linuxppc / linuxppc/issues

Tighten up vector entry to memcpy, etc. codes

Open
#93 0 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

enhancement medium
Dominant language
No language data
Stars
14
Forks
0
PR merge metrics
No merged PRs in 30d

Description

Currently, vmx operations have to set up a stack frame and save lr to call enter_vmx_copy. This could possibly be streamlined by just testing a couple of things inline (e.g., in_interrupt / msr & VEC) to avoid the stack and call overhead in the common case.

The cutoff for vector operations should probably also be lowered dynamically if userspace is not presently using the registers.

Contributor guide

No contributing guide indexed for this repository

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by locating enter_vmx_copy and the VMX operations that call it. Review how in_interrupt, MSR & VEC, and current userspace register use determine the path; done means reducing common-case stack and call overhead while dynamically lowering the vector-operation cutoff when appropriate.

Written by the indexing model from the issue text.

Assessment

Domain
operating-systems, performance
Issue type
Refactor
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
25/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.