From 12d05b7eb80250977049da09347208f0788e99a5 Mon Sep 17 00:00:00 2001
From: Cameron Gutman <aicommander@gmail.com>
Date: Mon, 20 Sep 2010 19:08:40 +0000
Subject: [PATCH] [TCPIP] - Process the timer event directly from the DPC
 instead of queuing a work item then raising to DISPATCH_LEVEL later when
 acquiring a spin lock - Optimize the spin lock operations in NBTimeout and
 IPDatagramReassemblyTimeout for being called at DISPATCH_LEVEL

svn path=/trunk/; revision=48833
---
 reactos/drivers/network/tcpip/include/ip.h |  6 ++++--
 reactos/drivers/network/tcpip/tcpip/main.c | 25 ----------------------
 reactos/lib/drivers/ip/network/ip.c        | 18 +++++++++++++---
 reactos/lib/drivers/ip/network/neighbor.c  |  5 ++---
 reactos/lib/drivers/ip/network/receive.c   |  5 ++---
 5 files changed, 23 insertions(+), 36 deletions(-)

diff --git a/reactos/drivers/network/tcpip/include/ip.h b/reactos/drivers/network/tcpip/include/ip.h
index dc6898d1d8a..9d467e593ea 100644
--- a/reactos/drivers/network/tcpip/include/ip.h
+++ b/reactos/drivers/network/tcpip/include/ip.h
@@ -205,7 +205,6 @@ extern LIST_ENTRY InterfaceListHead;
 extern KSPIN_LOCK InterfaceListLock;
 extern LIST_ENTRY NetTableListHead;
 extern KSPIN_LOCK NetTableListLock;
-extern BOOLEAN IpWorkItemQueued;
 
 PIP_PACKET IPCreatePacket(
   ULONG Type);
@@ -232,7 +231,10 @@ BOOLEAN IPRegisterInterface(
 VOID IPUnregisterInterface(
     PIP_INTERFACE IF);
 
-VOID NTAPI IPTimeout( PVOID Context );
+VOID NTAPI IPTimeoutDpcFn(PKDPC Dpc,
+                          PVOID DeferredContext,
+                          PVOID SystemArgument1,
+                          PVOID SystemArgument2);
 
 VOID IPDispatchProtocol(
     PIP_INTERFACE Interface,
diff --git a/reactos/drivers/network/tcpip/tcpip/main.c b/reactos/drivers/network/tcpip/tcpip/main.c
index d1ce6c73c1d..ced3628e5d0 100644
--- a/reactos/drivers/network/tcpip/tcpip/main.c
+++ b/reactos/drivers/network/tcpip/tcpip/main.c
@@ -24,8 +24,6 @@ UDP_STATISTICS UDPStats;
 /* Network timers */
 KTIMER IPTimer;
 KDPC IPTimeoutDpc;
-KSPIN_LOCK IpWorkLock;
-WORK_QUEUE_ITEM IpWorkItem;
 
 VOID TiWriteErrorLog(
     PDRIVER_OBJECT DriverContext,
@@ -578,28 +576,6 @@ VOID NTAPI TiUnload(
   TI_DbgPrint(MAX_TRACE, ("Leaving.\n"));
 }
 
-VOID NTAPI IPTimeoutDpcFn(
-    PKDPC Dpc,
-    PVOID DeferredContext,
-    PVOID SystemArgument1,
-    PVOID SystemArgument2)
-/*
- * FUNCTION: Timeout DPC
- * ARGUMENTS:
- *     Dpc             = Pointer to our DPC object
- *     DeferredContext = Pointer to context information (unused)
- *     SystemArgument1 = Unused
- *     SystemArgument2 = Unused
- * NOTES:
- *     This routine is dispatched once in a while to do maintainance jobs
- */
-{
-    if( !IpWorkItemQueued ) {
-	ExQueueWorkItem( &IpWorkItem, DelayedWorkQueue );
-	IpWorkItemQueued = TRUE;
-    }
-}
-
 NTSTATUS NTAPI
 DriverEntry(
   PDRIVER_OBJECT DriverObject,
@@ -630,7 +606,6 @@ DriverEntry(
 
   /* Initialize our periodic timer and its associated DPC object. When the
      timer expires, the IPTimeout deferred procedure call (DPC) is queued */
-  ExInitializeWorkItem( &IpWorkItem, IPTimeout, NULL );
   KeInitializeDpc(&IPTimeoutDpc, IPTimeoutDpcFn, NULL);
   KeInitializeTimer(&IPTimer);
 
diff --git a/reactos/lib/drivers/ip/network/ip.c b/reactos/lib/drivers/ip/network/ip.c
index a24cd4e6d39..e0b969f7ee0 100644
--- a/reactos/lib/drivers/ip/network/ip.c
+++ b/reactos/lib/drivers/ip/network/ip.c
@@ -63,9 +63,21 @@ PIP_PACKET IPInitializePacket(
 }
 
 
-void NTAPI IPTimeout( PVOID Context ) {
-    IpWorkItemQueued = FALSE;
-
+VOID NTAPI IPTimeoutDpcFn(PKDPC Dpc,
+                          PVOID DeferredContext,
+                          PVOID SystemArgument1,
+                          PVOID SystemArgument2)
+/*
+ * FUNCTION: Timeout DPC
+ * ARGUMENTS:
+ *     Dpc             = Pointer to our DPC object
+ *     DeferredContext = Pointer to context information (unused)
+ *     SystemArgument1 = Unused
+ *     SystemArgument2 = Unused
+ * NOTES:
+ *     This routine is dispatched once in a while to do maintainance jobs
+ */
+{
     /* Check if datagram fragments have taken too long to assemble */
     IPDatagramReassemblyTimeout();
 
diff --git a/reactos/lib/drivers/ip/network/neighbor.c b/reactos/lib/drivers/ip/network/neighbor.c
index ae5e3a5bb19..ebb3b2721fc 100644
--- a/reactos/lib/drivers/ip/network/neighbor.c
+++ b/reactos/lib/drivers/ip/network/neighbor.c
@@ -97,12 +97,11 @@ VOID NBTimeout(VOID)
  */
 {
     UINT i;
-    KIRQL OldIrql;
     PNEIGHBOR_CACHE_ENTRY *PrevNCE;
     PNEIGHBOR_CACHE_ENTRY NCE;
 
     for (i = 0; i <= NB_HASHMASK; i++) {
-        TcpipAcquireSpinLock(&NeighborCache[i].Lock, &OldIrql);
+        TcpipAcquireSpinLockAtDpcLevel(&NeighborCache[i].Lock);
 
         for (PrevNCE = &NeighborCache[i].Cache;
              (NCE = *PrevNCE) != NULL;) {
@@ -136,7 +135,7 @@ VOID NBTimeout(VOID)
             PrevNCE = &NCE->Next;
         }
 
-        TcpipReleaseSpinLock(&NeighborCache[i].Lock, OldIrql);
+        TcpipReleaseSpinLockFromDpcLevel(&NeighborCache[i].Lock);
     }
 }
 
diff --git a/reactos/lib/drivers/ip/network/receive.c b/reactos/lib/drivers/ip/network/receive.c
index afdca21600f..a7908ef6460 100644
--- a/reactos/lib/drivers/ip/network/receive.c
+++ b/reactos/lib/drivers/ip/network/receive.c
@@ -510,11 +510,10 @@ VOID IPDatagramReassemblyTimeout(
  *     to hold IP fragments that have taken too long to reassemble
  */
 {
-    KIRQL OldIrql;
     PLIST_ENTRY CurrentEntry, NextEntry;
     PIPDATAGRAM_REASSEMBLY CurrentIPDR;
 
-    TcpipAcquireSpinLock(&ReassemblyListLock, &OldIrql);
+    TcpipAcquireSpinLockAtDpcLevel(&ReassemblyListLock);
 
     CurrentEntry = ReassemblyListHead.Flink;
     while (CurrentEntry != &ReassemblyListHead)
@@ -539,7 +538,7 @@ VOID IPDatagramReassemblyTimeout(
        CurrentEntry = NextEntry;
     }
 
-    TcpipReleaseSpinLock(&ReassemblyListLock, OldIrql);
+    TcpipReleaseSpinLockFromDpcLevel(&ReassemblyListLock);
 }
 
 VOID IPv4Receive(PIP_INTERFACE IF, PIP_PACKET IPPacket)