diff options
Diffstat (limited to 'ep_run/cascade_probe.py')
| -rw-r--r-- | ep_run/cascade_probe.py | 158 |
1 files changed, 104 insertions, 54 deletions
diff --git a/ep_run/cascade_probe.py b/ep_run/cascade_probe.py index 572097c..2f1449a 100644 --- a/ep_run/cascade_probe.py +++ b/ep_run/cascade_probe.py @@ -1,8 +1,14 @@ -"""Cascade-EP gradient gate: L distinct standard transformer blocks, layered energy -E = sum_l 0.5||z_l - f_l(z_{l-1})||^2. Free equilibrium == the standard forward pass -(inference = plain LLM). Training = two-phase (±beta nudge) relaxation of z, weight -grad = (1/2beta)[dE/dtheta|+ - dE/dtheta|-]. Gate: cosine vs true BP gradient.""" -import argparse, math, pickle +"""Cascade-EP gradient gate v2 — L distinct standard transformer blocks, layered energy +E = sum_l 0.5||z_l - f_l(z_{l-1})||^2. Free equilibrium == the standard forward pass. +Two-phase (+-beta) relaxation of states -> local weight gradient; gate vs true BP. + +v2: relaxation schemes (jacobi = physical parallel | gsf/gsr = Gauss-Seidel fwd/reverse sweeps), + --include_io (emb/pos/tied-readout grads via the full EP formula), multi-batch gates, + machine-parseable SUMMARY line. Usage examples: + python3 cascade_probe.py --L 12 --K 480 + python3 cascade_probe.py --L 6 --scheme gsr --K 12 --include_io +""" +import argparse, math, pickle, time import numpy as np, torch, torch.nn as nn, torch.nn.functional as F from pathlib import Path @@ -11,7 +17,12 @@ ap.add_argument('--L', type=int, default=3); ap.add_argument('--C', type=int, de ap.add_argument('--H', type=int, default=4); ap.add_argument('--T', type=int, default=32) ap.add_argument('--B', type=int, default=4); ap.add_argument('--beta', type=float, default=0.03) ap.add_argument('--K', type=int, default=400); ap.add_argument('--eta', type=float, default=0.3) -ap.add_argument('--seed', type=int, default=0); ap.add_argument('--trained_warp', type=float, default=1.0) +ap.add_argument('--mom', type=float, default=0.9) +ap.add_argument('--scheme', choices=['jacobi', 'gsf', 'gsr'], default='jacobi') +ap.add_argument('--batches', type=int, default=4) +ap.add_argument('--include_io', action='store_true') # gate emb/pos/tied-readout too +ap.add_argument('--seed', type=int, default=0); ap.add_argument('--warp', type=float, default=1.0) +ap.add_argument('--ckpt', type=str, default='') # gate at a casc_bp_train checkpoint args = ap.parse_args() torch.manual_seed(args.seed) dev = 'cuda' if torch.cuda.is_available() else 'cpu' @@ -20,9 +31,6 @@ torch.set_float32_matmul_precision('highest') DD = Path('/home/yurenh2/ept/ep_run/data/tinystories_bpe') vocab = pickle.load(open(DD / 'meta.pkl', 'rb'))['vocab_size'] data = np.memmap(DD / 'val.bin', dtype=np.uint16, mode='r') -ix = torch.randint(len(data) - args.T - 1, (args.B,)) -x = torch.stack([torch.from_numpy(data[i:i + args.T].astype(np.int64)) for i in ix]).to(dev) -y = torch.stack([torch.from_numpy(data[i + 1:i + 1 + args.T].astype(np.int64)) for i in ix]).to(dev) class Block(nn.Module): """Standard pre-LN transformer block (distinct weights per layer, no recurrence).""" @@ -38,65 +46,107 @@ class Block(nn.Module): tok = nn.Embedding(vocab, args.C).to(dev) pos = nn.Embedding(args.T, args.C).to(dev) blocks = nn.ModuleList([Block(args.C, args.H) for _ in range(args.L)]).to(dev) -if args.trained_warp != 1.0: # crude "not-at-init" landscape +if args.ckpt: + sd = torch.load(args.ckpt, map_location=dev) + tok.load_state_dict(sd['tok']); pos.load_state_dict(sd['pos']); blocks.load_state_dict(sd['blocks']) + print(f"[gate] loaded {args.ckpt} (step {sd.get('step')}, val {sd.get('val', float('nan')):.4f})") +elif args.warp != 1.0: with torch.no_grad(): - for p in blocks.parameters(): p.mul_(args.trained_warp) + for p in blocks.parameters(): p.mul_(args.warp) mask = torch.triu(torch.full((args.T, args.T), float('-inf'), device=dev), 1) readout = lambda z: z @ tok.weight.t() +io_params = list(tok.parameters()) + list(pos.parameters()) +blk_params = list(blocks.parameters()) +gate_params = blk_params + (io_params if args.include_io else []) +NBT = args.B * args.T + +def get_batch(i): + g = torch.Generator().manual_seed(1000 + i) + ix = torch.randint(len(data) - args.T - 1, (args.B,), generator=g) + x = torch.stack([torch.from_numpy(data[j:j + args.T].astype(np.int64)) for j in ix]).to(dev) + y = torch.stack([torch.from_numpy(data[j + 1:j + 1 + args.T].astype(np.int64)) for j in ix]).to(dev) + return x, y def fwd_states(z0): zs = [z0] for b in blocks: zs.append(b(zs[-1], mask)) return zs -z0 = (tok(x) + pos(torch.arange(args.T, device=dev))[None]).detach() +def local_grad(zs, z0, l, beta, y): + """dF/dz_l with neighbors fixed (zs: list of L free states, 0-indexed block l).""" + zl = zs[l].detach().requires_grad_(True) + prev = z0 if l == 0 else zs[l - 1].detach() + obj = 0.5 * ((zl - blocks[l](prev, mask)) ** 2).sum() / NBT + if l + 1 < args.L: + obj = obj + 0.5 * ((zs[l + 1].detach() - blocks[l + 1](zl, mask)) ** 2).sum() / NBT + else: + obj = obj + beta * F.cross_entropy(readout(zl).reshape(-1, vocab), y.reshape(-1)) + return torch.autograd.grad(obj, zl)[0] -# ---------------- true BP reference ---------------- -for p in blocks.parameters(): p.requires_grad_(True) -zs = fwd_states(z0) -ce = F.cross_entropy(readout(zs[-1]).reshape(-1, vocab), y.reshape(-1)) -gbp = torch.autograd.grad(ce, list(blocks.parameters()), allow_unused=True) -gbp = [g if g is not None else torch.zeros(1, device=dev) for g in gbp] -print(f'BP ref: CE {ce.item():.4f}') - -# ---------------- two-phase cascade EP ---------------- -def relax(beta): - """minimize E + beta*CE over free states z_1..z_L by GD (free init = forward pass).""" +def relax(z0, y, beta): + """minimize F_beta over states; free init = forward pass. Returns relaxed states.""" with torch.no_grad(): zs = [z.detach().clone() for z in fwd_states(z0)[1:]] - for z in zs: z.requires_grad_(True) - opt = torch.optim.SGD(zs, lr=args.eta, momentum=0.9) - for k in range(args.K): - opt.zero_grad() - E = 0.0; prev = z0 - for z, b in zip(zs, blocks): E = E + 0.5 * ((z - b(prev, mask)) ** 2).sum(); prev = z - Fobj = E / (args.B * args.T) + beta * F.cross_entropy(readout(zs[-1]).reshape(-1, vocab), y.reshape(-1)) - Fobj.backward() - opt.step() - return [z.detach() for z in zs], (E / (args.B * args.T)).item() + if args.scheme == 'jacobi': + for z in zs: z.requires_grad_(True) + opt = torch.optim.SGD(zs, lr=args.eta, momentum=args.mom) + for _ in range(args.K): + opt.zero_grad() + E = 0.0; prev = z0 + for z, b in zip(zs, blocks): E = E + 0.5 * ((z - b(prev, mask)) ** 2).sum(); prev = z + (E / NBT + beta * F.cross_entropy(readout(zs[-1]).reshape(-1, vocab), y.reshape(-1))).backward() + opt.step() + return [z.detach() for z in zs] + order = range(args.L) if args.scheme == 'gsf' else range(args.L - 1, -1, -1) + bufs = [torch.zeros_like(z) for z in zs] + for _ in range(args.K): + for l in order: + g = local_grad(zs, z0, l, beta, y) + bufs[l].mul_(args.mom).add_(g) + zs[l] = (zs[l] - args.eta * bufs[l]).detach() + return zs -def dEdtheta(zs): - """dE/dtheta at fixed states (the local EP readout).""" - for p in blocks.parameters(): - if p.grad is not None: p.grad = None +def dFdtheta(zs, z0, y, beta, params): + """dF/dtheta at FIXED states (E-term local reads + beta*CE readout term for io params).""" E = 0.0; prev = z0 for z, b in zip(zs, blocks): E = E + 0.5 * ((z - b(prev, mask)) ** 2).sum(); prev = z - (E / (args.B * args.T)).backward() - return [(p.grad.clone() if p.grad is not None else torch.zeros(1, device=dev)) for p in blocks.parameters()] + obj = E / NBT + beta * F.cross_entropy(readout(zs[-1]).reshape(-1, vocab), y.reshape(-1)) + gs = torch.autograd.grad(obj, params, allow_unused=True) + return [g if g is not None else torch.zeros(1, device=dev) for g in gs] -zp, Ep = relax(+args.beta) -zm, Em = relax(-args.beta) -gp, gm = dEdtheta(zp), dEdtheta(zm) -gep = [(a - b) / (2 * args.beta) for a, b in zip(gp, gm)] -print(f'nudged relax E+: {Ep:.3e} E-: {Em:.3e} (K={args.K}, eta={args.eta}, beta={args.beta})') - -# ---------------- gate ---------------- -names = [n for n, _ in blocks.named_parameters()] flat = lambda gs: torch.cat([g.reshape(-1) for g in gs]) -cos_all = F.cosine_similarity(flat(gep), flat(gbp), dim=0).item() -print(f'\nGATE cos(cascadeEP, BP) overall: {cos_all:.4f}') -for l in range(args.L): - idx = [i for i, n in enumerate(names) if n.startswith(f'{l}.')] - c = F.cosine_similarity(flat([gep[i] for i in idx]), flat([gbp[i] for i in idx]), dim=0).item() - r = (flat([gep[i] for i in idx]).norm() / flat([gbp[i] for i in idx]).norm()).item() - print(f' block {l}: cos {c:.4f} |EP|/|BP| {r:.3f}') +names = ([f'blk.{n}' for n, _ in blocks.named_parameters()] + + ([f'io.{n}' for n, _ in list(tok.named_parameters()) + list(pos.named_parameters())] if args.include_io else [])) + +cos_b, shr_b, blkcos = [], [], [[] for _ in range(args.L)] +t0 = time.time() +for bi in range(args.batches): + x, y = get_batch(bi) + z0 = (tok(x) + pos(torch.arange(args.T, device=dev))[None]).detach() + # BP reference (embedding z0 grad flows for io gate) + z0ref = tok(x) + pos(torch.arange(args.T, device=dev))[None] + zs = [z0ref] + for b in blocks: zs.append(b(zs[-1], mask)) + ce = F.cross_entropy(readout(zs[-1]).reshape(-1, vocab), y.reshape(-1)) + gbp = list(torch.autograd.grad(ce, gate_params, allow_unused=True)) + gbp = [g if g is not None else torch.zeros(1, device=dev) for g in gbp] + # two-phase + zp = relax(z0, y, +args.beta); zm = relax(z0, y, -args.beta) + gp = dFdtheta(zp, z0, y, +args.beta, gate_params) + gm = dFdtheta(zm, z0, y, -args.beta, gate_params) + gep = [(a - b) / (2 * args.beta) for a, b in zip(gp, gm)] + cos_b.append(F.cosine_similarity(flat(gep), flat(gbp), dim=0).item()) + shr_b.append((flat(gep).norm() / flat(gbp).norm()).item()) + for l in range(args.L): + idx = [i for i, n in enumerate(names) if n.startswith(f'blk.{l}.')] + blkcos[l].append(F.cosine_similarity(flat([gep[i] for i in idx]), flat([gbp[i] for i in idx]), dim=0).item()) + +cm, cmin = float(np.mean(cos_b)), float(np.min(cos_b)) +sm = float(np.mean(shr_b)) +print('per-block cos: ' + ' '.join(f'{l}:{np.mean(v):.4f}' for l, v in enumerate(blkcos))) +if args.include_io: + idx = [i for i, n in enumerate(names) if n.startswith('io.')] + print(f'io cos (last batch): {F.cosine_similarity(flat([gep[i] for i in idx]), flat([gbp[i] for i in idx]), dim=0).item():.4f}') +print(f'SUMMARY scheme={args.scheme} L={args.L} C={args.C} K={args.K} eta={args.eta} beta={args.beta} ' + f'io={int(args.include_io)} warp={args.warp} ckpt={args.ckpt or "-"} ' + f'cos={cm:.4f} cosmin={cmin:.4f} shrink={sm:.3f} t={time.time()-t0:.1f}s') |