Comfy Aimdo 0.4.10 + Dynamic --reserve-vram + --vram-headroom

[rattus128]

#14396

comfy-aimdo 0.4.10 implements:

1: double sync on VBAR free operations. There are still hard-to-reproduce observable de-syncs between the cuda observed free memory and the real actuals. Syncing after the fact may help and this should be reasonably cheap given that is was already synced before the free operation.

2: Implement two VRAM headroom configuration mechanisms. --reserve-vram by popular demand, and a more dynamic form --vram-headroom.

Example Test Conditions:

Linux, 5090, 96GB, LTX2.3
8GB VRAM held in use by a script
--reserve-vram 12

Before:

Comfy uses more than 32 - 12GB VRAM.

[INFO] Prompt executed in 26.13 seconds

After:

The 12GB headroom is usable by the display driver and the 8GB background script so roughly 3GB is unused ✅

[INFO] Prompt executed in 26.59 seconds

--vram-headroom 12 (instead of --reserve-vram):

The 12GB headroom is absolute ✅

[INFO] Prompt executed in 32.40 seconds

Regression Tests:

Linux, 5090, 96GB, Ace-step turbo XL ✅
Linux, 5090, 96GB, stable cascade -> flux 2 ✅
Windows, 5060, 16GB, wan 2x14B FP8 ✅

[coderabbitai]

📝 Walkthrough

Walkthrough

A new --vram-headroom CLI argument (float, default 0) is added to cli_args.py to specify extra free VRAM in GiB that DynamicVRAM should keep available. In main.py, comfy_aimdo.control.init() is updated to pass a simple_vram_headroom value derived from args.reserve_vram (GiB→bytes, or None when unset), and comfy_aimdo.control.init_devices() is updated to pass (device_index, headroom_bytes) tuples instead of device indices alone. The comfy-aimdo dependency is bumped from 0.4.9 to 0.4.10 in requirements.txt.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately reflects the main changes: upgrading comfy-aimdo to 0.4.10 and introducing two VRAM headroom configuration mechanisms.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Description check	✅ Passed	The PR description accurately relates to the changeset, providing context for the comfy-aimdo 0.4.10 upgrade and explaining the two new VRAM headroom configuration mechanisms with test results.

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@comfy/cli_args.py`:
- Line 148: The --vram-headroom argument in the parser.add_argument call accepts
unbounded float values without validation, allowing negative values that can
cause inverted behavior in byte conversions downstream in main.py. Add a
non-negative validator to the argument definition using argparse's type
parameter or choices mechanism to ensure only non-negative float values are
accepted at parse time, preventing invalid negative headroom values from
reaching the DynamicVRAM logic.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: dc81ab66-eca6-4e74-9b4a-a560e345b849

📥 Commits

Reviewing files that changed from the base of the PR and between 7d4194d and bdf1ffc744905069ead89736837e2fa30ae2d557.

📒 Files selected for processing (3)

• comfy/cli_args.py
• main.py
• requirements.txt

[coderabbitai]

⚠️ Potential issue | 🟠 Major | ⚡ Quick win

Validate VRAM headroom inputs as non-negative at parse time.

Line 148 introduces an unbounded float; negative values flow into byte conversions in main.py (Lines 58 and 234), which can invert headroom behavior under DynamicVRAM. Add a non-negative validator for VRAM headroom inputs.

Suggested fix

+def non_negative_gb(value: str) -> float:
+    gb = float(value)
+    if gb < 0:
+        raise argparse.ArgumentTypeError("Value must be >= 0 GB.")
+    return gb
+
-parser.add_argument("--reserve-vram", type=float, default=None, help="Set the amount of vram in GB you want to reserve for use by your OS/other software. By default some amount is reserved depending on your OS.")
-parser.add_argument("--vram-headroom", type=float, default=0, help="Set the amount of vram in GB for DynamicVRAM to maintain as extra headroom above default. ComfyUI will try and keep this much VRAM completely free and unused, even counting VRAM from other apps.")
+parser.add_argument("--reserve-vram", type=non_negative_gb, default=None, help="Set the amount of vram in GB you want to reserve for use by your OS/other software. By default some amount is reserved depending on your OS.")
+parser.add_argument("--vram-headroom", type=non_negative_gb, default=0, help="Set the amount of vram in GB for DynamicVRAM to maintain as extra headroom above default. ComfyUI will try and keep this much VRAM completely free and unused, even counting VRAM from other apps.")

As per coding guidelines, comfy/** changes should prioritize memory-management safety and backward-compatible behavior.

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@comfy/cli_args.py` at line 148, The --vram-headroom argument in the
parser.add_argument call accepts unbounded float values without validation,
allowing negative values that can cause inverted behavior in byte conversions
downstream in main.py. Add a non-negative validator to the argument definition
using argparse's type parameter or choices mechanism to ensure only non-negative
float values are accepted at parse time, preventing invalid negative headroom
values from reaching the DynamicVRAM logic.

Source: Coding guidelines