CN105045729B - A kind of buffer consistency processing method and system of the remote agent with catalogue - Google Patents

Abstract

The invention discloses a cache consistency processing method and system of a remote agent with a directory, which enables the remote agent to obtain and process a local request initiated by a local request source, and when receiving a response message from the remote agent and data, return the response message and data to the local request source, write the corresponding directory and data into the directory cache and data cache respectively, and determine whether there are other target requests with the same address as the remote agent , if there is, then process the target requests sequentially, from the time when the local request is sent to the remote agent to occupy a directory and data cache, until the response message of the request is returned, and the internal cache resource of the remote agent becomes invalid , if there are other requests or listener messages from the same address that meet certain conditions and enter the remote agent, the request can be directly processed inside the remote agent, reducing message flow and getting a quick response without cross-node operations, reducing overhead.

Description

A remote agent cache consistency processing method and system with directory

technical field

The invention relates to the field of computer architecture, in particular to a method and a system for processing cache consistency with a directory of a remote agent.

Background technique

A multi-channel server system based on a coherent interconnection chip needs to maintain data cache consistency during the implementation process. In the process of implementing the current cache coherence protocol, the local proxy and the remote proxy act as the main body of proxying remote requests and local requests respectively, and are the two main parts of the coherence chip protocol processing.

In order to reduce interception messages in the intermediate process and speed up the response speed of the system, both the remote agent and the local agent can record the data status of the Cache Line cache line in the form of a "directory". However, as the multi-way server system manages more and more physical storage resources, the storage resource overhead of the "directory" method is also increasing, especially on the remote agent side of the multi-way system. Considering the balance, in the process of implementation, the remote agent has no "directory" and the local agent adopts a full "directory". There is a lack of a cache consistency processing method with a relatively small overhead and a remote agent with a directory.

Contents of the invention

In view of this, the main purpose of the present invention is to provide a cache consistency processing method and system for a remote agent with a directory, so that the remote agent has a directory with less overhead.

In order to achieve the above object, the present invention provides a cache consistency processing method with a remote proxy directory, including:

Step A: Make the remote agent obtain and process the local request initiated by the local request source;

Step B: When receiving the response message and data from the remote agent, return the response message and data to the local request source, and write the corresponding directory and data into the directory cache and data cache respectively ;

Step C: Judging whether there are other target requests with the same address as the remote agent, and if so, processing the target requests in sequence.

Preferably, other target requests identical to the address of the remote agent include:

The local request source sends a local request to the address of the remote agent and a remote listening request from the address of the remote agent.

Preferably, processing the target request includes:

determine the type of the target request;

When the type of the target request is a local request, process the target request according to the priority level of the local request and the directory state information in the directory cache;

When the type of the target request is a remote listening request, the target request is processed according to the priorities of the remote listening request and the directory status information in the directory cache.

Preferably, the state information includes modified state, exclusive state, shared state and invalid state;

The modified state has the same priority as the exclusive state and is higher than the shared state, and the shared state has a higher priority than the invalid state.

Preferably, when the type of the target request is a local request, the target request is processed according to the priority levels of the local request and the directory status information in the directory cache:

judging whether the priority level of the directory in the directory cache is higher than or equal to the priority level of the local request;

If the priority level of the directory in the directory cache is higher than or equal to the priority level of the local request, keep the local state information of the remote address data unchanged, initiate local listening, and return when the response of the local listening When modifying the directory information corresponding to the local request source;

Judging whether the same-address request queue is empty and the condition that the cache resource needs to be released is satisfied, if not, return to the step C, if satisfied, judge whether the directory status information is in the modified state, and end when the directory state information is not in the modified state Process, when the directory status information is in the modified state, judge whether there is only one request source with a copy, if so, end the process, otherwise initiate a shared state write-back request, release the corresponding resource and end when receiving the write-back completion information process;

If the priority level of the directory in the directory cache is lower than the priority level of the local request, initiate an invalidation interception of the local request, invalidate the data in the source of the local request, and initiate to the remote address when the invalidation interception response returns Write back request, when receiving the write back request completion information, initiate the current local request to the remote end.

Preferably, when the type of the target request is a remote listening request, processing the target request according to the priority level of the remote listening request and the directory status information in the directory cache includes:

Judging whether the state information of the directory of the directory cache and the state information of the remote listening request are shared states, if so, return a shared state response message to the remote end, and return to step C, otherwise initiate and communicate with the remote end For the same local listening request or invalid listening request as the listening request, when the response of the local listening request or invalid listening request is returned, update or invalidate the local directory cache and data cache according to the returned response, and return to step C.

The present invention also provides a remote proxy cache consistency processing system with directories, including:

The initial processing module is used to enable the remote agent to obtain and process the local request initiated by the local request source;

A response module, configured to return the response message and data to the local request source when receiving the response message and data from the remote agent, and write the corresponding directory and data into the directory cache and data cache;

The same address processing module is used to judge whether there are other target requests with the same address as the remote agent, and if so, process the target requests sequentially.

Preferably, other target requests identical to the address of the remote agent include:

The local request source sends a local request to the address of the remote agent and a remote listening request from the address of the remote agent.

Applying the cache consistency processing method and system of a remote agent with directory provided by the present invention enables the remote agent to obtain and process the local request initiated by the local request source, and when receiving the response message from the remote agent and data, return the response message and data to the local request source, write the corresponding directory and data into the directory cache and data cache respectively, and determine whether there are other targets with the same address as the remote agent Request, if there is, process the target request in sequence, from the time when the local request is sent to the remote agent to occupy a directory and data cache, until the response message of the request is returned, and the internal cache resource of the remote agent becomes invalid If there are other requests or listener messages from the same address that meet certain conditions and enter the remote agent, the request can be directly processed inside the remote agent, reducing message flow and getting a quick response without cross-node operations, reducing overhead .

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only It is an embodiment of the present invention, and those skilled in the art can also obtain other drawings according to the provided drawings without creative work.

Fig. 1 is the flow chart of Embodiment 1 of a cache consistency processing method with a remote agent with a directory in the present invention;

Fig. 2 is the flow chart of Embodiment 2 of a cache consistency processing method with a remote agent with directory in the present invention;

FIG. 3 is a schematic diagram of a cache structure in Embodiment 2 of the present invention;

FIG. 4 is a schematic structural diagram of Embodiment 3 of a cache consistency processing system with a remote proxy directory in the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Embodiment one:

The present invention provides a method for processing cache consistency of a remote agent with a directory. FIG. 1 shows a flow chart of Embodiment 1 of the method for processing cache consistency with a remote agent with a directory of the present invention, including:

Step S101: Make the remote agent obtain and process the local request initiated by the local request source;

The local request message is processed, and the remote agent obtains and processes the local request.

Step S102: When receiving the response message and data from the remote agent, return the response message and data to the local request source, and write the corresponding directory and data into the directory cache and data cache respectively ;

Return the response message and corresponding data of the remote agent to the request source, and write the corresponding directory and data into the directory cache and data cache respectively.

Step S103: Determine whether there are other target requests with the same address as the remote agent, and if so, process the target requests in sequence.

The type of target request includes the local request sent by the local request source to the address of the remote agent and the remote listening request from the address of the remote agent, and it is judged whether there is a local request or a remote listening request with the same address , if there is, write the corresponding queuing sequence according to the order in which these request or listening messages enter the pipeline and process them sequentially.

Applying a method for processing cache consistency with a remote agent with a directory provided in this embodiment enables the remote agent to obtain and process the local request initiated by the local request source. When receiving the response message from the remote agent and data, return the response message and data to the local request source, write the corresponding directory and data into the directory cache and data cache respectively, and determine whether there are other target requests with the same address as the remote agent , if there is, then process the target requests sequentially, from the time when the local request is sent to the remote agent to occupy a directory and data cache, until the response message of the request is returned, and the internal cache resource of the remote agent becomes invalid , if there are other requests or listener messages from the same address that meet certain conditions and enter the remote agent, the request can be directly processed inside the remote agent, reducing message flow and getting a quick response without cross-node operations, reducing overhead.

Embodiment two:

Fig. 2 shows Embodiment 2 of the cache consistency processing method of the remote proxy belt directory of the present invention, and the specific steps are as follows:

① Scheduling starts, the remote agent normally processes the local request initiated by the local request source, waits until the response and data of the request are returned to the remote agent, returns the remote response message and corresponding data to the request source, and saves the directory And data information, write directory cache and data cache. During this time, if there are other local requests or remote listening messages with the same address entering the remote agent, these requests or listening messages can be written into the corresponding queuing sequence in the order of entering the pipeline.

② Determine whether the queuing sequence corresponding to the remote address is empty. If it is empty, the scheduling process ends, and the corresponding cache resource can be occupied by other requests. Otherwise, it is necessary to determine whether the message to be processed in the queue sequence is a local request message or a remote listening message, and determine the required data The status is compared with the directory information status of records in the directory cache for priority. Among them, the four sub-cases introduced by the relationship between the two are as described in the following processes 3, 4, 5, and 6.

③ If the message is a local request message, and the directory information in the directory cache needs to be downgraded or maintained, that is, the directory level in the current directory cache is higher than or equal to the directory level required by the local request message. Then the data in the directory cache does not need to be updated, the directory does not need to be modified or only modified at the same level, and a listening message is sent to the local request source. After the listening response is returned, a copy of the master data in the cache is sent to the request Source, and according to the actual copy data, modify the bit information of the latest copy data in the tag directory cache to complete the request. If the condition cannot be satisfied, the subsequent queuing request queue is empty, and there is a new message application to occupy the cache resource, then the process jumps to 2. Otherwise, it is necessary to determine whether the current directory cache status is M status. If it is M status and more than one local request source has data cache information, initiate a writeback request that can mark the local data as S status, and wait for the writeback response to be received Then release the resource. Otherwise, release the resource directly.

④ If the message is a local request message, and the directory information in the directory cache needs to be upgraded, that is, the directory level in the current directory cache is lower than the directory level required by the local request message. Then the remote agent sends an invalidation listening message to the request source with the latest copy. After receiving the invalidation listening response, it sends a write-back request to the remote end according to the directory cache information. After the write-back response is collected, it jumps to Process 1, processing the current request packet.

⑤ If the message is a remote listening message, and the directory information in the directory cache and the directory information required by the listening message are both in the S state. Then the remote agent directly returns the S-state response message and jumps to process 2.

⑥ If the message is a remote listening message, and the directory information in the directory cache is different from the directory information required by the listening message, it is in the S state. Then it needs to judge according to the directory state required by the listening message and the directory information in the current cache. If the former has a high priority or the directory status required by the former is E state, the remote agent initiates an invalidation listening request to the request source with the latest local data, otherwise, the remote agent initiates a request to the remote request source with the latest local data The listener message is the same as the listener message at the end. After all the interception messages are collected, invalidate or update the local directory cache and data cache according to the interception response, and jump to process 2.

In this embodiment, according to the processing capability of the remote agent, cache resources with directories are pre-allocated on the remote agent, and a schematic diagram of the cache structure is shown in FIG. 3 . Each item of the cache resource consists of index ID, directory cache and data cache. Among them, the index ID is in one-to-one correspondence with the state information table items occupied by the current processing request in the remote agent; the directory cache consists of the local state information of 2Bit remote address data and the directory information corresponding to N Bit local request sources. Among them, ST0, ST1 are initialized to 0, 2B'00 indicates that the data corresponding to the remote address is invalid, marked as I, 2B'01 is shared, marked as S, 2B'10 is exclusive, marked as E, 2B'11 is a modified state, marked as M. We stipulate that the E state and M state are the highest priority, the S state is next, and the I priority is the lowest. Then when the state of the data corresponding to the remote address is changed from high priority to low priority, it is called downgrading, and vice versa is called upgrading. The conversion of E state and M state is called maintenance. The number N of directory information corresponding to each local request source corresponds to the number of local request sources that can initiate requests to the remote end. It is initialized to 0. If the bit corresponding to the request source is marked as 1, it means that the bit corresponds to The requesting source of has the latest replica data. The data cache stores the latest master data corresponding to the remote address, where 0 to M indicates the length of the remote data, which is generally fixed.

Embodiment three:

The present invention also provides a cache consistency processing system with a remote proxy directory. FIG. 4 shows a schematic structural diagram of Embodiment 3 of the cache consistency processing system with a remote proxy directory in the present invention, including:

The initial processing module 101 is configured to enable the remote agent to obtain and process the local request initiated by the local request source;

The response module 102 is configured to return the response message and data to the local request source when receiving the response message and data from the remote agent, and write the corresponding directory and data into the directory cache respectively and data caching;

The same address processing module 103 is configured to judge whether there are other target requests with the same address as the remote agent, and if so, process the target requests in sequence.

Other target requests identical to the address of the remote proxy in this embodiment include:

The local request source sends a local request to the address of the remote agent and a remote listening request from the address of the remote agent.

Applying the cache coherency processing system with directory provided by the remote agent in this embodiment enables the remote agent to obtain and process the local request initiated by the local request source. When receiving the response message and data, return the response message and data to the local request source, write the corresponding directory and data into the directory cache and data cache respectively, and determine whether there are other target requests with the same address as the remote agent , if there is, then process the target requests sequentially, from the time when the local request is sent to the remote agent to occupy a directory and data cache, until the response message of the request is returned, and the internal cache resource of the remote agent becomes invalid , if there are other requests or listener messages from the same address that meet certain conditions and enter the remote agent, the request can be directly processed inside the remote agent, reducing message flow and getting a quick response without cross-node operations, reducing overhead.

It should be noted that each embodiment in this specification is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. For the same and similar parts in each embodiment, refer to each other, that is, Can. As for the system embodiment, because it is basically similar to the method embodiment, the description is relatively simple, and for the related parts, please refer to the part of the description of the method embodiment.

Finally, it should also be noted that in this document, the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article or apparatus comprising a set of elements not only includes those elements, but also other elements not expressly listed, or elements inherent in the process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising said element.

The method, system and mobile terminal provided by the present invention have been introduced in detail above. In this paper, specific examples have been used to illustrate the principle and implementation of the present invention. The descriptions of the above embodiments are only used to help understand the methods and methods of the present invention. Its core idea; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation and application scope. limit.

Claims (2)

1. A cache consistency processing method of a remote proxy band directory, characterized in that, comprising: Step A: Make the remote agent obtain and process the local request initiated by the local request source; Step B: When receiving the response message and data from the remote agent, return the response message and data to the local request source, and write the corresponding directory and data into the directory cache and data cache respectively ; Step C: judging whether there are other target requests with the same address as the remote agent, and if so, processing the target requests in sequence; Wherein, the other target requests include a local request sent by a local request source to the address of the remote agent and a remote listening request from the address of the remote agent; the processing of the target request includes: judging the the type of the target request; when the type of the target request is a local request, process the target request according to the priority level of the local request and the directory state information cached in the directory; when the type of the target request is a remote When listening to the request, process the target request according to the priority level of the remote listening request and the directory status information of the directory cache; the directory status information includes: modified state, exclusive state, shared state and invalid state; The modified state has the same priority as the exclusive state, and is higher than the shared state, and the shared state has a higher priority than the invalid state; When the type of the target request is the local request, determine whether the priority level of the directory cached by the directory is higher than or equal to the priority level of the local request; if the priority level of the directory cached by the directory is higher than or When it is equal to the priority level of the local request, keep the local state information of the remote address data unchanged, initiate local interception, and modify the directory information corresponding to the local request source when the response of the local interception is returned; determine the same address Whether the request queue is empty and the condition that the cache resource needs to be released is satisfied, if not, return to the step C, if satisfied, determine whether the directory status information is in the modified state, end the process when the directory state information is not in the modified state, and when When the directory status information is in the modified state, when judging whether there is only one request source with a copy, if so, end the process, otherwise initiate a shared state write-back request, release the corresponding resource and end the process when receiving the write-back completion message; if When the priority level of the directory in the directory cache is lower than the priority level of the local request, initiate invalidation monitoring of the local request, invalidate the data in the source of the local request, and initiate a write to the remote address when the invalidation monitoring response returns Return request, when receiving the write-back request completion information, initiate the current local request to the remote end; When the type of the target request is a remote listening request, it is judged whether the status information of the directory cached in the directory and the status information of the remote listening request are shared, and if so, return the shared status to the far end Respond to the message, and return to step C, otherwise initiate the same local interception request or invalidation interception request as the remote interception request, when the local interception request or invalidation interception request response returns, according to the returned response Update or invalidate the local directory cache and data cache, and return to step C. 2. A cache coherency processing system with a remote proxy band directory, characterized in that it comprises: The initial processing module is used to enable the remote agent to obtain and process the local request initiated by the local request source; A response module, configured to return the response message and data to the local request source when receiving the response message and data from the remote agent, and write the corresponding directory and data into the directory cache and data cache; The same address processing module is used to judge whether there are other target requests with the same address as the remote agent, and if so, process the target requests sequentially; wherein, the other target requests include those sent by the local request source to the remote agent. The local request of the address of the end proxy and the remote listening request from the address of the remote proxy; the processing of the target request includes: judging the type of the target request; when the type of the target request is a local request , process the target request according to the priority level of the local request and the directory state information cached in the directory; when the type of the target request is a remote listening request, process the target request according to the remote listening request and the directory The priority level of the cached directory state information processes the target request; the directory state information includes: modified state, exclusive state, shared state and invalid state; the priority level of the modified state is the same as that of the exclusive state, and is higher than the Shared state, the priority level of the shared state is higher than the invalid state; when the type of the target request is the local request, it is judged whether the priority level of the directory in the directory cache is higher than or equal to the local request priority level; if the priority level of the directory in the directory cache is higher than or equal to the priority level of the local request, keep the local state information of the remote address data unchanged, initiate local monitoring, and when the local monitoring Modify the directory information corresponding to the local request source when the listened response is returned; judge whether the same-address request queue is empty and the condition that the cache resource needs to be released is satisfied, if not, return to the same-address processing module, and if so, judge the directory status information Whether it is in the modified state, when the directory status information is not in the modified state, end the process, when the directory status information is in the modified state, judge whether only one request source has a copy, if so, end the process, otherwise initiate the shared state For a write-back request, when the write-back completion message is received, the corresponding resources are released and the process ends; if the priority level of the directory in the directory cache is lower than the priority level of the local request, the invalidation interception of the local request is initiated, and the invalidation local request source Data, when the failure listening response returns, initiate a write-back request to the remote address, and when receiving the completion information of the write-back request, initiate a current local request to the remote end; when the type of the target request is remote detection When listening to the request, judge whether the state information of the directory cached in the directory and the state information of the remote listening request are in a shared state, if so, return a shared state response message to the remote end, and return the same address processing Module, otherwise initiate the same local listening request or invalidation listening request as the remote listening request, when the local listening request or invalidation listening request response returns, update or invalidate the local directory cache and The data is cached and returned to the same-address processing module.