Agent skill

Flamegraphs

by mohitmishra786 in mohitmishra786/low-level-dev-skills

Flamegraph generation and interpretation skill. An agent skill from mohitmishra786/low-level-dev-skills.

MITAuto-check passedDevelopment

Install Flamegraphs

skills CLI

$ npx skills add mohitmishra786/low-level-dev-skills --skill flamegraphs -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI

$ gh skill install mohitmishra786/low-level-dev-skills flamegraphs --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy

$ git clone --depth 1 https://github.com/mohitmishra786/low-level-dev-skills.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/profilers/flamegraphs .claude/skills/flamegraphs && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Paste into Claude Code

Install the "flamegraphs" agent skill from https://github.com/mohitmishra786/low-level-dev-skills/tree/main/skills/profilers/flamegraphs into .claude/skills/flamegraphs/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "flamegraphs", then confirm the skill loads.

Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

$skill-installer

$skill-installer install https://github.com/mohitmishra786/low-level-dev-skills/tree/main/skills/profilers/flamegraphs

Type this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.

skills CLI

$ npx skills add mohitmishra786/low-level-dev-skills --skill flamegraphs -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install mohitmishra786/low-level-dev-skills flamegraphs --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/mohitmishra786/low-level-dev-skills.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/profilers/flamegraphs .agents/skills/flamegraphs && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "flamegraphs" agent skill from https://github.com/mohitmishra786/low-level-dev-skills/tree/main/skills/profilers/flamegraphs into .agents/skills/flamegraphs/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "flamegraphs", then confirm the skill loads.

Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add mohitmishra786/low-level-dev-skills --skill flamegraphs -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install mohitmishra786/low-level-dev-skills flamegraphs --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/mohitmishra786/low-level-dev-skills.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/profilers/flamegraphs .cursor/skills/flamegraphs && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "flamegraphs" agent skill from https://github.com/mohitmishra786/low-level-dev-skills/tree/main/skills/profilers/flamegraphs into .cursor/skills/flamegraphs/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "flamegraphs", then confirm the skill loads.

Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

gemini skills install

$ gemini skills install https://github.com/mohitmishra786/low-level-dev-skills.git --path skills/profilers/flamegraphs

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add mohitmishra786/low-level-dev-skills --skill flamegraphs -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install mohitmishra786/low-level-dev-skills flamegraphs --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/mohitmishra786/low-level-dev-skills.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/profilers/flamegraphs .gemini/skills/flamegraphs && rm -rf skills-src

Use ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.

Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/

Paste into Gemini CLI

Install the "flamegraphs" agent skill from https://github.com/mohitmishra786/low-level-dev-skills/tree/main/skills/profilers/flamegraphs into .gemini/skills/flamegraphs/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "flamegraphs", then confirm the skill loads.

Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

GitHub CLI

$ gh skill install mohitmishra786/low-level-dev-skills flamegraphs

Installs for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).

skills CLI

$ npx skills add mohitmishra786/low-level-dev-skills --skill flamegraphs -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/mohitmishra786/low-level-dev-skills.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/profilers/flamegraphs .github/skills/flamegraphs && rm -rf skills-src

Use ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.

GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/

Paste into GitHub Copilot

Install the "flamegraphs" agent skill from https://github.com/mohitmishra786/low-level-dev-skills/tree/main/skills/profilers/flamegraphs into .github/skills/flamegraphs/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "flamegraphs", then confirm the skill loads.

GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add mohitmishra786/low-level-dev-skills --skill flamegraphs -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install mohitmishra786/low-level-dev-skills flamegraphs --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/mohitmishra786/low-level-dev-skills.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/profilers/flamegraphs .opencode/skills/flamegraphs && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "flamegraphs" agent skill from https://github.com/mohitmishra786/low-level-dev-skills/tree/main/skills/profilers/flamegraphs into .opencode/skills/flamegraphs/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "flamegraphs", then confirm the skill loads.

OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

Facts

Skill name: flamegraphs
GitHub stars: 253
Token cost: ~1.2k tokens
SKILL.md length: 350 words
Files: 2 (incl. references)
Skills in repo: 138
Repo updated: Jun 27, 2026
First seen: Oct 7, 2026
Licence: MIT

At a glance

Flamegraph generation and interpretation skill. An agent skill from mohitmishra786/low-level-dev-skills.

Works in 7 steps: Install FlameGraph tools → perf → flamegraph (most common path) → Differential flamegraph (before/after) → …
Converting perf
SKILL.md covers Purpose, Triggers, Workflow and References, plus 1 more section
Calls git and go; reaches github.com

What it does

Flamegraphs is an agent skill from mohitmishra786/low-level-dev-skills. Flamegraph generation and interpretation skill. Use when converting perf, Valgrind Callgrind, or other profiler output into SVG flamegraphs using Brendan Gregg's FlameGraph tools, or when reading flamegraphs to identify performance bottlenecks. Activates on queries about flamegraphs, stackcollapse, flamegraph.svg, identifying hot frames, wide vs tall frames, or performance visualisation.

Its SKILL.md is about 1.2k tokens, which your agent loads only when the skill is triggered. The skill folder holds 2 other files, including reference files (for example `references/tools.md`).

It sits in Development, covering Performance optimization. The repository describes itself as: A curated suite of AI agent skills for systems and low-level programming with C/C++, Rust, and Zig toolchains, covering compilers, debuggers, profilers, build systems…. The licence is MIT.

When your agent uses it

Converting perf
Valgrind Callgrind
Other profiler output into SVG flamegraphs using Brendan Greggs FlameGraph tools
Reading flamegraphs to identify performance bottlenecks

Example prompts

“/flamegraphs”

Workflow steps

7 steps, taken from the step headings in SKILL.md.

Install FlameGraph tools
perf → flamegraph (most common path)
Differential flamegraph (before/after)
Callgrind → flamegraph
Other profiler inputs
Reading flamegraphs
flamegraph.pl options

What it can do on your machine

Read from SKILL.md and the folder at commit bdc5847. It shows what the files ask for, not the result of running them.

Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
Shell commands in SKILL.md call:
- git
- go
From the folder's file list and the shell code blocks in SKILL.md.
Network
Hosts in commands or code, which the agent is likely to contact:
- github.com
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Flamegraphs loads about 1.2k tokens when it runs, and up to ~3k if it reads all its reference files. Until then it costs about 101 tokens; SKILL.md has 350 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~101
When it runs · the whole SKILL.md, loaded when a task matches: ~1.2k
With references · SKILL.md plus every file in references/, read only if the agent opens them: ~3k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from mohitmishra786/low-level-dev-skills at commit bdc5847, republished under its MIT licence (© mohitmishra786). 350 words, ~1,230 tokens.

Download SKILL.mdSave it as .claude/skills/flamegraphs/SKILL.md (or your agent's skills folder). This skill also uses 1 other file; get the full folder from GitHub.

name: flamegraphs
description: Flamegraph generation and interpretation skill. Use when converting perf, Valgrind Callgrind, or other profiler output into SVG flamegraphs using Brendan Gregg's FlameGraph tools, or when reading flamegraphs to identify performance bottlenecks. Activates on queries about flamegraphs, stackcollapse, flamegraph.svg, identifying hot frames, wide vs tall frames, or performance visualisation.

Flamegraphs

Purpose

Guide agents through the pipeline from profiler data to SVG flamegraph, and teach interpretation of flamegraphs to drive concrete optimisation decisions.

Triggers

"How do I generate a flamegraph from perf data?"
"How do I read a flamegraph?"
"The flamegraph shows a wide frame — what does that mean?"
"How do I generate a flamegraph from Callgrind?"
"I want to compare two flamegraphs (before/after)"

Workflow

1. Install FlameGraph tools

bash

git clone https://github.com/brendangregg/FlameGraph
# No install needed; scripts are in the repo
export PATH=$PATH:/path/to/FlameGraph

2. perf → flamegraph (most common path)

bash

# Step 1: record
perf record -F 999 -g -o perf.data ./prog

# Step 2: generate script output
perf script -i perf.data > out.perf

# Step 3: collapse stacks
stackcollapse-perf.pl out.perf > out.folded

# Step 4: generate SVG
flamegraph.pl out.folded > flamegraph.svg

# Step 5: view
xdg-open flamegraph.svg     # Linux
open flamegraph.svg          # macOS

One-liner:

bash

perf record -F 999 -g ./prog && perf script | stackcollapse-perf.pl | flamegraph.pl > fg.svg

3. Differential flamegraph (before/after)

bash

# Collect two profiles
perf record -g -o before.data ./prog_old
perf record -g -o after.data ./prog_new

# Collapse
perf script -i before.data | stackcollapse-perf.pl > before.folded
perf script -i after.data  | stackcollapse-perf.pl > after.folded

# Diff (red = regressed, blue = improved)
difffolded.pl before.folded after.folded | flamegraph.pl > diff.svg

4. Callgrind → flamegraph

bash

valgrind --tool=callgrind --callgrind-out-file=cg.out ./prog
stackcollapse-callgrind.pl cg.out | flamegraph.pl > fg.svg

5. Other profiler inputs

bash

# Go pprof
go tool pprof -raw -output=prof.txt prog
stackcollapse-go.pl prof.txt | flamegraph.pl > fg.svg

# DTrace
dtrace -x ustackframes=100 -n 'profile-99 /execname=="prog"/ { @[ustack()] = count(); }' \
  -o out.stacks sleep 10
stackcollapse.pl out.stacks | flamegraph.pl > fg.svg

# Java (async-profiler)
async-profiler -d 30 -f out.collapsed PID
flamegraph.pl out.collapsed > fg.svg

6. Reading flamegraphs

A flamegraph is a call-stack visualisation:

X axis: time on CPU (not time sequence) — wider = more time
Y axis: call stack depth — taller = deeper call chain
Color: random (no significance) — unless using differential mode

What to look for:

Pattern	Meaning	Action
Wide frame near bottom	Function itself is hot	Optimise that function
Wide frame with tall narrow towers	Calling many different callees	Hot dispatch; reduce call overhead
Very tall stack with wide base	Deep recursion	Check recursion depth; consider iterative approach
Plateau at the top	Leaf function with no callees	This leaf is the actual hotspot
Many narrow identical stacks	Many threads doing the same work	Consider parallelism or batching

Identifying the actionable hotspot:

Find the widest top frame (a frame with no or narrow children above it)
That is where CPU time is actually spent
Trace down to understand what called it and why

Show full SKILL.md (112 more words)Show less

Differential flamegraph:

Red frames: more time in new profile (regression)
Blue frames: less time in new profile (improvement)
Frames only in one profile appear solid colored

7. flamegraph.pl options

bash

flamegraph.pl --title "My App" \
              --subtitle "Release build, workload X" \
              --width 1600 \
              --height 16 \
              --minwidth 0.5 \
              --colors java \
              out.folded > fg.svg

Option	Effect
`--title`	SVG title
`--width`	Width in pixels
`--height`	Frame height in pixels
`--minwidth`	Omit frames < N% (reduces clutter)
`--colors`	Palette: `hot` (default), `mem`, `io`, `java`, `js`, `perl`, `red`, `green`, `blue`
`--inverted`	Icicle chart (roots at top)
`--reverse`	Reverse stacks
`--cp`	Consistent palette (same frame = same color across SVGs)

References

For tool installation, stackcollapse scripts, and palette options, see references/tools.md.

Use skills/profilers/linux-perf to collect perf data
Use skills/profilers/valgrind to collect Callgrind data
Use skills/compilers/clang for LLVM PGO from sampling profiles

Files

SKILL.md and 1 other file (references) in skills/profilers/flamegraphs of mohitmishra786/low-level-dev-skills.

SKILL.md
references/tools.md

Open the folder on GitHubat commit bdc5847

Compare with similar skills

Flamegraphs next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Flamegraphs compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
Flamegraphs this skillmohitmishra786/low-level-dev-skills	253	—	~1.2k	Automated safety check: Pass	MIT	3 mo ago
Code Review ChecklistshareAI-lab/learn-claude-code	78k	5 repos	~1.1k	Automated safety check: Pass	MIT	10 days ago
LLM Torch Profiler Analysissgl-project/sglang	37k	2 repos	~6.4k	Automated safety check: Pass	Apache-2.0	today
Pycrazyguitar/pysheeet	8.2k	—	~886	Automated safety check: Pass	MIT	yesterday
Cmux Debugging Guidemanaflow-ai/cmux	28k	1 repos	~1.1k	Automated safety check: Pass	Custom licence	today
Electron Heap Snapshot Analysiskeybase/client	9.3k	—	~875	Automated safety check: Pass	BSD-3-Clause	yesterday

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DevelopmentAuto-check passed
LLM Torch Profiler Analysis
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Questions about Flamegraphs

What does Flamegraphs do?

Flamegraph generation and interpretation skill. An agent skill from mohitmishra786/low-level-dev-skills. Flamegraphs is an agent skill from mohitmishra786/low-level-dev-skills. Flamegraph generation and interpretation skill.

When should I use Flamegraphs?

Flamegraphs fits situations like: converting perf; valgrind Callgrind; other profiler output into SVG flamegraphs using Brendan Greggs FlameGraph tools; reading flamegraphs to identify performance bottlenecks.

How do I install Flamegraphs in Claude Code?

Run `npx skills add mohitmishra786/low-level-dev-skills --skill flamegraphs -a claude-code`. Or copy the skill folder (skills/profilers/flamegraphs in mohitmishra786/low-level-dev-skills) into .claude/skills/flamegraphs in your project. Claude Code loads it when a task matches its description.

How do I install Flamegraphs in Codex?

Run `npx skills add mohitmishra786/low-level-dev-skills --skill flamegraphs -a codex`. Or copy the skill folder (skills/profilers/flamegraphs in mohitmishra786/low-level-dev-skills) into .agents/skills/flamegraphs in your project. Codex loads it when a task matches its description.

Can I use Flamegraphs in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add mohitmishra786/low-level-dev-skills --skill flamegraphs -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/flamegraphs, .gemini/skills/flamegraphs, .github/skills/flamegraphs and .opencode/skills/flamegraphs in your project.

What does Flamegraphs need to run?

Going by SKILL.md and its folder, Flamegraphs needs the command-line tools its instructions call (git and go).

Does Flamegraphs access the network?

SKILL.md names 1 domain. In commands or code: github.com; the agent is likely to contact it when it follows the instructions. This is read from the text; nothing was executed.

Is Flamegraphs safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Flamegraphs use?

Flamegraphs is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Flamegraphs use?

About 1.2k tokens (SKILL.md is roughly 4.9k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 1.8k tokens, read only when the agent opens those files.

What are the alternatives to Flamegraphs?

Skills that share tags, products or a category with Flamegraphs: Code Review Checklist (shareAI-lab/learn-claude-code, 78k stars), LLM Torch Profiler Analysis (sgl-project/sglang, 37k stars), Py (crazyguitar/pysheeet, 8.2k stars) and Cmux Debugging Guide (manaflow-ai/cmux, 28k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Flamegraphs?

mohitmishra786 (a GitHub user) maintains it in mohitmishra786/low-level-dev-skills, which has 253 GitHub stars. The repository holds 138 skills in this directory. The repository was last updated on June 27, 2026.

Source: mohitmishra786/low-level-dev-skills on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.

Install Flamegraphs

Facts

At a glance

What it does

When your agent uses it

Example prompts

Workflow steps

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

Flamegraphs

Purpose

Triggers

Workflow

1. Install FlameGraph tools

2. perf → flamegraph (most common path)

3. Differential flamegraph (before/after)

4. Callgrind → flamegraph

5. Other profiler inputs

6. Reading flamegraphs

7. flamegraph.pl options

References

Related skills

Files

Compare with similar skills

Similar skills

More from mohitmishra786/low-level-dev-skills

Related

Questions about Flamegraphs