llama: print memory breakdown on exit (ggml-org#15860)

* llama: print memory breakdown on exit

Author: JohannesGaessler

common/sampling.cpp

@@ -332,6 +332,7 @@ void common_perf_print(const struct llama_context * ctx, const struct common_sam
     }
     if (ctx) {
         llama_perf_context_print(ctx);
+        llama_memory_breakdown_print(ctx);
     }
 }
 

ggml/include/ggml-backend.h

@@ -314,7 +314,8 @@ extern "C" {
     GGML_API int                  ggml_backend_sched_get_n_splits(ggml_backend_sched_t sched);
     GGML_API int                  ggml_backend_sched_get_n_copies(ggml_backend_sched_t sched);
 
-    GGML_API size_t               ggml_backend_sched_get_buffer_size(ggml_backend_sched_t sched, ggml_backend_t backend);
+    GGML_API ggml_backend_buffer_type_t ggml_backend_sched_get_buffer_type(ggml_backend_sched_t sched, ggml_backend_t backend);
+    GGML_API size_t                     ggml_backend_sched_get_buffer_size(ggml_backend_sched_t sched, ggml_backend_t backend);
 
     GGML_API void                 ggml_backend_sched_set_tensor_backend(ggml_backend_sched_t sched, struct ggml_tensor * node, ggml_backend_t backend);
     GGML_API ggml_backend_t       ggml_backend_sched_get_tensor_backend(ggml_backend_sched_t sched, struct ggml_tensor * node);

ggml/src/ggml-backend.cpp

@@ -1793,6 +1793,14 @@ ggml_backend_t ggml_backend_sched_get_backend(ggml_backend_sched_t sched, int i)
     return sched->backends[i];
 }
 
+ggml_backend_buffer_type_t ggml_backend_sched_get_buffer_type(ggml_backend_sched_t sched, ggml_backend_t backend) {
+    GGML_ASSERT(sched);
+    int backend_index = ggml_backend_sched_backend_id(sched, backend);
+    GGML_ASSERT(backend_index >= 0 && backend_index < sched->n_backends);
+
+    return sched->bufts[backend_index];
+}
+
 size_t ggml_backend_sched_get_buffer_size(ggml_backend_sched_t sched, ggml_backend_t backend) {
     GGML_ASSERT(sched);
     int backend_index = ggml_backend_sched_backend_id(sched, backend);

include/llama.h

@@ -1329,24 +1329,25 @@ extern "C" {
     //
     // Performance utils
     //
-    // NOTE: Used by llama.cpp examples, avoid using in third-party apps. Instead, do your own performance measurements.
+    // NOTE: Used by llama.cpp examples/tools, avoid using in third-party apps. Instead, do your own performance measurements.
     //
 
     struct llama_perf_context_data {
-        double t_start_ms;
-        double t_load_ms;
-        double t_p_eval_ms;
-        double t_eval_ms;
-
-        int32_t n_p_eval;
-        int32_t n_eval;
-        int32_t n_reused; // number of times a ggml compute graph had been reused
+        // ms == milliseconds
+        double t_start_ms;  // absolute start time
+        double t_load_ms;   // time needed for loading the model
+        double t_p_eval_ms; // time needed for processing the prompt
+        double t_eval_ms;   // time needed for generating tokens
+
+        int32_t n_p_eval;   // number of prompt tokens
+        int32_t n_eval;     // number of generated tokens
+        int32_t n_reused;   // number of times a ggml compute graph had been reused
     };
 
     struct llama_perf_sampler_data {
-        double t_sample_ms;
+        double t_sample_ms; // time needed for sampling in ms
 
-        int32_t n_sample;
+        int32_t n_sample;   // number of sampled tokens
     };
 
     LLAMA_API struct llama_perf_context_data llama_perf_context      (const struct llama_context * ctx);
@@ -1358,6 +1359,9 @@ extern "C" {
     LLAMA_API void                           llama_perf_sampler_print(const struct llama_sampler * chain);
     LLAMA_API void                           llama_perf_sampler_reset(      struct llama_sampler * chain);
 
+    // print a breakdown of per-device memory use via LLAMA_LOG:
+    LLAMA_API void llama_memory_breakdown_print(const struct llama_context * ctx);
+
     //
     // training
     //

src/llama-context.cpp

@@ -2027,6 +2027,21 @@ void llama_context::perf_reset() {
     n_reused    = 0;
 }
 
+std::map<ggml_backend_buffer_type_t, llama_memory_breakdown_data> llama_context::memory_breakdown() const {
+    std::map<ggml_backend_buffer_type_t, llama_memory_breakdown_data> ret;
+    for (const auto & buft_size : model.memory_breakdown()) {
+        ret[buft_size.first].model += buft_size.second;
+    }
+    for (const auto & buft_size : memory->memory_breakdown()) {
+        ret[buft_size.first].context += buft_size.second;
+    }
+    for (const auto & backend_ptr : backends) {
+        ggml_backend_t backend = backend_ptr.get();
+        ret[ggml_backend_sched_get_buffer_type(sched.get(), backend)].compute += ggml_backend_sched_get_buffer_size(sched.get(), backend);
+    }
+    return ret;
+}
+
 //
 // training
 //
@@ -2765,6 +2780,142 @@ void llama_perf_context_reset(llama_context * ctx) {
     ctx->perf_reset();
 }
 
+void llama_memory_breakdown_print(const struct llama_context * ctx) {
+    const std::vector<ggml_backend_dev_t> & devices = ctx->get_model().devices;
+
+    std::map<ggml_backend_buffer_type_t, llama_memory_breakdown_data> memory_breakdown = ctx->memory_breakdown();
+
+    std::vector<std::array<std::string, 9>> table_data;
+    table_data.reserve(devices.size());
+    const std::string template_header = "%s: | %s | %s   %s    %s   %s   %s   %s    %s |\n";
+    const std::string template_gpu    = "%s: | %s | %s = %s + (%s = %s + %s + %s) + %s |\n";
+    const std::string template_other  = "%s: | %s | %s   %s    %s = %s + %s + %s    %s |\n";
+
+    table_data.push_back({template_header, "memory breakdown [MiB]", "total", "free", "self", "model", "context", "compute", "unaccounted"});
+
+    constexpr size_t MiB = 1024 * 1024;
+    const std::vector<std::string> desc_prefixes_strip = {"NVIDIA ", "GeForce ", "Tesla ", "AMD ", "Radeon ", "Instinct "};
+
+    // track seen buffer types to avoid double counting:
+    std::set<ggml_backend_buffer_type_t> seen_buffer_types;
+
+    // accumulative memory breakdown for each device and for host:
+    std::vector<llama_memory_breakdown_data> mb_dev(devices.size());
+    llama_memory_breakdown_data              mb_host;
+
+    for (const auto & buft_mb : memory_breakdown) {
+        ggml_backend_buffer_type_t          buft = buft_mb.first;
+        const llama_memory_breakdown_data & mb   = buft_mb.second;
+        if (ggml_backend_buft_is_host(buft)) {
+            mb_host.model   += mb.model;
+            mb_host.context += mb.context;
+            mb_host.compute += mb.compute;
+            seen_buffer_types.insert(buft);
+            continue;
+        }
+        ggml_backend_dev_t dev = ggml_backend_buft_get_device(buft);
+        if (dev) {
+            int i_dev = -1;
+            for (size_t i = 0; i < devices.size(); i++) {
+                if (devices[i] == dev) {
+                    i_dev = i;
+                    break;
+                }
+            }
+            if (i_dev != -1) {
+                mb_dev[i_dev].model   += mb.model;
+                mb_dev[i_dev].context += mb.context;
+                mb_dev[i_dev].compute += mb.compute;
+                seen_buffer_types.insert(buft);
+                continue;
+            }
+        }
+    }
+
+    // print memory breakdown for each device:
+    for (size_t i = 0; i < devices.size(); i++) {
+        ggml_backend_dev_t          dev = devices[i];
+        llama_memory_breakdown_data mb  = mb_dev[i];
+
+        const std::string name = ggml_backend_dev_name(dev);
+        std::string desc = ggml_backend_dev_description(dev);
+        for (const std::string & prefix : desc_prefixes_strip) {
+            if (desc.length() >= prefix.length() && desc.substr(0, prefix.length()) == prefix) {
+                desc = desc.substr(prefix.length());
+            }
+        }
+
+        size_t free, total;
+        ggml_backend_dev_memory(dev, &free, &total);
+
+        const size_t self = mb.model + mb.context + mb.compute;
+        const size_t unaccounted = total - self - free;
+
+        table_data.push_back({
+            template_gpu,
+            "  - " + name + " (" + desc + ")",
+            std::to_string(total / MiB),
+            std::to_string(free / MiB),
+            std::to_string(self / MiB),
+            std::to_string(mb.model / MiB),
+            std::to_string(mb.context / MiB),
+            std::to_string(mb.compute / MiB),
+            std::to_string(unaccounted / MiB)});
+    }
+
+    // print memory breakdown for host:
+    {
+        const size_t self = mb_host.model + mb_host.context + mb_host.compute;
+        table_data.push_back({
+            template_other,
+            "  - Host",
+            "", // total
+            "", // free
+            std::to_string(self / MiB),
+            std::to_string(mb_host.model / MiB),
+            std::to_string(mb_host.context / MiB),
+            std::to_string(mb_host.compute / MiB),
+            ""}); // unaccounted
+    }
+
+    // print memory breakdown for all remaining buffer types:
+    for (const auto & buft_mb : memory_breakdown) {
+        ggml_backend_buffer_type_t          buft = buft_mb.first;
+        const llama_memory_breakdown_data & mb   = buft_mb.second;
+        if (seen_buffer_types.count(buft) == 1) {
+            continue;
+        }
+        const std::string name = ggml_backend_buft_name(buft);
+        const size_t self = mb.model + mb.context + mb.compute;
+        table_data.push_back({
+            template_other,
+            "  - " + name,
+            "", // total
+            "", // free
+            std::to_string(self / MiB),
+            std::to_string(mb.model / MiB),
+            std::to_string(mb.context / MiB),
+            std::to_string(mb.compute / MiB),
+            ""}); // unaccounted
+        seen_buffer_types.insert(buft);
+    }
+
+    for (size_t j = 1; j < table_data[0].size(); j++) {
+        size_t max_len = 0;
+        for (const auto & td : table_data) {
+            max_len = std::max(max_len, td[j].length());
+        }
+        for (auto & td : table_data) {
+            td[j].insert(j == 1 ? td[j].length() : 0, max_len - td[j].length(), ' ');
+        }
+    }
+    for (const auto & td : table_data) {
+        LLAMA_LOG_INFO(td[0].c_str(),
+            __func__, td[1].c_str(), td[2].c_str(), td[3].c_str(), td[4].c_str(), td[5].c_str(),
+            td[6].c_str(), td[7].c_str(), td[8].c_str());
+    }
+}
+
 //
 // training
 //

src/llama-context.h

@@ -17,9 +17,17 @@ class llama_batch_allocr;
 class llama_io_read_i;
 class llama_io_write_i;
 
+// "memory" as in abstract memory for the context
 struct llama_memory_i;
 struct llama_memory_context_i;
 
+// "memory" as in physical memory for a buffer type, in bytes
+struct llama_memory_breakdown_data {
+    size_t model   = 0; // memory allocated for the model
+    size_t context = 0; // memory allocated for the context
+    size_t compute = 0; // memory allocated for temporary compute buffers
+};
+
 struct llama_context {
     // init scheduler and compute buffers, reserve worst-case graphs
     llama_context(
@@ -144,6 +152,8 @@ struct llama_context {
     llama_perf_context_data perf_get_data() const;
     void perf_reset();
 
+    std::map<ggml_backend_buffer_type_t, llama_memory_breakdown_data> memory_breakdown() const;
+
     //
     // training
     //

src/llama-kv-cache-iswa.cpp

@@ -113,6 +113,14 @@ llama_pos llama_kv_cache_iswa::seq_pos_max(llama_seq_id seq_id) const {
     return kv_swa->seq_pos_max(seq_id);
 }
 
+std::map<ggml_backend_buffer_type_t, size_t> llama_kv_cache_iswa::memory_breakdown() const {
+    std::map<ggml_backend_buffer_type_t, size_t> mb = kv_base->memory_breakdown();
+    for (const auto & buft_size : kv_swa->memory_breakdown()) {
+        mb[buft_size.first] += buft_size.second;
+    }
+    return mb;
+}
+
 llama_memory_context_ptr llama_kv_cache_iswa::init_batch(llama_batch_allocr & balloc, uint32_t n_ubatch, bool embd_all) {
     GGML_UNUSED(embd_all);
 

src/llama-kv-cache-iswa.h

@@ -56,6 +56,8 @@ class llama_kv_cache_iswa : public llama_memory_i {
     llama_pos seq_pos_min(llama_seq_id seq_id) const override;
     llama_pos seq_pos_max(llama_seq_id seq_id) const override;
 
+    std::map<ggml_backend_buffer_type_t, size_t> memory_breakdown() const override;
+
     // state write/load
 
     void state_write(llama_io_write_i & io, llama_seq_id seq_id = -1, llama_state_seq_flags flags = 0) const override;

src/llama-kv-cache.cpp

@@ -473,6 +473,14 @@ llama_pos llama_kv_cache::seq_pos_max(llama_seq_id seq_id) const {
     return cells.seq_pos_max(seq_id);
 }
 
+std::map<ggml_backend_buffer_type_t, size_t> llama_kv_cache::memory_breakdown() const {
+    std::map<ggml_backend_buffer_type_t, size_t> ret;
+    for (const ggml_backend_buffer_ptr & buf_ptr : bufs) {
+        ret[ggml_backend_buffer_get_type(buf_ptr.get())] += ggml_backend_buffer_get_size(buf_ptr.get());
+    }
+    return ret;
+}
+
 llama_memory_context_ptr llama_kv_cache::init_batch(
             llama_batch_allocr & balloc,
             uint32_t n_ubatch,

src/llama-kv-cache.h

@@ -121,6 +121,8 @@ class llama_kv_cache : public llama_memory_i {
     llama_pos seq_pos_min(llama_seq_id seq_id) const override;
     llama_pos seq_pos_max(llama_seq_id seq_id) const override;
 
+    std::map<ggml_backend_buffer_type_t, size_t> memory_breakdown() const override;
+
     // state write/load
 
     void state_write(llama_io_write_i & io, llama_seq_id seq_id = -1, llama_state_seq_flags flags = 0) const override;