nihilist/VeraCrypt
1
0
Fork 0
mirror of https://github.com/veracrypt/VeraCrypt synced 2024-11-27 05:23:34 +01:00
Code Issues Packages Projects Releases Wiki Activity

Windows Driver: Optimize spinlock usage in CompleteIrpWorkItemRoutine

Browse Source 
Reduce the critical section protected by spinlock to only cover the list manipulation operation. Move the ActiveWorkItems counter decrement outside the spinlock using InterlockedDecrement, and separate event signaling from the locked section.
This change minimizes time spent at raised IRQL (DISPATCH_LEVEL) and reduces potential for lock contention.
This commit is contained in:
Mounir IDRASSI 2024-11-22 15:19:10 +01:00
parent 9490336357
commit 5a85c54c6e
No known key found for this signature in database
GPG Key ID: FC1B00364B3FE937
1 changed files with 4 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
src/Driver/EncryptedIoQueue.c
View File

@ -271,6 +271,7 @@ static VOID CompleteIrpWorkItemRoutine(PDEVICE_OBJECT DeviceObject, PVOID Contex
PCOMPLETE_IRP_WORK_ITEM workItem = (PCOMPLETE_IRP_WORK_ITEM)Context; PCOMPLETE_IRP_WORK_ITEM workItem = (PCOMPLETE_IRP_WORK_ITEM)Context;
EncryptedIoQueueItem* item = (EncryptedIoQueueItem * ) workItem->Item; EncryptedIoQueueItem* item = (EncryptedIoQueueItem * ) workItem->Item;
EncryptedIoQueue* queue = item->Queue; EncryptedIoQueue* queue = item->Queue;
KIRQL oldIrql;
UNREFERENCED_PARAMETER(DeviceObject); UNREFERENCED_PARAMETER(DeviceObject);
__try __try
@ -283,19 +284,14 @@ static VOID CompleteIrpWorkItemRoutine(PDEVICE_OBJECT DeviceObject, PVOID Contex
} }
__finally __finally
{ {
// Return the work item to the free list
KIRQL oldIrql;
KeAcquireSpinLock(&queue->WorkItemLock, &oldIrql);
// Decrement ActiveWorkItems
LONG activeWorkItems = InterlockedDecrement(&queue->ActiveWorkItems);
// If no active work items remain, signal the event // If no active work items remain, signal the event
if (activeWorkItems == 0) if (InterlockedDecrement(&queue->ActiveWorkItems) == 0)
{ {
KeSetEvent(&queue->NoActiveWorkItemsEvent, IO_NO_INCREMENT, FALSE); KeSetEvent(&queue->NoActiveWorkItemsEvent, IO_NO_INCREMENT, FALSE);
} }
// Return the work item to the free list
KeAcquireSpinLock(&queue->WorkItemLock, &oldIrql);
InsertTailList(&queue->FreeWorkItemsList, &workItem->ListEntry); InsertTailList(&queue->FreeWorkItemsList, &workItem->ListEntry);
KeReleaseSpinLock(&queue->WorkItemLock, oldIrql); KeReleaseSpinLock(&queue->WorkItemLock, oldIrql);