feat(mem): add config-driven allocator trim

[aider4ryder]

Summary

• release freed glibc allocator pages after hard AIAgent.close() and TUI turn completion
• clear per-turn history and kwargs snapshots before trimming so reclaimed objects are no longer referenced
• make unsupported allocators/platforms fail open and rate-limit non-forced trim calls
• configure the feature through context.memory_trim.enabled and context.memory_trim.cooldown_seconds in config.yaml
• keep profile-specific HERMES_HOME active until the post-turn trim reads that session's config

Why this replaces #62961

#62961 established the allocator mechanism and cleanup boundaries, but it was closed because its kill switch and cooldown were environment-variable controls and the advertised config.yaml plumbing was absent. This revision removes those behavioral environment variables, adds the settings to DEFAULT_CONFIG, and tests the config contract and profile-ordering boundary.

Tests

uv run --with pytest python -m pytest \
  tests/hermes_cli/test_mem_trim.py \
  tests/test_tui_gateway_server.py \
  tests/hermes_cli/test_set_config_value.py \
  -q -o addopts=
# 378 passed

uv run --with ruff ruff check \
  hermes_cli/mem_trim.py hermes_cli/config.py run_agent.py \
  tui_gateway/server.py tests/hermes_cli/test_mem_trim.py \
  tests/test_tui_gateway_server.py
# All checks passed

uv run --with ty ty check \
  hermes_cli/mem_trim.py tests/hermes_cli/test_mem_trim.py
# All checks passed

A bounded Linux/glibc allocator probe allocated 256 MiB of small blocks and observed RSS fall from 272.7 MiB before trim to 27.5 MiB after trim_memory(force=True); the helper returned True.

Safety

• no-op on non-Linux or non-glibc allocators
• config kill switch overrides forced calls
• exceptions and unavailable symbols fail open
• cooldown prevents per-turn collection thrash
• post-turn trim runs before restoring a profile-specific HERMES_HOME, so the correct profile config is used

AI-assisted development disclosure

This revision was implemented and tested with AI assistance. The original allocator design from #62961 was replayed only after a clean apply check; the configuration-policy and profile-ordering adaptations were developed with failing regression tests before implementation.

[teknium1]

Thanks for re-scoping the earlier allocator-trim work around config.yaml; current main still has no equivalent trim at run_agent.py:3604-3628 or the TUI finalizer at tui_gateway/server.py:9365-9377.

Problems

• run_agent.py:3547 resolves trim configuration during AIAgent.close() without a profile context. Current tui_gateway/server.py:689-713 invokes agent.close() during teardown without installing the session's profile_home, so a resumed profile can use the default profile's context.memory_trim setting.

Suggested changes

• Resolve the trim decision in a profile-scoped teardown path, or carry profile/config state to the agent, and add a two-profile regression covering a disabled profile.
• Use load_config_readonly() for the helper's read-only lookup; hermes_cli/config.py:6837-6874 documents it specifically for allocation-sensitive hot reads.

This is an automated hermes-sweeper review.

[teknium1]

This resolves config at close time, but AIAgent has no profile-home input. tui_gateway/server.py:_teardown_session calls agent.close() after the per-turn override has been reset, so a resumed profile that disables trimming can consult the default profile config. Move the decision into a profile-scoped caller (or carry profile/config state on the agent) and add a profile-isolation regression.

[GottZ]

This was generated by AI during triage.

Summary

Three PRs address retained RSS in long-running processes by invoking glibc malloc_trim after releasing stale references. #62961 introduced the allocator helper and TUI/agent cleanup boundaries, #63708 replaced its environment-variable controls with config.yaml settings and profile-aware TUI ordering, and #66355 expanded that design across gateway, TUI, slash-worker, and agent lifecycles with telemetry.

Related pull requests

• #62961 [closed] duplicate — (+274/-0) — closed baseline, superseded by #63708: it directly targets retained allocator pages with rate-limited trims after agent close and TUI turns, but its behavioral environment variables and missing config plumbing conflict with AGENTS.md:102-106, as cited by the automated close verdict.
• #63708 related — (+345/-0) — close as superseded by the #66355 → #76905 salvage path: it preserves #62961's trim mechanism while moving controls into context.memory_trim and keeping the profile override active for the TUI post-turn read. Despite the keep_open review on #63708, which identified unscoped AIAgent.close() configuration and requested load_config_readonly(), the later consolidated implementation carried this core diff and broader lifecycle coverage into #76905.
• #66355 [closed] duplicate — (+644/-0) — closed in favor of #76905, but relevant as the consolidated reference implementation: it incorporates the config-driven helper and TUI cleanup from #63708, then adds gateway housekeeping, idle-reaper, slash-worker, telemetry, and agent-close coverage. Despite the keep_open review on #66355, which flagged nested forced trims, missing documentation, and lifecycle-test gaps, the contributor closure records that its five lifecycle hooks and tests were re-anchored onto current main and salvaged into #76905.

Duplicates

#62961 and #63708 substantially overlap on the allocator helper plus agent-close and TUI turn boundaries; #63708 supersedes #62961's configuration approach. #66355 then consolidates that work with broader lifecycle coverage, and was itself superseded by the salvage in #76905, yielding the chain #62961 → #63708 → #66355 → #76905.

Suggested consolidation

Close #63708 as duplicate of the consolidated salvage #76905, making the full supersession chain explicit: #62961 → #63708 → #66355 → #76905. This follows the existing automated close decision on #62961 and the contributor-recorded closure of #66355 in favor of #76905; no merge recommendation is warranted here.

Complex graph

flowchart LR
    classDef open fill:#dbeafe,stroke:#1d4ed8,color:#1e3a8a
    classDef merged fill:#dcfce7,stroke:#15803d,color:#14532d
    classDef closed fill:#e5e7eb,stroke:#6b7280,color:#1f2937
    classDef unverified fill:#f3f4f6,stroke:#9ca3af,color:#374151
    classDef best stroke-width:3px,stroke:#b45309
    classDef target stroke-width:3px,stroke:#4338ca
    subgraph Dup62961 ["PRs duplicating each other"]
        P62961["PR #62961 (closed)"]
        P63708["PR #63708 (open)"]
        P66355["PR #66355 (closed)"]
    end
    class P62961 closed
    class P63708 open
    class P66355 closed
    class P63708 target
    click P62961 "https://github.com/NousResearch/hermes-agent/pull/62961"
    click P63708 "https://github.com/NousResearch/hermes-agent/pull/63708"
    click P66355 "https://github.com/NousResearch/hermes-agent/pull/66355"

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Graph: solid arrow = fixes / best fix, dashed arrow = partial or unverified (see edge label); boxed group = PRs duplicating each other; amber border = best fix; indigo border = target; gray node = closed (state tag in the node label).

Cross-PR triage: Reviewed 3 pull requests and 0 issues in this complex. Each diff was read against this issue; Assessment working set: 55 kB of PR diffs, 7 kB of issue/PR text, 3 kB of discussion (5 comments), 0 verify verdicts. verdicts reflect diff content, not PR titles. Part of an automated triage batch.

[aider4ryder]

FYI — this already landed upstream. Config-driven allocator trim is covered by PR #76905 (commit da43a8527b47), which adds hermes_cli/mem_trim.py + config plumbing. Superseded.