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feat(benchmarks): full ecosystem command rows (spec 4.1)#219

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Jul 2, 2026
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feat(benchmarks): full ecosystem command rows (spec 4.1)#219
NathanFlurry merged 8 commits into
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stack/feat-benchmarks-full-ecosystem-command-rows-spec-4-1-soqurlqr

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@NathanFlurry NathanFlurry commented Jul 2, 2026

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Every agent-facing command now has a verified host-vs-VM row: sh_pipeline,
cd_tmp_pwd, echo_hello, cat_small/big, grep_small/big, sed_substitution,
find_1000, tar_small/big, gzip_small/big, jq_extract joining ls_100 and
git_init_commit — 16 rows, zero skips, every row asserts output correctness
(match counts, extract-diff round trips, exact stdout, sha shape). Vendored
wasm command binaries are validated at startup and missing ones fail loudly.
Two-tier fixtures on the size-sensitive commands per the 1.5 convention;
memory column included. First release-build numbers (warm vmCmd p50 vs host):
echo 29ms/11x, cd 51ms/14x, cat 42ms/18x, sed 49ms/23x, jq 102ms/6.5x,
git 1.17s/47x, gzip_big 629ms/54x, tar_big 5.1s/631x, grep_big 7.7s/961x,
find_1000 5.3s/1470x — the Phase 5.2 worklist, now measured honestly.

…s via event

The sidecar drains process output before emitting process_exited and the
frame stream + event pump are FIFO, so once the exit event is observed no
trailing output can follow it; the host-side quiet-turn drain (2 turns at
10ms) only remains for the snapshot-poll fallback exit path. Also stop
awaiting signal-state refreshes on the exec critical path (start + first
output) — kill paths await the in-flight refresh instead — and clean up
the parked refresh in finishProcess so fallback exits release it too.

Warm host-driven exec p50: node -e '' 30ms -> ~17ms, wasm true 52ms ->
39ms; whole wasm-command-floor lane down ~13ms/row; bench:gate green.
New regression test: 10 sequential fast-exit 64KiB stdout captures.
Bake the constant wasm runner + wasi shim (~300KB of JS previously
recompiled per exec) into the per-process V8 userland snapshot via
guest_runtime.snapshot_userland_code, keyed and cached process-wide.
Mode env AGENTOS_WASM_SNAPSHOT_RUNNER=auto|block|off: auto probes the
snapshot cache without blocking (async warm kicked once per process)
and falls back to the byte-identical inline runner until ready, so the
cold path is unchanged. The sync-RPC glue is re-evaluated per exec (the
snapshot-baked copy cannot bind session bridge fns). Module bytes are
now base64-encoded once per module in a bounded, fingerprint-validated
cache (64 entries, warn on evict, debug log reports per-entry and
cumulative cache bytes) instead of fs::read+encode per exec. Adds
AGENTOS_V8_SESSION_PHASES timers (snapshot_get / blob_clone /
isolate_new / user_code_execute) and a measured NOTE against
EagerCompile at snapshot build (moves cost to isolate deserialize).

Warm wasm floor p50: true 39->33ms, pwd 48->43ms, ls-empty 81->75ms,
date-version 127->115ms (52/62/96/140 before PR #212); cold first-exec
improved; wasm suite green; bench:gate green. Remaining floor is
isolate-per-exec + module decode — pooling tracked as Stage C.
The filtered install (--filter @secure-exec/benchmarks...) omitted
packages/build-tools, so every bench-gate run died in the v8-bridge build
script (missing Node dependencies) before gating anything — the PR gate has
never actually run green on CI.
Pre-created V8 session workers (thread + snapshot-restored isolate, keyed by
snapshot digest + heap limit) are claimed at session create via a warm hint,
taking isolate_new (~4.2ms) and blob_clone off the per-exec critical path.
Workers are never reused across guests (each exec still gets a virgin
isolate); a wrong hint falls back to the existing lazy-create path. Capacity
per key via AGENTOS_V8_WARM_ISOLATES (default 2, 0 disables); refill after
claim; pool transitions logged; warm_worker_hit/miss counters in the session
phases output.

Seeding is deliberately conservative: auto mode stays snapshot-only and only
AGENTOS_WASM_SNAPSHOT_RUNNER=block seeds workers (wasm-runner key + default
node key). Reason: creating isolates on background threads while other
isolates execute guest WebAssembly deterministically SIGSEGVs the pinned V8
130 (WasmCodePointerTable::AllocateUninitializedEntry inside Isolate::New,
even under the isolate lifecycle lock — the race is against V8-internal wasm
threads). Backtraces + notes in the rusty-v8-upgrade todo; enabling default
seeding rides that upgrade.

Warm floors (block, this host): node -e '' 17 -> 14.4ms p50, wasm true
33 -> ~30ms (warm_worker_hit 64/67, isolate_new down to 3 background calls);
pwd 42.6 -> 37.5ms, printf-0b 44.7 -> 40.2ms, date 115 -> 111ms. wasm suite
8.9s (was 96s, pool+snapshot amortize debug isolates); v8-runtime tests and
bench:gate green.
Module bytes now ride the in-process runtime protocol as Arc<Vec<u8>> from a
raw-bytes cache (same bounded/fingerprinted semantics as the base64 cache it
replaces) and are injected pre-exec as a __agentOSWasmModuleBytes Uint8Array;
the runner prefers it over the AGENTOS_WASM_MODULE_BASE64 env fallback, so the
per-exec base64 encode/decode (4.3ms @267KB, ~23ms @2.5MB) is gone in both
snapshot and inline modes. The userland (wasm-runner) snapshot script is now
compiled with EagerCompile: the fatter-blob isolate cost it causes is prepaid
by parked warm workers, so the runner function no longer lazy-compiles inside
user_code_execute.

Warm floors (block, this host): wasm true 30 -> 19.7ms p50 (52ms at the start
of the 3.2 campaign), echo hello 24.0ms, pwd 29.3ms, ls-empty ~39ms (was 96),
date --version 30.4ms (was 140 — module-size tax eliminated), printf-64k 136ms
(stdout streaming path, separate finding). Injection failure fails the exec
loudly. wasm + v8-runtime suites green; bench:gate green (require_100_small
flaked 4.3x once and passed 1.13x on rerun — bimodal, pre-existing, tracked).
WASM/shell commands write the kernel VFS, but a JS guest's mapped-shadow
read arms returned the shadow's answer — including ENOENT — without
materializing kernel state: readdir listed only shadow entries, exists and
readlink probed only the shadow. Anything a wasm command created was
invisible to node (fs.readdirSync ENOENT on a directory the client API could
list). readdir now materializes the path from the kernel, merges kernel
children into the shadow listing by name (shadow wins), and tolerates
kernel ENOENT/ENOTDIR for shadow-only dirs; exists/readlink materialize
first like fs.access always did. Mapped unlink/rmdir now mirror the removal
into the kernel (best-effort, ENOENT tolerated) — the shadow cannot express
deletions, so the new merge would otherwise resurrect a kernel-backed file
in the very listing that follows the unlink.

Five service regressions: wasm-mkdir visible to node readdir+stat, shell
mkdir+redirect children merged, shadow/kernel union lists both writers'
files exactly once, same-process shadow readdir, and unlink-no-resurrect
(same process + next process). Discriminator repro (direct mkdir / shell
mkdir / node mkdir / shell redirect) all visible; wasm suite green; focused
readdir lane runs again (was ENOENT on its shell-made fixtures); bench:gate
green (readdir_small +0.05ms from the kernel merge — 3.3 targets that row).
readdir (spec 3.3): the mapped-shadow arm now derives is_directory from the
getdents d_type (DirEntry::file_type) instead of an anchored openat2 + statx
per entry (symlinks keep the resolving fallback so symlink-to-dir still
reports a directory), drops its redundant materialize-from-kernel side effect
(the kernel union merge subsumes it for listing; opens still materialize),
and the response crosses as one raw status-2 buffer ([kind][u32le len][name]
per entry) decoded directly in the bridge instead of JSON->CBOR->V8 objects.
fs/readdir_small guest 0.23 -> ~0.09ms p50 (4.5x node; Accept <=0.1ms met);
readdir_big 0.57ms. promises.readdir stays on the CBOR path.

streams (spec 3.4): new _fsWritevRaw / fs.writevSync raw multi-buffer RPC
([u32 count] + per-buffer [u32 len][bytes], sequential-write semantics), and
WriteStream's end-flush sends its buffered chunks as ONE writev instead of an
RPC per chunk. fs/stream_copy_big guest 7.6 -> 4.3ms, stream_copy_small
1.03 -> 0.63ms. The <=3ms Accept is NOT met — measured floor: the residual is
sync-bridge byte throughput (~1.5ms per MiB per direction; a 1MiB copy is 2
large transfers), proven by an RPC-count probe (read-ahead batching to 1 RPC
per direction made it SLOWER from extra copies and was reverted; the probe
artifacts and the rejected round-2 read-ahead live in
~/progress/secure-exec/2026-07-02-*). Bridge byte-throughput is filed as the
Phase 5 unblocker (same root cause as the stdout 1.3ms/KiB-chunk finding).

Service regressions: raw readdir Dirent semantics (incl. symlink cases),
writev stream-copy order, all five mapped-shadow tests; bench:gate green.
Every agent-facing command now has a verified host-vs-VM row: sh_pipeline,
cd_tmp_pwd, echo_hello, cat_small/big, grep_small/big, sed_substitution,
find_1000, tar_small/big, gzip_small/big, jq_extract joining ls_100 and
git_init_commit — 16 rows, zero skips, every row asserts output correctness
(match counts, extract-diff round trips, exact stdout, sha shape). Vendored
wasm command binaries are validated at startup and missing ones fail loudly.
Two-tier fixtures on the size-sensitive commands per the 1.5 convention;
memory column included. First release-build numbers (warm vmCmd p50 vs host):
echo 29ms/11x, cd 51ms/14x, cat 42ms/18x, sed 49ms/23x, jq 102ms/6.5x,
git 1.17s/47x, gzip_big 629ms/54x, tar_big 5.1s/631x, grep_big 7.7s/961x,
find_1000 5.3s/1470x — the Phase 5.2 worklist, now measured honestly.
@NathanFlurry

NathanFlurry commented Jul 2, 2026

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Stack for rivet-dev/secure-exec

Get stack: forklift get 219
Push local edits: forklift submit
Merge when ready: forklift merge 219

@NathanFlurry NathanFlurry changed the base branch from stack/perf-fs-readdir-raw-fast-path-stream-writev-coalescing-js-lane-xlprnvwv to main July 2, 2026 23:42
@NathanFlurry NathanFlurry merged commit e0790b2 into main Jul 2, 2026
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@NathanFlurry NathanFlurry deleted the stack/feat-benchmarks-full-ecosystem-command-rows-spec-4-1-soqurlqr branch July 2, 2026 23:42
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