Changeset 44397 in vbox for trunk/src/VBox/VMM/VMMR3/PDMAsyncCompletionFileNormal.cpp

Timestamp:

Jan 27, 2013 8:23:39 PM (12 years ago)

Author:

vboxsync

Message:

AsyncCompletion: Only use range locks if the request is unaligned, pass everything through otherwise

File:

• trunk/src/VBox/VMM/VMMR3/PDMAsyncCompletionFileNormal.cpp (modified) (12 diffs)

trunk/src/VBox/VMM/VMMR3/PDMAsyncCompletionFileNormal.cpp

@@ -638 +638 @@
 static bool pdmacFileAioMgrNormalIsRangeLocked(PPDMASYNCCOMPLETIONENDPOINTFILE pEndpoint,
                                                RTFOFF offStart, size_t cbRange,
-                                               PPDMACTASKFILE pTask)
+                                               PPDMACTASKFILE pTask, bool fAlignedReq)
 {
     AssertMsg(   pTask->enmTransferType == PDMACTASKFILETRANSFER_WRITE
               || pTask->enmTransferType == PDMACTASKFILETRANSFER_READ,
                  ("Invalid task type %d\n", pTask->enmTransferType));
+
+    /*
+     * If there is no unaligned request active and the current one is aligned
+     * just pass it through.
+     */
+    if (!pEndpoint->AioMgr.cLockedReqsActive && fAlignedReq)
+        return false;
 
     PPDMACFILERANGELOCK pRangeLock;
@@ -659 +666 @@
 
     /* Check whether we have one of the situations explained below */
-    if (   pRangeLock
-#if 0 /** @todo later. For now we will just block all requests if they interfere */
-        && (   (pRangeLock->fReadLock && pTask->enmTransferType == PDMACTASKFILETRANSFER_WRITE)
-            || (!pRangeLock->fReadLock)
-#endif
-        )
+    if (pRangeLock)
     {
         /* Add to the list. */
@@ -690 +692 @@
                                           PPDMASYNCCOMPLETIONENDPOINTFILE pEndpoint,
                                           RTFOFF offStart, size_t cbRange,
-                                          PPDMACTASKFILE pTask)
+                                          PPDMACTASKFILE pTask, bool fAlignedReq)
 {
     LogFlowFunc(("pAioMgr=%#p pEndpoint=%#p offStart=%RTfoff cbRange=%zu pTask=%#p\n",
                  pAioMgr, pEndpoint, offStart, cbRange, pTask));
 
-    AssertMsg(!pdmacFileAioMgrNormalIsRangeLocked(pEndpoint, offStart, cbRange, pTask),
+    AssertMsg(!pdmacFileAioMgrNormalIsRangeLocked(pEndpoint, offStart, cbRange, pTask, fAlignedReq),
               ("Range is already locked offStart=%RTfoff cbRange=%u\n",
                offStart, cbRange));
+
+    /*
+     * If there is no unaligned request active and the current one is aligned
+     * just don't use the lock.
+     */
+    if (!pEndpoint->AioMgr.cLockedReqsActive && fAlignedReq)
+    {
+        pTask->pRangeLock = NULL;
+        return VINF_SUCCESS;
+    }
 
     PPDMACFILERANGELOCK pRangeLock = (PPDMACFILERANGELOCK)RTMemCacheAlloc(pAioMgr->hMemCacheRangeLocks);
@@ -716 +728 @@
     /* Let the task point to its lock. */
     pTask->pRangeLock = pRangeLock;
+    pEndpoint->AioMgr.cLockedReqsActive++;
 
     return VINF_SUCCESS;
@@ -729 +742 @@
                  pAioMgr, pEndpoint, pRangeLock));
 
-    AssertPtr(pRangeLock);
+    /* pRangeLock can be NULL if there was no lock assigned with the task. */
+    if (!pRangeLock)
+        return NULL;
+
     Assert(pRangeLock->cRefs == 1);
 
@@ -737 +753 @@
     pRangeLock->pWaitingTasksTail = NULL;
     RTMemCacheFree(pAioMgr->hMemCacheRangeLocks, pRangeLock);
+    pEndpoint->AioMgr.cLockedReqsActive--;
 
     return pTasksWaitingHead;
@@ -772 +789 @@
      */
     int  rc = VINF_SUCCESS;
-    bool fLocked = pdmacFileAioMgrNormalIsRangeLocked(pEndpoint, pTask->Off, pTask->DataSeg.cbSeg, pTask);
+    bool fLocked = pdmacFileAioMgrNormalIsRangeLocked(pEndpoint, pTask->Off, pTask->DataSeg.cbSeg, pTask,
+                                                      true /* fAlignedReq */);
     if (!fLocked)
     {
@@ -800 +818 @@
         rc = pdmacFileAioMgrNormalRangeLock(pAioMgr, pEndpoint, pTask->Off,
                                             pTask->DataSeg.cbSeg,
-                                            pTask);
+                                            pTask, true /* fAlignedReq */);
 
         if (RT_SUCCESS(rc))
@@ -826 +844 @@
     size_t cbToTransfer = RT_ALIGN_Z(pTask->DataSeg.cbSeg + (pTask->Off - offStart), 512);
     PDMACTASKFILETRANSFER enmTransferType = pTask->enmTransferType;
+    bool fAlignedReq =     cbToTransfer == pTask->DataSeg.cbSeg
+                        && offStart == pTask->Off;
 
     AssertMsg(   pTask->enmTransferType == PDMACTASKFILETRANSFER_WRITE
@@ -853 +873 @@
      */
     int  rc = VINF_SUCCESS;
-    bool fLocked = pdmacFileAioMgrNormalIsRangeLocked(pEndpoint, offStart, cbToTransfer, pTask);
+    bool fLocked = pdmacFileAioMgrNormalIsRangeLocked(pEndpoint, offStart, cbToTransfer, pTask, fAlignedReq);
     if (!fLocked)
     {
@@ -863 +883 @@
         AssertMsg(hReq != NIL_RTFILEAIOREQ, ("Out of request handles\n"));
 
-        if (   RT_UNLIKELY(cbToTransfer != pTask->DataSeg.cbSeg)
-            || RT_UNLIKELY(offStart != pTask->Off)
+        if (   !fAlignedReq
             || ((pEpClassFile->uBitmaskAlignment & (RTR3UINTPTR)pvBuf) != (RTR3UINTPTR)pvBuf))
         {
@@ -929 +948 @@
             AssertRC(rc);
 
-            rc = pdmacFileAioMgrNormalRangeLock(pAioMgr, pEndpoint, offStart, cbToTransfer, pTask);
-
+            rc = pdmacFileAioMgrNormalRangeLock(pAioMgr, pEndpoint, offStart, cbToTransfer, pTask, fAlignedReq);
             if (RT_SUCCESS(rc))
             {