measure(BENCH-QWEN38-27B): both withheld cells are clean, the c1 pairing is discarded on clock spread, and c8 has no denominator on this box

.agents/benchmarking.md

@@ -81,6 +81,14 @@ sudo nvidia-smi -lgc 2100        # pin, before the first leg
 sudo nvidia-smi -rgc             # release, after the last one
 ```
 
+**This works on the host path only.** Inside an `rc` lease `nvidia-smi -lgc`
+returns `LGC_RC=4`, "The current user does not have permission to change
+clocks", even as root, measured 2026-08-19 on `dgx:gpu0` in three jobs. Fleet
+devices are reachable by lease only, so for them the SM clock can be SAMPLED and
+not pinned, and a pairing may be refused on within-run spread with no lever to
+fix it. Read
+[`environment.md`](environment.md) before you plan a paired series.
+
 Pinning is a **shared-host mutation**. Never run `-lgc` or `-rgc` while another
 session holds `$HOME/gpu.lock` — it silently reprices their in-flight
 measurement, which is the very defect this section exists for. Take the lock,

.agents/environment.md

@@ -119,12 +119,17 @@ reimage, so host-side oracle work needs `sudo -n docker run` against
 `vllmcpp-build:gb10` or `nvidia/cuda:13.0.1-devel-ubuntu24.04`, reached over
 `ssh`, which is the bypass. **The sentence this paragraph used to carry, "no
 vLLM leg of any row can currently run on `dgx.casa` by a lease-compliant path",
-is FALSIFIED for the BUILD step and still holds for a MODEL RUN.** On 2026-08-18
+is FALSIFIED, for the BUILD step and for a MODEL RUN alike.** On 2026-08-18
 two `rc run` jobs built the pin from source inside a lease, installed the wheel,
 imported it, and reported `cuda True NVIDIA GB10`
 ([#1185](https://github.com/mudler/vllm.cpp/issues/1185), and "The pinned oracle
-builds inside a lease on `dgx:gpu0`" further down). Nobody has run a model that
-way, so no oracle-side MEASUREMENT is unblocked yet. Read the old reason
+builds inside a lease on `dgx:gpu0`" further down). On 2026-08-19 the same pin
+then SERVED: `vllm serve` on a 52 GiB bf16 checkpoint, from a lease, no `ssh` and
+no container image, three clean benchmark legs (`.agents/benchmark-record.md`,
+`BENCH-QWEN38-27B-BF16` c1, and "A model DOES run inside a lease" below). So
+oracle-side MEASUREMENT from a lease is no longer blocked; what is still
+unreachable is the image-based path SGLang needs
+([#1265](https://github.com/mudler/vllm.cpp/issues/1265)). Read the old reason
 carefully before you quote it, because it was never the worker's missing
 toolchain. "The lease carries bytes, and the exec bit is a mount option" below
 measures staged content starting under the dynamic loader and after a copy to
@@ -145,6 +150,63 @@ already has one. This row measured `dgx`'s worker and adds the part that turns
 an open gap into a blocker for the parity gates, which is that the ORACLE VENV
 is also unreachable from a lease.
 
+### Clock pinning does NOT work inside an `rc` lease, measured 2026-08-19
+
+[#1354](https://github.com/mudler/vllm.cpp/issues/1354) owns this.
+
+`nvidia-smi -lgc` is refused inside the leased worker, in a job running as
+**root**:
+
+```text
+$ nvidia-smi -lgc 2190
+The current user does not have permission to change clocks for GPU 0000000F:01:00.0.
+LGC_RC=4
+```
+
+Reproduced in three separate `rc run` jobs on `dgx:gpu0` on 2026-08-19
+(`.agents/benchmark-record.md`, `BENCH-QWEN38-27B-BF16` c1/c8). The container is
+root but lacks the capability the driver requires.
+
+**This outlives one campaign, and it is a records defect as much as a capability
+one.** [`benchmarking.md`](benchmarking.md) instructs "Pin the clocks before
+measuring, under the lock", and **every clock-pinned figure in this
+repository's records was taken over the retired host + `ssh` + `flock` path**.
+The migration to `rc` leases silently removed clock pinning and no record said
+so. Same class as [#1265](https://github.com/mudler/vllm.cpp/issues/1265): a
+capability the records assume, which the current access path does not provide.
+
+**Consequence for anyone measuring from a lease.** The SM clock can only be
+SAMPLED, never pinned. `tools/bench/gpu_clock_state.py` still works and is the
+only attribution such a number carries. Plan for its within-run rule to fail:
+the 2026-08-19 series recorded within-run spreads of 12.92% to 26.36% across
+nine windows on a thermally throttling GB10, against the 5% ceiling, and
+`gpu_clock_state compare` therefore returned `PAIRING_VERDICT=DISCARD` on every
+c1 pairing even though the cross-arm rule passed perfectly. Two arms measured in
+a lease may not be dividable, so budget for absolutes and say so in advance
+rather than discovering it after the GPU time is spent.
+
+**A model DOES run inside a lease.** The same series ran the pinned oracle
+`0.1.dev1+g555967922` as a server on a 52 GiB bf16 checkpoint from a lease, no
+`ssh` and no container image, and it served three clean benchmark legs. That
+retires the "nobody has run a model that way" reading of
+[#1185](https://github.com/mudler/vllm.cpp/issues/1185) recorded above. What is
+still unreachable is the image-based path SGLang needs
+([#1265](https://github.com/mudler/vllm.cpp/issues/1265)).
+
+**And one instrument rule, paid for in the same series.** A guard whose
+threshold sits inside the guarded configuration's own operating point
+manufactures the finding it was meant to detect. A 12,000 MB `MemAvailable`
+watchdog killed a healthy `vllm serve` 18 s after it reached `/health`, which
+read as "the denominator collapses in a lease" — and the arithmetic refuted it:
+`0.85 x 122,502 MB` reserved by design predicts 12,223 MB free against an
+observed floor of 11,917 MB, a 306 MB match, and the same server later ran three
+clean legs at a ~7,500 MB steady state. **A tripped guard is evidence about the
+GUARD until its threshold is shown to sit outside the guarded thing's operating
+point.** Predict the number from the configuration before believing the verdict,
+and keep instrument thresholds strictly apart from engine knobs: moving the
+floor changes nothing about what is measured, and moving
+`gpu_memory_utilization` changes what the number means.
+
 ### The lease carries bytes, and the exec bit is a mount option, measured 2026-08-17
 
 Probed with two `rc run -d dgx:gpu0 --max-runtime 3m` jobs,