Changeset 59448 in vbox for trunk/include/VBox

Timestamp:

Jan 22, 2016 6:45:31 PM (9 years ago)

Author:

vboxsync

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

105199

Message:

Devices/Storage: More work on the new I/O interface

Implement a new memory manager for allocating I/O buffers using a modified buddy algorithm.
The difference is that when both buddies are freed they don't coalesce automatically. This is to avoid
always splitting blocks up when the guest just wants to do 4KB transfers all the time. The defragmentation
will be done in one step if they allocator notices that it can't allocate enough memory from the correct bin
or bins which contain bigger blocks even though there is enough free memory (needs to be implemented).
The amount of I/O memory is static while the VM is running which makes the memory consumption by the I/O
stack more predictable. If requests can't allocate enough memory they need to chop up the transfer into smaller
parts. In case they can't allocate any I/O memory they are placed on a waiting list and are processed
when there is memory again.
The amount of usable I/O memory can be tuned with the "IoBufMax" CFGM key to accomodate for different workloads
and defaults to 5MB.

File:

• trunk/include/VBox/vmm/pdmstorageifs.h (modified) (3 diffs)

trunk/include/VBox/vmm/pdmstorageifs.h

@@ -629 +629 @@
      * @param   pvIoReqAlloc    The allocator specific memory for this request.
      * @param   offDst          The destination offset from the start to write the data to.
-     * @param   pvSrc           Where to read the data from.
+     * @param   pSgBuf          The S/G buffer to read the data from.
      * @param   cbCopy          How many bytes to copy.
      */
     DECLR3CALLBACKMEMBER(int, pfnIoReqCopyFromBuf, (PPDMIMEDIAEXPORT pInterface, PDMMEDIAEXIOREQ hIoReq,
-                                                    void *pvIoReqAlloc, uint32_t offDst, const void *pvSrc,
+                                                    void *pvIoReqAlloc, uint32_t offDst, PRTSGBUF pSgBuf,
                                                     size_t cbCopy));
 
@@ -645 +645 @@
      * @param   pvIoReqAlloc    The allocator specific memory for this request.
      * @param   offSrc          The offset from the start of the buffer to read the data from.
-     * @param   pvDst           Where to store the data.
+     * @param   pSgBuf          The S/G buffer to write the data to.
      * @param   cbCopy          How many bytes to copy.
      */
     DECLR3CALLBACKMEMBER(int, pfnIoReqCopyToBuf, (PPDMIMEDIAEXPORT pInterface, PDMMEDIAEXIOREQ hIoReq,
-                                                  void *pvIoReqAlloc, uint32_t offSrc, void *pvDst,
+                                                  void *pvIoReqAlloc, uint32_t offSrc, PRTSGBUF pSgBuf,
                                                   size_t cbCopy));
 
@@ -655 +655 @@
 
 /** PDMIMEDIAAEXPORT interface ID. */
-#define PDMIMEDIAEXPORT_IID                  "03c197d8-953c-4e24-b5bf-477379471cca"
+#define PDMIMEDIAEXPORT_IID                  "1385d27b-8648-4174-ac73-02148c479c90"