Merge pull request #1343 from siliceum/fix/better-tracefs-detection

Better tracefs detection

Author: wolfpld

public/client/TracySysTrace.cpp

@@ -558,14 +558,27 @@ static char* GetTraceFsPath()
     char* ret = nullptr;
     while( auto ent = getmntent( f ) )
     {
-        if( strcmp( ent->mnt_fsname, "tracefs" ) == 0 )
+        if( strcmp( ent->mnt_type, "tracefs" ) == 0 )
         {
             auto len = strlen( ent->mnt_dir );
-            ret = (char*)tracy_malloc( len + 1 );
+            // ret may be != nullptr if we already saw a debugfs entry
+            ret = (char*)tracy_realloc( ret, len + 1 );
             memcpy( ret, ent->mnt_dir, len );
             ret[len] = '\0';
             break;
         }
+        else if( !ret && strcmp( ent->mnt_type, "debugfs" ) == 0 )
+        {
+            const char* tracingDirName = "tracing";
+            const size_t tracingDirNameLen = strlen( tracingDirName );
+            auto debugFsPathLen = strlen( ent->mnt_dir );
+            ret = (char*)tracy_malloc( debugFsPathLen + 1 + tracingDirNameLen + 1 );
+            memcpy( ret, ent->mnt_dir, debugFsPathLen );
+            ret[debugFsPathLen] = '/';
+            memcpy( ret + debugFsPathLen + 1, tracingDirName, tracingDirNameLen );
+            ret[debugFsPathLen + 1 + tracingDirNameLen] = '\0';
+            // Don't break to allow for tracefs to be found later as it is the preferred path
+        }
     }
     endmntent( f );
     return ret;
@@ -578,15 +591,21 @@ bool SysTraceStart( int64_t& samplingPeriod )
 #endif
 
     const auto paranoidLevelStr = ReadFile( "/proc/sys/kernel/perf_event_paranoid" );
-    if( !paranoidLevelStr ) return false;
-#ifdef TRACY_VERBOSE
-    int paranoidLevel = 2;
-    paranoidLevel = atoi( paranoidLevelStr );
+    if( !paranoidLevelStr )
+    {
+        TracyDebug( "Failed to read perf_event_paranoid, cannot setup system tracing." );
+        return false;
+    }
+
+    const int paranoidLevel = atoi( paranoidLevelStr );
     TracyDebug( "perf_event_paranoid: %i", paranoidLevel );
-#endif
 
     auto traceFsPath = GetTraceFsPath();
-    if( !traceFsPath ) return false;
+    if( !traceFsPath )
+    {
+        TracyDebug( "Failed to get tracefs path, cannot setup system tracing." );
+        return false;
+    }
     TracyDebug( "tracefs path: %s", traceFsPath );
 
     int switchId = -1, wakingId = -1, vsyncId = -1;