System and method for pre-calculating checksums
View Patent ↗In a packet transmission system that uses checksums, partial checksum calculations may be performed during periods of processor underutilization while the data is awaiting final output processing for transport. A system wide checksum service process may coordinate checksum calculations across multiple network protocol layers. The checksum calculations for the buffered data may be performed according to a priority assigned to the buffered data. For example, buffered data whose transmission is imminent may have a higher priority than buffered data that will be transmitted at a later time. Applications that generate data for transmission may register those portions with the service for checksum calculation. To simplify the process, a metadata structure may be created for the data portion, and used to manage the checksum calculations.
1. A method comprising:
storing a first portion of data to await output processing for transmission in a packet;
determining that a resource utilization is below a predetermined threshold while the first portion of data is awaiting output processing;
performing a checksum calculation on the first portion of data in response to determining that the resource utilization is below the predetermined threshold;
storing results of the checksum calculation; and
assigning different checksum priorities to different data portions based on time-to-output values for the different data portions.
2. The method of claim 1 , further comprising:
beginning output processing to formulate a packet carrying the first portion of data, wherein the output processing includes the following:
retrieving the stored results of the checksum calculation;
using the retrieved results in a further checksum calculation; and
finalizing and transmitting the packet.
3. The method of claim 1 , further comprising maintaining a plurality of checksum calculation queues corresponding to the different priorities.
4. The method of claim 1 , further comprising adjusting each of the assigned priorities as a transmission time for the first portion of data approaches.
5. The method of claim 1 , further comprising:
managing checksum calculations across multiple network layers in a layered network protocol, wherein checksum calculations for data at a first network layer are performed at a higher priority than checksum calculations for data at a second network layer.
6. The method of claim 1 , further comprising:
completing the checksum calculation on the first portion of data,
wherein the step of completing the checksum calculation includes a step of retrieving cached checksum information that was used in a previous packet.
7. The method of claim 1 , further comprising:
managing checksum calculations at an application stage, a transport buffer stage and transport output stage, wherein partial checksum calculations are performed at the application stage and transport buffer stage at a lower priority than checksum calculations performed at the transport output stage.
8. A computer-readable medium, storing computer-executable instructions that, when executed, cause an apparatus to:
store a first portion of data to await output processing for transmission in a packet;
determine that a resource utilization is below a predetermined threshold while the first portion of data is awaiting output processing;
perform a checksum calculation on the first portion of data in response to determining that the resource utilization is below the predetermined threshold;
store results of the checksum calculation; and
assign different checksum priorities to different data portions based on time-to-output values for the different data portions.
9. The computer-readable medium of claim 8 , further storing computer-executable instructions that, when executed, cause the apparatus to:
begin output processing to formulate a packet carrying the first portion of data, wherein the output processing includes the following:
retrieving the stored results of the checksum calculation;
using the retrieved results in a further checksum calculation; and
finalizing and transmitting the packet.
10. The computer-readable medium of claim 8 , further storing computer-executable instructions that, when executed, cause the apparatus to:
maintain a plurality of checksum calculation queues corresponding to the different priorities.
11. The computer-readable medium of claim 8 , further storing computer-executable instructions that, when executed, cause the apparatus to:
adjust each of the assigned priorities as a transmission time for the first portion of data approaches.
12. The computer-readable medium of claim 8 , further storing computer-executable instructions that, when executed, cause the apparatus to:
manage checksum calculations across multiple network layers in a layered network protocol, wherein checksum calculations for data at a first network layer are performed at a higher priority than checksum calculations for data at a second network layer.
13. The computer-readable medium of claim 8 , further storing computer-executable instructions that, when executed, cause the apparatus to:
complete the checksum calculation on the first portion of data,
wherein completing the checksum calculation includes retrieving cached checksum information that was used in a previous packet.
14. The computer-readable medium of claim 8 , further storing computer-executable instructions that, when executed, cause the apparatus to:
manage checksum calculations at an application stage, a transport buffer stage and transport output stage, wherein partial checksum calculations are performed at the application stage and transport buffer stage at a lower priority than checksum calculations performed at the transport output stage.
15. An apparatus, comprising:
a processor; and
memory storing instructions that, when executed by the processor, cause the apparatus to:
store a first portion of data to await output processing for transmission in a packet;
determine that a resource utilization is below a predetermined threshold while the first portion of data is awaiting output processing;
perform a checksum calculation on the first portion of data in response to determining that the resource utilization is below the predetermined threshold;
store results of the checksum calculation; and
assign different checksum priorities to different data portions based on time-to-output values for the different data portions.
16. The apparatus of claim 15 , wherein the instructions, when executed by the processor, cause the apparatus to:
begin output processing to formulate a packet carrying the first portion of data, wherein the output processing includes the following:
retrieving the stored results of the checksum calculation;
using the retrieved results in a further checksum calculation; and
finalizing and transmitting the packet.
17. The apparatus of claim 15 , wherein the instructions, when executed by the processor, cause the apparatus to:
maintain a plurality of checksum calculation queues corresponding to the different priorities.
18. The apparatus of claim 15 , wherein the instructions, when executed by the processor, cause the apparatus to:
adjust each assigned priority as a transmission time for the first portion of data approaches.
19. The apparatus of claim 15 , wherein the instructions, when executed by the processor, cause the apparatus to:
manage checksum calculations across multiple network layers in a layered network protocol, wherein checksum calculations for data at a first network layer are performed at a higher priority than checksum calculations for data at a second network layer.
20. The apparatus of claim 15 , wherein the instructions, when executed by the processor, cause the apparatus to:
complete the checksum calculation on the first portion of data,
wherein completing the checksum calculation includes retrieving cached checksum information that was used in a previous packet.
21. The apparatus of claim 15 , wherein the instructions, when executed by the processor, cause the apparatus to:
manage checksum calculations at an application stage, a transport buffer stage and transport output stage, wherein partial checksum calculations are performed at the application stage and transport buffer stage at a lower priority than checksum calculations performed at the transport output stage.