metal : page align the data ptr

ggml-ci

Author: ggerganov

ggml-metal.m

@@ -2656,6 +2656,14 @@ ggml_backend_buffer_t ggml_backend_metal_buffer_from_ptr(void * data, size_t siz
     ctx->n_buffers = 0;
 
     const size_t size_page = sysconf(_SC_PAGESIZE);
+
+    // page-align the data ptr
+    {
+        const uintptr_t offs = (uintptr_t) data % size_page;
+        data  = (void *) ((char *) data - offs);
+        size += offs;
+    }
+
     size_t size_aligned = size;
     if ((size_aligned % size_page) != 0) {
         size_aligned += (size_page - (size_aligned % size_page));