Merged TLB for Nested Address Translation Latency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing virtual memory systems face significant latency and performance issues due to nested address translation processes, which involve multiple look-ups in separate translation look-aside buffers (TLBs), leading to increased translation latency and inefficient invalidation of TLB entries.
Innovation Solution
A merged TLB structure is introduced that caches mappings between effective addresses and real addresses, including information on intermediate virtual addresses, allowing for direct translation and efficient invalidation of specific entries, thereby reducing latency and improving performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If nested address translation is implemented with separate TLBs for process-scoped and partition-scoped translation, then address translation functionality is provided, but translation latency increases due to multiple look-ups
Solution Approach 1:
The patent combines process-scoped TLB and partition-scoped TLB into a single unified TLB structure. This merged TLB stores both process virtual address to intermediate virtual address mappings and intermediate virtual address to real address mappings in one data structure, eliminating the need for sequential look-ups in separate TLBs and reducing translation latency.
Solution Approach 2:
The merged TLB entries are structured to contain nested mapping information. Each TLB entry includes both the process-scoped translation (effective address to intermediate virtual address) and the partition-scoped translation (intermediate virtual address to real address) in a hierarchical format, allowing the system to traverse nested translations within a single TLB lookup operation.
2Adaptability or versatility
If separate TLBs are used for process-scoped and partition-scoped translation, then independent translation scopes are maintained, but the number of TLB entries invalidated during updates increases
Solution Approach 1:
The merged TLB structure allows for selective invalidation of specific entry types based on the scope of translation being updated. When a process-scoped translation changes, only the relevant process-scoped entries are invalidated, and when a partition-scoped translation changes, only the affected partition-scoped entries are invalidated, rather than invalidating all entries in separate TLBs.
Solution Approach 2:
The merged TLB is organized into distinct segments or regions for process-scoped translations and partition-scoped translations. This segmentation allows the system to independently manage and invalidate entries in each scope without affecting the other, maintaining the independence of translation scopes while reducing the total number of invalidated entries.
Data Source
AI summary
A method and system of translating addresses is disclosed that includes receiving an effective address for translation, providing a processor and a translation buffer where the translation buffer has a plurality of entries, wherein each entry contains a mapping of an effective address directly to a corresponding real address, and information on a corresponding intermediate virtual address. The method and system further include determining whether the translation buffer has an entry matching the effective address, and in response to the translation buffer having an entry with a matching effective address, providing the real address translation from the entry having the matching effective address.