kokkos: W3SIN4's stress scan with one sea point per vector lane…

docs/GLOSSARY.md

@@ -704,7 +704,7 @@ and [kokkos/src/fortran_iface/PATCH.md](../kokkos/src/fortran_iface/PATCH.md).
 | resident VA / `ww_va_host_read` / `ww_va_host_write` / `ww_va_device` / `ww_va_report` / `ww_srce_batch_va` | the device copy of the spectrum `VA(NSPEC,0:NSEALM)` that lives for the run (WFIP-0005), with a state per grid saying which copy holds the newer bits (`HOST`, `DEVICE`, `BOTH`); the C calls W3WAVE makes before a host read or write of `VA`, the one a kernel shim makes before reading the device copy, the traffic report, and the batched `W3SRCE` that works in place on the device copy `(v)` [kokkos/src/fortran_iface/resident_c.hpp](../kokkos/src/fortran_iface/resident_c.hpp) | The protocol of `Kokkos::DualView` (modify, sync) over WW3's own array; with no kernel on the device copy no call copies anything. Wrapped by `W3KOKKOS_VA_HOST_READ` / `_WRITE` in `w3kokkos_residentmd.F90` on the fork. | [kokkos/src/fortran_iface/PATCH.md](../kokkos/src/fortran_iface/PATCH.md) |
 | `WW_KOKKOS_VA_RESIDENT` / `WW_KOKKOS_VA_COUNT` | diagnostics of the resident VA, ignoring `WW_KOKKOS_ALL`: `=1` makes every host sync call push a host-newer `VA` to the device and copy it back, so a host write without its sync call shows in the output; the count prints the traffic line and the copy counters at exit `(v)` [kokkos/src/fortran_iface/resident_shim.cpp](../kokkos/src/fortran_iface/resident_shim.cpp) | Default unset. On the CPU both copies are `memcpy`, so the bits cannot change. | [kokkos/src/fortran_iface/PATCH.md](../kokkos/src/fortran_iface/PATCH.md) |
 | `WW_KOKKOS_VA_CHECK` / `WW_KOKKOS_VA_POISON` | diagnostics of the resident VA, read once, ignoring `WW_KOKKOS_ALL`, which compare or overwrite only the stale copy: `VA_CHECK=1` makes every sync call check what the state claims before it copies (unless `HOST`, the host `VA` still holds the bits of the last sync, so a host write without its `W3KOKKOS_VA_HOST_WRITE` stops the model; with `BOTH`, `d_va` holds them too, so a kernel that wrote `d_va` without marking it does); `VA_POISON=1` fills the host `VA` with a quiet NaN after every kernel write of `d_va`, so a host read without its sync, or a column the partial read misses, puts NaN in the output `(v)` [kokkos/src/fortran_iface/resident_shim.cpp](../kokkos/src/fortran_iface/resident_shim.cpp) | Default unset; a correct run writes the same bits with either. Added by the mutation audit of 2026-10-17. | [docs/log/2026-10-17-mutation-audit.md](log/2026-10-17-mutation-audit.md) |
-| `WW_KOKKOS_SRCE_LANES` | sea points per team of the batched `W3SRCE` launch on a host backend, 1 to 8, read once; each point runs the statements it runs alone, the points of a team take turns `(v)` [kokkos/src/fortran_iface/srce_shim.cpp](../kokkos/src/fortran_iface/srce_shim.cpp) | Default 1, today's one point per team; a device always uses 1. The lane layer of plan 005: later units vectorise across the points of a team. | [docs/compound/plans/2026-10-18-005-srce-points-in-lanes-plan.md](compound/plans/2026-10-18-005-srce-points-in-lanes-plan.md) |
+| `WW_KOKKOS_SRCE_LANES` | the most sea points per team of the batched `W3SRCE` launch on a host backend, 1 to 8, read once; each point runs the statements it runs alone, the points of a team take turns `(v)` [kokkos/src/fortran_iface/srce_shim.cpp](../kokkos/src/fortran_iface/srce_shim.cpp) | Default 8 (the owner, 2026-10-18), 1 for one point per team; a launch with fewer points than lanes times threads uses 1, and a device always uses 1. The lane layer of plan 005, which `W3SIN4`'s stress scan vectorises across (L2). | [docs/compound/plans/2026-10-18-005-srce-points-in-lanes-plan.md](compound/plans/2026-10-18-005-srce-points-in-lanes-plan.md) |
 | `WW_KOKKOS_OUTG_STAGED` | a diagnostic of the outg unit, read once: `=1` makes a host backend take the device's path of `ww_outg_va`, the inputs copied into the shim's own buffers, the fields computed into buffers, and only the fields a host reader needs copied back, so a field the copy-back selection misses keeps its old bits in WW3's array and shows in `out_grd.ww3` `(v)` [kokkos/src/fortran_iface/outg_shim.cpp](../kokkos/src/fortran_iface/outg_shim.cpp) | Default unset: on Serial and OpenMP the kernel writes WW3's arrays in place. | [docs/log/2026-10-17-mutation-audit.md](log/2026-10-17-mutation-audit.md) |
 | `WW_KOKKOS_STRICT` | environment variable read once by `ww_kokkos_strict()`: `=1` makes every place where a part asked on Kokkos would run the Fortran stop the model with `EXTCDE` and a `NDSE` line naming the part and the reason: `KOKKOS_PART` under `WW_KOKKOS_ALL=1`, the two `W3SRCE` set-up fallbacks and the per-step `W3SRCE` gate (`W3KOKKOS_SRCE_STEP`). Unset, those places run the Fortran as before and the shim prints one line at exit, `ww_kokkos: calls left on the Fortran (...): SRCE=<n> ...` `(v)` [kokkos/src/fortran_iface/part_flags.cpp](../kokkos/src/fortran_iface/part_flags.cpp) | Default unset. The regtest matrix's Kokkos run sets it, its Fortran runs unset it, so a pair cannot compare the Fortran with itself unseen. | [kokkos/src/fortran_iface/PATCH.md](../kokkos/src/fortran_iface/PATCH.md), section 24 |
 | `WW_KOKKOS_PRESET` / `presets.txt` | environment variable naming a line `PRESET <name> <PART,...>` of `kokkos/src/fortran_iface/presets.txt`: `ww_kokkos_flag` turns its parts on as if each `WW_KOKKOS_<PART>` were `1`; a set `WW_KOKKOS_<PART>` still wins, and `W3INIT` stops on a name the file lacks. `resident` is the only preset (`SRCE,XYP3,KTP3,OUTG,IOPE,UPDV,CPRT`) `(v)` [kokkos/src/fortran_iface/presets.txt](../kokkos/src/fortran_iface/presets.txt) | The file is the one list: CMake compiles it into the shim, `scripts/ww3-gpu.sh --kokkos resident` and the matrix's `WW3GPU_KOKKOS=resident` read it. | [kokkos/src/fortran_iface/PATCH.md](../kokkos/src/fortran_iface/PATCH.md), section 25 |

docs/compound/plans/2026-10-18-005-srce-points-in-lanes-plan.md

@@ -86,8 +86,8 @@ change a bit.
 | Unit | What | Done when |
 |---|---|---|
 | S0 | One-thread profile of today's batch, libm separated from the rest | the shares below are measured; the go/no-go of S0 is applied |
-| L1 | The lane layer: teams of `W` points (`WW_KOKKOS_SRCE_LANES`, 1 to 8, 1 reproduces today), each section run for the team's points in turn with today's scalar routines | **Done** 2026-10-18: `full` and `smoke` byte-identical with 1 and 8 (`kokkos/port_report/W3SRCE_KOKKOS.md`, "Points per team"). The point-minor scratch moves to L2, the first unit that reads it |
-| L2 | `W3SIN4` on lanes (its stress loop, `st4_sin4.hpp:198-249`) | byte-identical; kernel time of `W3SRCE` measured with and without, 1 thread |
+| L1 | The lane layer: teams of `W` points (`WW_KOKKOS_SRCE_LANES`, 1 to 8, 1 reproduces today, default 8 since L2), each section run for the team's points in turn with today's scalar routines | **Done** 2026-10-18: `full` and `smoke` byte-identical with 1 and 8 (`kokkos/port_report/W3SRCE_KOKKOS.md`, "Points per team"). The point-minor scratch moves to L2, the first unit that reads it |
+| L2 | `W3SIN4` on lanes (its stress loop, `st4_sin4.hpp:198-249`) | **Done** 2026-10-18: byte-identical on `smoke` and `full`; one-thread `W3SRCE` kernel 105.17 s to 99.77 s, 5.1 % ([log](../../log/2026-10-18-srce-lanes-sin4.md)) |
 | L3 | `W3SDS4` on lanes, the libmvec sites left as lane loops | the same |
 | L4 | The integration and the initialisation (`srce_kernel.hpp:177-400`) | the same |
 | L5 | `W3SPR4`, `W3SLN1`, `W3SDB1`, `W3SBT1` | the same |

docs/log/2026-10-18-goal-c3e7eecf-handover.md

@@ -0,0 +1,66 @@
+# Handover of goal `c3e7eecf`: the NOAA record, the ten-run median, points in lanes up to `W3SIN4`
+
+2026-10-18, an agent for M. Hoffmann (Claude Code session `ec4548a3-46a8-46e2-be0a-2d74c3e7eecf`).
+What this session finished, what is open, and what it learned, for whoever continues. It picks up
+where [the `abbb0456` handover](2026-10-18-goal-abbb0456-handover.md) stops; every claim names its
+record, and nothing here was re-run for this entry.
+
+## What worked (merged)
+
+| Result | Record |
+|---|---|
+| The NOAA progress record after #191: pin `50a10730`, seven preset parts with `CPRT`, strict mode, the NaN fill, one copy of `VA` to the device on `full`, 22 regtest entries with 0 files different and the four FAIL rows kept, a status table up front; the READMEs link it; gaps 6, 7 and 13 of the readiness list marked at the pin | PR #197; `docs/NOAA_PROGRESS_RECORD_202610.md`, `docs/PRODUCTION_READINESS_202610.md` |
+| The record's speed figure: median of ten alternated runs on `main`'s code (`5cd0140`), `full`, 32 threads, NOAA WW3 26.18 s, Kokkos resident 15.84 s, 1.65 times less wall time, every output byte-identical to run 1's; regtest pending ⚠ (22 entries, not the whole matrix) | PR #197; the record, section 3 |
+| Plan 005, sea points in the vector lanes of the batched `W3SRCE`, with its per-lane parity argument and units S0 to L7 | `docs/compound/plans/2026-10-18-005-srce-points-in-lanes-plan.md` |
+| S0: one thread of the resident batch is 51.1 % scalar per-point code lanes can reach, 39.0 % DIA, 8.9 % libm and libmvec | `docs/log/2026-10-18-srce-lanes-s0-profile.md` |
+| L1: `SrcePoint` sections with the kernel's bodies moved verbatim, `w3srce_lanes`, `WW_KOKKOS_SRCE_LANES` (1 to 8, host only; default 1 in #197, 8 since #199); `smoke` and `full` byte-identical with 1 and 8 | `kokkos/port_report/W3SRCE_KOKKOS.md`, "Points per team" |
+| PR #198's conflict with `main` resolved by a merge (no history rewritten) | merge commit `41f4197` |
+
+## Open work
+
+| Item | State | Next step |
+|---|---|---|
+| PR #199, plan 005 L2: `W3SIN4`'s stress scan on 8-wide vectors | `smoke`, `full` byte-identical with 8 points per team; one-thread kernel 105.17 s to 99.77 s (5.1 %); CUDA `--build-only` clean; merged with `main` | the regtest matrix with `WW_KOKKOS_SRCE_LANES=8` (the matrix passes the variable through to its Kokkos runs, `regtests/cmake/ww3gpu_common.cmake`, `ww3gpu_kokkos_env`); the owner's review of the loop nesting and of the explicit vector types (the PR body) |
+| Plan 005 L3: `W3SDS4` on lanes | not started; 24.8 % of the batch in S0, the largest unit left | split `w3sds4_point` as L2 split `W3SIN4`; the five libmvec sites (`st4_libmvec.hpp`) stay a loop over the lanes, each lane calling today's grouped code; time it pinned (`taskset -c 2`) as L2 was |
+| Plan 005 L4 to L7 | not started | the integration and `w3srce_team` (9.9 %), `W3SPR4` and the small terms, the DIA layout, then a median of three at 32 threads on an idle machine |
+| The opportunity and GFS-Wave analysis of 2026-10-18 | written by a sub-agent into the session's scratch directory, not committed; three of its claims checked (the `Kokkos::single` sites, the batched `W3SRCE` switch gate refusing `FLD2` and `SEED` and needing `LN1`, `7a23cd77` being plan 004's GFS.v17 commit) ⚠ the rest not checked | if wanted, redo it into `docs/compound/plans/`; its order for GFS-Wave was: read GFS.v17's switch, grid and compiler from the UFS weather model; plan 004; `W3FLD2` and the `SEED` and no-`LN1` paths in the batched `W3SRCE`; a `SHRD` build of `ww3_ufs1.1`; profile, restart pair, the Intel compiler; an ADR before any MPI work (ADR-0017) |
+
+## Waiting on the owner
+
+- The decisions plan 005 names: whether the host may call the transcribed vector libm
+  (`libm_device.hpp`) inside lane loops, and whether a sampled check is enough for `powf` and
+  `atan2f` (`docs/GPU_LIBM_BITS_202610.md`); whether to skip `W3SDS4`'s zero weights (not
+  bit-neutral: `0 x Inf` is NaN).
+- The restart pair (`scripts/restart_pair.sh`), still never run.
+- The `bench/results/` record of the ten-run median, once WW3's regtests have passed on `5cd0140`
+  beyond the 22 entries.
+- Whether the regtests of #191 move the `regtested` cells of `kokkos/ports.tsv` for the resident
+  parts to "yes"; the ledger still says "no".
+- From the `abbb0456` handover, still open: the strict-OUTG/POISON follow-up branch
+  (`goal/abbb0456-8241-strict-outg-poison`, no PR), the Fortran A/B harness branch, #196.
+
+## Left on disk, not in the repository
+
+- `~/code/ww3-gpu-2/noaa-timing.sh` (untracked): the timing of the record, `bash noaa-timing.sh
+  [N]`, N alternated runs each, the load printed at the start and the end. It moves `WW3/` to the
+  checked-out commit's pin first.
+- `~/code/ww3-gpu-2` is on `goal/c3e7eecf-6142-srce-lanes-sin4`, `WW3/` at `50a10730`.
+
+## Traps met (for whoever continues)
+
+- **A one-thread timing on the i9-14900 is no measure unless pinned.** The same code took 113 s to
+  155 s in four unpinned runs as the thread moved between performance and efficiency cores; pinned
+  to CPU 2 (`taskset -c 2`), three runs agreed within 0.1 s.
+- **The load average counts the timed job's own threads.** A 32-thread run shows a load of 25 to 27
+  with nothing else on the machine; read the load before the job starts.
+- **g++ leaves a lane loop with selects scalar under its default `-ftrapping-math`**: it sinks the
+  values only one side of a select uses into a branch and will not speculate them back
+  ("unsupported control flow in loop"). Plan 005 uses GCC vector types instead of changing that
+  flag for every kernel; `-fopt-info-vec-all` on the shim's translation unit, inside the pinned
+  shell, tells which loops vectorised.
+- **`serial-debug` has no `-march`**: a function that returns a 32-byte vector by value warns
+  `-Wpsabi` there; pass vectors by reference.
+- **`pkill -f <pattern>` from a tool shell kills that shell too** when the pattern is in its own
+  command line; kill by PID.
+- **Merged means finished**: work after a merged PR goes on a new `goal/` branch from `main`, as L2
+  did after #197 merged.