#!/usr/bin/env python3 """ Experiment 5: Relaxation Mechanism Ablation Falsifies or confirms whether weight relaxation is structural prediction (BVP) or generic regularization. Five seeds throughout. Configs (all d=1024, 4L, 1000 steps, 10% active): 1. dense 2. dense + relax_graph (alpha=0.1) 3. dense + relax_roll (alpha=0.1) 4. ema_only 5. ema + relax_graph (alpha=0.1) 6. ema + relax_roll (alpha=0.1) 7. ema + relax_random (random similarity matrix) 8. ema + relax_shuffled_graph (real stats, broken structure) Alpha sweep (graph, ema): 0.0, 0.01, 0.05, 0.1, 0.2, 0.5, 0.9 Diagnostics per run: - Val loss every 50 steps - grad_cos: cosine similarity between relaxer delta and dense oracle gradient - mag_ratio: ||relaxer_delta|| / ||oracle_grad|| on inactive chunks - mask_jaccard: step-to-step overlap of active set """ import argparse,json,math,os,random,sys,time,urllib.request from collections import defaultdict import torch,torch.nn as nn,torch.nn.functional as F import tiktoken print("imports ok",flush=True) class Corpus: _i=None @classmethod def get(cls,bs,dev): if cls._i is None: cls._i=cls(bs,dev) return cls._i def __init__(self,bs,dev): self.block_size,self.device=bs,dev p="input.txt" if not os.path.exists(p): urllib.request.urlretrieve("https://raw.githubusercontent.com/karpathy/char-rnn/master/data/tinyshakespeare/input.txt",p) enc=tiktoken.get_encoding("gpt2"); t=enc.encode(open(p).read()) self.vocab_size=enc.n_vocab; d=torch.tensor(t,dtype=torch.long) si=int(0.9*len(d)); self.train_data,self.val_data=d[:si],d[si:] print(f"Corpus: V={self.vocab_size} train={len(self.train_data):,} val={len(self.val_data):,}",flush=True) def get_batch(self,split,bs,gen=None): d=self.train_data if split=="train" else self.val_data ix=torch.randint(len(d)-self.block_size-1,(bs,),generator=gen) x=torch.stack([d[i:i+self.block_size] for i in ix]) y=torch.stack([d[i+1:i+self.block_size+1] for i in ix]) return x.to(self.device),y.to(self.device) def mg(s): g=torch.Generator(device="cpu"); g.manual_seed(s); return g class SparseBwd(torch.autograd.Function): @staticmethod def forward(ctx,x,w,b,ac,cs,sdx): ctx.save_for_backward(x,w,ac); ctx.hb=b is not None; ctx.sdx=sdx; ctx.cs=cs return F.linear(x,w,b) @staticmethod def backward(ctx,gy): x,w,ac=ctx.saved_tensors; cs=ctx.cs xf=x.reshape(-1,x.shape[-1]); gf=gy.reshape(-1,gy.shape[-1]) gw=torch.zeros_like(w) gb=torch.zeros(w.shape[0],device=w.device,dtype=w.dtype) if ctx.hb else None gx=torch.zeros_like(xf) if ctx.sdx else gf@w for c in ac.tolist(): s,e=c*cs,(c+1)*cs; sl=gf[:,s:e] gw[s:e]=sl.t()@xf if gb is not None: gb[s:e]=sl.sum(0) if ctx.sdx: gx+=sl@w[s:e] return gx.reshape(x.shape),gw,gb,None,None,None class SL(nn.Linear): def __init__(self,i,o,bias=True): super().__init__(i,o,bias=bias) self.se=False; self.sdx=False; self.ac=None; self.cs=64 def forward(self,x): if not self.se or self.ac is None: return F.linear(x,self.weight,self.bias) return SparseBwd.apply(x,self.weight,self.bias,self.ac,self.cs,self.sdx) class Attn(nn.Module): def __init__(self,d,nh,bs,do): super().__init__(); self.nh=nh; self.hd=d//nh self.qkv=SL(d,3*d); self.proj=SL(d,d); self.drop=nn.Dropout(do) self.register_buffer("mask",torch.tril(torch.ones(bs,bs)).view(1,1,bs,bs)) def forward(self,x): B,T,C=x.shape; q,k,v=self.qkv(x).split(C,2) q=q.view(B,T,self.nh,self.hd).transpose(1,2) k=k.view(B,T,self.nh,self.hd).transpose(1,2) v=v.view(B,T,self.nh,self.hd).transpose(1,2) a=(q@k.transpose(-2,-1))/math.sqrt(self.hd) a=a.masked_fill(self.mask[:,:,:T,:T]==0,float("-inf")) a=self.drop(F.softmax(a,dim=-1)) return self.proj((a@v).transpose(1,2).contiguous().view(B,T,C)) class FFN(nn.Module): def __init__(self,d,do): super().__init__(); self.fc=SL(d,4*d); self.proj=SL(4*d,d); self.drop=nn.Dropout(do) def forward(self,x): return self.drop(self.proj(F.gelu(self.fc(x)))) class Blk(nn.Module): def __init__(self,d,nh,bs,do): super().__init__(); self.ln1=nn.LayerNorm(d); self.attn=Attn(d,nh,bs,do) self.ln2=nn.LayerNorm(d); self.mlp=FFN(d,do) def forward(self,x): x=x+self.attn(self.ln1(x)); return x+self.mlp(self.ln2(x)) class GPT(nn.Module): def __init__(self,V,bs,nl,nh,d,do): super().__init__(); self.te=nn.Embedding(V,d); self.pe=nn.Embedding(bs,d) self.blocks=nn.Sequential(*[Blk(d,nh,bs,do) for _ in range(nl)]) self.ln=nn.LayerNorm(d); self.head=nn.Linear(d,V) def forward(self,idx,tgt=None): B,T=idx.shape; x=self.te(idx)+self.pe(torch.arange(T,device=idx.device))[None] lo=self.head(self.ln(self.blocks(x))) return lo,F.cross_entropy(lo.view(-1,lo.size(-1)),tgt.view(-1)) if tgt is not None else None def np(self): return sum(p.numel() for p in self.parameters()) def gsl(m): return [x for x in m.modules() if isinstance(x,SL)] class Sched: def __init__(self,model,frac,cs,dev,beta=0.95,sim_hist=128,min_sim=8): self.frac,self.cs,self.dev,self.beta=frac,cs,dev,beta self.sim_hist,self.min_sim=sim_hist,min_sim self.lins=gsl(model); self.m2i,self.m2l={},{}; off=0 for m in self.lins: m.cs=cs; nc=m.out_features//cs; assert m.out_features%cs==0 self.m2i[m]=torch.arange(off,off+nc,device=dev) self.m2l[m]=torch.arange(nc,device=dev); off+=nc self.nc=off; self.ema=torch.zeros(self.nc,device=dev) self.act=torch.zeros(self.nc,dtype=torch.bool,device=dev) self.prev_act=torch.zeros(self.nc,dtype=torch.bool,device=dev) self.mass_history=[]; self.similarity=None def gf(self,step,wu,an): if step0 and step=0.999: self.act.fill_(True); self._inst(); return k=max(1,int(f*self.nc)); self.act.fill_(False) idx=torch.topk(self.ema+1e-9*torch.rand_like(self.ema),k=k).indices self.act[idx]=True; self._inst() def _inst(self): for m,gi in self.m2i.items(): m.ac=self.m2l[m][self.act[gi]] @torch.no_grad() def update(self,step,wu): cur=torch.zeros_like(self.ema) for m,ids in self.m2i.items(): if m.weight.grad is None: continue s=m.weight.grad.square().view(len(ids),self.cs,-1).sum((1,2)) if m.bias is not None and m.bias.grad is not None: s+=m.bias.grad.square().view(len(ids),self.cs).sum(1) cur[ids]=torch.sqrt(s+1e-30) obs=self.act; new=obs&(self.ema==0); old=obs&~new self.ema[new]=cur[new]; self.ema[old]=self.beta*self.ema[old]+(1-self.beta)*cur[old] if stepself.sim_hist: self.mass_history=self.mass_history[-self.sim_hist:] if len(self.mass_history)>=self.min_sim: self._build_sim() return cur def _build_sim(self): H=torch.stack(self.mass_history) H=(H-H.mean(0,keepdim=True))/(H.std(0,keepdim=True)+1e-6) S=torch.clamp((H.T@H)/max(1,H.shape[0]-1),min=0) S.fill_diagonal_(0) ok=torch.zeros_like(S,dtype=torch.bool) for _,ids in self.m2i.items(): ok[ids[:,None],ids[None,:]]=True self.similarity=torch.where(ok,S,torch.zeros_like(S)) def mask_jaccard(self): if self.prev_act.sum()==0: return 0.0 i=(self.act&self.prev_act).sum().item() u=(self.act|self.prev_act).sum().item() return i/max(u,1) class GraphRelaxer: def __init__(self, sched, alpha=0.1, iters=3): self.sched,self.alpha,self.iters=sched,alpha,iters @torch.no_grad() def relax(self): S=self.sched.similarity if S is None: return {} act=self.sched.act; deltas={} for m,ids in self.sched.m2i.items(): nc=len(ids); cs=self.sched.cs; di=m.weight.shape[1] S_local=S[ids][:,ids] rs=S_local.sum(1,keepdim=True)+1e-12; S_n=S_local/rs la=act[ids]; li=~la if li.sum()==0: continue W=m.weight.data.view(nc,cs,di); W_before=W[li].clone() for _ in range(self.iters): Wf=W.reshape(nc,-1); Wa=(S_n@Wf).view(nc,cs,di) W[li]=(1-self.alpha)*W[li]+self.alpha*Wa[li] m.weight.data=W.view(m.out_features,di) deltas[m]=W[li]-W_before return deltas class RollRelaxer: def __init__(self, sched, alpha=0.1, iters=3): self.sched,self.alpha,self.iters=sched,alpha,iters @torch.no_grad() def relax(self): act=self.sched.act; deltas={} for m,ids in self.sched.m2i.items(): nc=len(ids); cs=self.sched.cs; di=m.weight.shape[1] la=act[ids]; li=~la if li.sum()==0: continue W=m.weight.data.view(nc,cs,di); W_before=W[li].clone() for _ in range(self.iters): Wp=torch.roll(W,1,dims=0); Wn=torch.roll(W,-1,dims=0) Wa=(Wp+Wn)/2.0 W[li]=(1-self.alpha)*W[li]+self.alpha*Wa[li] m.weight.data=W.view(m.out_features,di) deltas[m]=W[li]-W_before return deltas class RandomRelaxer: def __init__(self, sched, alpha=0.1, iters=3): self.sched,self.alpha,self.iters=sched,alpha,iters self._rand_sim=None def _get_rand_sim(self): if self._rand_sim is not None: return self._rand_sim S=self.sched.similarity if S is None: return None R=torch.rand_like(S)*S.abs().mean() R.fill_diagonal_(0) ok=torch.zeros_like(R,dtype=torch.bool) for _,ids in self.sched.m2i.items(): ok[ids[:,None],ids[None,:]]=True self._rand_sim=torch.where(ok,R,torch.zeros_like(R)) return self._rand_sim @torch.no_grad() def relax(self): S=self._get_rand_sim() if S is None: return {} act=self.sched.act; deltas={} for m,ids in self.sched.m2i.items(): nc=len(ids); cs=self.sched.cs; di=m.weight.shape[1] S_local=S[ids][:,ids] rs=S_local.sum(1,keepdim=True)+1e-12; S_n=S_local/rs la=act[ids]; li=~la if li.sum()==0: continue W=m.weight.data.view(nc,cs,di); W_before=W[li].clone() for _ in range(self.iters): Wf=W.reshape(nc,-1); Wa=(S_n@Wf).view(nc,cs,di) W[li]=(1-self.alpha)*W[li]+self.alpha*Wa[li] m.weight.data=W.view(m.out_features,di) deltas[m]=W[li]-W_before return deltas class ShuffledGraphRelaxer: def __init__(self, sched, alpha=0.1, iters=3): self.sched,self.alpha,self.iters=sched,alpha,iters self._shuf_sim=None def _get_shuf_sim(self): if self._shuf_sim is not None: return self._shuf_sim S=self.sched.similarity if S is None: return None Ss=S.clone() for _,ids in self.sched.m2i.items(): n=len(ids) block=Ss[ids][:,ids].clone() perm=torch.randperm(n,device=S.device) block=block[perm][:,perm] block.fill_diagonal_(0) Ss[ids[:,None],ids[None,:]]=block self._shuf_sim=Ss return self._shuf_sim @torch.no_grad() def relax(self): S=self._get_shuf_sim() if S is None: return {} act=self.sched.act; deltas={} for m,ids in self.sched.m2i.items(): nc=len(ids); cs=self.sched.cs; di=m.weight.shape[1] S_local=S[ids][:,ids] rs=S_local.sum(1,keepdim=True)+1e-12; S_n=S_local/rs la=act[ids]; li=~la if li.sum()==0: continue W=m.weight.data.view(nc,cs,di); W_before=W[li].clone() for _ in range(self.iters): Wf=W.reshape(nc,-1); Wa=(S_n@Wf).view(nc,cs,di) W[li]=(1-self.alpha)*W[li]+self.alpha*Wa[li] m.weight.data=W.view(m.out_features,di) deltas[m]=W[li]-W_before return deltas class NullRelaxer: def relax(self): return {} class CAdam: def __init__(self,model,lr=3e-4,cs=64): self.model,self.lr,self.cs=model,lr,cs self.st={}; self.p2m={} for m in gsl(model): if m.weight is not None: self.p2m[m.weight]=m if m.bias is not None: self.p2m[m.bias]=m def zero_grad(self): for p in self.model.parameters(): p.grad=None @torch.no_grad() def step(self): for p in self.model.parameters(): if p.grad is None: continue if p not in self.st: self.st[p]={"m":torch.zeros_like(p),"v":torch.zeros_like(p)} m,v=self.st[p]["m"],self.st[p]["v"] sm=self.p2m.get(p); ac=getattr(sm,'ac',None) if sm else None if ac is None: m.mul_(0.9).add_(p.grad,alpha=0.1); v.mul_(0.999).addcmul_(p.grad,p.grad,value=0.001) p.sub_(m/(torch.sqrt(v)+1e-8),alpha=self.lr) else: m.mul_(0.9).add_(p.grad,alpha=0.1); v.mul_(0.999).addcmul_(p.grad,p.grad,value=0.001) for c in ac.tolist(): s,e=c*self.cs,(c+1)*self.cs p.data[s:e].sub_(m[s:e]/(torch.sqrt(v[s:e])+1e-8),alpha=self.lr) @torch.no_grad() def ev(model,corpus,bs,n=20,seed=9999): model.eval(); ls=[model(*corpus.get_batch("val",bs,mg(seed+i)))[1].item() for i in range(n)] model.train(); a=sum(ls)/len(ls); return a,math.exp(min(a,20)) def compute_relaxer_diagnostics(model, sched, relaxer_deltas, x, y, corpus, bs, cs): """ Compare relaxer delta on inactive chunks to what dense gradient would have been. Returns (grad_cos, mag_ratio) or (None, None) if not applicable. """ if not relaxer_deltas: return None, None # Need gradients enabled for the dense forward/backward for m in gsl(model): m.se=False for p in model.parameters(): p.grad=None with torch.enable_grad(): _,lo=model(x,y) lo.backward() cos_sims=[]; mag_ratios=[] with torch.no_grad(): for m,delta in relaxer_deltas.items(): if m not in sched.m2i: continue ids=sched.m2i[m]; nc=len(ids); di=m.weight.shape[1] la=sched.act[ids]; li=~la if li.sum()==0 or m.weight.grad is None: continue dense_g=m.weight.grad.view(nc,cs,di)[li] d_flat=delta.reshape(-1); g_flat=dense_g.reshape(-1) dn=d_flat.norm(); gn=g_flat.norm() if dn>1e-12 and gn>1e-12: cos_sims.append(F.cosine_similarity(d_flat.unsqueeze(0),g_flat.unsqueeze(0)).item()) mag_ratios.append((dn/gn).item()) for m in gsl(model): m.se=True for p in model.parameters(): p.grad=None if not cos_sims: return None, None return sum(cos_sims)/len(cos_sims), sum(mag_ratios)/len(mag_ratios) def run1(mode, steps, bs, bsz, nl, nh, d, cs, af, wu, an, lr, dev, seed, alpha=0.1, iters=3, diag_interval=100): torch.manual_seed(seed); random.seed(seed) if torch.cuda.is_available(): torch.cuda.manual_seed_all(seed) corpus=Corpus.get(bsz,dev) model=GPT(corpus.vocab_size,bsz,nl,nh,d,0.1).to(dev) for m in gsl(model): m.cs=cs is_dense = mode.startswith("dense") is_sparse = not is_dense needs_relax = "relax" in mode sched=None if is_sparse: sched=Sched(model,af,cs,dev) elif needs_relax: sched=Sched(model,af,cs,dev) opt=CAdam(model,lr,cs) if not needs_relax: relaxer=NullRelaxer() elif "random" in mode: relaxer=RandomRelaxer(sched,alpha,iters) elif "shuffled" in mode: relaxer=ShuffledGraphRelaxer(sched,alpha,iters) elif "roll" in mode: relaxer=RollRelaxer(sched,alpha,iters) elif "graph" in mode: relaxer=GraphRelaxer(sched,alpha,iters) else: relaxer=NullRelaxer() np_=model.np() val_curve=[]; grad_cos_log=[]; mag_ratio_log=[]; jaccard_log=[] if dev=="cuda": torch.cuda.synchronize() t0=time.perf_counter() for step in range(steps): x,y=corpus.get_batch("train",bs,mg(step)) if is_sparse: sched.choose(step,wu,an) for m in gsl(model): m.se=True; m.sdx=False else: for m in gsl(model): m.se=False; m.ac=None if sched: sched.choose(step,wu,an) opt.zero_grad(); _,loss=model(x,y); loss.backward() if sched: sched.update(step,wu) jaccard_log.append((step, sched.mask_jaccard())) opt.step() relax_deltas={} if needs_relax and step>=wu+an: if is_dense and sched: for m,ids in sched.m2i.items(): m.ac=sched.m2l[m][sched.act[ids]] relax_deltas=relaxer.relax() if is_dense and sched: for m in gsl(model): m.ac=None if step%50==0: vl,_=ev(model,corpus,bs,n=10,seed=7777) val_curve.append((step,vl)) if step%diag_interval==0 and step>=wu+an and relax_deltas and sched: gc,mr=compute_relaxer_diagnostics(model,sched,relax_deltas,x,y,corpus,bs,cs) if gc is not None: grad_cos_log.append((step,gc)) mag_ratio_log.append((step,mr)) if step%200==0: print(f" step {step}/{steps} loss={loss.item():.4f}",flush=True) if dev=="cuda": torch.cuda.synchronize() wall=time.perf_counter()-t0 for m in gsl(model): m.se=False vl,vp=ev(model,corpus,bs,n=30) del model; torch.cuda.empty_cache() if dev=="cuda" else None return { "vl":vl,"vp":vp,"wall":wall,"ms":1000*wall/steps,"np":np_,"tl":loss.item(), "val_curve":val_curve,"grad_cos":grad_cos_log,"mag_ratio":mag_ratio_log, "jaccard":jaccard_log, } def runs(cfg,seeds): rs=[] for s in seeds: c=dict(cfg); c["seed"]=s; rs.append(run1(**c)) vls=[r["vl"] for r in rs]; ml=sum(vls)/len(vls) sl=(sum((x-ml)**2 for x in vls)/max(1,len(vls)-1))**0.5 return {"ml":ml,"sl":sl,"rs":rs,"ms":sum(r["ms"] for r in rs)/len(rs)} def main(): p=argparse.ArgumentParser() p.add_argument("--device",default="cuda"); p.add_argument("--steps",type=int,default=1000) p.add_argument("--seeds",default="42,123,456,789,1024") p.add_argument("--d",type=int,default=1024); p.add_argument("--nl",type=int,default=4) p.add_argument("--nh",type=int,default=8); p.add_argument("--bs",type=int,default=8) p.add_argument("--bsz",type=int,default=256); p.add_argument("--cs",type=int,default=64) p.add_argument("--af",type=float,default=0.10); p.add_argument("--wu",type=int,default=50) p.add_argument("--an",type=int,default=200); p.add_argument("--lr",type=float,default=3e-4) a=p.parse_args(); seeds=[int(s) for s in a.seeds.split(",")] if a.device=="cuda" and torch.cuda.is_available(): print(f"GPU: {torch.cuda.get_device_name()} VRAM: {torch.cuda.get_device_properties(0).total_memory/1e9:.1f}GB",flush=True) print(f"d={a.d} nl={a.nl} steps={a.steps} seeds={seeds}",flush=True) print(f"cs={a.cs} af={a.af} wu={a.wu} an={a.an} lr={a.lr}",flush=True) base=dict(steps=a.steps,bs=a.bs,bsz=a.bsz,nl=a.nl,nh=a.nh,d=a.d,cs=a.cs,af=a.af, wu=a.wu,an=a.an,lr=a.lr,dev=a.device,alpha=0.1,iters=3) configs=[ ("dense", "dense"), ("dense+relax_graph", "dense+relax_graph"), ("dense+relax_roll", "dense+relax_roll"), ("ema_only", "ema_only"), ("ema+relax_graph", "ema+relax_graph"), ("ema+relax_roll", "ema+relax_roll"), ("ema+relax_random", "ema+relax_random"), ("ema+relax_shuffled", "ema+relax_shuffled_graph"), ] print("\n"+"="*80,flush=True) print("EXP 5: Relaxation Mechanism Ablation (5 seeds)",flush=True) print("="*80,flush=True) R={} for name,mode in configs: print(f"\n--- {name} ({len(seeds)} seeds) ---",flush=True) R[name]=runs({**base,"mode":mode},seeds) print(f"\n{'Method':<25} | {'Val Loss':>20} | {'ms/step':>8}",flush=True) print("-"*60,flush=True) for name,_ in configs: r=R[name] print(f"{name:<25} | {r['ml']:.4f} ± {r['sl']:.4f} | {r['ms']:>7.1f}",flush=True) print(f"\n--- Alpha sweep (ema+relax_graph, 5 seeds) ---",flush=True) print(f"{'alpha':>6} | {'Val Loss':>20} | {'ms/step':>8}",flush=True) print("-"*42,flush=True) alpha_results={} for alpha in [0.0, 0.01, 0.05, 0.1, 0.2, 0.5, 0.9]: r=runs({**base,"mode":"ema+relax_graph","alpha":alpha},seeds) alpha_results[alpha]=r print(f"{alpha:>6.2f} | {r['ml']:.4f} ± {r['sl']:.4f} | {r['ms']:>7.1f}",flush=True) print(f"\n--- Diagnostics (grad_cos, mag_ratio) ---",flush=True) for name in ["ema+relax_graph","ema+relax_roll","ema+relax_random","ema+relax_shuffled"]: if name not in R: continue gc_all=[]; mr_all=[] for res in R[name]["rs"]: gc_all.extend([x[1] for x in res["grad_cos"]]) mr_all.extend([x[1] for x in res["mag_ratio"]]) if gc_all: gc_m=sum(gc_all)/len(gc_all); mr_m=sum(mr_all)/len(mr_all) print(f" {name:<25}: grad_cos={gc_m:.4f} mag_ratio={mr_m:.4f}",flush=True) all_results={"configs":R,"alpha_sweep":alpha_results} with open("exp5.json","w") as f: json.dump(all_results,f,indent=2,default=str) print("\n✓ exp5.json saved",flush=True) print(f"\nTotal: {len(configs)*len(seeds) + 7*len(seeds)} runs",flush=True) if __name__=="__main__": main()