Changeset 37214 in vbox for trunk/src/VBox/VMM/VMMR0

Timestamp:

May 25, 2011 2:38:28 PM (14 years ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

71916

Message:

GMMR0: Added a dedicated for empty chunks.

File:

• trunk/src/VBox/VMM/VMMR0/GMMR0.cpp (modified) (8 diffs)

trunk/src/VBox/VMM/VMMR0/GMMR0.cpp

@@ -467 +467 @@
 
 
-/** The GMMCHUNK::cFree shift count. */
+/** The GMMCHUNK::cFree shift count employed by gmmR0SelectFreeSetList. */
 #define GMM_CHUNK_FREE_SET_SHIFT    4
+/** Index of the list containing completely unused chunks.
+ * The code ASSUMES this is the last list. */
+#define GMM_CHUNK_FREE_SET_UNUSED_LIST  (GMM_CHUNK_NUM_PAGES >> GMM_CHUNK_FREE_SET_SHIFT)
+
 
 
@@ -481 +485 @@
      *  something is linked or unlinked from this set. */
     uint64_t            idGeneration;
-    /** Chunks ordered by increasing number of free pages. */
-    PGMMCHUNK           apLists[GMM_CHUNK_NUM_PAGES >> GMM_CHUNK_FREE_SET_SHIFT];
+    /** Chunks ordered by increasing number of free pages.
+     *  In the final list the chunks are completely unused. */
+    PGMMCHUNK           apLists[GMM_CHUNK_FREE_SET_UNUSED_LIST + 1];
 } GMMCHUNKFREESET;
 
@@ -1246 +1251 @@
             fRedoFromStart = false;
             iCountDown = 10240;
-            pChunk = pGMM->Private.apLists[RT_ELEMENTS(pGMM->Private.apLists) - 1];
+            pChunk = pGMM->Private.apLists[GMM_CHUNK_FREE_SET_UNUSED_LIST];
             while (pChunk)
             {
                 PGMMCHUNK pNext = pChunk->pFreeNext;
-                if (    pChunk->cFree == GMM_CHUNK_NUM_PAGES
-                    &&  (   !pGMM->fBoundMemoryMode
-                         || pChunk->hGVM == pGVM->hSelf))
+                Assert(pChunk->cFree == GMM_CHUNK_NUM_PAGES);
+                if (   !pGMM->fBoundMemoryMode
+                    || pChunk->hGVM == pGVM->hSelf)
                 {
                     uint64_t const idGenerationOld = pGMM->Private.idGeneration;
@@ -1800 +1805 @@
  *
  * @returns Free list index.
- * @param
+ * @param   cFree       The number of free pages in the chunk.
  */
 DECLINLINE(unsigned) gmmR0SelectFreeSetList(unsigned cFree)
 {
-    return (cFree - 1) >> GMM_CHUNK_FREE_SET_SHIFT;
+    unsigned iList = cFree >> GMM_CHUNK_FREE_SET_SHIFT;
+    AssertMsg(iList < RT_SIZEOFMEMB(GMMCHUNKFREESET, apLists) / RT_SIZEOFMEMB(GMMCHUNKFREESET, apLists[0]),
+              ("%d (%u)\n", iList, cFree));
+    return iList;
 }
 
@@ -2296 +2304 @@
 
     /* first round, pick from chunks with an affinity to the VM. */
-    for (unsigned i = 0; i < RT_ELEMENTS(pSet->apLists) && iPage < cPages; i++)
+    for (unsigned i = 0; i < GMM_CHUNK_FREE_SET_UNUSED_LIST && iPage < cPages; i++)
     {
         PGMMCHUNK pCurFree = NULL;
@@ -2321 +2329 @@
         /* second round, pick pages from the 100% empty chunks we just skipped above. */
         PGMMCHUNK pCurFree = NULL;
-        PGMMCHUNK pCur = pSet->apLists[RT_ELEMENTS(pSet->apLists) - 1];
+        PGMMCHUNK pCur = pSet->apLists[GMM_CHUNK_FREE_SET_UNUSED_LIST];
         while (pCur && iPage < cPages)
         {
             PGMMCHUNK pNext = pCur->pFreeNext;
-
-            if (    pCur->cFree == GMM_CHUNK_NUM_PAGES
-                &&  (   pCur->hGVM == hGVM
-                     || !pGMM->fBoundMemoryMode))
+            Assert(pCur->cFree == GMM_CHUNK_NUM_PAGES);
+
+            if (   pCur->hGVM == hGVM
+                || !pGMM->fBoundMemoryMode)
             {
                 gmmR0UnlinkChunk(pCur);
@@ -3047 +3055 @@
      * and relink the chunk if necessary.
      */
-    if (gmmR0SelectFreeSetList(pChunk->cFree) != gmmR0SelectFreeSetList(pChunk->cFree + 1))
+    unsigned const cFree = pChunk->cFree;
+    if (   !cFree
+        || gmmR0SelectFreeSetList(cFree) != gmmR0SelectFreeSetList(cFree + 1))
     {
         gmmR0UnlinkChunk(pChunk);
@@ -3055 +3065 @@
     else
     {
-        pChunk->cFree++;
+        pChunk->cFree = cFree + 1;
         pChunk->pSet->cFreePages++;
     }