Abstract:
A method, system and apparatus for transferring data from one partition of a partitioned system to another without using a network are provided. When a first partition needs to transfer data to a second partition, it marks the data, which is located in its part of the system&#39;s partitioned memory, as a “read-only” data and indicates so to partitioned system&#39;s firmware or hardware. This indication is usually manifested by passing a pointer to the data, as well as the identification of the partition to receive the data to the firmware or hardware. Upon being notified, the firmware or hardware of the partitioned system re-assigns the memory locations containing the data to the second partition and passes the pointer to the second partition. As a measure of (redundant) security, the second partition checks to see whether the data is indeed a “read-only” data. If so, it reads the data, else it does not. After reading the data, it so informs the firmware or hardware so that the memory locations of the data can be re-assigned back to the first partition. Thus, because the data never enters the network, it is transferred with the utmost security.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Technical Field  
           [0002]    The present invention is directed to a method and apparatus for managing a computer system. More specifically, the present invention is directed to a method and apparatus for transferring data from one partition of a partitioned computer system to another.  
           [0003]    2. Description of Related Art  
           [0004]    Presently, many computer manufacturers design computer systems with partitioning capability. To partition a computer system is to divide the computer system&#39;s resources (i.e., memory devices, processors etc.) into groups; thus, allowing for a plurality of operating systems to be concurrently executing on the computer system.  
           [0005]    Partitioning a computer system may be done for a variety of reasons. Firstly, it may be done for consolidation purposes. Clearly consolidating a variety of computer systems into one by running multiple application programs that previously resided on the different computer systems on only one reduces (i) cost of ownership of the system, (ii) system management requirements and (iii) footprint size.  
           [0006]    Secondly, partitioning may be done to provide production environment and test environment consistency. This, in turn, may inspire more confidence that an application program that has been tested successfully will perform as expected.  
           [0007]    Thirdly, partitioning a computer system may provide increased hardware utilization. For example, when an application program does not scale well across large numbers of processors, running multiple instances of the program on separate smaller partitions may provide better throughput.  
           [0008]    Fourthly, partitioning a system may provide application program isolation. When application programs are running on different partitions, they are guaranteed not to interfere with each other. Thus, in the event of a failure in one partition, the other partitions will not be affected. Furthermore, none of the application programs may consume an excessive amount of hardware resources. Consequently, no application programs will be starved out of required hardware resources.  
           [0009]    Lastly, partitioning provides increased flexibility of resource allocation. A workload that has resource requirements that vary over a period of time may be managed more easily if it is being run on a partition. That is, the partition may be easily altered to meet the varying demands of the workload.  
           [0010]    Currently, if a first partition needs to pass data to a second partition, it has to use the network. Specifically, the data has to travel the TCP/IP stack of the transmitting partition and enters the network. From the network, the data will enter the recipient partition through a network interface, travels up the recipient&#39;s TCP/IP stack to be processed. This is a time-consuming and CPU intensive task.  
           [0011]    Thus, what is needed is an apparatus and method of passing data from one partition to another without using a network.  
         SUMMARY OF THE INVENTION  
         [0012]    The present invention provides a method, system and apparatus for transferring data from one partition of a partitioned system to another without using a network. When a first partition needs to transfer data to a second partition, it marks the data, which is located in its part of the system&#39;s partitioned memory, as a “read-only” data and indicates so to partitioned system&#39;s firmware or hardware. This indication is usually manifested by passing a pointer to the data, as well as the identification of the partition to receive the data to the firmware or hardware. Upon being notified, the firmware or hardware of the partitioned system re-assigns the memory locations containing the data to the second partition and passes the pointer to the second partition. As a measure of (redundant) security, the second partition checks to see whether the data is indeed a “read-only” data. If so, it reads the data, else it does not. After reading the data, it so informs the firmware or hardware so that the memory locations of the data can be re-assigned back to the first partition. Thus, because the data never enters the network, it is transferred with the utmost security.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:  
         [0014]    [0014]FIG. 1 is an exemplary block diagram illustrating a distributed data processing system according to the present invention.  
         [0015]    [0015]FIG. 2 is an exemplary block diagram of a server apparatus according to the present invention.  
         [0016]    [0016]FIG. 3 is an exemplary block diagram of a client apparatus according to the present invention.  
         [0017]    [0017]FIG. 4 illustrates a logically partitioned (LPAR) computer system.  
         [0018]    [0018]FIG. 5 illustrates a mapping table of resources of an LPAR system.  
         [0019]    [0019]FIG. 6 illustrates a mapping table of resources after re-assignment of a buffer from a first partition to a second partition.  
         [0020]    [0020]FIG. 7 is a flow chart of a process that may be used when a partition needs to transfer data to another partition.  
         [0021]    [0021]FIG. 8 illustrates a flow chart of a process that may be used by a receiving partition.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0022]    With reference now to the figures, FIG. 1 depicts a pictorial representation of a network of data processing systems in which the present invention may be implemented. Network data processing system  100  is a network of computers in which the present invention may be implemented. Network data processing system  100  contains a network  102 , which is the medium used to provide communications links between various devices and computers connected together within network data processing system  100 . Network  102  may include connections, such as wire, wireless communication links, or fiber optic cables.  
         [0023]    In the depicted example, server  104  is connected to network  102  along with storage unit  106 . In addition, clients  108 ,  110 , and  112  are connected to network  102 . These clients  108 ,  110 , and  112  may be, for example, personal computers or network computers. In the depicted example, server  104  provides data, such as boot files, operating system images, and applications to clients  108 ,  110  and  112 . Clients  108 ,  110  and  112  are clients to server  104 . Network data processing system  100  may include additional servers, clients, and other devices not shown. In the depicted example, network data processing system  100  is the Internet with network  102  representing a worldwide collection of networks and gateways that use the TCP/IP suite of protocols to communicate with one another. At the heart of the Internet is a backbone of high-speed data communication lines between major nodes or host computers, consisting of thousands of commercial, government, educational and other computer systems that route data and messages. Of course, network data processing system  100  also may be implemented as a number of different types of networks, such as for example, an intranet, a local area network (LAN), or a wide area network (WAN). FIG. 1 is intended as an example, and not as an architectural limitation for the present invention.  
         [0024]    Referring to FIG. 2, a block diagram of a data processing system that may be implemented as a server, such as server  104  in FIG. 1, is depicted in accordance with a preferred embodiment of the present invention. Data processing system  200  may be a symmetric multiprocessor (SMP) system including a plurality of processors  202  and  204  connected to system bus  206 . Alternatively, a single processor system may be employed. Also connected to system bus  206  is memory controller/cache  208 , which provides an interface to local memory  209 . I/O bus bridge  210  is connected to system bus  206  and provides an interface to I/O bus  212 . Memory controller/cache  208  and I/O bus bridge  210  may be integrated as depicted.  
         [0025]    Peripheral component interconnect (PCI) bus bridge  214  connected to I/O bus  212  provides an interface to PCI local bus  216 . A number of modems may be connected to PCI local bus  216 . Typical PCI bus implementations will support four PCI expansion slots or add-in connectors. Communications links to network computers  108 ,  110  and  112  in FIG. 1 may be provided through modem  218  and network adapter  220  connected to PCI local bus  216  through add-in boards. Additional PCI bus bridges  222  and  224  provide interfaces for additional PCI local buses  226  and  228 , from which additional modems or network adapters may be supported. In this manner, data processing system  200  allows connections to multiple network computers. A memory-mapped graphics adapter  230  and hard disk  232  may also be connected to I/O bus  212  as depicted, either directly or indirectly.  
         [0026]    Those of ordinary skill in the art will appreciate that the hardware depicted in FIG. 2 may vary. For example, other peripheral devices, such as optical disk drives and the like, also may be used in addition to or in place of the hardware depicted. The depicted example is not meant to imply architectural limitations with respect to the present invention.  
         [0027]    The data processing system depicted in FIG. 2 may be, for example, an IBM e-Server pSeries system, a product of International Business Machines Corporation in Armonk, N.Y., running the Advanced Interactive Executive (AIX) operating system or LINUX operating system.  
         [0028]    With reference now to FIG. 3, a block diagram illustrating a data processing system is depicted in which the present invention may be implemented. Data processing system  300  is an example of a client computer. Data processing system  300  employs a peripheral component interconnect (PCI) local bus architecture. Although the depicted example employs a PCI bus, other bus architectures such as Accelerated Graphics Port (AGP) and Industry Standard Architecture (ISA) may be used. Processor  302  and main memory  304  are connected to PCI local bus  306  through PCI bridge  308 . PCI bridge  308  also may include an integrated memory controller and cache memory for processor  302 . Additional connections to PCI local bus  306  may be made through direct component interconnection or through add-in boards. In the depicted example, local area network (LAN) adapter  310 , SCSI host bus adapter  312 , and expansion bus interface  314  are connected to PCI local bus  306  by direct component connection. In contrast, audio adapter  316 , graphics adapter  318 , and audio/video adapter  319  are connected to PCI local bus  306  by add-in boards inserted into expansion slots. Expansion bus interface  314  provides a connection for a keyboard and mouse adapter  320 , modem  322 , and additional memory  324 . Small computer system interface (SCSI) host bus adapter  312  provides a connection for hard disk drive  326 , tape drive  328 , and CD-ROM drive  330 . Typical PCI local bus implementations will support three or four PCI expansion slots or add-in connectors.  
         [0029]    An operating system runs on processor  302  and is used to coordinate and provide control of various components within data processing system  300  in FIG. 3. The operating system may be a commercially available operating system, such as Windows 2000, which is available from Microsoft Corporation. An object oriented programming system such as Java may run in conjunction with the operating system and provide calls to the operating system from Java programs or applications executing on data processing system  300 . “Java” is a trademark of Sun Microsystems, Inc. Instructions for the operating system, the object-oriented operating system, and applications or programs are located on storage devices, such as hard disk drive  326 , and may be loaded into main memory  304  for execution by processor  302 .  
         [0030]    Those of ordinary skill in the art will appreciate that the hardware in FIG. 3 may vary depending on the implementation. Other internal hardware or peripheral devices, such as flash ROM (or equivalent nonvolatile memory) or optical disk drives and the like, may be used in addition to or in place of the hardware depicted in FIG. 3. Also, the processes of the present invention may be applied to a multiprocessor data processing system.  
         [0031]    As another example, data processing system  300  may be a stand-alone system configured to be bootable without relying on some type of network communication interface, whether or not data processing system  300  comprises some type of network communication interface. As a further example, data processing system  300  may be a Personal Digital Assistant (PDA) device, which is configured with ROM and/or flash ROM in order to provide non-volatile memory for storing operating system files and/or user-generated data.  
         [0032]    The depicted example in FIG. 3 and above-described examples are not meant to imply architectural limitations. For example, data processing system  300  may also be a notebook computer or hand held computer in addition to taking the form of a PDA. Data processing system  300  also may be a kiosk or a Web appliance.  
         [0033]    The present invention provides an apparatus and method of allowing data to be passed from one partition of a logically partitioned computer system to another without using a network. The invention may be local to client systems  108 ,  110  and  112  of FIG. 1 or to the server  104  or to both the server  104  and clients  108 ,  110  and  112 . Consequently, the present invention may reside on any data storage medium (i.e., floppy disk, compact disk, hard disk, ROM, RAM, etc.) used by a computer system.  
         [0034]    [0034]FIG. 4 illustrates a plurality of partitions of a computer system. Partition 1  410  has two (2) processors, two (2) I/O slots and used a percentage of the memory device. Partition 2  420  uses one (1) processor, five (5) I/O slots and also used a smaller percentage of the memory device. Partition 3  430  uses four (4) processors, five (5) I/O slots and uses a larger percentage of the memory device. Areas  440  and  450  of the computer system are not assigned to a partition and are unused. Note that in FIG. 4 only subsets of resources needed to support an operating system are shown.  
         [0035]    As shown, when a computer system is partitioned its resources are divided among the partitions. The resources that are not assigned to a partition are not used. More specifically, a resource may either belong to a single partition or not belong to any partition at all. If the resource belongs to a partition, it is known to and is only accessible to that partition. If the resource does not belong to any partition, it is neither known to nor is accessible to any partition. Note that one CPU may be shared by two or more partitions. In that case, the CPU will spend an equal amount of time processing data from the different partitions.  
         [0036]    The computer system ensures that the resources assigned to one partition are not used by another partition through a mapping table. FIG. 5 illustrates such table. In FIG. 5, CPU 1  and CPU 2 , memory location  1  to memory location  50  (i.e., M 1 -M 50 ) and input/output (I/O) slot 4  and slot 5  are mapped to partition 1    500 . Likewise, CPU 3 , M 51 -M 75  and I/O slot 6  to slot 10  are mapped to partition 2    502  and CPU 4  to CPU 7 , M 76 -M 150  and I/O slot 11  to I/O slot 15  are mapped to partitions  504 .  
         [0037]    As mentioned before, when a partition of a partitioned system needs to pass a piece of data to another partition of the system, it does so using the network (i.e., the data travels through the TCP/IP stack of the transmitting partition and onto the network, from there it enters the recipient partition, travels through its TCP/IP stack to be processed). This requires quite a bit of processing time and power.  
         [0038]    The invention temporarily re-assigns the portion of its memory containing the data to the other partition; thereby reducing the amount of time and work that the CPUs may expend. For example, if the data exists in memory locations M 1  to M 20  of partition, that part of the memory will be re-assigned to partition 2  as shown in FIG. 6. Once, partition 2  has finished reading the data, memory locations M 1  to M 20  will be re-assigned back to partition 1  (see FIG. 5). Before, assigning the memory locations containing the data to partition 2 , partition 1  ensures that the data is not modified by the recipient partition, the transmitting partition marks it a “read only” memory. As a redundant security, before using the data, partition 2  (the recipient partition) ascertains that the memory location containing the data is indeed a “read only” memory. If so, it will use the data; otherwise it will not. Hence the data is transmitted from one partition to another without ever entering the network. Furthermore, since the data never enters the network, it is transmitted with the utmost security.  
         [0039]    [0039]FIG. 7 is a flow chart of a process that may be used when a partition needs to transfer data to another partition. The process starts when a piece of data is to be transferred (steps  700  and  702 ). Then, the buffer containing the data is marked as a “read-only” buffer before passing the pointer to the buffer to the computer system&#39;s firmware or hardware that is going to re-assign the memory locations containing the data to the receiving partition. Of course the identification of the partition to receive the data is also passed to the firmware or hardware. After the firmware or hardware re-assigns the memory location containing the data to the receiving partition, the process ends (steps  704 - 710 ).  
         [0040]    [0040]FIG. 8 illustrates a flow chart of a process that may be used by a receiving partition. The process starts as soon as the receiving partition receives the pointer to a buffer containing data from the firmware (steps  800  and  802 ). A check is then made to ascertain that the buffer containing the data is a “read-only” buffer. If so, the receiving uses the data. Once done, the receiving partition informs the firmware or hardware. The firmware or hardware then assigns the memory locations containing the data back to the transmitting partition and the process ends (steps  804 ,  806 ,  808  and  814 ).  
         [0041]    If the buffer containing the data is not a “read-only” buffer, the receiving partition will not use the data and will inform the firmware or hardware that it did not read the data because it was not in a “read-only” buffer. The firmware or hardware will then inform the transmitting partition that the data was not read by the receiving partition and the reason why it was not read and re-assign the memory locations containing the data back to the transmitting partition. At this point, the transmitting partition has the option to attempt retransmission or not.  
         [0042]    The description of the present invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to best explain the principles of the invention, the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.