cpu: skip redudant ROPE cache updates (llama/20149)

diff --git a/src/ggml-cpu/ops.cpp b/src/ggml-cpu/ops.cpp
index 243f01caf8ee56115709307f1a00e929e7316047..2c372f9635b0eee5140b2ba670023aaa330b8d08 100644 (file)
--- a/src/ggml-cpu/ops.cpp
+++ b/src/ggml-cpu/ops.cpp
@@ -5803,28 +5803,33 @@ static void ggml_compute_forward_rope_flt(
 
     const int32_t * pos = (const int32_t *) src1->data;
 
+    int64_t last_i2 = -1;
+
     for (int64_t i3 = 0; i3 < ne3; i3++) { // batch
         for (int64_t i2 = 0; i2 < ne2; i2++) { // seq-len
-
-            float * cache = (float *) params->wdata + (ne0 + CACHE_LINE_SIZE_F32)*ith;
-            if (!mrope_used) {
-                const int64_t p = pos[i2];
-                ggml_rope_cache_init(p, freq_scale, freq_factors, corr_dims, ne0, ext_factor, attn_factor, cache, sin_sign, theta_scale);
-            }
-            else {
-                const int64_t p_t = pos[i2];
-                const int64_t p_h = pos[i2 + ne2];
-                const int64_t p_w = pos[i2 + ne2 * 2];
-                const int64_t p_e = pos[i2 + ne2 * 3];
-                ggml_mrope_cache_init(
-                    p_t, p_h, p_w, p_e, sections, is_imrope, is_vision,
-                    freq_scale, freq_factors, corr_dims, ne0, ext_factor, attn_factor, cache, sin_sign, theta_scale);
-            }
-
             for (int64_t i1 = 0; i1 < ne1; i1++) { // attn-heads
-                if (ir++ < ir0) continue;
+                if (ir++ < ir0) continue; // skip rows mapped to other threads
                 if (ir   > ir1) break;
 
+                float * cache = (float *) params->wdata + (ne0 + CACHE_LINE_SIZE_F32)*ith;
+                if (last_i2 != i2) {
+                    if (!mrope_used) {
+                        const int64_t p = pos[i2];
+                        ggml_rope_cache_init(p, freq_scale, freq_factors, corr_dims, ne0, ext_factor, attn_factor, cache, sin_sign, theta_scale);
+                    }
+                    else {
+                        const int64_t p_t = pos[i2];
+                        const int64_t p_h = pos[i2 + ne2];
+                        const int64_t p_w = pos[i2 + ne2 * 2];
+                        const int64_t p_e = pos[i2 + ne2 * 3];
+                        ggml_mrope_cache_init(
+                            p_t, p_h, p_w, p_e, sections, is_imrope, is_vision,
+                            freq_scale, freq_factors, corr_dims, ne0, ext_factor, attn_factor, cache, sin_sign, theta_scale);
+                    }
+
+                    last_i2 = i2;
+                }
+
                 T * src = (T *)((char *) src0->data + i3*nb03 + i2*nb02 + i1*nb01);
                 T * dst_data  = (T *)((char *)  dst->data + i3*nb3  + i2*nb2  + i1*nb1);