[*] Attempt to guess UNIX (Linux) CPU topology when missing file systems

Source/HWInfo/AuCpuId.cpp

@@ -17,6 +17,9 @@
 
 namespace Aurora::HWInfo
 {
+    static AuUInt32 gGuessedCores {};
+    static AuUInt32 gGuessedThreads {};
+    
     union CPUIdContext
     {
         struct
@@ -349,9 +352,14 @@ namespace Aurora::HWInfo
         );
     }
 
-    AUKN_SYM const CpuInfo &GetCPUInfo()
+    AuUInt32 GetCPUIDAPICDCores()
     {
-        return gCpuInfo;
+        return gGuessedCores;
+    }
+
+    AuUInt32 GetCPUIDAPICDThreads()
+    {
+        return gGuessedThreads;
     }
 
     void SetCpuId()
@@ -377,13 +385,42 @@ namespace Aurora::HWInfo
         
         gCpuInfo.cpuId.vendor = vendor;
 
+        {
+            auto regs = cpuid(1);
+            gGuessedThreads =  (regs.ebx >> 16) & 0xff;
+        }
+
         if (gCpuInfo.cpuId.vendor == "GenuineIntel")
         {
             gCpuInfo.cpuId.isIntel = true;
+
+            auto regs = cpuid(4);
+            gGuessedCores = ((regs.eax >> 26) & 0x3f) + 1; // DCP cache
+            
+            if (!gGuessedThreads)
+            {
+                gGuessedThreads = gGuessedCores;
+            }
         }
         else if (gCpuInfo.cpuId.vendor == "AuthenticAMD")
         {
             gCpuInfo.cpuId.isAMD = true;
+
+            if (!gGuessedCores)
+            {
+                auto regs = cpuid(0x80000008);
+                gGuessedCores =  (AuUInt32(regs.ecx) & 0xfful) + 1;
+
+                if (!gGuessedThreads)
+                {
+                    gGuessedThreads = gGuessedCores;
+                }
+            }
+        }
+
+        if (!gGuessedCores && gGuessedThreads)
+        {
+            gGuessedThreads = gGuessedCores;
         }
 
         // load bitset with flags for function 0x00000001

Source/HWInfo/AuCpuInfo.Linux.cpp

@@ -16,6 +16,9 @@
 
 namespace Aurora::HWInfo
 {
+    AuUInt32 GetCPUIDAPICDCores();
+    AuUInt32 GetCPUIDAPICDThreads();
+
     static AuUInt32 ReadUInt(const AuString &path)
     {
         AuString contents;
@@ -124,6 +127,74 @@ namespace Aurora::HWInfo
             gCpuInfo.maskAllCores.Add(cpuId);
         }
     }
+    
+    static void SetBasicAPICInformation()
+    {
+        if (gCpuInfo.uCores == 1 ||
+            gCpuInfo.uCores == 0)
+        {
+            gCpuInfo.uCores = GetCPUIDAPICDCores();
+        }
+        
+        if (!gCpuInfo.uThreads)
+        {
+            gCpuInfo.uThreads = GetCPUIDAPICDThreads();
+        }
+        else
+        {
+            return;
+        }
+        
+        if (gCpuInfo.uThreads & 1)
+        {
+            for (AU_ITERATE_N(i, gCpuInfo.uThreads))
+            {
+                auto mask = 1 << i;
+
+                gCpuInfo.maskPCores.SetBit(i);
+
+                gCpuInfo.threadTopology.push_back(mask);
+
+                CpuBitId coreId;
+                coreId.lower = mask;
+                gCpuInfo.coreTopology.push_back(coreId);
+                gCpuInfo.pCoreTopology.push_back(coreId);
+                gCpuInfo.maskAllCores.Add(coreId);
+            }
+            
+            if (gCpuInfo.uCores == 1 ||
+                gCpuInfo.uCores == 0)
+            {
+                gCpuInfo.uCores = gCpuInfo.uThreads;
+            }
+        }
+        else
+        {
+            auto uHalf = gCpuInfo.uThreads / 2;
+            for (AU_ITERATE_N(i, uHalf))
+            {
+                gCpuInfo.maskPCores.SetBit(i);
+                gCpuInfo.maskPCores.SetBit(i + uHalf);
+
+                auto maskA = 1u << i;
+                auto maskB = 1u << (i + uHalf);
+                auto maskC = maskA | maskB;
+
+                gCpuInfo.threadTopology.push_back(maskA);
+                gCpuInfo.threadTopology.push_back(maskB);
+
+                CpuBitId coreId;
+                coreId.lower = maskC;
+                gCpuInfo.coreTopology.push_back(coreId);
+                gCpuInfo.pCoreTopology.push_back(coreId);
+                gCpuInfo.maskAllCores.Add(coreId);
+            }
+
+            gCpuInfo.uCores = gCpuInfo.uThreads / 2;
+
+            gCpuInfo.bMaskMTHalf = true;
+        }
+    }
 
     void SetCpuTopologyLinux()
     {
@@ -131,9 +202,11 @@ namespace Aurora::HWInfo
         SetCpuA();
 
         gCpuInfo.uSocket  = AuMax(gCpuInfo.uSocket, AuUInt8(1));
-        gCpuInfo.uCores   = AuMax(gCpuInfo.uCores, AuUInt8(1));
-        gCpuInfo.uThreads = gCpuInfo.uThreads ?
-                            gCpuInfo.uThreads :
-                            get_nprocs();
+        
+        if (gCpuInfo.uCores == 1 ||
+            gCpuInfo.uCores == 0)
+        {
+            SetBasicAPICInformation();
+        }
     }
 }

Source/HWInfo/AuCpuInfo.NT.cpp

@@ -294,6 +294,8 @@ namespace Aurora::HWInfo
                 gCpuInfo.pCoreTopology.push_back(coreId);
                 gCpuInfo.maskAllCores.Add(coreId);
             }
+
+            gCpuInfo.uCores = gCpuInfo.uThreads;
         }
         else
         {
@@ -322,7 +324,6 @@ namespace Aurora::HWInfo
             }
 
             gCpuInfo.uCores = gCpuInfo.uThreads / 2;
-            gCpuInfo.uThreads = 2;
 
             gCpuInfo.bMaskMTHalf = true;
         }

Source/HWInfo/AuCpuInfo.cpp

@@ -60,4 +60,10 @@ namespace Aurora::HWInfo
         SetCpuTopology();
         SetFakeTopologyIfMissing();
     }
+
+
+    AUKN_SYM const CpuInfo &GetCPUInfo()
+    {
+        return gCpuInfo;
+    }
 }