diff -r 000000000000 -r bde4ae8d615e os/kernelhwsrv/kerneltest/e32test/lffs/bf_cpu.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/os/kernelhwsrv/kerneltest/e32test/lffs/bf_cpu.cpp	Fri Jun 15 03:10:57 2012 +0200
@@ -0,0 +1,305 @@
+// Copyright (c) 1996-2009 Nokia Corporation and/or its subsidiary(-ies).
+// All rights reserved.
+// This component and the accompanying materials are made available
+// under the terms of the License "Eclipse Public License v1.0"
+// which accompanies this distribution, and is available
+// at the URL "http://www.eclipse.org/legal/epl-v10.html".
+//
+// Initial Contributors:
+// Nokia Corporation - initial contribution.
+//
+// Contributors:
+//
+// Description:
+// Very simple test of CPU overhead
+// 
+//
+
+/**
+ @file bf_cpu.cpp
+*/
+
+#include <e32std.h>
+#include <e32std_private.h>
+#include <e32base.h>
+#include <e32base_private.h>
+#include <e32test.h>
+#include <e32svr.h>
+#include "user_config.h"
+
+
+#define TEST_WRITE_OVERHEAD
+#define NON_WRITING_LOOPS
+
+const TInt KAverageOverInSeconds=10;	///< Number of seconds to run tests for
+
+TInt64 Count;				///< Global variable used to count number of operations completed
+RSemaphore CountSem;		///< control access to Count;
+
+
+RTest test(_L("BF_CPU"));
+
+
+
+TBusLocalDrive	drive;
+TLocalDriveCapsV2Buf driveInfo;
+
+LOCAL_D TBool StopTest;		///< set to ETrue to stop the test
+
+
+#ifdef TEST_WRITE_OVERHEAD
+LOCAL_D TBool StopZeroTest;
+
+LOCAL_C TInt WriteZeroThread(TAny*)
+	/**
+	 * Performs writes of zero length continuously
+	 */
+	{
+#if 0
+	_LIT( KPanicCat, "ZERWRTH" );
+#endif
+	
+	TBuf8<513> buf;
+	buf.SetLength(513);
+	
+	while( !StopZeroTest )
+		{
+		// Return values are bogus when doing overhead testing
+		drive.Write( 513, buf );
+		}
+	return KErrNone;
+	}
+#endif
+
+
+LOCAL_C TInt WriteThread(TAny*)
+	/**
+	 * Performs writes continuously
+	 */
+	{
+	_LIT( KPanicCat, "WRTHRD" );
+	
+	TBuf8<512> buf;
+	buf.SetLength(512);
+	buf.Fill(0xFF);		// all 0xFF so we can repeatedly overwrite
+	
+	while( !StopTest )
+		{
+		TInt r = drive.Write( 0, buf );
+		if( KErrNone != r )
+			{
+			User::Panic( KPanicCat, r );
+			}
+		}
+	return KErrNone;
+	}
+
+
+
+LOCAL_C TInt CpuThread(TAny*)
+	/**
+	 * Just increments the counter
+	 */
+	{
+	while( !StopTest )
+		{
+		CountSem.Wait();
+#ifdef NON_WRITING_LOOPS
+		for( volatile TInt i = 5000; i > 0; i-- );
+#endif
+		++Count;
+		CountSem.Signal();
+		}
+	return KErrNone;
+	}
+
+
+void runTest()
+	{
+    RThread writeThread;
+	TInt r=writeThread.Create(_L("WRITER"),WriteThread,KDefaultStackSize,&User::Heap(),NULL);
+	test(r==KErrNone);
+
+	RThread cpuThread;
+	r=cpuThread.Create(_L("CPU-ER"),CpuThread,KDefaultStackSize,&User::Heap(),NULL);
+	test(r==KErrNone);
+
+#ifdef TEST_WRITE_OVERHEAD
+    RThread writeZeroThread;
+	r=writeZeroThread.Create(_L("WRITERZERO"),WriteZeroThread,KDefaultStackSize,&User::Heap(),NULL);
+	test(r==KErrNone);
+#endif
+
+	r = CountSem.CreateLocal(1);
+	test(r==KErrNone);
+
+
+	StopTest = EFalse;	// allow the test to run
+
+    TRequestStatus deadStatWrite;
+    TRequestStatus deadStatCpu;
+	writeThread.Logon( deadStatWrite );
+	cpuThread.Logon( deadStatCpu );
+	
+	// make writer thread have priority over CPU usage thread
+	writeThread.SetPriority( EPriorityMore );
+
+	// make this thread highest priority
+	RThread().SetPriority( EPriorityMuchMore );
+	
+	
+    cpuThread.Resume();
+	
+#ifdef TEST_WRITE_OVERHEAD
+    TRequestStatus deadStatWriteZero;
+	writeZeroThread.Logon( deadStatWriteZero );
+	// make writer thread have priority over CPU usage thread
+	writeZeroThread.SetPriority( EPriorityMore );
+	StopZeroTest = EFalse;
+	writeZeroThread.Resume();
+#endif
+	
+	// wait for thread to initialise
+	User::After(1000000);
+
+	CountSem.Wait();
+	Count=0;
+	CountSem.Signal();
+
+    User::After(KAverageOverInSeconds*1000000);
+    
+	CountSem.Wait();
+	TInt64 noWriteCount( Count );	// number of counts when not writing
+	CountSem.Signal();
+
+	
+#ifdef TEST_WRITE_OVERHEAD
+	// kill the zero writer
+	StopZeroTest = ETrue;
+	User::WaitForRequest( deadStatWriteZero );
+	CLOSE_AND_WAIT(writeZeroThread);
+#endif
+    
+	test.Printf( _L("Loops without writing = %ld"), noWriteCount );
+	
+	// start write thread
+	writeThread.Resume();
+	User::After(1000000);
+    
+	CountSem.Wait();
+	Count=0;
+	CountSem.Signal();
+
+    User::After(KAverageOverInSeconds*1000000);
+    
+	CountSem.Wait();
+	TInt64 withWriteCount( Count );	// number of counts when writing
+	CountSem.Signal();
+
+	test.Printf( _L("Loops while writing = %ld"), withWriteCount );
+	
+	// tell test to stop and wait for thread to exit.
+	cpuThread.Kill(KErrNone);
+	StopTest = ETrue;
+	User::WaitForRequest( deadStatWrite );
+	
+	CLOSE_AND_WAIT(writeThread);
+	CLOSE_AND_WAIT(cpuThread);
+    
+
+
+	TInt64 calc( withWriteCount );
+	calc = calc * 100;
+	calc = calc / noWriteCount;
+		
+	test.Printf( _L("%% CPU used = %d"), 100 - I64LOW(calc) );
+    }
+
+
+
+LOCAL_C TInt EraseSegment( TInt aSegmentNumber )
+	/**
+	 * Erases a segment on Flash
+	 *
+	 * @param aSegmentNumber index of segment to erase
+	 * @return KErrNone or error code
+	 */
+	{
+	TInt offset = aSegmentNumber * driveInfo().iEraseBlockSize;
+	
+	TInt r = drive.Format( offset, driveInfo().iEraseBlockSize );
+	test.Printf( _L("erase returns %d"), r );
+	return  r;
+	}
+
+
+
+
+void Initialize()
+	/**
+	 * Open channel to media driver
+	 */
+	{
+	//
+	// Load the media driver
+	//
+#ifndef SKIP_PDD_LOAD
+	test.Printf( _L("Loading %S\n"), &KLfsDriverName );
+	TInt r = User::LoadPhysicalDevice( KLfsDriverName );
+	test( KErrNone == r || KErrAlreadyExists == r );
+#endif
+
+#ifdef UNMOUNT_DRIVE
+	RFs fs;
+	test( KErrNone == fs.Connect() );
+#if 0
+	// XXX not EKA2
+	test( KErrNone == fs.SetDefaultPath( _L("Z:\\") ) );
+#endif
+	TFullName name;
+	fs.FileSystemName( name, KLffsLogicalDriveNumber );
+	if( name.Length() > 0 )
+		{
+		test.Printf( _L("Unmounting drive") );
+		test( KErrNone == fs.DismountFileSystem( _L("Lffs"), KLffsLogicalDriveNumber) );
+		User::After( 2000000 );
+		test.Printf( _L("Drive unmounted") );
+		}
+	fs.Close();
+#endif
+
+	//
+	// Open a TBusLogicalDevice to it
+	//
+	test.Printf( _L("Opening media channel\n") );
+	TBool changedFlag = EFalse;
+	test( KErrNone == drive.Connect( KDriveNumber, changedFlag ) );
+	
+	//
+	// Get size of Flash drive, block size, block count
+	//
+    drive.Caps(driveInfo);
+	}
+
+
+
+TInt E32Main()
+    {
+
+    test.Title();
+    test.Start(_L("Testing CPU overhead"));
+
+	Initialize();
+
+	test.Printf( _L("Erasing first segment") );
+	TInt r = EraseSegment( 0 );
+	test( KErrNone == r );
+	test.Printf( _L("Segment erased") );
+
+	runTest();
+
+	drive.Disconnect();
+    test.End();
+	return(KErrNone);
+    }
+