Abstract: A plurality of virtual processor threads are executed on the plurality of physical processor threads. In a data structure, information pertaining to a plurality of interrupt sources in the data processing system is maintained. The information includes a historical scope of transmission of interrupt commands for an interrupt source. Based on an interrupt request from an interrupt source, an interrupt master transmits a first interrupt bus command on an interconnect fabric of the data processing system to poll one or more interrupt snoopers regarding availability of one or more of the virtual processor threads to service an interrupt. The interrupt master updates the scope of transmission specified in the data structure based on a combined response to the first interrupt bus command. The interrupt master applies the scope of transmission specified in the data structure to a subsequent second interrupt bus command for the interrupt source.

Abstract: A plurality of virtual processor threads are executed on the plurality of physical processor threads. In a data structure, information pertaining to a plurality of interrupt sources in the data processing system is maintained. The information includes a historical scope of transmission of interrupt commands for an interrupt source. Based on an interrupt request from an interrupt source, an interrupt master transmits a first interrupt bus command on an interconnect fabric of the data processing system to poll one or more interrupt snoopers regarding availability of one or more of the virtual processor threads to service an interrupt. The interrupt master updates the scope of transmission specified in the data structure based on a combined response to the first interrupt bus command. The interrupt master applies the scope of transmission specified in the data structure to a subsequent second interrupt bus command for the interrupt source.

Abstract: Asynchronous completion notification is provided in a data processing system including one or more cores each executing one or more threads. A hardware unit of the data processing system receives and enqueues a request for processing and a source tag indicating at least a thread and core that issued the request. The hardware unit maintains a pointer to a completion area in a memory space. The completion area includes a completion granule for the hardware unit and thread. The hardware unit performs the processing requested by the request and computes an address of the completion granule based on the pointer and the source tag. The hardware unit then provides completion notification for the request by updating the completion granule with a value indicating a completion status.

Abstract: Techniques are disclosed for notifying network control software of new and moved source MAC addresses. In one embodiment, a switch may redirect a packet sent by a new or migrated virtual machine to the network control software as a notification. The switch does not forward the packet, thereby protecting against denial of service attacks. The switch further adds to a forwarding database a temporary entry which includes a “No_Redirect” flag for a new source MAC address, or updates an existing entry for a source MAC address that hits in the forwarding database by setting the “No_Redirect” flag. The “No_Redirect” flag indicates whether a notification has already been sent to the network control software for this source MAC address. The switch may periodically retry the notification to the network control software, until the network control software validates the source MAC address, depending on whether the “No_Redirect” is set.

Abstract: Techniques are disclosed for notifying network control software of new and moved source MAC addresses. In one embodiment, a switch may redirect a packet sent by a new or migrated virtual machine to the network control software as a notification. The switch does not forward the packet, thereby protecting against denial of service attacks. The switch further adds to a forwarding database a temporary entry which includes a “No_Redirect” flag for a new source MAC address, or updates an existing entry for a source MAC address that hits in the forwarding database by setting the “No_Redirect” flag. The “No_Redirect” flag indicates whether a notification has already been sent to the network control software for this source MAC address. The switch may periodically retry the notification to the network control software, until the network control software validates the source MAC address, depending on whether the “No_Redirect” is set.

Abstract: Techniques are disclosed for notifying network control software of new and moved source MAC addresses. In one embodiment, a switch detects packets sent by a new or migrated virtual machine, and sends a copy of a detected packet to the network control software as a notification. The switch further learns the source MAC address, thereby permitting the entry to be used for normal forwarding prior to validation of the entry and the VM associated therewith by the network control software. Until the network control software has validated the VM, the switch may periodically retry the notification to the network control software. “No_Redirect” and “Not_Validated” flags may be used to indicate whether a notification has already been attempted and thus no retry is necessary, and that the VM associated with the VM has not yet been validated, respectively.

Abstract: An approach is described for routing data to a plurality of output terminals via a integrated switch router including a crossbar switch having both a crossbar and a plurality of crossbar bypass lines. Whereas the crossbar may connect each input of the crossbar switch to each output of the crossbar switch, each of the plurality of crossbar bypass lines may connect a single input of the crossbar switch to a corresponding single output of the crossbar switch. According to such approach, a replicated copy of a multicast packet may be forwarded to an output terminal via a crossbar bypass line in parallel with other data forwarded via the crossbar, thus increasing integrated switch router bandwidth.

Abstract: A method for synchronizing multicast message subflows in a switched network includes associating, with a processing device, a first destination identifier corresponding to a multicast message with a first queue that corresponds to a first output port of a switching device, associating, with a processing device, a second destination identifier corresponding to the multicast message with a second queue that corresponds to a second output port of the switching device, pausing the first queue in response to a message counter corresponding to the first queue crossing a first predetermined threshold, and unpausing the first queue in response to the message counter crossing a second predetermined threshold, wherein the message counter indicates a quantity of data that has been forwarded by the first queue but remains to be forwarded by the second queue.

Abstract: Techniques are provided for retrieving entries from a routing table or a forwarding database in a distributed network switch. The forwarding database includes match and mask registers used to compare routing entries and return matching routing entries to a requesting management controller. The forwarding database uses a separate timeout value associated with the forwarding database to avoid timeout errors for general register operations, and allows for an asynchronous dump operation of routing entries.

Abstract: An approach is described for routing data to a plurality of output terminals via a integrated switch router including a crossbar switch having both a crossbar and a plurality of crossbar bypass lines. Whereas the crossbar may connect each input of the crossbar switch to each output of the crossbar switch, each of the plurality of crossbar bypass lines may connect a single input of the crossbar switch to a corresponding single output of the crossbar switch. According to such approach, a replicated copy of a multicast packet may be forwarded to an output terminal via a crossbar bypass line in parallel with other data forwarded via the crossbar, thus increasing integrated switch router bandwidth.

Abstract: Techniques are provided for retrieving entries from a routing table or a forwarding database in a distributed network switch. The forwarding database includes match and mask registers used to compare routing entries and return matching routing entries to a requesting management controller. The forwarding database uses a separate timeout value associated with the forwarding database to avoid timeout errors for general register operations, and allows for an asynchronous dump operation of routing entries.

Abstract: Techniques are provided for retrieving entries from a routing table or a forwarding database in a distributed network switch. The forwarding database includes match and mask registers used to compare routing entries and return matching routing entries to a requesting management controller. The forwarding database uses a separate timeout value associated with the forwarding database to avoid timeout errors for general register operations, and allows for an asynchronous dump operation of routing entries.

Abstract: Techniques are provided for retrieving entries from a routing table or a forwarding database in a distributed network switch. The forwarding database includes match and mask registers used to compare routing entries and return matching routing entries to a requesting management controller. The forwarding database uses a separate timeout value associated with the forwarding database to avoid timeout errors for general register operations, and allows for an asynchronous dump operation of routing entries.

Abstract: Techniques are provided for managing a routing table in a distributed network switch. The distributed network switch is divided into logical switch partitions, or logical networks, that may share a routing table. The shared routing table is configured with counters and thresholds to control utilization of the routing table on a per-logical network basis. When counters exceed certain threshold, the routing table is modified to reduce routing entries within the routing table or pause insertion of new routing entries.

Abstract: Techniques are provided for hash-based routing table management in a distributed network switch. A frame having a source address and a destination address is received. If no routing entry for the source address is found in a routing table of a switch module in the distributed network switch, routing information is determined for the source address and a routing entry is generated. The routing table is modified to include the routing entry and based on a set of hash functions.

Abstract: Techniques are provided for hash-based routing table management in a distributed network switch. A frame having a source address and a destination address is received. If no routing entry for the source address is found in a routing table of a switch module in the distributed network switch, routing information is determined for the source address and a routing entry is generated. The routing table is modified to include the routing entry and based on a set of hash functions.

Abstract: Receive a request to write a unit of data, having a first half of bits and a second half of bits, to an index of a ternary content addressable memory (TCAM). Generate a first error-correcting code (ECC) codeword for first bits of the first half of bits of the unit of data and first bits of the second half of bits of the unit of data. Generate a second error-correcting code (ECC) codeword for second bits of the first half of bits of the unit of data and second bits of the second half of bits of the unit of data. Store the first half of bits of the unit of data in the first row of the index. Store the second half of bits of the unit of data in the second row of the index.

Abstract: Receive a request to write a unit of data, having a first half of bits and a second half of bits, to an index of a ternary content addressable memory (TCAM). Generate a first error-correcting code (ECC) codeword for first bits of the first half of bits of the unit of data and first bits of the second half of bits of the unit of data. Generate a second error-correcting code (ECC) codeword for second bits of the first half of bits of the unit of data and second bits of the second half of bits of the unit of data. Store the first half of bits of the unit of data in the first row of the index. Store the second half of bits of the unit of data in the second row of the index.

Abstract: Techniques are provided for hash-based routing table management in a distributed network switch. A frame having a source address and a destination address is received by a switch module having bridge elements and a routing table divided into slices of buckets, each slice having a respective property and including one or more buckets. If a routing entry for the source address is found in a first slice of a first set of buckets of the routing table responsive to a lookup request for the source address, and the property of the first slice satisfies a replication condition, then the routing entry is replicated to a second set of buckets of the routing table.

Abstract: Techniques are provided for multicast miss notification for a distributed network switch. In one embodiment, a bridge element in the distributed network switch receives a frame destined for a multicast group on a network. If a local multicast forwarding table of the bridge element does not include any forwarding entry for the multicast group, a forwarding entry is selected from the local multicast forwarding table as a candidate for being replaced. An indication of the candidate is sent to a management controller in the distributed network switch.