Changeset 16160 in vbox for trunk/src/VBox/HostDrivers/Support/solaris

Timestamp:

Jan 22, 2009 12:03:33 PM (16 years ago)

Author:

vboxsync

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

41899

Message:

Solaris/vboxdrv: avoid heap allocs on small ioctl transfers, helps lock contention skipping kmem_alloc and using the stack.

File:

• trunk/src/VBox/HostDrivers/Support/solaris/SUPDrv-solaris.c (modified) (6 diffs)

trunk/src/VBox/HostDrivers/Support/solaris/SUPDrv-solaris.c

@@ -695 +695 @@
     int         rc;
     uint32_t    cbBuf = 0;
-    SUPREQHDR   Hdr;
+    union 
+    {
+        SUPREQHDR   Hdr;
+        uint8_t     abBuf[64];
+    }           StackBuf;
     PSUPREQHDR  pHdr;
 
@@ -702 +706 @@
      * Read the header.
      */
-    if (RT_UNLIKELY(IOCPARM_LEN(iCmd) != sizeof(Hdr)))
-    {
-        LogRel((DEVICE_NAME ":VBoxDrvSolarisIOCtlSlow: iCmd=%#x len %d expected %d\n", iCmd, IOCPARM_LEN(iCmd), sizeof(Hdr)));
+    if (RT_UNLIKELY(IOCPARM_LEN(iCmd) != sizeof(StackBuf.Hdr)))
+    {
+        LogRel((DEVICE_NAME ":VBoxDrvSolarisIOCtlSlow: iCmd=%#x len %d expected %d\n", iCmd, IOCPARM_LEN(iCmd), sizeof(StackBuf.Hdr)));
         return EINVAL;
     }
-    rc = ddi_copyin((void *)iArg, &Hdr, sizeof(Hdr), Mode);
+    rc = ddi_copyin((void *)iArg, &StackBuf.Hdr, sizeof(StackBuf.Hdr), Mode);
     if (RT_UNLIKELY(rc))
     {
@@ -713 +717 @@
         return EFAULT;
     }
-    if (RT_UNLIKELY((Hdr.fFlags & SUPREQHDR_FLAGS_MAGIC_MASK) != SUPREQHDR_FLAGS_MAGIC))
-    {
-        LogRel((DEVICE_NAME ":VBoxDrvSolarisIOCtlSlow: bad header magic %#x; iCmd=%#x\n", Hdr.fFlags & SUPREQHDR_FLAGS_MAGIC_MASK, iCmd));
+    if (RT_UNLIKELY((StackBuf.Hdr.fFlags & SUPREQHDR_FLAGS_MAGIC_MASK) != SUPREQHDR_FLAGS_MAGIC))
+    {
+        LogRel((DEVICE_NAME ":VBoxDrvSolarisIOCtlSlow: bad header magic %#x; iCmd=%#x\n", StackBuf.Hdr.fFlags & SUPREQHDR_FLAGS_MAGIC_MASK, iCmd));
         return EINVAL;
     }
-    cbBuf = RT_MAX(Hdr.cbIn, Hdr.cbOut);
-    if (RT_UNLIKELY(    Hdr.cbIn < sizeof(Hdr)
-                    ||  Hdr.cbOut < sizeof(Hdr)
+    cbBuf = RT_MAX(StackBuf.Hdr.cbIn, StackBuf.Hdr.cbOut);
+    if (RT_UNLIKELY(    StackBuf.Hdr.cbIn < sizeof(StackBuf.Hdr)
+                    ||  StackBuf.Hdr.cbOut < sizeof(StackBuf.Hdr)
                     ||  cbBuf > _1M*16))
     {
-        LogRel((DEVICE_NAME ":VBoxDrvSolarisIOCtlSlow: max(%#x,%#x); iCmd=%#x\n", Hdr.cbIn, Hdr.cbOut, iCmd));
+        LogRel((DEVICE_NAME ":VBoxDrvSolarisIOCtlSlow: max(%#x,%#x); iCmd=%#x\n", StackBuf.Hdr.cbIn, StackBuf.Hdr.cbOut, iCmd));
         return EINVAL;
     }
@@ -730 +734 @@
      * Buffer the request.
      */
-    pHdr = RTMemTmpAlloc(cbBuf);
-    if (RT_UNLIKELY(!pHdr))
-    {
-        LogRel((DEVICE_NAME ":VBoxDrvSolarisIOCtlSlow: failed to allocate buffer of %d bytes for iCmd=%#x.\n", cbBuf, iCmd));
-        return ENOMEM;
+    if (cbBuf <= sizeof(StackBuf))
+        pHdr = &StackBuf.Hdr;
+    else
+    {
+        pHdr = RTMemTmpAlloc(cbBuf);
+        if (RT_UNLIKELY(!pHdr))
+        {
+            LogRel((DEVICE_NAME ":VBoxDrvSolarisIOCtlSlow: failed to allocate buffer of %d bytes for iCmd=%#x.\n", cbBuf, iCmd));
+            return ENOMEM;
+        }
     }
     rc = ddi_copyin((void *)iArg, pHdr, cbBuf, Mode);
     if (RT_UNLIKELY(rc))
     {
-        LogRel((DEVICE_NAME ":VBoxDrvSolarisIOCtlSlow: copy_from_user(,%#lx, %#x) failed; iCmd=%#x. rc=%d\n", iArg, Hdr.cbIn, iCmd, rc));
-        RTMemFree(pHdr);
+        LogRel((DEVICE_NAME ":VBoxDrvSolarisIOCtlSlow: copy_from_user(,%#lx, %#x) failed; iCmd=%#x. rc=%d\n", iArg, cbBuf, iCmd, rc));
+        if (pHdr != &StackBuf.Hdr)
+            RTMemFree(pHdr);
         return EFAULT;
     }
@@ -748 +758 @@
      */
     rc = supdrvIOCtl(iCmd, &g_DevExt, pSession, pHdr);
-
+    PFNRT a = RTMpIsCpuWorkPending;
+    
     /*
      * Copy ioctl data and output buffer back to user space.
@@ -771 +782 @@
         rc = EINVAL;
 
-    RTMemTmpFree(pHdr);
+    if (pHdr != &StackBuf.Hdr)
+        RTMemTmpFree(pHdr);
     return rc;
 }