From 9b07458c4dec01ab881ae166ce31587cc422284f Mon Sep 17 00:00:00 2001
From: Timo Kreuzer <timo.kreuzer@reactos.org>
Date: Thu, 20 Feb 2014 23:03:04 +0000
Subject: [PATCH] [NTOSKRNL] Implement MmAdjustWorkingSetSize

svn path=/trunk/; revision=62275
---
 reactos/ntoskrnl/mm/ARM3/mmsup.c | 113 ++++++++++++++++++++++++++++++-
 1 file changed, 111 insertions(+), 2 deletions(-)

diff --git a/reactos/ntoskrnl/mm/ARM3/mmsup.c b/reactos/ntoskrnl/mm/ARM3/mmsup.c
index 0ec4999bb4f..b1e61323562 100644
--- a/reactos/ntoskrnl/mm/ARM3/mmsup.c
+++ b/reactos/ntoskrnl/mm/ARM3/mmsup.c
@@ -15,6 +15,12 @@
 #define MODULE_INVOLVED_IN_ARM3
 #include "../ARM3/miarm.h"
 
+/* GLOBALS ********************************************************************/
+
+SIZE_T MmMinimumWorkingSetSize;
+SIZE_T MmMaximumWorkingSetSize;
+SIZE_T MmPagesAboveWsMinimum;
+
 /* PUBLIC FUNCTIONS ***********************************************************/
 
 /*
@@ -40,8 +46,111 @@ MmAdjustWorkingSetSize(IN SIZE_T WorkingSetMinimumInBytes,
                        IN ULONG SystemCache,
                        IN BOOLEAN IncreaseOkay)
 {
-    UNIMPLEMENTED;
-    return STATUS_NOT_IMPLEMENTED;
+    SIZE_T MinimumWorkingSetSize, MaximumWorkingSetSize;
+    SSIZE_T Delta;
+    PMMSUPPORT Ws;
+    NTSTATUS Status;
+
+    /* Check for special case: empty the working set */
+    if ((WorkingSetMinimumInBytes == -1) &&
+        (WorkingSetMaximumInBytes == -1))
+    {
+        UNIMPLEMENTED;
+        return STATUS_NOT_IMPLEMENTED;
+    }
+
+    /* Assume success */
+    Status = STATUS_SUCCESS;
+
+    /* Get the working set and lock it */
+    Ws = &PsGetCurrentProcess()->Vm;
+    MiLockWorkingSet(PsGetCurrentThread(), Ws);
+
+    /* Calculate the actual minimum and maximum working set size to set */
+    MinimumWorkingSetSize = (WorkingSetMinimumInBytes != 0) ?
+        (WorkingSetMinimumInBytes / PAGE_SIZE) : Ws->MinimumWorkingSetSize;
+    MaximumWorkingSetSize = (WorkingSetMaximumInBytes != 0) ?
+        (WorkingSetMaximumInBytes / PAGE_SIZE) : Ws->MaximumWorkingSetSize;
+
+    /* Check if the new maximum exceeds the global maximum */
+    if (MaximumWorkingSetSize > MmMaximumWorkingSetSize)
+    {
+        MaximumWorkingSetSize = MmMaximumWorkingSetSize;
+        Status = STATUS_WORKING_SET_LIMIT_RANGE;
+    }
+
+    /* Check if the new minimum is below the global minimum */
+    if (MinimumWorkingSetSize < MmMinimumWorkingSetSize)
+    {
+        MinimumWorkingSetSize = MmMinimumWorkingSetSize;
+        Status = STATUS_WORKING_SET_LIMIT_RANGE;
+    }
+
+    /* Check if the new minimum exceeds the new maximum */
+    if (MinimumWorkingSetSize > MaximumWorkingSetSize)
+    {
+        DPRINT1("MinimumWorkingSetSize > MaximumWorkingSetSize\n");
+        Status = STATUS_BAD_WORKING_SET_LIMIT;
+        goto Cleanup;
+    }
+
+    /* Calculate the minimum WS size adjustment and check if we increase */
+    Delta = MinimumWorkingSetSize - Ws->MinimumWorkingSetSize;
+    if (Delta > 0)
+    {
+        /* Is increasing ok? */
+        if (!IncreaseOkay)
+        {
+            DPRINT1("Privilege for WS size increase not held\n");
+            Status = STATUS_PRIVILEGE_NOT_HELD;
+            goto Cleanup;
+        }
+
+        /* Check if the number of available pages is large enough */
+        if (((SIZE_T)Delta / 1024) > (MmAvailablePages - 128))
+        {
+            DPRINT1("Not enough available pages\n");
+            Status = STATUS_INSUFFICIENT_RESOURCES;
+            goto Cleanup;
+        }
+
+        /* Check if there are enough resident available pages */
+        if ((SIZE_T)Delta >
+            (MmResidentAvailablePages - MmSystemLockPagesCount - 256))
+        {
+            DPRINT1("Not enough resident pages\n");
+            Status = STATUS_INSUFFICIENT_RESOURCES;
+            goto Cleanup;
+        }
+    }
+
+    /* Update resident available pages */
+    if (Delta != 0)
+    {
+        InterlockedExchangeAddSizeT(&MmResidentAvailablePages, -Delta);
+    }
+
+    /* Calculate new pages above minimum WS size */
+    Delta += max((SSIZE_T)Ws->WorkingSetSize - MinimumWorkingSetSize, 0);
+
+    /* Subtract old pages above minimum WS size */
+    Delta -= max((SSIZE_T)Ws->WorkingSetSize - Ws->MinimumWorkingSetSize, 0);
+
+    /* If it changed, add it to the global variable */
+    if (Delta != 0)
+    {
+        InterlockedExchangeAddSizeT(&MmPagesAboveWsMinimum, Delta);
+    }
+
+    /* Set the new working set size */
+    Ws->MinimumWorkingSetSize = MinimumWorkingSetSize;
+    Ws->MaximumWorkingSetSize = MaximumWorkingSetSize;
+
+Cleanup:
+
+    /* Unlock the working set and return the status */
+    MiUnlockWorkingSet(PsGetCurrentThread(), Ws);
+    return Status;
 }
 
 /*
-- 
2.17.1