Methods for Consistency of Channel -Path- Reconnection with Direct I/O - Execution

• Item type: Journal(1)
• 公開日: 1995-05-15
• タイトル: Methods for Consistency of Channel -Path- Reconnection with Direct I/O - Execution
• タイトル / 言語: en
• タイトル: Methods for Consistency of Channel -Path- Reconnection with Direct I/O - Execution
• 言語: eng
• キーワード / 主題Scheme: Other
• キーワード / 主題: 論文
• 資源タイプ / 資源タイプ識別子: http://purl.org/coar/resource_type/c_6501
• 資源タイプ: journal article
• その他タイトル / その他のタイトル: 入出力方式
• 著者所属: Software Development Department General Purpose Computer Division Hitachi Ltd
• 著者所属: Department 3 Systems Development Laboratory Hitachi Ltd
• 著者所属: Department 3 Systems Development Laboratory Hitachi Ltd
• 著者所属(英): en
• 著者所属(英): Software Development Department, General Purpose Computer Division, Hitachi Ltd
• 著者所属(英): en
• 著者所属(英): Department 3, Systems Development Laboratory, Hitachi Ltd
• 著者所属(英): en
• 著者所属(英): Department 3, Systems Development Laboratory, Hitachi Ltd
• 著者名: Hidenori, Umeno; Taro, Inoue; Shunji, Tanaka
• 著者名(英): Hidenori, Umeno; Taro, Inoue; Shunji, Tanaka
• 論文抄録 / 内容記述タイプ: Other
• 論文抄録 / 内容記述: Methods are presented for the consistency of the Channel-Path-Reconnection (CPR) with the Direct I/O-Execution (DIO) . The CPR is the native function of the channel subsystem and dynamically reconnects devices to free channel-paths at ends of I/O operations. The CPR is effective in a channel-path-group which is a set of channel-paths and defined by an OS to use it. The CPR is the key function to enhance I/O response. On the other hand the DIO means that real host computers directly execute the I/O instructions and I/O interrupts of virtual machines (VMs) ~vithout intervention of a virtual machine monitor (VMM) which is a control program for controlling the VMs. The DIO is the key feature to improve VM CPU performance. Conventionally in shared channel-paths by the VMs guest OSs (i.e. OSs in VMs) cannot use the CP^R and the DIO at the same time. This restriction comes from uniqueness requirement of a channel-path : A channel-path with the CPR has to belong to only one channel-path-group. This requirement is reasonable in real machine environment. In VM environment multiple guest OSs are going to define their own channel-path-groups that contain shared channel-paths. The definitions do not satisfy the above-stated uniqueness requirement. Therefore they are rejected and the guest OSs cannot use the CPR to the shared channel-paths though they can use the D]:O for other I/O instructions. The proposed method.s consist of handshakings which mean mod:ifying OSs for VMs and several hardware extensions for channel-path-groups and channel-path modes. Channel-path-groups are recognized by their identifiers. In the handshakings the VMM gives the OSs channel-path-group identifiers that satisfy the uniqueness requirement of channel-paths based on the forms of channel-path allocation. One of the hardware extensions eases the uniqueness requirement of channel-paths that is the uniqueness is required only in guest OSs and not in a total system. The extension enables the guest OSs to compose their own channel-path-groups that contain shared channel-paths under the DIO. Any one of the proposed methods can provide consistency of the CPR with the DIO to the VMS Whether channel-paths are shared by the VMS or not.
• 論文抄録(英) / 内容記述タイプ: Other
• 論文抄録(英) / 内容記述: Methods are presented for the consistency of the Channel-Path-Reconnection (CPR) with the Direct I/O-Execution (DIO) . The CPR is the native function of the channel subsystem, and dynamically reconnects devices to free channel-paths at ends of I/O operations. The CPR is effective in a channel-path-group, which is a set of channel-paths, and defined by an OS to use it. The CPR is the key function to enhance I/O response. On the other hand, the DIO means that real host computers directly execute the I/O instructions and I/O interrupts of virtual machines (VMs) ~vithout intervention of a virtual machine monitor (VMM), which is a control program for controlling the VMs. The DIO is the key feature to improve VM CPU performance. Conventionally, in shared channel-paths by the VMs, guest OSs (i.e., OSs in VMs) cannot use the CP^R and the DIO at the same time. This restriction comes from uniqueness requirement of a channel-path : A channel-path with the CPR has to belong to only one channel-path-group. This requirement is reasonable in real machine environment. In VM environment, multiple guest OSs are going to define their own channel-path-groups that contain shared channel-paths. The definitions do not satisfy the above-stated uniqueness requirement. Therefore, they are rejected and the guest OSs cannot use the CPR to the shared channel-paths, though they can use the D]:O for other I/O instructions. The proposed method.s consist of handshakings, which mean mod:ifying OSs for VMs, and several hardware extensions for channel-path-groups and channel-path modes. Channel-path-groups are recognized by their identifiers. In the handshakings, the VMM gives the OSs channel-path-group identifiers that satisfy the uniqueness requirement of channel-paths based on the forms of channel-path allocation. One of the hardware extensions eases the uniqueness requirement of channel-paths, that is, the uniqueness is required only in guest OSs, and not in a total system. The extension enables the guest OSs to compose their own channel-path-groups that contain shared channel-paths under the DIO. Any one of the proposed methods can provide consistency of the CPR with the DIO to the VMS Whether channel-paths are shared by the VMS or not.
• 書誌レコードID / 収録物識別子タイプ: NCID
• 書誌レコードID / 収録物識別子: AN00116647
• 書誌情報: 情報処理学会論文誌; 巻 36, 号 5, p. 1239-1251, 発行日 1995-05-15
• ISSN / 収録物識別子タイプ: ISSN
• ISSN / 収録物識別子: 1882-7764