From 02be8f5da8955883a86787b83eb8272e6ecdc80a Mon Sep 17 00:00:00 2001
From: Georgi Gerganov <ggerganov@gmail.com>
Date: Thu, 20 Aug 2026 13:35:15 +0300
Subject: [PATCH] Revert "tensor-split meta backend fixes (ggml/26502)"
 (llama/27433)

This reverts commit d59d455fd8ea09e5a2e87ce2a9d668267ffb5ccd.
---
 ggml/src/ggml-backend-impl.h   |  1 -
 ggml/src/ggml-backend-meta.cpp | 20 ++------------------
 ggml/src/ggml-backend.cpp      |  2 --
 3 files changed, 2 insertions(+), 21 deletions(-)

diff --git a/ggml/src/ggml-backend-impl.h b/ggml/src/ggml-backend-impl.h
index 40cea024c..9c56ec30c 100644
--- a/ggml/src/ggml-backend-impl.h
+++ b/ggml/src/ggml-backend-impl.h
@@ -83,7 +83,6 @@ extern "C" {
     GGML_API ggml_backend_buffer_t ggml_backend_multi_buffer_alloc_buffer(ggml_backend_buffer_t * buffers, size_t n_buffers);
     GGML_API bool                  ggml_backend_buffer_is_multi_buffer(ggml_backend_buffer_t buffer);
     GGML_API void                  ggml_backend_multi_buffer_set_usage(ggml_backend_buffer_t buffer, enum ggml_backend_buffer_usage usage);
-    GGML_API void                  ggml_backend_meta_buffer_set_usage (ggml_backend_buffer_t buffer, enum ggml_backend_buffer_usage usage);
 
     //
     // Backend (meta)
diff --git a/ggml/src/ggml-backend-meta.cpp b/ggml/src/ggml-backend-meta.cpp
index 775ae9926..7654ea1f3 100644
--- a/ggml/src/ggml-backend-meta.cpp
+++ b/ggml/src/ggml-backend-meta.cpp
@@ -1118,6 +1118,7 @@ static struct ggml_backend_meta_split_state ggml_backend_meta_get_split_state(
 }
 
 static struct ggml_backend_meta_split_state ggml_backend_meta_get_split_state(const struct ggml_tensor * tensor, bool assume_sync) {
+    GGML_ASSERT(ggml_backend_buffer_is_meta(tensor->buffer));
     ggml_backend_meta_buffer_context * buf_ctx = (ggml_backend_meta_buffer_context *) tensor->buffer->context;
     return ggml_backend_meta_get_split_state(buf_ctx->get_simple_tensor_container(tensor), tensor, assume_sync);
 }
@@ -1177,15 +1178,7 @@ static enum ggml_status ggml_backend_meta_buffer_init_tensor_impl(ggml_backend_m
         t_ij->flags = tensor->flags;
         memcpy(t_ij->op_params, tensor->op_params, sizeof(tensor->op_params));
         ggml_set_name(t_ij, tensor->name);
-
         t_ij->buffer = simple_buf;
-        if (simple_buf) {
-            // the backend that owns the buffer will set .extra
-            ggml_backend_buffer_init_tensor(simple_buf, t_ij);
-        } else {
-            t_ij->extra = tensor->extra;
-        }
-
         t_ij->view_src = tensor->view_src;
         t_ij->view_offs = tensor->view_offs;
         if (t_ij->view_src != nullptr && ggml_backend_buffer_is_meta(t_ij->view_src->buffer)) {
@@ -1216,6 +1209,7 @@ static enum ggml_status ggml_backend_meta_buffer_init_tensor_impl(ggml_backend_m
             t_ij->data = (char *) ggml_backend_buffer_get_base(simple_buf)
                 + size_t(tensor->data) - size_t(ggml_backend_buffer_get_base(tensor->buffer));
         }
+        t_ij->extra = tensor->extra;
         for (int i = 0; i < GGML_MAX_SRC; i++) {
             t_ij->src[i] = tensor->src[i];
             if (tensor->src[i] == tensor) {
@@ -1508,16 +1502,6 @@ bool ggml_backend_buffer_is_meta(ggml_backend_buffer_t buf) {
     return buf != nullptr && buf->iface.free_buffer == ggml_backend_meta_buffer_iface.free_buffer;
 }
 
-void ggml_backend_meta_buffer_set_usage(ggml_backend_buffer_t buffer, enum ggml_backend_buffer_usage usage) {
-    GGML_ASSERT(ggml_backend_buffer_is_meta(buffer));
-    ggml_backend_meta_buffer_context * buf_ctx = (ggml_backend_meta_buffer_context *) buffer->context;
-    for (size_t i = 0; i < buf_ctx->bufs.size(); i++) {
-        if (buf_ctx->bufs[i]) {
-            ggml_backend_buffer_set_usage(buf_ctx->bufs[i].get(), usage);
-        }
-    }
-}
-
 static ggml_backend_buffer_t ggml_backend_meta_buffer_type_alloc_buffer(ggml_backend_buffer_type_t buft, size_t size) {
     const size_t n_simple_bufts = ggml_backend_meta_buft_n_bufts(buft);
 
diff --git a/ggml/src/ggml-backend.cpp b/ggml/src/ggml-backend.cpp
index e519bdf50..3d6310f3f 100644
--- a/ggml/src/ggml-backend.cpp
+++ b/ggml/src/ggml-backend.cpp
@@ -182,8 +182,6 @@ void ggml_backend_buffer_set_usage(ggml_backend_buffer_t buffer, enum ggml_backe
     // FIXME: add a generic callback to the buffer interface
     if (ggml_backend_buffer_is_multi_buffer(buffer)) {
         ggml_backend_multi_buffer_set_usage(buffer, usage);
-    } else if (ggml_backend_buffer_is_meta(buffer)) {
-        ggml_backend_meta_buffer_set_usage(buffer, usage);
     }
 }