Flexible and extensible receive side scaling

• US 8,150,981 B2
• Filed: 08/28/2009
• Issued: 04/03/2012
• Est. Priority Date: 06/28/2006
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Goglin, Stephen D., Cornett, Linden
• Primary Examiner(s): Lim, Krisna
• Application Number:
  US12/549,891
• Publication Number:
  US 20100061377A1
• Time in Patent Office: 949 Days
• Field of Search: 709/228, 709/223, 370/218, 370/355
• US Class Current: 709/228
• CPC Class Codes: H04L 12/56 Packet switching systems
• CPC Class Codes: H04L 45/745 Address table lookup; Address filtering
• CPC Class Codes: H04L 47/10 Flow control; Congestion control

Abstract

In an embodiment, a method is provided. The method of this embodiment provides in response to receiving a packet, looking up a packet characteristic in one of at least one protocol table to determine one or more fields of the packet to use as a hash value, applying a hash function to the hash value to obtain a hash result, and using the hash result to determine one of a plurality of processors on which to process the packet.

Claims

1. A computer implemented method for distributing packets across a plurality of processors of a computer, said method comprising:

in response to receiving a packet, looking up a packet characteristic in one of at least one protocol table stored on a computer readable memory to determine one or more fields of the packet to use as a hash value;

applying a hash function to the hash value to obtain a hash result;

using the hash result to determine one of said plurality of processors on which to process the packet; and

transmitting said packet to said determined one of said plurality of processors.

2. The method of claim 1, wherein said looking up a packet characteristic in one of at least one protocol table to determine one or more fields of the packet to use as a hash value comprises:

obtaining an offset and a mask corresponding to the packet characteristic; and

applying the mask to the packet at a start bit of the packet plus the offset.

3. The method of claim 2, wherein the packet characteristic comprises a protocol.

4. The method of claim 2, wherein the packet characteristic comprises a port identifier.

5. The method of claim 1, wherein said looking up a packet characteristic in one of at least one protocol table to determine one or more fields of the packet to use as a hash value comprises:

performing the following until there are no further layers to reveal;

revealing a next layer to expose a protocol; and

if the exposed protocol is a supported protocol, obtaining one or more default fields of the packet;

setting the revealed next layer to the last revealed protocol;

looking up the packet characteristic corresponding to the last revealed layer in one of the at least one protocol table to obtain an offset and a mask; and

if the packet characteristic is found, applying the offset and the mask to the packet.

6. The method of claim 5, additionally comprising if the packet characteristic is not found in the one of at least one protocol table, then using the one or more default fields as the hash value.

7. The method of claim 6, wherein if there are no default fields, sending the packet to a default one of the plurality of processors.

8. An apparatus for distributing packets across a plurality of processors, said apparatus comprising:

a computer comprising said plurality of processors; and

logic configured to run on said computer, said logic configured to;

in response to receiving a packet, look up a packet characteristic in one of at least one protocol table stored on a computer readable memory to determine one or more fields of the packet to use as a hash value;

apply a hash function to the hash value to obtain a hash result; and

use the hash result to determine one of said plurality of processors on which to process the packet; and

transmit said packet to said determined one of said plurality of processors.

9. The apparatus of claim 8, wherein said looking up a packet characteristic in one of at least one protocol table to determine one or more fields of the packet to use as a hash value comprises:

obtaining an offset and a mask corresponding to the packet characteristic; and

applying the mask to the packet at a start bit of the packet plus the offset.

10. The apparatus of claim 8, wherein said looking up a packet characteristic in one of at least one protocol table to determine one or more fields of the packet to use as a hash value comprises:

performing the following until there are no further layers to reveal;

revealing a next layer to expose a protocol; and

if the exposed protocol is a supported protocol, obtaining one or more default fields of the packet;

setting the revealed next layer to the last revealed protocol;

looking up the packet characteristic corresponding to the last revealed layer in one of the at least one protocol table to obtain an offset and a mask; and

if the packet characteristic is found, applying the offset and the mask to the packet.

11. The apparatus of claim 10, additionally comprising if the packet characteristic is not found in the one of at least one protocol table, then using the one or more default fields as the hash value.

12. The apparatus of claim 11, wherein if there are no default fields, sending the packet to a default one of the plurality of processors.

13. A system comprising:

a circuit card that is capable of being coupled to a circuit board via a circuit card slot of said circuit board, the circuit card including logic operable to;

in response to receiving a packet, look up a packet characteristic in one of at least one protocol table to determine one or more fields of the packet to use as a hash value;

in response to receiving a packet, look up a packet characteristic in one of at least one protocol table to determine one or more fields of the packet to use as a hash value

apply a hash function to the hash value to obtain a hash result; and

use the hash result to determine one of a plurality of processors on which to process the packet.

14. The system of claim 13, wherein said logic to look up a packet characteristic in one of at least one protocol table to determine one or more fields of the packet to use as a hash value comprises logic to:

obtain an offset and a mask corresponding to the packet characteristic; and

apply the mask to the packet at a start bit of the packet plus the offset.

15. The system of claim 13, wherein said logic to look up a packet characteristic in one of at least one protocol table to determine one or more fields of the packet to use as a hash value comprises logic to:

perform the following until there are no further layers to reveal;

revealing a next layer to expose a protocol; and

if the exposed protocol is a supported protocol, obtaining one or more default fields of the packet;

set the revealed next layer to the last revealed protocol;

look up the packet characteristic corresponding to the last revealed layer in one of the at least one protocol table to obtain an offset and a mask; and

if the packet characteristic is found, apply the offset and the mask to the packet.

16. The system of claim 15, additionally comprising if the packet characteristic is not found in the one of at least one protocol table, then using the one or more default fields as the hash value.

17. The system of claim 16, wherein if there are no default fields, sending the packet to a default one of the plurality of processors.

18. A system comprising:

a plurality of processors;

a plurality of receive queues, each of said plurality of receive queues associated with only one of said plurality of processors; and

a circuit card configured to receive a packet, the circuit card including logic operable to;

in response to receiving a packet, look up a packet characteristic in one of at least one protocol table to determine one or more fields of the packet to use as a hash value;

apply a hash function to the hash value to obtain a hash result;

use the hash result to determine one of said plurality of processors on which to process the packet; and

transmitting said packet to a receive queue associated with said determined one of said plurality of processors.

19. The system of claim 18, wherein said logic to look up a packet characteristic in one of at least one protocol table to determine one or more fields of the packet to use as a hash value comprises logic to:

obtain an offset and a mask corresponding to the packet characteristic; and

apply the mask to the packet at a start bit of the packet plus the offset.

20. The system of claim 18, wherein said logic to look up a packet characteristic in one of at least one protocol table to determine one or more fields of the packet to use as a hash value comprises logic to:

perform the following until there are no further layers to reveal;

revealing a next layer to expose a protocol; and

if the exposed protocol is a supported protocol, obtaining one or more default fields of the packet;

set the revealed next layer to the last revealed protocol;

look up the packet characteristic corresponding to the last revealed layer in one of the at least one protocol table to obtain an offset and a mask; and

if the packet characteristic is found, apply the offset and the mask to the packet.

21. The system of claim 20, additionally comprising if the packet characteristic is not found in the one of at least one protocol table, then using the one or more default fields as the hash value.

22. The system of claim 21, wherein if there are no default fields, sending the packet to a default one of the plurality of processors.