Failed to suspend screensaver.");
+      return;
+    }
 
   s_screensaver_suspended = true;
 }
@@ -70,6 +72,27 @@ void PlatformMisc::ResumeScreensaver()
   s_screensaver_suspended = false;
 }
 
+template<typename T>
+static std::optional<T> sysctlbyname(const char* name)
+{
+  T output = 0;
+  size_t output_size = sizeof(output);
+  if (sysctlbyname(name, &output, &output_size, nullptr, 0) != 0)
+    return std::nullopt;
+
+  return output;
+}
+
+size_t PlatformMisc::GetRuntimePageSize()
+{
+  return sysctlbyname<u32>("hw.pagesize").value_or(0);
+}
+
+size_t PlatformMisc::GetRuntimeCacheLineSize()
+{
+  return static_cast<size_t>(std::max<s64>(sysctlbyname<s64>("hw.cachelinesize").value_or(0), 0));
+}
+
 bool PlatformMisc::PlaySoundAsync(const char* path)
 {
   NSString* nspath = [[NSString alloc] initWithUTF8String:path];
@@ -80,46 +103,44 @@ bool PlatformMisc::PlaySoundAsync(const char* path)
   return result;
 }
 
-bool CocoaTools::CreateMetalLayer(WindowInfo *wi)
+bool CocoaTools::CreateMetalLayer(WindowInfo* wi)
 {
   // Punt off to main thread if we're not calling from it already.
   if (![NSThread isMainThread])
   {
     bool ret;
-    dispatch_sync(dispatch_get_main_queue(), [&ret, wi]() {
-      ret = CreateMetalLayer(wi);
-    });
+    dispatch_sync(dispatch_get_main_queue(), [&ret, wi]() { ret = CreateMetalLayer(wi); });
     return ret;
   }
-  
+
   CAMetalLayer* layer = [CAMetalLayer layer];
   if (layer == nil)
   {
     Log_ErrorPrint("Failed to create CAMetalLayer");
     return false;
   }
-  
+
   NSView* view = (__bridge NSView*)wi->window_handle;
   [view setWantsLayer:TRUE];
   [view setLayer:layer];
   [layer setContentsScale:[[[view window] screen] backingScaleFactor]];
-  
+
   wi->surface_handle = (__bridge void*)layer;
   return true;
 }
 
-void CocoaTools::DestroyMetalLayer(WindowInfo *wi)
+void CocoaTools::DestroyMetalLayer(WindowInfo* wi)
 {
   if (!wi->surface_handle)
     return;
-  
+
   // Punt off to main thread if we're not calling from it already.
   if (![NSThread isMainThread])
   {
     dispatch_sync(dispatch_get_main_queue(), [wi]() { DestroyMetalLayer(wi); });
     return;
   }
-  
+
   NSView* view = (__bridge NSView*)wi->window_handle;
   CAMetalLayer* layer = (__bridge CAMetalLayer*)wi->surface_handle;
   [view setLayer:nil];

src/util/platform_misc_unix.cpp

@@ -121,6 +121,34 @@ void PlatformMisc::ResumeScreensaver()
   s_screensaver_suspended = false;
 }
 
+size_t PlatformMisc::GetRuntimePageSize()
+{
+  int res = sysconf(_SC_PAGESIZE);
+  return (res > 0) ? static_cast<size_t>(res) : 0;
+}
+
+size_t PlatformMisc::GetRuntimeCacheLineSize()
+{
+  int l1i = sysconf(_SC_LEVEL1_DCACHE_LINESIZE);
+  int l1d = sysconf(_SC_LEVEL1_ICACHE_LINESIZE);
+  int res = (l1i > l1d) ? l1i : l1d;
+  for (int index = 0; index < 16; index++)
+  {
+    char buf[128];
+    snprintf(buf, sizeof(buf), "/sys/devices/system/cpu/cpu0/cache/index%d/coherency_line_size", index);
+    std::FILE* fp = std::fopen(buf, "rb");
+    if (!fp)
+      break;
+
+    std::fread(buf, sizeof(buf), 1, fp);
+    std::fclose(fp);
+    int val = std::atoi(buf);
+    res = (val > res) ? val : res;
+  }
+
+  return (res > 0) ? static_cast<size_t>(res) : 0;
+}
+
 bool PlatformMisc::PlaySoundAsync(const char* path)
 {
 #ifdef __linux__

src/util/platform_misc_win32.cpp

@@ -8,7 +8,9 @@
 #include "common/small_string.h"
 #include "common/string_util.h"
 
+#include <algorithm>
 #include <cinttypes>
+#include <memory>
 
 #include "common/windows_headers.h"
 #include <mmsystem.h>
@@ -53,6 +55,35 @@ void PlatformMisc::ResumeScreensaver()
   s_screensaver_suspended = false;
 }
 
+size_t PlatformMisc::GetRuntimePageSize()
+{
+  SYSTEM_INFO si = {};
+  GetSystemInfo(&si);
+  return si.dwPageSize;
+}
+
+size_t PlatformMisc::GetRuntimeCacheLineSize()
+{
+  DWORD size = 0;
+  if (!GetLogicalProcessorInformation(nullptr, &size) && GetLastError() != ERROR_INSUFFICIENT_BUFFER)
+    return 0;
+
+  std::unique_ptr<SYSTEM_LOGICAL_PROCESSOR_INFORMATION[]> lpi =
+    std::make_unique<SYSTEM_LOGICAL_PROCESSOR_INFORMATION[]>(
+      (size + (sizeof(SYSTEM_LOGICAL_PROCESSOR_INFORMATION) - 1)) / sizeof(SYSTEM_LOGICAL_PROCESSOR_INFORMATION));
+  if (!GetLogicalProcessorInformation(lpi.get(), &size))
+    return 0;
+
+  u32 max_line_size = 0;
+  for (u32 i = 0; i < size / sizeof(SYSTEM_LOGICAL_PROCESSOR_INFORMATION); i++)
+  {
+    if (lpi[i].Relationship == RelationCache)
+      max_line_size = std::max<u32>(max_line_size, lpi[i].Cache.LineSize);
+  }
+
+  return max_line_size;
+}
+
 bool PlatformMisc::PlaySoundAsync(const char* path)
 {
   const std::wstring wpath(FileSystem::GetWin32Path(path));