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* vgsp: fail4 - route pending-pass releases through opdef withholding ↵Arthur Hanson Rasmusson15 hours
| | | | | | | | | | | | | | | | | | (cold-run gap) The fwd-defer arm took priority over svc_opdef_release, so a pass whose op was still pending recorded its fence release in svc_fwd_rel (applied at the hold break / fallback) instead of the opdef slot - the fence fired while the copy was still owed, the driver refilled the ping-pong staging, and the late capture/read got refilled bytes (cold-run vector_add gap: one to four chunks per cold boot). svc_fwd_defer_arm() is now skipped when svc.op_tr_pending, so those releases go through svc_opdef_release and apply only when the retried pass has no pending op (the op has run by then). Measured cold-run vector_add bad across this iteration: 193536 -> 100352 (r323) -> 479232 (r324 wrong queue-pending experiment, reverted) -> 66560 (r325, ~1 chunk). All other acceptance items green on r325 (mail OK, smi OK, matmul OK, transformer OK).
* vgsp: fail4 - carry the channel into pending releases; hold the fence on ↵Arthur Hanson Rasmusson15 hours
| | | | | | | | | | | | | | | | | | | | | | | | | | | | denied passes Two fixes for the cold-boot classes (CONT.60): 1) Pending releases starved forever: svc_apply_pending resolved the pool semaphore with h=0, but the verified pool resolver is channel-keyed - it never matched the per-channel pool entries while the very same lookup at decode time succeeded (matmul r322: 'pool-rel cand ... rrc=0 cur=0' then 'pending release starved va=0x121000010 payload=1 tries=4/64...' forever, the client hung and the boot died). Pending entries now record the channel they were decoded for (struct svc_pending_release.h, set from svc.cur_ch which svc_decode_stream stamps at its top) and svc_apply_pending resolves with it. Also applies to the 'completion hint rc=-2' class. 2) The fence escaped on denied passes: in the P6b wave-2 overflow branch the release was queued only when n_ops>0; a denied pass (n_ops==0) but op-pending (a copy still owed) applied the release inline, letting the driver refill the ping-pong staging before the copy ran - the cold-run capture gap (vector_add run 1 bad=157696/193536). The queue condition is now n_ops>0 || svc.op_tr_pending. Measured (r323 fresh boot, full sequence): mail OK, nvidia-smi OK, matmul OK (no death - the r322 killer), transformer OK (no stall), vector_add cold-run bad=100352 (two chunks, down from 157696-193536; warm runs remain bad=0).
* vgsp: sync gsp_sema_service.c to fail4 after cherry-pick conflict ↵Arthur Hanson Rasmusson15 hours
| | | | (wd_rewind_off_until struct member repair)
* vgsp: fail4 - LAND ALL H2D CHUNKS: consume the staging snapshot; capture on ↵Arthur Hanson Rasmusson15 hours
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | first decode vector_add was deterministic-wrong (bad=786335 checksum=359549561 identical across boots) because the 1MB H2D chunk copies always read the driver's ping-pong staging AFTER it had been refilled (the fence release applied long before the late op execution; 60+ rc=-2 retry storms per chunk). Two wiring fixes (r314-r315): 1) The decode-time snapshot was NEVER CONSUMED: svc_copy looked it up (svc_copy_snap_lookup at the top) and freed it on success, but no code read from it - every copy fell through to the live per-page source resolution and read refilled staging. The source read loop now takes the bytes from the snapshot when present (memcpy from snap + o). The copy also no longer needs a live source translation, so it executes on its first allowed pass instead of storming retries. 2) Capture on the DENIED pass too: the old capture gate lived in the op-build block (allowed passes only - by then the fence fired and staging was refilled). The denied device-dst copy branch now captures immediately (pipeline-order moment), same translation-probe guard. Measured r315 (fresh boot): vector_add first run bad=157696 (cold-run capture coverage gap), second run bad=0 checksum=392344090.5 STATUS OK with ALL EIGHT chunks clean and no retry storms (~75 s, guest survives). Previously 786335 bad / identical checksum every boot.
* vgsp: fail4 - cure the stale-wedge republish loop; enable staging snapshots ↵Arthur Hanson Rasmusson15 hours
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | for the sw-copy client Two fixes, both demanded by live evidence: 1) Stale-wedge republish loop (r311-r312): the pump's per-channel write-back did not persist gr_pub_armed, so the residual watchdog re-armed every pass; its recovery kept zeroing the completion word and re-publishing (pub-adv/ zero/stale-wedge 3s cycles, exit: pub-adv pa=... val=104 cur=0 last=0). The word oscillated under a live client that then never completed (r311 vector_add wedged; guest sshd died). Persist gr_pub_armed/counter_gen in the write-back and keep them (plus slot_pend_tries) across same-generation re-registration. Also guard the residue zero: never zero a completion word authored by the live session generation (r312 instrumentation: pub-adv-wrc + stale-recover- zero + skip witness). Verified r313: stale-wedge rows 0 (was 66+), client completes, guest survives. 2) Staging snapshot capture for the sw-copy client (r311): the decode-time H2D capture gate required src_aperture == CE_APERTURE_SYS, but the driver sends no SET_SRC_PHYS_MODE for the 1MB chunk copies, so src_ap defaulted to VID and the gate never matched - zero captures on every run r302-r310 while executions read the (driver-refilled) staging late. Gate judge is now the translation: capture when the first source page resolves through SYS. First verified captures (r311: 2-3 per run, real client bytes in first4) - partial coverage only; the remaining pipeline-order gap is the open lead (see handoff CONT.57). Diagnostics kept: snapgate witness, pub-adv-wrc, stale-recover-zero[-skip].
* vgsp: fail4 - denied device-dst copies hold+retry (fix the chunk drop)Arthur Hanson Rasmusson15 hours
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Root cause of the vector_add chunk drop (CONT.55 chase): the sw-copy client's GR-classified GRCE channel (eng=0, h=0x5c000059) decodes its 1MB H2D chunk copies as CE transfers, but ops on that channel run only once the pin/trust stream (injected) reaches each push page. The first pass over a chunk push lands before that; with allow_ops=0 the copy was never built and the entry was consumed silently. All later passes classify as replays (slot_ops_complete=1), so the entry was never retried: 6 of 8 chunks skipped, kernel computed on stale VRAM (vector_add r302-r307: 2-5 of 8 chunk ops ever existed, the rest never ran; the +2MB 'phase' signature is stale residue). Fix: a denied launch that WOULD have built a type=1 device-dst copy (no remap, both offsets, out >= SVC_VAS_FLOOR) with a trusted push now marks the pass op-pending. op_tr_pending un-completes the slot, so the next pass is treated fresh and the copy runs as soon as trust (injected with allow=1) or the operand translation arrives - the existing m163/opdef hold+retry machinery. Replay passes are deliberately eligible (that is what makes the retry possible); a per-slot slot_pend_tries cap (4 per put epoch) prevents a slot whose trust never arrives from wedging the channel in 10s hold cycles. Measured (r308, sema_dbg): all 8 consecutive chunk dsts build ops (0x...cc..d3) and retry to success - 28 CEAUDIT rc=0 soft copies, 38 rc=0 vs 20 rc=-2 executions; previously max 5 dsts and only the last 2-3 ran. Regression checks on r309 with the fix: probe RAWA2+PROBE2B bad=0, victory_mail OK, victory_matmul OK (one transient first-run fail, clean re-run), transformer OK. vector_add now advances through the full H2D set but still does not complete (retry storms stretch the copy phase; the run later wedges in the GR stale-wedge recovery loop - named as the next lead). Diagnostics kept (dbg-gated, bounded): sema-pend set/hold witness, sema-consume consumed-slot witness, sema-entry de-gated for eng=0 channels, dmatrace extended with replay/eng/pend_would, budgets raised under sema_dbg so boot init cannot spend the trace before the run.
* vgsp: fail4 r297-r300 - decode-time staging snapshot (H2D shapes only) + ↵Arthur Hanson Rasmusson15 hours
| | | | | | | | | | | | | | | | | | | | | ops-order release guard 1. CONT.53 step (1): device-dst copies from host sources now snapshot the source at op-build (bounded pool 16 x 4 MB, 30 s TTL) and execute from the snapshot, so the staging read happens at the push's processing position. 2. The capture gate is aperture-based (dst VID, src SYS) after the r300 captures showed a naive VA-floor gate also caught D2H readbacks and froze pre-kernel zeros. 3. Ops-order release guard: a pass that built ops queues its releases through the pending pass instead of applying inline, so a fence never clears before the pass's copy ops read their source. A/B (r297/r299/r300): snapshots fire (6-7 per run) but the +2 MB phase persists (win@0/1M = exp[+2M]); the r300 capture contents show the H2D op sources already carry late-chunk data at decode - the scrambling is at the driver's staging hand-off into the push stream, before our service sees the op (next instrument: correlate the client's PTRS with per-capture buffer identity).
* vgsp: fail4 - pipeline-order source snapshot for held staged copiesArthur Hanson Rasmusson15 hours
| | | | | | | | | | | | | | | | | | | | The m169 device-dst guard defers a staged H2D up to 3 s; the driver's ping-pong staging buffers are overwritten meanwhile, so a deferred read returned a later chunk's content (the +2 MB vector_add phase = the 2x1 MB staging stride). Held copies now snapshot their source at hold time (bounded: 8 slots x 4 MB, 30 s TTL) and the retried execution copies from the snapshot, matching the hardware's in-order staging read. r296 A/B: the snapshot never fires for vector_add - its H2D dsts resolve with pins promptly and execute without the hold; the +2 MB persists identically. So the staging overrun happens WITHOUT the guard: the driver's 2-buffer staging discipline relies on the copy's completion fence (a semaphore applied when the copy executes) to pace the restaging; if our completion for chunk i arrives before/independent of the staging read, the driver restages and our later decode reads chunk i+2. Next lead: the staging fence's increment timing vs the copy's execution (the release-before-work class extended to the H2D staging fences), not the m169 hold.
* vgsp: fail4 - definitive rec-content witness (data[0..2] first8 at the rec hpa)Arthur Hanson Rasmusson15 hours
| | | | | | | | | | | | r295 measurement: rec[0] va=0x72a93cc00000 hpa=0x119155000 first8=43100000 43108000 = floats 144.0 144.5 = a[524288..524289] - i.e. the first A-rec's backing page already holds the +2 MB data, before copy-in. Chained with the r285 upload witnesses (the H2D op sources read the other buffer's chunk-2/3 data), the +2 MB phase originates on the HOST-BUFFER side of the uploads (the pinned/staged source resolution for the client's host buffers), not in the GMMU walk (verified correct against the driver's own format: PD3[48:47]/PD2[46:38]/ PD1[37:29]/PD0[28:21]/PT[20:12]).
* vgsp: fail4 - device-survival chain for the large-buffer sequence + CE ↵Arthur Hanson Rasmusson18 hours
| | | | | | | | | | | | | | | | | | | | | | | | | | | | both-side op advance Survival (the death cascade is gone for the full user sequence): 1. pool residue re-seed applies ABSOLUTE (cur=0) - the UVM assert (uvm_channel.c:204) that took the device down no longer fires (committed earlier in 67148bd8). 2. completion-hint window 10s->1.5s (67148bd8). 3. status-ring free-space discipline in gsp_rm_send_flags: the guest's consumption cursor (msgqRxHeader.readPtr at stat+rxHdrOff, the msgqTxGetFreeSpace source) gates EVENT posts; events drop freely when short, replies wait (bounded) and proceed. A guard rejects a cursor the guest cannot be behind (peer > our writePtr - the observed mirror tracks writePtr+1 and gating on it silenced every wake-up and wedged the clients). Verified live: mail OK, nvidia-smi OK, victory_matmul OK, vector_add completes (content still wrong) and victory_transformer STATUS OK AFTER it - no ISR panic, no guest death, guest ssh alive. Content: CE linear auto-advance now applied to BOTH offset registers after each executed op (the driver re-sets one side per op and the engine advances the other; H2D ops showed an explicit advancing dst with a fixed src base: the device a held h_a[0..1MB) replicated). vector_add content still FAIL (~66% bad) - the H2D operand stream under retry/replay passes is the next lead (opadd rows show five dst x two src combos with heavy retry multiplicity).
* vgsp: fail4 r259-r262 - capture ring (4 slots) + diagnostic budgets; CE ↵Arthur Hanson Rasmusson22 hours
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | auto-advance tried and reverted 1. svc_gr_cand is now a 4-slot ring addressed by an accessor macro (svc_gr_cand -> ring[pos]); captures that would overwrite a DIFFERENT launch's unconsumed candidate move to a free slot, and svc_gr_request selects this channel's oldest unconsumed candidate before consuming; the defer-arm gate checks any unconsumed candidate. Struct tag renamed svc_gr_cand_rec to keep the macro safe. (The streams2 cross survives this - it is not (only) the single slot; see the new evidence in the handoff.) 2. Diagnostic budgets raised for the triage (opadd/op_trace 2048, memsets rc-log 2048). These exposed the real memset shape: the 8 MB cudaMemset is SIXTEEN grid=1024/block=512 kernel launches whose win0 param bank is fully correct (dst patched to the reloc, w0x168=0x5a5a5a5a, launches OK) - yet the D2H readback returns zeros, so the loss is between the engine's stores and the readback pages (the rec hpa/landing class, GRVAUDIT unlanded mass), not the params. 3. A CE-style per-op dst auto-advance was implemented, evaluated (no memset improvement) and reverted - re-sets are decoded and the risk to the green clients was not justified. Verified on r262 (boot 1 of the acceptance round): ctaid_probe RAWA 0 1 2 3 4 5 6 7 + PROBE2 bad=0; transformer STATUS OK; streams2 bad=65536 (red); memcpy_roundtrip wedged the guest (flaky: green on r254, wedges on r260/r262).
* vgsp: fail4 r254-r257 - small-fill hold + copy landing ledger + per-launch ↵Arthur Hanson Rasmusson24 hours
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | reloc half Three fixes on top of 54cf842c, targeting the big-buffer clients: 1. m163 parity for fills: a small failing FILL op with a virtual device destination is now held/retried like the small copies (-ENOENT with the pins still landing was silently counted nomap and the release applied - the 8 MB cudaMemset landed only partially). Verified: memcpy_roundtrip now reaches STATUS OK (RT1 bad=0 csum exact, MSET bad=0, h_m all 0x5A). 2. svc_copy landing ledger parity with svc_fill: a large virtual-dst copy records its landing pages so the GR rec build (m171 ledger preference) follows the page the copy actually wrote. streams2's c1 moved from a stale-page mix ([28.0, 28.625, 29.25]) to the correct-page values ([0.0, 0.125, 0.25]). 3. Per-launch relocated-data base: concurrent forwarded launches (streams2's vadd pair) shared one base and their bounce windows overlapped; the base now alternates across the grown region's two halves keyed to the capture push (retries keep their half), cap halved accordingly. Also raise the per-page data attribution budget (16 -> 192 pages) for span forensics. Remaining on streams2/victory_multikernel: the single-slot svc_gr_cand capture is overwritten by the second concurrent launch before the work item consumes it - ctaid-probe evidence: c1 == a2+b2 exactly (the stream-2 result in the stream-1 output) with the in-tree candidate-overwrite witness present. Next: make the capture a small FIFO drained in order by the gsp-phys-work item.
* vgsp: fail4 r249-r252 - GRCE slot-run rule + arg-rec order fix; probe fully ↵Arthur Hanson Rasmusson24 hours
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | green Two fixes on top of c66a0172: 1. Slot rule for LOAD_INLINE_DATA runs: in the UVM upload pushes each run fills a whole 32 KB slot - its data runs to the next run header (or to the next 0x8000 boundary for the last run), regardless of the count field (observed slot starts every 0x8000: cnt=4095 and cnt=2497/2753 variants). Compact pushes keep the count*4 reading. The old reading truncated each slot run to half its data and walked the tail as methods. 2. Argument-ring order: the bridge's arg-block search must see the run's START as the inline-write destination; the new cursor advance must not leak into rec->dst_va (an end-of-run dst_va made the QMD param patch miss and the engine never consumed the launch - regression found and bisected against the pre-session ko via victory_mail). Verified one boot (r251/r252, standard params): ctaid_probe RAWA 0 1 2 3 4 5 6 7 + last8 16376..16383, PROBE1/PROBE2/PROBE2B bad=0; transformer STATUS OK; victory_mail STATUS OK. Residual (distinct class, NOT the H2D delivery): streams2 bad=65534, memcpy_roundtrip bad=8388608, victory_multikernel bad=2883066. Their big spans collapse to a single rec/bank entry in the launch tables ('bank 0 hit @0x168: VA -> reloc' for one page of the span) and the engine write-back replicates one page across the span (OUT-ALIAS-WIT partners) - the original span-aliasing class on the large-buffer paths.
* vgsp: fail4 r242-r248 - GRCE LOAD_INLINE_DATA cursor advance + H2D decode ↵Arthur Hanson Rasmusson24 hours
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | instruments The probe/mallocecho H2D (cudaMemcpy H2D of a 64 KB device buffer) arrives as LOAD_INLINE_DATA method runs (op=3, subch=1, addr 0x1b4) carrying the payload inline in the push, split across several runs (and, depending on pool state, across several pushes of one sequence). The inline-write handler wrote every run at st.offset_out without advancing, so a multi-run upload kept only the last run's words and the readback page held deterministic junk (RAWA 16382 16383 8193...). Fix: a LOAD_INLINE_DATA run advances the destination cursor by the bytes it wrote (hardware FIFO semantics); consecutive runs of one upload now tile from the first destination. Verified (fresh boot, standard params): mallocecho d-afterH2D head 0 1 2 3 4 5 6 7 (was junk); ctaid_probe RAWA first8 0 1 2 3 4 5 6 7 (was 16382 16383 8193 8194...). Residual: the upload spans multiple runs/pushes and only the first 4095-word run lands today (bad=12289, tail zeros) - the remaining runs are still lost to the decoder's run-boundary handling (see sema-next-hdr captures). Instruments added (all gsp_sema_dbg-gated, bounded, session-reset): sema-pushall (de-windowed push decode trace with page_pa), sema-opadd, sema-copyent, sema-dmatrace (denied transfers), sema-bigrun (count>=1024 runs on len>=8192 pushes with cursor state), sema-lid-hdr, sema-skiprun, sema-mystery, sema-next-hdr (header after each big LID run). LDA/xfer-raw/stream dumps de-gated from ch->h_object!=0 so unidentified channels are visible.
* vgsp: fail4 r239 - widen per-recp content witnesses to n_data<=1024 (probe ↵Arthur Hanson Rasmusson26 hours
| | | | | | | | | | | | | | | | | | | | | | class is ~950 recs) The probe's launches carry ~950-970 recs (its 2 MB VA arena is one span), so the <=64-rec gates on A-TRACE pt=P3 (engine-read source content) and READ-DIVERGE-WIT (fill vs copy-path vs ledger per rec) never fired for the probe - exactly the launches they were built for. Raise both gates to 1024; budgets unchanged (128 lines / first 8 recs), so the transformer's 1418-rec launches stay out. r239 findings this rides on: the probe's H2D (h_A->d_A) leaves ZERO host trace (no copy, no launch, no audit in a continuous 6.6k-line dmesg stream) and A's vidmem reads as deterministic junk from the very first post-upload read; the driver's 512-thread memset kernel zero-writes with fe_esr=0x80000000 and the 3x fresh-attempt retry path (fresh qmdwin bank + win0 bank + rebuilt PB) does NOT recover it. A minimal new repro (blk512) shows the band bug without any probe machinery: grid(8,1)x512 writes 4/4 buffers perfectly while grid(16,4)x(16,16) 'out[i]=i' is deterministically bad=12288 (rows >= 16), with the engine-side scan reporting 31/31 changed pages - the by>=1 stores exist somewhere the client does not read.
* vgsp: newbind holds are residual-only and short (r237 T2 3 s GP_GET delay)Arthur Hanson Rasmusson26 hours
| | | | | | | | | | | | | | | | | | r237-2: T2's GR channel carried T1's residual put=115; my 3 s empty-decode hold delayed the host's GP_GET during the residual walk, and the guest unwound at binding+3.46 s (zeroed PROMOTE_CTX, then full FREE) - exactly when the host finally consumed the residual. The guest's ctx-init patience is ~3 s, so the hold must never delay the walk that long. - New SVC_GR_NEWBIND_HOLD_MS 1200u and per-channel wd_newbind_hold_until: the hold windows (empty-decode and unmapped entry) now apply only while it is fresh (<1.2 s; the rebuild lands in ~0.8 s) and only when put == get (residual context, no producer work pending). Any pending producer work is walked without delay, so GP_GET always advances promptly. - wd_newbind_until (3 s) still governs retry eligibility; the opdef drop, chanswitch log, pending-map/rebuild path are unchanged. make kernel green.
* vgsp: fail4 r235 - A-TRACE dir tag + 64KB copies exempt from bigcopy budgetArthur Hanson Rasmusson43 hours
| | | | | | | | | | | | | | | | | | | | | | r235: only 4 of the probe's ~9 64KB copies reached the ring (the sema_bigcopy_log budget had absorbed the rest - the A H2D is missing entirely), and the events lack direction/buffer identity. Now: - every total==65536 copy bypasses the bigcopy budget (its own 128-line A-TRACE budget still bounds volume) so the probe's H2D and all D2H readbacks always appear; - A-TRACE carries dir=H2D/D2H (device=VID low-pa, host=SYS high-pa) plus pt=P1/P2 (upload read/landed) or P4/P4R (readback source/result). r235 decode so far: the A upload lands ([0 1 2 3] in device pa 0x7800000 at t=.94) and the SAME device page is later rewritten to [16382 16383 8193 8194] - h_A's own values at shifted offsets - with the pattern repeated across consecutive device pages (0x7800000/0x7810000/ 0x7820000), i.e. a repeated-page/offset-wrapped write inside the emulated copy or engine path, not client-side. The trace fix makes the next capture name the exact path (missing H2D included). (cherry picked from commit 9b35145136c949405c7fb4d22b3405c174ecb055)
* vgsp: stale-replay leg is now strictly non-harmful (r235 second-client death)Arthur Hanson Rasmusson43 hours
| | | | | | | | | | | | | | | | | | | | | | | | | | | | r235-2 mechanism: at R2's ctx-init one pass fired 8 'stale-replay rewind=1' lines (waited_ms=3491, incl. fresh channels with sub=6 put=1) and set each channel's pin-batch rewind cooldown to +24 s. The rewind is the retry path for a fresh context (its init pushes are decoded before the pins land; the rewind re-decodes them once the translations exist), so disabling it killed R2 exactly like it would every next client (r233 P2+, r235 R2-R4). R1 (working) fired zero tokens. The 3 s window misread a normal init oscillation (rewind replaying a just-consumed entry) as a rewind livelock. - Removed the rewind cooldown entirely: wd_rewind_off_until field, write-back, watchdog clear/set and the svc_handle_map_add skip are gone. The pin-batch rewind is never manipulated by any recovery. - stale-replay now requires SVC_GR_STALE_REPLAY_MS (10 s) of stalled position with consumption happening (a genuine livelock; r225 wedge was 42 s+), keeps its window accumulating until then, and clamps last_get = put at most once per put epoch (wd_epoch_done). - Token updated: '... reason=stale-replay reset=0 clamp=1 ...' (no rewind manipulation; clamp is bookkeeping, a rewind may undo it). Epoch legs (residual/dead-range), stale-entry, newbind window, pending-map/rebuild path, kill-recovery, r220 guard and the m181 rule are unchanged. make kernel green. (cherry picked from commit 459384e02bba4eca04fa3eca2365a731a4a7a33a)
* vgsp: bounded newbind/rebuild diagnostic tokens (r234 discrimination)Arthur Hanson Rasmusson43 hours
| | | | | | | | | | | | | | | | | | | | | | | | | r233: ctaid_probe attempt-1 completed (newbind fix works) but the NEXT client (P2, fresh process after P1's CLEAN teardown+flush) stalled with zero tokens. witness-r233.log shows why: after the last FREE (180966.07) and rebuild #40 (180967.07) the guest sends ZERO traffic for 9+ s (only 'completion hint rc=-2'); no channel binding ever exists, so no entry-level recovery (pending-map/chanswitch/stale-entry) can apply. Pattern across boots: a CLEAN client exit is followed by a pre-registration stall; a KILLED client is followed by a working client. Diagnostics added (bounded 16/session each): - 'GR-STALL-newbind h=... put=... get=... action=window reason=stale-entry-newbind' when a binding's freshness window is armed (proves the reconcile runs per binding, not just once). - 'GR-STALL-rebuild consumed=1 by=svc_thread ...' when the service loop consumes svc.rebuild_now (proves the forced rebuild is taken; rules out the stale-flag hypothesis). wd_chanswitch/wd_newbind_until are per-channel/per-binding (armed on every !same_gen registration) - no global-state stomping between clients. make kernel green. (cherry picked from commit 2e6921f4fe7d2a0dcd478430981367a6e354465c)
* vgsp: fail4 r234 - A-TRACE end-to-end 64KB copy trace + RDW rec-dump arming lineArthur Hanson Rasmusson43 hours
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | r233: the probe ran (attempt-1 completes now) with the same deterministic foreign readback, while REC-DUMP/READ-DIVERGE-WIT/READ-ORDER-WIT/ledger DIVERGE were all absent from the capture. The r231/r233 rings only cover the transformer_mt window (6-7 GRID-WITs, 15 sema-bigcopy lines, all of the transformer); the probe's launches are outside the saved ring, so the witness absence is not yet attributable to the code. Two additions make the next capture self-contained: - RDW nrecs=<n> launch_va=<push>: one arming line per forwarded launch (budget 256) - a capture can never confuse 'witness did not run' with 'no recs'; probe-class launches must show nrecs>0. - A-TRACE, four labeled points for every 64 KB copy and every small launch (budgets 128/128): pt=P1 H2D source read (src_int4 as ints; expect 0 1 2 3) pt=P2 H2D destination right after the copy (dst_int4_after) pt=P3 engine-read point: for <=64-rec launches, the first recs' source-page content the copy-in stages (w0..15 per rec) pt=P4 D2H source read (the engine-authored page as ints) pt=P4R D2H host-side readback after the copy The probe A buffer is ints 0..16383; the first point where the pattern breaks is the bug site. Stats check for the elision class: r231's probe-window stats show copy_skipped=0 copy_soft=0 copy_fail=0 and no device-dst guard lines, so no forwarded/skip elision is in play in that window; the trace decides where the read/write split actually occurs. Build green. (cherry picked from commit 98bfc75410b214f7de3dfc6ef80bff76118ff14d)
* vgsp: fail4 r233 - budgeted REC-DUMP + READ-DIVERGE-WIT (fill vs copy-path ↵Arthur Hanson Rasmusson43 hours
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | vs ledger) r231/r232: the probe-class launches produced zero REC-DUMP lines while the transformer's 8+2 appeared - the per-line pr_info_ratelimited was suppressed wholesale during the probe's post-stall logging burst. REC-DUMP now uses plain pr_info under a boot-wide 512-line budget, so a <=64-rec launch always dumps its full rec table. READ-DIVERGE-WIT (sema service, rec-build loop): for small launches the three resolutions of each VA are compared side by side - the fill's dg->pa (the page whose content the copy-in stages; exactly what the engine reads), svc_op_translate (the H2D/D2H copy path's resolver) and the ledger's write landing. A page-level split is logged with op_src/op_rc and an op-miss token. Bounded: first 8 recs, boot budget 128. Static permutation check (negative): reloc_va is assigned sequentially in fill order (svc_gr_data_fill), copy-in/out iterate recs in order, the engine reads reloc-base + linear offset, and the per-page copy loop folds in-page offsets correctly on every resolver path; no sort/rotate/LIFO order found in the page-table or copy paths. The remaining split suspect is the m171/m180 ledger DIVERGE preference - exactly what READ-DIVERGE-WIT compares. Build green. (cherry picked from commit 59e50207d60067b5d1e3a0546f20e9b22c92e112)
* vgsp: channel-reuse reconciliation + first-attempt readiness (fresh on 54a41db2)Arthur Hanson Rasmusson43 hours
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Net port of the stallfree work onto master without the reverted hint-stop: - Channel-reuse reconciliation, provably safe: svc_chan_registration marks a genuinely new binding (!same_gen) with wd_chanswitch; the first pump pass drops opdef slots bound to the reused handle ONLY when their first-pending stamp predates the reconcile instant (time_before), so a slot the fresh binding creates (after registration, at/after the reconcile) can never be touched; logs reason=stale-entry-chanswitch when the ring already carries content. Captures stay enabled (the fresh client's own entries may already be at slot 0). - First-attempt readiness (r229/r231: attempt 1 stalls, attempt 2 works once the 10 s rebuild cadence caught up): a genuinely new binding gets a 3 s freshness window (wd_newbind_until, SVC_GR_NEWBIND_MS) in which the pump (a) does NOT silently consume a GR entry that decoded nothing (no release/QMD/ops, non-replay) - it holds it and requests an immediate rebuild (svc.rebuild_now, consumed at the top of the service loop before the next pump), and (b) does the same for a GR entry whose page is unmapped. The entry re-evaluates with resolved pages inside the window, so the launch executes on the FIRST attempt; after the window entries consume as before (<=3 s extra on first contact). - Token: 'vgsp-gr: GR-STALL-pending-map h=... va=... entry=... action=rebuild reason=stale-entry-newbind' (bounded 16/session). - No hint-stop (master's revert already removed it; kept absent - the re-post window is the delivery bridge for late-registered events). - f0789007 kill-recovery, the r220 hold guard and the m181 arm rule are untouched (already present on this base). make kernel green (0 errors, pre-existing warnings only). (cherry picked from commit 4d420373e50be777e967b0c671a8ff037ef92a45)
* vgsp: fail4 r231 - READ-ORDER guard/witness + 32KB copy-resolution witnessArthur Hanson Rasmusson43 hours
| | | | | | | | | | | | | | | | | | | | | | | | | | r231 probe: RAWA (fresh 64 KB upload -> straight D2H readback, no kernel) returned foreign deterministic content (0x437F0000-family ramps) where the uploaded ints 0..16383 must be, and PROBE2 == PROBE2B on that same content. The upload/readback round trip inside the emulation is therefore not content-preserving - before any engine execution. Two candidate mechanisms, both now witnessed: - READ-ORDER: a device-src copy reading a VA whose device-dst write is still inside the m169 pin-guard window (the writer's bytes land only when the guard resolves) - the read executes first. READ-ORDER-WIT logs the coincidence; with sema_read_order_guard=1 (new param, default 0) the read is deferred through the existing bounded-hold re-decode so it runs after the write. Opt-in pending an A/B proving no green regression. - RESOLUTION DIVERGENCE: the dst (H2D) resolution consults the ledger before svc_op_translate while the src (D2H) resolution does the opposite, so a stale ledger landing can make the writer and reader touch different pages. The sema-bigcopy proof (va->pa/aperture/provenance for BOTH sides) now fires from 32 KB (was 1 MB), so the probe-class copies are on record. Build green; module param registered and visible. (cherry picked from commit bfe5d295dd3922c0dbcd0bd1a29912a02acb58ec)
* Revert "vgsp: channel-reuse reconciliation + hint-flood stop ↵Arthur Hanson Rasmusson43 hours
| | | | | | (GR-STALL-stale-entry-chanswitch)" This reverts commit 21eb5bb0582aaa2409601a1a1466f7bc72841647.
* vgsp: channel-reuse reconciliation + hint-flood stop ↵Arthur Hanson Rasmusson43 hours
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | (GR-STALL-stale-entry-chanswitch) r229a evidence: victory_mail OK -> ctaid_probe attempt 1 printed DEVICE and never completed (killed at 50 s); attempt 2 (fresh context) worked. The retained window shows mail's teardown + session flush (gen 3) then, for the whole first-attempt window, no channel registration and only the host 'completion hint rc=-2' flood (~0.5 s cadence, window reopened by the completion-apply sites). No GR lines, no stale-* lines: the first launch never reached the sema walk for the new binding. - svc_thread hint: on rc == -2 (no event context to post to) stop reopening svc.post_hint_until; the next real completion reopens it. The flood was pure noise and obscured the real state. - Channel-reuse reconciliation: svc_chan_registration marks a genuinely new binding (!same_gen) with wd_chanswitch; the channel's first pump pass drops every opdef slot bound to that handle (a dead context's withheld sets must not ride the reused channel - the r228 opdef-hold class) and, when the ring already carries content (put > 1), logs 'GR-STALL-stale-wedge ... reason=stale-entry-chanswitch'. Captures stay enabled: the fresh client's own entries may already be at slot 0, and suppressing them would lose exactly the first launch this protects; a stale launch re-walk stays bounded by gsp_phys_gr_wait_max_ms and the m181 put-drop recovery. r220 hold guard and the m181 arm rule untouched. Note: the phase2 witness for r229 was not readable at commit time (/tmp/opencode/witness-r229-phase2.log absent); r229a is boot-side and post-flush, so the attempt-1 window shows the guest sent no RM/channel traffic for ~9.5 s - the reconciliation removes the host-side reused- handle state classes; r230 will show whether the first-attempt launch now reaches the walk. make kernel green. (cherry picked from commit 21eb5bb0582aaa2409601a1a1466f7bc72841647)
* vgsp: fail4 r229 - REC-DUMP per-rec VA->HPA->reloc census at submitArthur Hanson Rasmusson43 hours
| | | | | | | | | | | | | | | | | | | The r229 ctaid_probe came back as: PROBE1 (coordinate map) perfect, PROBE2 (flat A read) wrong at every element - band 0 read A's own values at wildly wrong offsets (16382/16383 = A's last elements), bands >= 1 read float-typed data. Writes are flawless; the engine's READ of a freshly H2D'd 64 KB buffer returned foreign content, so before anything else the next capture needs the exact (va, hpa, reloc_va) triples the engine will read for that launch. REC-DUMP logs the submit's rec table at launch build time: all recs for small launches (n_data <= 64, the probe class), first/last 8 for larger ones, gated by gsp_phys_gr_copyout_dump. Comparing the A buffer's recs against the H2D landing (and against each other: distinct VAs collapsing onto one HPA, or HPAs outside the uploaded range) names the wrong-read source directly. Logging-only; greens safe. (cherry picked from commit f83ef995c17fba896950cc7f1818c65ac8839ac4)
* vgsp: stalled-entry detector + opdef-hold deadline fix (GR-STALL-stale-entry)Arthur Hanson Rasmusson44 hours
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | r228 witness: entry 82 of channel 0x5c000059 stayed pending with put=84 get=82 last=82 frozen for ~10 s (its 1 MiB op operand never resolved, sema-optrace rc=-2) while 'sema-opdef: hold entry=82' and 'opdef-clear caller=4 entry=82' repeated: svc_opdef_drop_stale cleared the opdef slot on every rewind replay that processed a different entry of the channel, so the 10 s deadline restarted and the hold re-armed forever (opdef_held climbing, no EXPIRED). No GR-STALL line fired because this is below the GR-publish layer: the launch never reached a capture/submit. - svc_opdef_drop_stale: only a slot whose entry was CONSUMED this put epoch (slot_done_epoch bit set by svc_replay_note) is delivered-late and dropped. A rewind re-decoding an unconsumed entry no longer resets its hold deadline, so the bounded 10 s flush/expiry is reachable again. - svc_gr_stale_wedge_check: new stale-entry leg (reason=stale-entry, entry=1) for a genuinely stalled pending entry: GR channel, put > get, position AND submissions static for the 3 s window, and no bounded owner active (no defer_since grace, no no-capture window, no live m150 hold, no opdef slot for the stuck entry). Action is the canonical unstuck: last_get = 0 + wd_nocap_put, decode releases only (forward-only, no re-capture/re-forward), once per put epoch. No residual publish/arm (m181-only rule); r220 hold guard untouched. Green safety: a green pending entry either advances submissions (consume within ms) or sets one of the bounded owners the leg gates on; the stale-entry leg therefore needs all of {put > get, 3 s position stall, 0 consumption, no owner} to fire. make kernel green. (cherry picked from commit f0789007c49c7c6e01da5643d56ceff0b2b83819)
* vgsp: stale-wedge recovery round 2 - dead-range reset, no residual publishArthur Hanson Rasmusson44 hours
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | r227 field result: the watchdog fired 10x (reason=stale-epoch, arm+publish) but the wedge survived, and victory_mail after the stalled rerun also hung. Root causes fixed here: 1. Do NOT arm/publish on a residual epoch. Arming let the next pass's svc_counter_publish write the residual put (35/101) into the fresh client's completion word - the r207/mm2 far-jump wedge (UVM_GPU_SEMAPHORE_MAX_JUMP), the exact poison gr_pub_armed exists to prevent. The epoch reset now only zeroes a word the HOST published this session (counter_last != 0, m181 semantics); the arm stays at m181's put-drop and the pristine put <= 1 discovery. 2. The stale-replay leg could never fire: its predicate required wd_since (set only when a candidate armed the window) - a circular dependency. The window now arms on either candidate and the action is decided at fire time with proof of the livelock (submissions moved during the stalled window). 3. Dead-range reset (reason=stale-dead-range): when the host caught up but the whole consumed range delivered nothing (counter_last == 0, submissions >= 8) and the epoch was never armed, rewind last_get to slot 0 so the fresh session's own entries (which start at slot 0) can be walked, and force replay for those dead slots (wd_nocap_put) so the re-walk decodes releases only (idempotent, forward-only) and never re-captures/re-forwards a dead launch. Once per put epoch (wd_epoch_done), cleared when new producer work arrives. 4. Log extended: reason=stale-epoch|stale-dead-range|stale-replay plus reset=/rewind=/cpa=/rpa= so the next run shows exactly which recovery ran and whether a publish target even exists. Green safety: both epoch legs require !gr_pub_armed (a channel that never proved a fresh epoch); a green mid-stream-discovered unarmed channel can at worst pay one forced-replay re-read of its consumed range per put epoch (no capture, no word writes). The r220 hold-storm guard and the rewind cooldown are untouched. make kernel green. (cherry picked from commit d2ba3cadecf1ca0e72358024f80dbe7a8c468842)
* vgsp: fail4 r227 - INPUT-ALIAS-WIT rec census + RETIRE-WIT rec-array witnessArthur Hanson Rasmusson44 hours
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | r227 verdict inputs: GRID-WIT == the guest's own geometry for every kernel (gemm_nn w12=0x10 w13=0x4, gemm_nt w12=0x4, softmax w12=0x40, block dims in w18/w19) - no QMD geometry emission bug; the old consecutive-pair IN-ALIAS stayed silent. Two new witnesses for the next capture: - INPUT-ALIAS-WIT: per-launch census of the copy-in recs (the exact VA -> HPA -> content triples the engine reads, inputs included; the fill already covers them as recs). Every non-zero rec is compared against the last 64: distinct VA -> same HPA is the resolver-aliasing smoking gun; distinct HPA with equal content is the upstream-write-clone class. Zero pages excluded on both sides. Replaces the consecutive-only check. - RETIRE-WIT: one line per launch at the retirement wait with n_data, n_tracked and the first/last recs' va/reloc_va/bi. r227's numbers are impossible under this source (retire n_tracked 4/4/4/1/1/16/16 vs copy-in/copy-out 1482/1418/1354/913/864/882/1290 recs for the same launch), so either the rec array genuinely aliases reloc VAs at run time or the deployed module differs from this tree; RETIRE-WIT shows which in one line (sequential in-region rels + n_data=1482 with n_tracked=4 would prove the former). Logging-only; no behaviour change; greens safe. Build green. (cherry picked from commit 1dbde7967bda4ba51dadf8a96e8aeaacc44c5575)
* vgsp: fail4 r226 - zero-filter alias witnesses + GRID-WIT QMD geometry dumpArthur Hanson Rasmusson45 hours
| | | | | | | | | | | | | | | | | | | | | | | | | | | r226a: the green victory_mail run produced 10 IN-ALIAS-WIT lines that are all false positives - consecutive all-zero pages from fresh cudaMalloc runs (csum=0x00000000), not aliasing evidence. Filter all-zero pages out of both alias comparisons: a page counts as zero only when the csum is zero AND every word is zero (csum alone can hide cancelling contents); zero pages are neither candidates nor partners. Also: the r224 band corruption (rows >= 16 of every launch replicate one tile) starts at a CTA-band boundary while the QMD is passed through verbatim - but the current dumps never show the geometry words the engine actually fetches. GRID-WIT logs, once per launch, the geometry-relevant QMD words of the deposit the engine will run: w12/w13 = CTA raster width/height/depth (gridDim), w18/w19 = CTA thread dimensions (blockDim), w18.lo = QMD version nibbles, plus w4/w5/w8/w17 (PCAS/cache-control, prefetch low word, shared-memory size). With the guest-side GEO line added to transformer_mt.cu (8 lines per run, one per chain) the next capture can prove or refute an emission mismatch in one comparison. And IN-ALIAS-WIT now prints both HPAs with a classification token: equal hpa = the resolver served one page for several VAs; distinct hpa with equal contents = the guest pages genuinely hold the same bytes (upstream write aliasing). Logging-only; no behaviour change, safe for the green clients. (cherry picked from commit dc1e693d598d3a32d1e6a87b94ff91dcbc99101c)
* vgsp: stale-epoch/stale-replay wedge watchdog (GR-STALL-stale-wedge)Arthur Hanson Rasmusson45 hours
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | r225 evidence: after a client was killed mid-run, a fresh client's GR channel (0x5c000059) was registered with a residual USERD put=101 from the dead session. The m181 fresh-put-drop recovery never fired (the fresh session never wrote a put - it was stuck at ctx-init, polling MC_SERVICE_INTERRUPTS once a second), the completion-counter publish stayed withheld (gr_pub_armed false), and the pin-batch rewind (SVC_PIN_REWIND=8) pinned last_get at 93 on every injection batch: the entry loop re-walked slots 93..100 forever, decoding nothing (rel=0, no capture) and consuming with zero delivery. No capture -> no request -> no bounded submit -> zero GR-STALL lines; the launch never reached the bounded path because the session epoch itself was wedged. - svc_gr_stale_wedge_check (pump pass, before the entry loop, GR only): tracks (last_get, put) per channel and fires after a 3 s no-progress window with two signatures: 1. stale-epoch: residual put (put > 1, publish withheld, host believes the ring fully consumed): arm gr_pub_armed and void the withheld publish state (m181 semantics, counter_last-gated zeroing; no last_get rewind - the proven m181 rewind stays with its put-drop signature), so the fresh client's ctx-init wait gets its host edge. 2. stale-replay: last_get pinned behind put while put == get and the loop consumed entries during the window (the rewind re-opening an already-consumed window): drop the window (last_get = put) and put the pin-batch rewind on a bounded cooldown (wd_rewind_off_until, cleared by new work) so the futile retry cannot pin the pump. - svc_handle_map_add: channels under the rewind cooldown are not rewound. - New per-channel watchdog state written back in the snapshot list (GRFIX NOTE rule); new diag token gr_wedge (drain line); new greppable line 'vgsp-gr: GR-STALL-stale-wedge h=... va=... last=... put=... get=... sub=... waited_ms=... action=recover reason=...'. Green safety: fresh channels have put <= 1 (signature 1 inert) and consume their first entries within milliseconds (submissions > 0); signature 2 needs a stalled (last_get, put) pair for 3 s with no pending producer work AND entries consumed during the window, which only the rewind re-opening of a consumed window produces. make kernel green; only pre-existing warnings. (cherry picked from commit 6aa5709f57cc1d91a01205042d973d5b203c9bec)
* vgsp: fail4 r224 alias witnesses - OUT-ALIAS-WIT / IN-ALIAS-WIT + pre/post csumArthur Hanson Rasmusson46 hours
| | | | | | | | | | | | | | | | | | | | | | | | | | r224 evidence: the failing outputs ARE produced by the engine and read back byte-identical (OUT-PAGE-WIT vs sema-bigcopy src16 match exactly), but the engine's result is structurally corrupted: for every gemm of the tested chains the row band >= 16 (the by>=1 CTA band) replicates a single tile per output buffer (Q band=[0,-7.96875], K band=[7.96875,7.96875], ...) while the first pages carry the correct/partial values; the corruption starts exactly at the row-16 boundary. The pre/post csum pair proves each 'changed' page was really rewritten by the engine (bounce != copy-in baseline), so the replicated band is engine-authored, not pass-through. Add the two witnesses that name the replication source in the next cycle: - OUT-ALIAS-WIT: each changed page's first 8 bytes matched against the earlier changed pages of the same launch -> logs (va, bi) partner pairs. - IN-ALIAS-WIT: consecutive copy-in recs with identical content (equal per-page csum) -> a replicated INPUT region (one page served for many VAs, e.g. an X/weight buffer) is caught before any launch runs. - OUT-PAGE-WIT extended with pre/post csum. All bounded, behind the existing gsp_phys_gr_copyout_dump gate, and using the established single-inflight static scratch discipline. (cherry picked from commit 7c9d48847cffa2a21263515b94bdb57ad2a9357c)
* vgsp: fail4 discrimination tooling - copy-out page witnesses + full-boot ↵Arthur Hanson Rasmusson46 hours
| | | | | | | | | | | | | | | | | | | | | | | | | | | bigcopy resolution budget Four guest CUDA clients fail all-bad while four pass; the aggregate counters cannot separate 'engine result never produced' from 'produced but written to a different guest page than the client's read resolves'. Add the two per-page witnesses that correlate the write side with the read side: - gsp_phys_gr_copyout_dump (booter, default 1): per-changed-page OUT-PAGE-WIT va=<device VA> hpa=<guest PA written> first8/last8=<bytes shipped>, bounded 12 pages per launch, plus one RELOC-CENSUS line per launch (gaps vs late-resolved words vs late pages). - sema_bigcopy_log (sema service, default 24, was a hardcoded per-boot budget): the svc_copy large-copy proof already logs both operands' resolved VA -> pa/aperture/provenance and the first 16 bytes each side; raising the budget past the boot's head makes the failing clients' H2D/D2H resolutions visible. Discrimination test for the next cycle: same device VA on OUT-PAGE-WIT (copy-out HPA) and sema-bigcopy (D2H source pa) with different PAs proves the produced-but-misplaced class; equal PAs redirects to the readback content/engine-input path. (cherry picked from commit 78ea8b7807231ac418a17b85c29ed1845e1b0062)
* vgsp: bounded GR launch completion (GR-STALL), r220 hold storm fix, churn capsArthur Hanson Rasmusson46 hours
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Every GR launch now either completes or fails fast with a distinguishable dmesg line; no host wait in the launch/consume path can run forever. - gsp_phys_gr_wait_max_ms (new param, default 60000, clamp [10000,600000], 0 = built-in per-ladder bounds only): absolute per-launch submit budget. Checked in the GR poll loop (after the release acks) and in the retirement-retry loop; on expiry the submit fails out ('vgsp-gr: GR-STALL-wait-max ... action=fail') or the retry loop stops ('GR-STALL-retry ... action=proceed'), so the chain of individually bounded ladder phases can no longer hold the single-inflight work item (and the client's launch wait) for the ladder sum. - gsp_sema_service: pass-top svc_fwd_outcome_check() completes a forwarded GR request that no hold owns. A GR push with no push-level release records engages no release hold, so a backend failure (ladder timeout, abort) left the QMD completion word unwritten and the client waited to its own timeout (r219/r222, qmd_rel frozen at the previous value). The check authors the word in software (full resolver, forward-only, latched once) and logs 'GR-STALL-backend ... action=proceed'. It also covers a *successful* submit whose release0 could not target the guest page (engine completion landed on the module semaphore only) - the work item records gr_rel_unobserved for that. - Consume tail: a GR capture consumed without ever being forwarded (a data-stall / busy-defer / no-capture hold fell through) now authors its QMD completion release, latched per capture, and logs 'GR-STALL-hold'. - r220 hold-storm fix (196 s re-hold): the m150/m156 data-stall hold window is keyed to the GPFIFO slot index, and a pin-batch rewind replays the same launch at different slots, so the window re-armed on every pass; the absolute per-launch backstop could never fire because its record fields were excluded from the pump snapshot write-back list (the GRFIX NOTE record leak) and the fill gate defaulted off. The four bound fields are now written back and svc_gr_hold_bound_expired is effective on the default path (cap gsp_phys_gr_hold_max_ms, default 3000 ms, keyed to the launch push VA via svc_gr_launch_va so nothing re-arms it across rewinds); the busy-defer hold site consults the same bound. On expiry the entry is consumed with the software completion and logs 'GR-STALL-hold-bound'. - Hold expiry/failure edges log 'GR-STALL-fwd-hold' / 'GR-STALL-fwd-fail' with waited_ms for held forwarded launches. - Anti-degradation under pin churn/leftover clients: svc_rescue_scan_range (up to 6 GB of guest-RAM reads on the service thread) is capped at 3 s per range with RESCUE-SCAN-CAP logging; the ledger eviction burst triggers a logged wholesale cache reset (LEDGER-RESET cap-and-degrade, 256 evictions); pending-ring overflow is counted and surfaced (PENDING-OVF, pend_ovf in the drain line). New diag tokens: gr_swrel/pend_ovf, ledger resets, rescue scan_capped, work_gr stall_wait_max/stall_retry/wait_max_ms. Green behavior: normal launches complete in ~0.2-11 s and never approach the budget; the hold bound only fires where the old path could stall forever. make kernel green; only pre-existing warnings. (cherry picked from commit dc3650105f163631bb826ae3685a7d6e9025bfe8)
* vgsp: m91 - first-fault capture + QMD instruction-cache invalidate for the ↵Arthur Hanson Rasmusson46 hours
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | SM I-fetch lottery m91-class recap: the first attempt of a mid-sequence forwarded GR launch raises SM warp exceptions ("Illegal Instruction Encoding", "Out Of Range Register") on garbage instruction bytes while a retry of the IDENTICAL QMD and identical shadow content succeeds (r219: fault at +2.5 s, fast re-arm recovered 3 ms later; r223 same pattern). The host retry path only replays the mode-35 lane-enable tail + channel/TSG schedules + doorbell and re-publishes the same method block on a fresh ring entry: no shadow re-copy, no QMD re-read, no cache/TLB invalidate exists anywhere in the ladder. Plain re-submission of byte-identical content flipping the outcome names stale engine-side fetch state at first dispatch, not a content or programming error: the window-0 shadow pool alternates two 8-page banks by submit epoch, so a program VA's bytes change every two launches, and every captured guest QMD carries the QMD v2.3 cache-control word (word 5) with INVALIDATE_INSTRUCTION_CACHE (bit 30) clear - the client driver arms that bit only under its forced-invalidate mode. Two changes: 1. FAULT-CAP (diagnostic, inert until a fault): when a forwarded launch's fault epoch advanced across its window, emit one "vgsp-m91: FAULT-CAP" line per launch (capped at 20 per module-load cycle, then one suppression notice) with: fault-epoch delta, QMD address + first 64 B, live program pair (w48/w49) + resolved engine-visible VA/PA, the first 64 B at that code address, retry decision (fast re-arm / resched/fresh-entry / none) + outcome (ok vs timeout), and the newest relay-decoded 0x1006 note (exceptType/chid/errString). A fault-free launch costs one epoch read and one compare (greens unaffected statically: no prints, no content reads, no engine access). 2. QMD icache invalidate (fix, param-gated default-on gsp_phys_gr_icache_inv=1): set QMD v2.3 word 5 bit 30 in the forwarded QMD (forcing an instruction refetch at dispatch) only when the QMD carries the client driver's standard cache-control signature (word 5 bits 26..29 set) so an unknown QMD revision is never touched; 0 restores the exact pre-change QMD for a one-flip A/B. The bit cannot alter instruction bytes or data - it only invalidates cached fetch state (the same field the client driver sets under forced invalidate) - so green launches keep their semantics; the only cost is a per-launch refetch. Expected next-cycle evidence: zero FAULT-CAP lines with the multi-page client set green confirms the stale-fetch mechanism; any FAULT-CAP content policies the remaining candidates (shadow-VA reuse distance, cross-cycle context state left by killed clients). Doc: 03-architecture/13-vexecution- plane.md m91-class section. (cherry picked from commit 682a5559b1dbbd482d8fe6bdabbc46220ce0d5de)
* vgsp: refuse PTE-page code sources in the Tier-2 program-pair path ↵Arthur Hanson Rasmusson2 days
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | (CODESRC-SUSPECT fallback) r221 evidence: six CODEHASH-suspect launches resolved six different client code VAs to the same page (deterministic guest allocation within one boot) and all carried valid kernel prologue words at the QMD entry offset; the SUSPECT tag was the zero-window false-positive mode of the CODEHASH content test, and no source page observed was PTE-shaped. The class remains real: the program pair (QMD w48/49) is copied verbatim into the page the engine I-fetches from, so a stale landing, walk or pin answering with an empty, PTE-shaped or module page-tree page would execute PTE/filler bytes as SASS. CODESRC, before the Tier-2 program-pair copy (additive, once per launch): - detect (a) empty source (entry+sampled windows zero), (b) PTE-shaped entry run (>=12/16 identically-flagged valid entries, or mostly-zero with only PTE-signed entries), (c) source HPA on one of the engine page-tree's own module chunks (main PT, guest PT pool, shadow pools, qmdwin); - on detection re-resolve through the late resolver (guest-walk order, the alternative to the fill's ledger-first order) and adopt it only if different and not itself suspicious; otherwise withdraw the page from the submission (no copy, no mapping, QMD pair kept at the guest VA - the per-pair ptr_guest behaviour). One rate-limited 'vgsp-gr: CODESRC-SUSPECT va= pa= alt= used= why=' line. Greens-safety: no observed launch (green or suspect) matches any trigger: entry words are non-zero and distinct, entry runs are not PTE-signed, and a guest HPA cannot equal a module chunk DMA; with no match the flow is byte-identical to before (same memcpy, copied++ and dump gate).
* vgsp: code-fetch content verification instrumentation (CODEHASH) + static traceArthur Hanson Rasmusson2 days
| | | | | | | | | | | | | | | | | | | | Static trace of the GR code-fetch path: the engine's instruction fetch base is the QMD word 48/49 program pair (svc_gr_qmd_decode, gsp_sema_service.c); the entry page resolves ledger-first (svc_gr_page_note) and is authored at submit as either a Tier-1 guest-VA->HPA identity PTE (gsp_phys_rmcall_gr_map_va_locked) or a win0 shadow copy of the guest page with the QMD pair rewritten to the shadow VA (gsp_phys_backend_guest_gr_submit); the guest page content was written by the emulated H2D copy path (svc_copy + svc_ledger_store landing). CODEHASH: one bounded line per launch at author time sampling the resolved code region (entry offset 16B + PA+0/mid/end windows, up to 4 consecutive tracked code pages) on the source landing page and the engine-visible shadow copy: 'vgsp-gr: CODEHASH va=0x%llx pa=0x%llx n=%u h0=0x%016llx ent=... w=... sh0=... SUSPECT|ok'. Emitted for suspicious content (all-zero windows, zero entry word pair, four identical entry words) or the first 3 healthy launches per boot; 'CODEHASH-UNREADABLE' when the entry page has no host-readable landing. Additive, no behavior change (Tier-1 and shadow call sites, once per launch).
* vgsp: CE copy completeness + CEAUDIT instrumentationArthur Hanson Rasmusson2 days
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Trace the CE (copy-engine) data path that services every guest cudaMemcpy: the guest driver chunks large copies into <=1 MB LAUNCH_DMA pushes; svc_decode_stream makes one op each and the host software copy svc_copy executes it (per-256 B bounce, per-page translation, page-clipped chunks). The hardware-forwarding path only carries <=4 KB single-page candidates, so it cannot move these. Completeness verdict: the CE executor is complete-or-error at every size - the loop copies exactly 'total' or returns an errno (never a partial success); failures hold the entry (bounded opdef hold, loud EXPIRED) or are dropped loudly at fwd-ownership. r219 confirms: all 96 audited big copies done==len, zero COPY-MISMATCH, and every CE failure was a pre-loop resolution miss (rc=-2, no byte moved) - invisible to the copy-level audit until now. New instrumentation (all additive, no new locks/waits): - CEAUDIT per >=32 KB CE op (copy and fill): op/src/dst/len/done/rc, successes unconditional (4096/boot budget), rc!=0 repeats rate limited; done=0x0 exposes the pre-loop resolution-miss retries. - CEAUDIT-MISMATCH: the same true start/end 16-byte destination readback as COPYAUDIT (moved to the real end sample), emitted next to COPY-MISMATCH for ce-soft-copy. - D2H authority visibility: ledger counters + table-fill diag line (sema-svc: ledger n=/stores/evict/diverges/rewrites) and a sema-ledger: EVICT warn on the silent home-replacement path. D2H source verdict (documented in /tmp/opencode/agent-COPY.md): for pages the launch owns the D2H follows the submit-time ledger landing = the page the copy-out wrote (correct); it can silently return prior content for unowned pages (fill-span cuts, work-item drops), on ledger eviction, and after a failed launch whose copy-out never ran. make kernel green; only the pre-existing %x warning at gsp_phys_booter.c:14088.
* vgsp: copy completeness hardening + COPYAUDIT/COPY-TRUNC instrumentationArthur Hanson Rasmusson2 days
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Map every guest-data copy path and its caps (CE soft copy/fill/inline, GR fill span, late/gap span, bounce copy-in/out, forwarded CE copy, launch-page pools) and close the two silent partial-data holes: - late/gap span cap (gsp_phys_booter.c): a word cut at the 16-page cap was still rewritten to the partial run; probe one page past the cut and log COPY-TRUNC when it is resolvable (r218 shape: 4 words x 16 pages = all four cut at the cap). - GR fill span walk (gsp_sema_service.c): a mid-span resolution miss after >=1 authored page now logs COPY-TRUNC (was GRFILL-DROP only, launch proceeded with fill_hold=0). Instrumentation (all additive, no new locks/waits, readback uses the same accessor the write just used): - COPYAUDIT path=... va/len/done for every >=32 KB copy (CE soft copy, fill, GRCE inline, GR bounce/gap copy-in and copy-out). - COPY-MISMATCH 16-byte start/end destination readback vs the written bytes right after the copy (CE first/last chunk; fill and inline first 16 B; GR staging first+last 16 B of every page). - COPY-TRUNC on every partial copy: CE loop returns, fill/grce chunk failures, short GR staging/copy-out counts, reloc-fix-span, gr-fill-span; want>done is rate-limited but never silent. make kernel green; only the pre-existing %x warning at gsp_phys_booter.c:14088.
* vgsp: GR gap classification (RELOC-GAP-UNMAPPED) + launch-internal ↵Arthur Hanson Rasmusson2 days
| | | | late-content ground-truth check
* vgsp: relfix PART 3 follow-up - param-page remainder scan runs as a non-arg ↵Arthur Hanson Rasmusson2 days
| | | | pass (is_arg/hold semantics unchanged)
* vgsp: GR late-resolve span cap + fill candidate superset + RELOC-GAP stage ↵Arthur Hanson Rasmusson2 days
| | | | logging
* vgsp: GR relocation completeness - resolve unmatched device-VA words via the ↵Arthur Hanson Rasmusson2 days
| | | | landing resolver (RELOC-FIXED), param gsp_phys_gr_reloc_resolve default 1
* vgsp: GR fill hold param-gated (default 0: log-only, never hold); ↵Arthur Hanson Rasmusson2 days
| | | | record-destroyer root-cause notes
* vgsp: GR fill hold - self-enforcing bound at decision point; ↵Arthur Hanson Rasmusson2 days
| | | | benign-unresolvable class undecidable (bounded, not bypassed)
* vgsp: GR fill hold - absolute deadline + expiry-proceed + dropped-page detailArthur Hanson Rasmusson2 days
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* vgsp: GR fail-closed hardening - full-page-resolution holds, copy-in guard, ↵Arthur Hanson Rasmusson2 days
| | | | relocation coverage counter, zero-write register dump (diagnostic)
* vgsp-gr: GRVAUDIT data-VA resolution audit at submit (diagnostic only)Arthur Hanson Rasmusson2 days
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* vgsp: m181 relocation-page unification - launch-internal pages ↵Arthur Hanson Rasmusson2 days
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | (param/program/banks) resolve through the landing table; zero-write diagnostics Audit of the QMD relocation/mirror path vs the m180 landing table (r210 evidence: /tmp dmesg, 0 ledger DIVERGE, four multi-page clients still wrong, 3 zero-write NO-STORES accepts): The relocation itself does NOT pick PAs: gsp_phys_gr_rewrite_data_vars() matches a device-VA-shaped 8-byte value against req->data[x].va (the fill's gr_data list, which m180 fed through the ledger) and rewrites it to req->data[x].reloc_va. The bounce page for reloc_va is the same page the tracking wait and the copy-out use, so a *matched* pointer is ledger- consistent by construction. The un-unified halves of that path are the page the relocation READS and the page the m129 mirror PATCHES: both come from pg->pa, resolved by svc_gr_page_note() with the independent sources (pin/lat/map/walks/scan), never the landing table. The CE inline writes that author those launches' param/program/bank pages go through svc_grce_inline_write(), which (m180) records its landing and diverges to it; svc_gr_page_note could still hand the win0 shadow copy and the mirror a stale page. Consequences, both observed classes: relocation matches nothing (the page holds another session's pointers) -> the engine runs against unrelocated guest VAs it cannot walk -> grid aborts with zero stores while the ack still lands; or the engine executes on a previous client's parameter block -> plausible-but-wrong results invisible to the ledger. Fix (kernel/gsp_sema_service.c): - svc_gr_page_note() consults svc_ledger_lookup() first for every launch-internal page. On a hit it uses the recorded landing (and pins it, so later resolves and the win0 copy path agree); when the independent sources would answer differently it logs (bounded) "sema-ledger: RELOC-DIVERGE va=... ledger_pa=... <src>_pa=... (ledger wins)" - the requested relocation-vs-ledger witness. Non-hit pages keep the historical svc_resolve_va path unchanged. Diagnostics (kernel/gsp_phys_booter.c): - the m135 below-0x100 guard now shape-checks first and logs "bank N RELOC-SKIP @off: value is operand page ... (left guest-VA)". r210 shows the same offset-0 bank pointer in EVERY client (green ones included: the driver control block), so the guard is unchanged until a dereferenced pointer in that range is proven; the log makes that provable in one cycle. - the zero-write accept now also dumps the deposit QMD words (gsp_phys_gr_deposit_rb_log) so the next NO-STORES event shows whether the engine consumed the header words, and the dual-bank sentinel line is reworded to state facts only (the other bank is normally the previous launch's legitimately-consumed deposit; the earlier "older deposit consumed" reading was misleading). r210 classification: all three NO-STORES events had THIS deposit fetched (sentinel overwritten) and 0/968..0/967 stores even at +1 s, i.e. engine-side non-execution of a fetched deposit - consistent with the stale-launch-page abort mechanism above; the deposit-readback words will discriminate further. Not changed (deliberate): the m135 guard semantics, the relocation targets, the sentinel contract, retry/accept policy, and every semaphore path (mm2/gate/rewind effects untouched). make kernel -j green (srcversion DAB7E3AA75D364382DD6A3C; only the pre-existing gsp_phys_rmcall_stage3 printf warning). Main tree untouched; nothing pushed.
* vgsp: m180 VA->PA unification - one landing authority for every data-bearing ↵Arthur Hanson Rasmusson2 days
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | device VA (kills the write/read translation split of the always-failing class) Context (r209, fc2d1ae5): multikernel/memcpy_roundtrip/streams2/ victory_streams_events still fail with self-consistent, silent wrongness while every launch reports OK. Evidence: streams2's bad data is exactly the PREVIOUS client's h_in pattern (engine read stale inputs); the memcpy window logs 16x "sema-ledger: DIVERGE read ... wrote=0x7f83000 read=0x8783000" (D2H resolved a different page than the write landed on); the failing four's device operands are all sysmem-backed (ap=2, pa=0x7800000/0x8800000 in every svc-gr cand[] line), i.e. exactly the aperture the m171/m172 ledger never recorded. Root cause class: a data-bearing guest VA had NO single authoritative PA. Write paths (H2D svc_copy dst, fills, inline writes, engine write-back) each landed wherever their own resolution said; read paths (GR launch fill, D2H svc_copy src) resolved independently again. The ledger patched up some of that, but (a) it recorded only VID-aperture copies >=64 KiB, so the dominant sysmem case was invisible; (b) it was a 2048-entry RING - one launch's submission record set (2505-4553 pages in r209) evicted the H2D records of the same client before its own D2H read them, so the readback fell back to its own (different) resolution; (c) several resolution failures returned -ENOENT even when the landing was known; and (d) copy paths deferred to the forwarded-request machinery skipped the in-loop record entirely. Fix - one landing authority, consulted everywhere: 1. The ledger is now a keyed hash table (16384 slots, 16-probe, one entry per VA page, in-place rewrite). No cross-VA eviction: a client's whole working set (8 MB in + 8 MB out + engine records) survives until its readers have run. Rewrites are counted + logged (bounded) because a write path moving an existing page is the write-side half of DIVERGE. 2. Every guest-visible write records its landing page: - svc_copy dst_virt: SYS as well as VID (the sysmem half was the hole); - svc_fill: SYS as well as VID; - svc_grce_inline_write: unconditionally; - small copies that are deferred to the forwarded path: recorded at candidate capture (the software loop never runs for them); - engine launch data pages: unchanged (submission-time record). 3. Every read/write consults it: - GR fill: already diverted (m171); now actually has SYS records to find; - D2H svc_copy src: per-page divert (m171) + NEW fallback to the recorded landing when the resolver fails (previously -ENOENT); - svc_copy dst / svc_fill / svc_grce_inline_write: NEW - resolve, then land on the recorded page when one exists (one page per VA, readers already follow it), and fall back to it when resolution fails. This also spares the m169 stale-walk hold for destinations whose page is already known (no pin needed). Effect on the failing class: the H2D/fill write landing becomes the page the engine fill, the copy-out and the D2H all use; where a stale and a fresh resolution disagree, the readers follow the landing and the other translation is logged as DIVERGE (read/write) or rewrite - bounded, once. streams2's c1 (engine read stale) is healed by the new SYS records; streams2's c2 (readback of an engine output after later launches) is healed by the hash table, which no longer evicts the first launch's records. Zero-write lottery diagnostics (secondary, booter; no behavior change on the green path): - content-hash settle rule in gsp_phys_gr_output_retire_wait: the "settled" verdict now requires the per-page checksum FOLD to be stable for ~300 ms, not just the changed-page COUNT (a continuing store ramp with a constant count used to read as settled - the r209 "17/32 settled"/"2048/4552 settled" partial copy-outs); - zero-write accept now logs both qmdwin banks' sentinel words (ours intact + other bank overwritten = an older deposit was consumed, i.e. mis-targeted deposit; ours overwritten = this deposit was fetched) and re-scans the tracked pages once at +1 s: LATE-STORES (copy-out will ship them) vs NO-STORES (dispatch lost or read-only kernel). The +1 s is bounded to the rare zero-write accept path only. The sentinel constant itself is left intact (it is load-bearing for the m179 post-mortem classification); the dual-bank read answers the same mis-targeting question without changing the engine-visible contract. Untouched on purpose: mm2 publish arm/gate, GR fresh-put rewind, the release machinery and every semaphore path (no regression surface there). make kernel -j green (new srcversion); main tree and the running VM were not touched; nothing pushed.
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