From 1b7f2c6dabba2334bfd9e353d50242059d2efaf1 Mon Sep 17 00:00:00 2001
From: Sam Spilsbury <smspillaz@gmail.com>
Date: Tue, 8 Aug 2023 12:33:21 +0300
Subject: [PATCH] ggml-alloc: Don't try to re-use buffers of external tensors

They might be weights that came from another context, so we
have no control over them (and they might be re-used elsewhere
so writing to them would be a bad idea).
---
 ggml-alloc.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/ggml-alloc.c b/ggml-alloc.c
index 5e1be61ff..200b82ab7 100644
--- a/ggml-alloc.c
+++ b/ggml-alloc.c
@@ -394,6 +394,14 @@ static void allocate_node(struct ggml_allocr * alloc, struct ggml_tensor * node)
                     if (parent == NULL) {
                         break;
                     }
+
+                    // if the node's data is external, then we cannot re-use it
+                    if ((char *) parent->data < (char *) alloc->data ||
+                        (char *) parent->data > ((char *) alloc->data + alloc->size)) {
+                        AT_PRINTF("not reusing parent %s for %s as %p is external\n", parent->name, node->name, parent->data);
+                        continue;
+                    }
+
                     struct hash_node * p_hn = hash_get(ht, parent);
                     if (parent->data != NULL && p_hn->n_children == 1 && p_hn->n_views == 0 && ggml_are_same_layout(node, parent)) {
                         if (ggml_is_view(parent)) {