Control of pre-fetch traffic
First Claim
1. A method of controlling traffic generated by a processor, the method comprising:
- attaching, at the processor, a pre-fetch identifier to a pre-fetch request to flag the pre-fetch request as a pre-fetch request, rather than a non-pre-fetch request, the pre-fetch request requesting an item from a memory hierarchy, wherein the item comprises a piece of data or an instruction;
transmitting the pre-fetch request from the processor to the memory hierarchy; and
in response to receiving, at the processor, an abort response corresponding to the pre-fetch request, removing at least a portion of data stored locally to the processor relating to the pre-fetch request, wherein the abort response is received at the processor from the memory hierarchy and the abort response is generated by a node of the memory hierarchy based on the pre-fetch identifier.
8 Assignments
0 Petitions
Accused Products
Abstract
Methods and systems for improved control of traffic generated by a processor are described. In an embodiment, when a device generates a pre-fetch request for a piece of data or an instruction from a memory hierarchy, the device includes a pre-fetch identifier in the request. This identifier flags the request as a pre-fetch request rather than a non-pre-fetch request, such as a time-critical request. Based on this identifier, the memory hierarchy can then issue an abort response at times of high traffic which suppresses the pre-fetch traffic, as the pre-fetch traffic is not fulfilled by the memory hierarchy. On receipt of an abort response, the device deletes at least a part of any record of the pre-fetch request and if the data/instruction is later required, a new request is issued at a higher priority than the original pre-fetch request.
13 Citations
20 Claims
-
1. A method of controlling traffic generated by a processor, the method comprising:
-
attaching, at the processor, a pre-fetch identifier to a pre-fetch request to flag the pre-fetch request as a pre-fetch request, rather than a non-pre-fetch request, the pre-fetch request requesting an item from a memory hierarchy, wherein the item comprises a piece of data or an instruction; transmitting the pre-fetch request from the processor to the memory hierarchy; and in response to receiving, at the processor, an abort response corresponding to the pre-fetch request, removing at least a portion of data stored locally to the processor relating to the pre-fetch request, wherein the abort response is received at the processor from the memory hierarchy and the abort response is generated by a node of the memory hierarchy based on the pre-fetch identifier. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A method of controlling traffic generated by a processor, the method comprising:
-
receiving, at a node in a memory hierarchy, a pre-fetch request from the processor, the prefetch request including a pre-fetch identifier and requesting an item stored in the memory hierarchy, wherein the item comprises a piece of data or an instruction; based on the pre-fetch identifier and an assessment of traffic levels within a part of the memory hierarchy, determining whether to generate an abort response corresponding to the pre-fetch request; if the assessment determines that an abort response is to be generated, generating the abort response corresponding to the pre-fetch request; and transmitting the abort response to the processor. - View Dependent Claims (8, 9, 10, 11)
-
-
12. A system comprising:
-
a plurality of devices arranged to generate requests for items from a memory hierarchy, wherein an item comprises a piece of data or an instruction; at least a portion of the memory hierarchy; and at least one bus connecting the plurality of devices and the memory hierarchy, wherein at least one of the plurality of devices comprises; first hardware logic arranged to attach a pre-fetch identifier to a pre-fetch request to flag the pre-fetch request as a pre-fetch request rather than a non-pre-fetch request, the pre-fetch request requesting an item from a memory hierarchy and transmit the pre-fetch request from the device to the memory hierarchy; and second hardware logic arranged to remove at least a portion of data stored locally to the device relating to a pre-fetch request in response to receiving an abort response corresponding to the pre-fetch request, wherein the abort response is generated by a node in the memory hierarchy based on the pre-fetch identifier. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19)
-
-
20. A method of resetting a portion of a system, the method comprising:
-
generating an abort all response in a memory hierarchy; and in response to receiving the abort all response at a processor, removing at least a portion of data stored locally to the processor relating to any unfulfilled requests for data items stored in the memory hierarchy previously sent to the memory hierarchy.
-
Specification