1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/os/kernelhwsrv/kernel/eka/memmodel/epoc/flexible/mmu/mthrash.cpp Fri Jun 15 03:10:57 2012 +0200
1.3 @@ -0,0 +1,171 @@
1.4 +// Copyright (c) 2008-2009 Nokia Corporation and/or its subsidiary(-ies).
1.5 +// All rights reserved.
1.6 +// This component and the accompanying materials are made available
1.7 +// under the terms of the License "Eclipse Public License v1.0"
1.8 +// which accompanies this distribution, and is available
1.9 +// at the URL "http://www.eclipse.org/legal/epl-v10.html".
1.10 +//
1.11 +// Initial Contributors:
1.12 +// Nokia Corporation - initial contribution.
1.13 +//
1.14 +// Contributors:
1.15 +//
1.16 +// Description:
1.17 +// Other possible inputs to thrashing detection:
1.18 +// - cache size and free ram
1.19 +// - pin failures
1.20 +//
1.21 +
1.22 +
1.23 +
1.24 +#include <kernel/kern_priv.h>
1.25 +#include "mthrash.h"
1.26 +
1.27 +const TInt KUpdatePeriod = 1000; // Update every second
1.28 +
1.29 +DThrashMonitor TheThrashMonitor;
1.30 +
1.31 +DThrashMonitor::DThrashMonitor() :
1.32 + iRunning(EFalse),
1.33 + iUpdateTimer(NULL, this),
1.34 + iUpdateDfc(UpdateDfcFunc, this, 0),
1.35 + iThrashLevel(0),
1.36 + iThresholdThrashing(200),
1.37 + iThresholdGood(150)
1.38 + {
1.39 + }
1.40 +
1.41 +void DThrashMonitor::Start()
1.42 + {
1.43 + TBool alreadyRunning = __e32_atomic_swp_ord32(&iRunning, ETrue);
1.44 + if (alreadyRunning)
1.45 + return;
1.46 +
1.47 + // reset
1.48 + memclr(&iCount[0], sizeof(iCount));
1.49 + iLastUpdateTime = NKern::TickCount();
1.50 +
1.51 + iUpdateDfc.SetDfcQ(Kern::DfcQue0());
1.52 + TInt r = iUpdateTimer.OneShot(KUpdatePeriod, iUpdateDfc);
1.53 + __NK_ASSERT_ALWAYS(r == KErrNone);
1.54 + }
1.55 +
1.56 +TInt DThrashMonitor::ThrashLevel()
1.57 + {
1.58 + return iThrashLevel;
1.59 + }
1.60 +
1.61 +TInt DThrashMonitor::SetThresholds(TUint aThrashing, TUint aGood)
1.62 + {
1.63 + if (aThrashing < aGood || aThrashing > 255)
1.64 + return KErrArgument;
1.65 + iThresholdThrashing = aThrashing;
1.66 + iThresholdGood = aGood;
1.67 + return KErrNone;
1.68 + }
1.69 +
1.70 +void DThrashMonitor::UpdateCount(TCount aCount, TInt aDelta)
1.71 + {
1.72 + TCountData& c = iCount[aCount];
1.73 +
1.74 + NKern::FMWait(&iMutex);
1.75 +
1.76 + TUint32 currentTime = NKern::TickCount();
1.77 + c.iTotal += (TInt64)c.iCount * (currentTime - c.iLastUpdateTime);
1.78 + c.iCount += aDelta;
1.79 + c.iLastUpdateTime = currentTime;
1.80 +
1.81 + if(!iUpdateTimer.IsPending())
1.82 + {
1.83 + TInt r = iUpdateTimer.OneShot(KUpdatePeriod, iUpdateDfc);
1.84 + __NK_ASSERT_ALWAYS(r == KErrNone);
1.85 + }
1.86 +
1.87 + NKern::FMSignal(&iMutex);
1.88 +
1.89 + __NK_ASSERT_DEBUG(c.iCount >= 0);
1.90 + }
1.91 +
1.92 +void DThrashMonitor::NotifyStartPaging()
1.93 + {
1.94 + UpdateCount(ECountThreadsPaging, 1);
1.95 + }
1.96 +
1.97 +void DThrashMonitor::NotifyEndPaging()
1.98 + {
1.99 + UpdateCount(ECountThreadsPaging, -1);
1.100 + }
1.101 +
1.102 +void DThrashMonitor::UpdateDfcFunc(TAny* aPtr)
1.103 + {
1.104 + DThrashMonitor* self = (DThrashMonitor*)aPtr;
1.105 + self->RecalculateThrashLevel();
1.106 + }
1.107 +
1.108 +void DThrashMonitor::RecalculateThrashLevel()
1.109 + {
1.110 + TInt currentTime = NKern::TickCount();
1.111 + TInt elapsedTicks = currentTime - iLastUpdateTime;
1.112 +
1.113 + NKern::FMWait(&iMutex);
1.114 + for (TInt i = 0 ; i < EMaxCount ; ++i)
1.115 + {
1.116 + TCountData& c = iCount[i];
1.117 + c.iTotal += (TInt64)c.iCount * (currentTime - c.iLastUpdateTime);
1.118 + c.iAverage = (TInt)((256 * c.iTotal) / elapsedTicks);
1.119 + c.iTotal = 0;
1.120 + c.iLastUpdateTime = currentTime;
1.121 + }
1.122 + NKern::FMSignal(&iMutex);
1.123 +
1.124 + TInt pagingActivity = Min(iCount[ECountThreadsPaging].iAverage, 255);
1.125 +
1.126 + // Base thrash level entirely on the average number of threads paging
1.127 + TInt newThrashLevel = pagingActivity;
1.128 + TInt oldThrashLevel = iThrashLevel;
1.129 +
1.130 + // Make thrash level increase slowly over time, but decrease quickly
1.131 + if (newThrashLevel > oldThrashLevel)
1.132 + newThrashLevel = (3 * oldThrashLevel + pagingActivity) >> 2;
1.133 +
1.134 + iThrashLevel = newThrashLevel;
1.135 +
1.136 + // Notify user-side if thrashing thresholds passed
1.137 + TBool notifyChange = EFalse;
1.138 + if (oldThrashLevel < iThresholdThrashing && newThrashLevel >= iThresholdThrashing)
1.139 + {
1.140 + iIsThrashing = ETrue;
1.141 + notifyChange = ETrue;
1.142 + }
1.143 + else if (iIsThrashing && oldThrashLevel >= iThresholdGood && newThrashLevel < iThresholdGood)
1.144 + {
1.145 + iIsThrashing = EFalse;
1.146 + notifyChange = ETrue;
1.147 + }
1.148 +
1.149 + if (notifyChange)
1.150 + {
1.151 + NKern::ThreadEnterCS();
1.152 + Kern::AsyncNotifyChanges(EChangesThrashLevel);
1.153 + NKern::ThreadLeaveCS();
1.154 + }
1.155 +
1.156 + iLastUpdateTime = currentTime;
1.157 +
1.158 + if(iThrashLevel != 0)
1.159 + {
1.160 + NKern::FMWait(&iMutex);
1.161 + if(!iUpdateTimer.IsPending())
1.162 + {
1.163 + TInt r = iUpdateTimer.Again(KUpdatePeriod);
1.164 + if (r == KErrArgument)
1.165 + {
1.166 + r = iUpdateTimer.OneShot(KUpdatePeriod, iUpdateDfc);
1.167 + }
1.168 + __NK_ASSERT_ALWAYS(r == KErrNone);
1.169 + }
1.170 + NKern::FMSignal(&iMutex);
1.171 +
1.172 + }
1.173 +
1.174 + }