Add option not to abort on cuda OOM

Warning: Not ready for merge.
Add option not to abort on cuda OOM but return a ggml_status.
The goal is NOT to be able to continue decoding when OOM but just to do
a clean controlled exit at higher level.
Needs cmake GGML_NO_ABORT_ON_OOM=ON (default OFF)
Retouch ggml_tallocr_alloc to return a ggml_status.
Retouch init_tensor to return a ggml_status.
Add a bool option for ggml_cuda_error() to abort or not, default true.
Add a new macro CUDA_CHECK_NO_ABORT()
Ass a new unit test to check the GGML_NO_ABORT_ON_OOM flow.

.gitignore

@@ -1,4 +1,5 @@
 build/
+release/
 build-*/
 out/
 tmp/

CMakeLists.txt

@@ -87,6 +87,7 @@ option(GGML_GPROF                  "ggml: enable gprof"
 
 # build
 option(GGML_FATAL_WARNINGS    "ggml: enable -Werror flag"    OFF)
+option(GGML_NO_ABORT_ON_OOM   "ggml: enable no abort on OOM (experimental)" OFF)
 
 # sanitizers
 option(GGML_SANITIZE_THREAD    "ggml: enable thread sanitizer"    OFF)

include/ggml-alloc.h

@@ -19,7 +19,7 @@ struct ggml_tallocr {
 };
 
 GGML_API struct ggml_tallocr ggml_tallocr_new(ggml_backend_buffer_t buffer);
-GGML_API void                ggml_tallocr_alloc(struct ggml_tallocr * talloc, struct ggml_tensor * tensor);
+GGML_API enum ggml_status    ggml_tallocr_alloc(struct ggml_tallocr * talloc, struct ggml_tensor * tensor);
 
 // Graph allocator
 /*

src/CMakeLists.txt

@@ -60,6 +60,10 @@ if (GGML_FATAL_WARNINGS)
     endif()
 endif()
 
+if (GGML_NO_ABORT_ON_OOM)
+    add_compile_definitions(GGML_NO_ABORT_ON_OOM)
+endif()
+
 if (GGML_ALL_WARNINGS)
     if (NOT MSVC)
         list(APPEND WARNING_FLAGS -Wall -Wextra -Wpedantic -Wcast-qual -Wno-unused-function)

src/ggml-alloc.c

@@ -89,14 +89,18 @@ struct ggml_tallocr ggml_tallocr_new(ggml_backend_buffer_t buffer) {
     return talloc;
 }
 
-void ggml_tallocr_alloc(struct ggml_tallocr * talloc, struct ggml_tensor * tensor) {
+enum ggml_status ggml_tallocr_alloc(struct ggml_tallocr * talloc, struct ggml_tensor * tensor) {
     size_t size = ggml_backend_buffer_get_alloc_size(talloc->buffer, tensor);
     size = GGML_PAD(size, talloc->alignment);
 
     if (talloc->offset + size > ggml_backend_buffer_get_size(talloc->buffer)) {
-        GGML_LOG_ERROR("%s: not enough space in the buffer to allocate %s (needed %zu, available %zu)\n",
+        GGML_LOG_ERROR("%s: not enough space in the buffer to allocate tensor '%s' (needed %zu, available %zu)\n",
                 __func__, tensor->name, size, ggml_backend_buffer_get_size(talloc->buffer) - talloc->offset);
+#ifdef GGML_NO_ABORT_ON_OOM
+        return GGML_STATUS_ALLOC_FAILED;
+#else
         GGML_ABORT("not enough space in the buffer");
+#endif
     }
 
     void * addr = (char *)ggml_backend_buffer_get_base(talloc->buffer) + talloc->offset;
@@ -105,6 +109,7 @@ void ggml_tallocr_alloc(struct ggml_tallocr * talloc, struct ggml_tensor * tenso
     assert(((uintptr_t)addr % talloc->alignment) == 0);
 
     ggml_backend_tensor_alloc(talloc->buffer, tensor, addr);
+    return GGML_STATUS_SUCCESS;
 }
 
 // dynamic tensor allocator
@@ -150,6 +155,7 @@ static void remove_allocated_tensor(struct ggml_dyn_tallocr * alloc, size_t offs
 }
 #endif
 
+// Check with reviewer: could that function returns a ggm_status (offset being an arg)
 static size_t ggml_dyn_tallocr_alloc(struct ggml_dyn_tallocr * alloc, size_t size, const struct ggml_tensor * tensor) {
     size = aligned_offset(NULL, size, alloc->alignment);
 
@@ -179,6 +185,7 @@ static size_t ggml_dyn_tallocr_alloc(struct ggml_dyn_tallocr * alloc, size_t siz
             // this should never happen
             GGML_LOG_ERROR("%s: not enough space in the buffer to allocate %zu bytes, largest block available %zu bytes\n",
                     __func__, size, max_avail);
+            // Note: no way to honor GGML_NO_ABORT_ON_OOM since that fn returns the offset, not a ggml_status
             GGML_ABORT("not enough space in the buffer");
         }
     }
@@ -378,6 +385,7 @@ struct ggml_gallocr {
 };
 
 ggml_gallocr_t ggml_gallocr_new_n(ggml_backend_buffer_type_t * bufts, int n_bufs) {
+    //GGML_LOG_TRACE("%s: nbufs=%d\n", __func__, n_bufs);
     ggml_gallocr_t galloc = (ggml_gallocr_t)calloc(1, sizeof(struct ggml_gallocr));
     GGML_ASSERT(galloc != NULL);
 
@@ -670,7 +678,10 @@ static void ggml_gallocr_alloc_graph_impl(ggml_gallocr_t galloc, struct ggml_cgr
     }
 }
 
+// Returns true on success, false otherwise
+// Check with reviewers: any cons to return a ggml_status?
 bool ggml_gallocr_reserve_n(ggml_gallocr_t galloc, struct ggml_cgraph * graph, const int * node_buffer_ids, const int * leaf_buffer_ids) {
+    //GGML_LOG_TRACE("ggml_gallocr_reserve_n\n");
     size_t min_hash_size = graph->n_nodes + graph->n_leafs;
     // add 25% margin to avoid hash collisions
     min_hash_size += min_hash_size / 4;
@@ -865,6 +876,7 @@ static bool ggml_gallocr_needs_realloc(ggml_gallocr_t galloc, struct ggml_cgraph
     return false;
 }
 
+// Check with reviewers: any cons to return a ggml_status here?
 bool ggml_gallocr_alloc_graph(ggml_gallocr_t galloc, struct ggml_cgraph * graph) {
     if (ggml_gallocr_needs_realloc(galloc, graph)) {
         if (galloc->n_buffers == 1) {
@@ -954,7 +966,9 @@ static bool alloc_tensor_range(struct ggml_context * ctx,
     for (struct ggml_tensor * t = first; t != last; t = ggml_get_next_tensor(ctx, t)) {
         if (t->data == NULL) {
             if (t->view_src == NULL) {
-                ggml_tallocr_alloc(&tallocr, t);
+                enum ggml_status s = ggml_tallocr_alloc(&tallocr, t);
+                if (s != GGML_STATUS_SUCCESS)
+                    GGML_LOG_WARN("%s: failed to alloc tensor %s \n", __func__, t->name);
             } else if (t->buffer == NULL) {
                 ggml_backend_view_init(t);
             }

src/ggml-backend-impl.h

@@ -44,7 +44,7 @@ extern "C" {
         // base address of the buffer
         void *       (*get_base)     (ggml_backend_buffer_t buffer);
         // (optional) initialize a tensor in the buffer (eg. add tensor extras)
-        void         (*init_tensor)  (ggml_backend_buffer_t buffer, struct ggml_tensor * tensor);
+        enum ggml_status  (*init_tensor)  (ggml_backend_buffer_t buffer, struct ggml_tensor * tensor);
         // tensor data access
         void         (*memset_tensor)(ggml_backend_buffer_t buffer,       struct ggml_tensor * tensor,     uint8_t value, size_t offset, size_t size);
         void         (*set_tensor)   (ggml_backend_buffer_t buffer,       struct ggml_tensor * tensor, const void * data, size_t offset, size_t size);

src/ggml-cpu/amx/amx.cpp

@@ -50,10 +50,11 @@ static void * ggml_backend_amx_buffer_get_base(ggml_backend_buffer_t buffer) {
     return (void *) (buffer->context);
 }
 
-static void ggml_backend_amx_buffer_init_tensor(ggml_backend_buffer_t buffer, struct ggml_tensor * tensor) {
+static ggml_status ggml_backend_amx_buffer_init_tensor(ggml_backend_buffer_t buffer, struct ggml_tensor * tensor) {
     tensor->extra = (void *) ggml::cpu::amx::get_tensor_traits(buffer, tensor);
 
     GGML_UNUSED(buffer);
+    return GGML_STATUS_SUCCESS;
 }
 
 static void ggml_backend_amx_buffer_memset_tensor(ggml_backend_buffer_t buffer, struct ggml_tensor * tensor,

src/ggml-cpu/ggml-cpu-aarch64.cpp

@@ -4135,10 +4135,11 @@ static const ggml::cpu::tensor_traits * ggml_aarch64_get_optimal_repack_type(con
     return nullptr;
 }
 
-static void ggml_backend_cpu_aarch64_buffer_init_tensor(ggml_backend_buffer_t buffer, struct ggml_tensor * tensor) {
+static ggml_status ggml_backend_cpu_aarch64_buffer_init_tensor(ggml_backend_buffer_t buffer, struct ggml_tensor * tensor) {
     tensor->extra = (void *) const_cast<ggml::cpu::tensor_traits *>(ggml_aarch64_get_optimal_repack_type(tensor));
 
     GGML_UNUSED(buffer);
+    return GGML_STATUS_SUCCESS;
 }
 
 static void ggml_backend_cpu_aarch64_buffer_set_tensor(ggml_backend_buffer_t buffer, struct ggml_tensor * tensor,

src/ggml-cuda/common.cuh

@@ -79,18 +79,19 @@
 
 #define GGML_CUDA_MAX_STREAMS 8
 
-[[noreturn]]
-void ggml_cuda_error(const char * stmt, const char * func, const char * file, int line, const char * msg);
+// Print the error. Will also abort if abort true
+void ggml_cuda_error(const char * stmt, const char * func, const char * file, int line, const char * msg, bool abort);
 
-#define CUDA_CHECK_GEN(err, success, error_fn)                                      \
+#define CUDA_CHECK_GEN(err, success, error_fn, abort)                                      \
      do {                                                                           \
         auto err_ = (err);                                                          \
         if (err_ != (success)) {                                                    \
-            ggml_cuda_error(#err, __func__, __FILE__, __LINE__, error_fn(err_));    \
+            ggml_cuda_error(#err, __func__, __FILE__, __LINE__, error_fn(err_), abort);    \
         }                                                                           \
     } while (0)
 
-#define CUDA_CHECK(err) CUDA_CHECK_GEN(err, cudaSuccess, cudaGetErrorString)
+#define CUDA_CHECK(err) CUDA_CHECK_GEN(err, cudaSuccess, cudaGetErrorString, true)
+#define CUDA_CHECK_NO_ABORT(err) CUDA_CHECK_GEN(err, cudaSuccess, cudaGetErrorString, false)
 
 #if CUDART_VERSION >= 12000 || defined(GGML_USE_MUSA)
     static const char * cublas_get_error_str(const cublasStatus_t err) {
@@ -113,15 +114,16 @@ void ggml_cuda_error(const char * stmt, const char * func, const char * file, in
     }
 #endif // CUDART_VERSION >= 12000
 
-#define CUBLAS_CHECK(err) CUDA_CHECK_GEN(err, CUBLAS_STATUS_SUCCESS, cublas_get_error_str)
+#define CUBLAS_CHECK(err) CUDA_CHECK_GEN(err, CUBLAS_STATUS_SUCCESS, cublas_get_error_str, true)
 
 #if !defined(GGML_USE_HIP)
 static const char * cu_get_error_str(CUresult err) {
     const char * err_str;
     cuGetErrorString(err, &err_str);
     return err_str;
 }
-#define CU_CHECK(err) CUDA_CHECK_GEN(err, CUDA_SUCCESS, cu_get_error_str)
+// Will print error and abort
+#define CU_CHECK(err) CUDA_CHECK_GEN(err, CUDA_SUCCESS, cu_get_error_str, true)
 #endif
 
 #if CUDART_VERSION >= 11100 || defined(GGML_USE_MUSA)