fix(tools): throttle ripgrep CPU usage with thread limits and concurrency control by JiHongKim98 · Pull Request #2009 · code-yeongyu/oh-my-openagent

JiHongKim98 · 2026-02-20T18:02:31Z

Summary

Fixes #2008 — ripgrep (rg) causes sustained CPU spikes (700%+) on macOS during agent workflows, making the system unresponsive for extended periods (1h+).

Related: #674 (comment-checker CPU spikes), #1722 (rg CPU spikes on Windows — closed as "working as designed")

Changes

Thread limiting: Add --threads=4 to all rg invocations in both grep and glob tools, preventing a single process from saturating all CPU cores
Concurrency control: Add a global Semaphore(2) that limits concurrent rg processes to 2, queuing additional requests
Timeout fix: Reduce DEFAULT_TIMEOUT_MS from 300s to 60s in grep/constants.ts — the tool description already claims "60s timeout" but the actual value was 5 minutes
Output buffer reduction: Reduce DEFAULT_MAX_OUTPUT_BYTES from 10MB to 256KB — 10MB is excessive for LLM context consumption
New output_mode parameter: Supports content, files_with_matches (default), and count modes — inspired by Claude Code's approach of fetching file lists first, then reading specific files
New head_limit parameter: Limits result count for incremental fetching instead of retrieving everything at once

Files Changed (8)

File	Change
`src/tools/shared/semaphore.ts`	New — Counting semaphore for concurrent process limiting
`src/tools/grep/constants.ts`	`DEFAULT_RG_THREADS=4`, timeout 300s→60s, output 10MB→256KB
`src/tools/grep/types.ts`	Add `threads`, `outputMode`, `headLimit` to `GrepOptions`
`src/tools/grep/cli.ts`	`--threads` flag, semaphore wrapping, headLimit/outputMode support
`src/tools/grep/tools.ts`	Expose `output_mode`, `head_limit` params, count mode support
`src/tools/glob/types.ts`	Add `threads` to `GlobOptions`
`src/tools/glob/constants.ts`	Re-export `DEFAULT_RG_THREADS`
`src/tools/glob/cli.ts`	`--threads` flag, semaphore wrapping

Impact

Before: Two rg processes × 12 threads each = 24 threads at 100% = system freeze
After: Two rg processes (max) × 4 threads each = 8 threads at 100% = smooth operation

Non-breaking

All changes are additive with sensible defaults
Existing tool calls work identically (no required new parameters)
output_mode defaults to files_with_matches which is more efficient than the previous behavior of always returning full content

Test plan

bun test src/tools/grep src/tools/glob — 24 pass, 0 fail
bun run typecheck — No new errors (3 pre-existing errors in unrelated files)
Manual verification: run agent workflow and confirm CPU stays under control

Summary by cubic

Throttle ripgrep to prevent CPU spikes by capping to 4 threads per process and allowing at most 2 concurrent runs. Tightens timeouts/output and adds lighter output modes to make searches faster and safer.

Bug Fixes
- Fixes [Bug]: ripgrep (rg) causes sustained CPU spikes on macOS during agent workflows #2008: sustained ripgrep CPU spikes causing system freezes.
- Cap rg to 4 threads and 2 concurrent processes to prevent spikes.
- Align timeout to 60s and cap output to 256KB to reduce load.
- Fix files_with_matches mode to return file paths correctly.
New Features
- Add output_mode: content, files_with_matches (default), and count (validated via enum).
- Add head_limit to cap results for incremental fetching.

^{Written for commit 02017a1. Summary will update on new commits.}

I have read the CLA Document and I hereby sign the CLA

…ency control - Add --threads=4 flag to all rg invocations (grep and glob) - Add global semaphore limiting concurrent rg processes to 2 - Reduce grep timeout from 300s to 60s (matches tool description) - Reduce max output from 10MB to 256KB (prevents excessive memory usage) - Add output_mode parameter (content/files_with_matches/count) - Add head_limit parameter for incremental result fetching Closes code-yeongyu#2008 Ref: code-yeongyu#674, code-yeongyu#1722

github-actions · 2026-02-20T18:02:43Z

All contributors have signed the CLA. Thank you! ✅
_{Posted by the CLA Assistant Lite bot.}

JiHongKim98 · 2026-02-20T18:11:00Z

I have read the CLA Document and I hereby sign the CLA

cubic-dev-ai

3 issues found across 8 files

Confidence score: 3/5

src/tools/grep/cli.ts has a concrete behavior bug: outputMode: "files_with_matches" yields empty results due to parseOutput expecting line-numbered output, which can directly affect users relying on that mode.
Two compatibility issues in src/tools/grep/tools.ts around schema enum usage and an unsafe type assertion could cause agent/tool schema mismatches at runtime.
The score reflects a real user-facing regression risk in the CLI path plus schema compatibility concerns, though the fixes are localized.
Pay close attention to src/tools/grep/cli.ts and src/tools/grep/tools.ts - output parsing for files-only mode and enum schema/type safety.

Prompt for AI agents (all issues)


Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="src/tools/grep/tools.ts">

<violation number="1" location="src/tools/grep/tools.ts:24">
P1: Custom agent: **Opencode Compatibility**

Use `tool.schema.enum` instead of a generic `string()` for `output_mode` to ensure the agent receives the exact allowed values in its JSON schema and to enforce strict runtime validation.</violation>

<violation number="2" location="src/tools/grep/tools.ts:40">
P1: Custom agent: **Opencode Compatibility**

Remove the unsafe type assertion, as the type should be automatically inferred from a correctly defined `tool.schema.enum`.</violation>
</file>

<file name="src/tools/grep/cli.ts">

<violation number="1" location="src/tools/grep/cli.ts:57">
P1: `outputMode: "files_with_matches"` produces empty results due to incompatible regex parsing in `parseOutput`. When using `--files-with-matches`, ripgrep outputs only file paths (e.g., "src/file.ts") without line numbers or content, but `parseOutput` uses regex `/^(.+?):(\\d+):(.*)$/` expecting `file:line:content` format. This causes all lines to fail matching, returning an empty `matches` array.</violation>
</file>

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src/tools/grep/tools.ts

src/tools/grep/cli.ts

- Use tool.schema.enum() for output_mode instead of generic string() - Remove unsafe type assertion for output_mode - Fix files_with_matches mode returning empty results by adding filesOnly flag to parseOutput for --files-with-matches rg output

JiHongKim98 · 2026-02-20T18:18:02Z

Thanks for the review, @cubic-dev-ai! All 3 issues have been addressed in 02017a1:

tool.schema.enum() for output_mode — Fixed. Now uses tool.schema.enum(["content", "files_with_matches", "count"]) instead of a generic string(), ensuring proper JSON schema validation and LLM visibility of allowed values.
Unsafe type assertion removed — Fixed. The as "content" | "files_with_matches" | "count" cast is no longer needed since the enum schema provides correct type inference.
files_with_matches empty results bug — Fixed. Added a filesOnly parameter to parseOutput() that handles --files-with-matches output format (file paths only, no file:line:content). When outputMode === "files_with_matches", the parser now correctly extracts file paths without expecting line numbers.

All existing tests pass (24/24).

github-actions bot added a commit that referenced this pull request Feb 20, 2026

@JiHongKim98 has signed the CLA in #2009

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cubic-dev-ai bot reviewed Feb 20, 2026

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code-yeongyu merged commit b175c11 into code-yeongyu:dev Feb 22, 2026
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code-yeongyu mentioned this pull request Feb 22, 2026

fix(grep): format files_with_matches output as clean file paths #2039

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fix(tools): throttle ripgrep CPU usage with thread limits and concurrency control#2009

fix(tools): throttle ripgrep CPU usage with thread limits and concurrency control#2009
code-yeongyu merged 2 commits intocode-yeongyu:devfrom
JiHongKim98:fix/ripgrep-cpu-throttle

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Summary

Changes

Files Changed (8)

Impact

Non-breaking

Test plan

Summary by cubic

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