From 7a5ffd192dd01b43a7cf50dee9d7ffcfd9228fef Mon Sep 17 00:00:00 2001
From: JustVugg <JustVugg@users.noreply.github.com>
Date: Mon, 6 Jul 2026 19:56:24 +0200
Subject: [PATCH] async I/O: WILLNEED readahead of the next expert block while
 computing the current one

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
---
 c/glm.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/c/glm.c b/c/glm.c
index f3028c0..fee5d78 100644
--- a/c/glm.c
+++ b/c/glm.c
@@ -814,6 +814,18 @@ static void moe(Model *m, Layer *l, int layer, float *x, int S, float *out){
             #pragma omp parallel for schedule(dynamic,1)
             for(int q=0;q<nmiss;q++) expert_load(m,layer,uniq[base+missk[q]],&m->ws[q]);
             m->t_edisk += now_s()-t0; }
+        /* I/O ASINCRONO: readahead (WILLNEED) del blocco SUCCESSIVO mentre calcoliamo
+         * questo — il kernel legge in background, le pread dopo trovano cache calda */
+        if(base+64<nu){
+            int nb2 = nu-(base+64)<64 ? nu-(base+64) : 64;
+            for(int j=0;j<nb2;j++){ int eid=uniq[base+64+j]; int found=0;
+                ESlot *P=m->pin[layer];
+                for(int z=0;z<m->npin[layer] && !found;z++) if(P[z].eid==eid) found=1;
+                ESlot *Sl=m->ecache[layer];
+                for(int z=0;z<m->ecn[layer] && !found;z++) if(Sl[z].eid==eid) found=1;
+                if(!found) expert_prefetch(m,layer,eid);
+            }
+        }
         for(int j=0;j<nb;j++){ int eid=uniq[base+j]; ESlot *e=use[j];
             int nr=0;                                 /* righe (posizioni) che usano questo expert */
             for(int s=0;s<S;s++) for(int kk=0;kk<keff[s];kk++)