ggml : add NUMA support (#1556)

* detect NUMA systems and pin work threads to nodes (linux)

* disable mmap prefetch/readahead for NUMA systems

* avoid sending finalize op to thread pool if it does nothing

* silence robot

* fix args

* make --numa a param

* recommendation that n_nodes evenly divide n_threads did not warrant such aggressive enforcement

* lower synchronization overhead

* statically allocate

* move numa state to g_state

* add description for --numa

* ggml : minor style changes

* ggml : minor style + try fix sanitizer build

* llama : allow to initialize backend with NUMA support

* llama : avoid ggml include in llama-util.h

* ggml : style / formatting

* ggml : fix handling of ops with n_threads > n_tasks > 1

* server : utilize numa parameter

---------

Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>

examples/common.cpp

@@ -343,6 +343,8 @@ bool gpt_params_parse(int argc, char ** argv, gpt_params & params) {
             params.use_mmap = false;
         } else if (arg == "--mtest") {
             params.mem_test = true;
+        } else if (arg == "--numa") {
+            params.numa = true;
         } else if (arg == "--export") {
             params.export_cgraph = true;
         } else if (arg == "--verbose-prompt") {
@@ -488,6 +490,9 @@ void gpt_print_usage(int /*argc*/, char ** argv, const gpt_params & params) {
     if (llama_mmap_supported()) {
         fprintf(stderr, "  --no-mmap             do not memory-map model (slower load but may reduce pageouts if not using mlock)\n");
     }
+    fprintf(stderr, "  --numa                attempt optimizations that help on some NUMA systems\n");
+    fprintf(stderr, "                        if run without this previously, it is recommended to drop the system page cache before using this\n");
+    fprintf(stderr, "                        see https://github.com/ggerganov/llama.cpp/issues/1437\n");
 #ifdef LLAMA_SUPPORTS_GPU_OFFLOAD
     fprintf(stderr, "  -ngl N, --n-gpu-layers N\n");
     fprintf(stderr, "                        number of layers to store in VRAM\n");

examples/common.h

@@ -76,6 +76,7 @@ struct gpt_params {
     bool use_mmap          = true;  // use mmap for faster loads
     bool use_mlock         = false; // use mlock to keep model in memory
     bool mem_test          = false; // compute maximum memory usage
+    bool numa              = false; // attempt optimizations that help on some NUMA systems
     bool export_cgraph     = false; // export the computation graph
     bool verbose_prompt    = false; // print prompt tokens before generation
 };

examples/embedding/embedding.cpp

@@ -35,7 +35,7 @@ int main(int argc, char ** argv) {
         params.prompt = gpt_random_prompt(rng);
     }
 
-    llama_init_backend();
+    llama_init_backend(params.numa);
 
     llama_model * model;
     llama_context * ctx;

examples/main/README.md

@@ -262,6 +262,10 @@ These options help improve the performance and memory usage of the LLaMA models.
 
 -   `--no-mmap`: Do not memory-map the model. By default, models are mapped into memory, which allows the system to load only the necessary parts of the model as needed. However, if the model is larger than your total amount of RAM or if your system is low on available memory, using mmap might increase the risk of pageouts, negatively impacting performance. Disabling mmap results in slower load times but may reduce pageouts if you're not using `--mlock`. Note that if the model is larger than the total amount of RAM, turning off mmap would prevent the model from loading at all.
 
+### NUMA support
+
+-   `--numa`: Attempt optimizations that help on some systems with non-uniform memory access. This currently consists of pinning an equal proportion of the threads to the cores on each NUMA node, and disabling prefetch and readahead for mmap. The latter causes mapped pages to be faulted in on first access instead of all at once, and in combination with pinning threads to NUMA nodes, more of the pages end up on the NUMA node where they are used. Note that if the model is already in the system page cache, for example because of a previous run without this option, this will have little effect unless you drop the page cache first. This can be done by rebooting the system or on Linux by writing '3' to '/proc/sys/vm/drop\_caches' as root.
+
 ### Memory Float 32
 
 -   `--memory-f32`: Use 32-bit floats instead of 16-bit floats for memory key+value. This doubles the context memory requirement and cached prompt file size but does not appear to increase generation quality in a measurable way. Not recommended.

examples/main/main.cpp

@@ -105,7 +105,7 @@ int main(int argc, char ** argv) {
         params.prompt = gpt_random_prompt(rng);
     }
 
-    llama_init_backend();
+    llama_init_backend(params.numa);
 
     llama_model * model;
     llama_context * ctx;

examples/perplexity/perplexity.cpp

@@ -147,7 +147,7 @@ int main(int argc, char ** argv) {
         params.prompt = gpt_random_prompt(rng);
     }
 
-    llama_init_backend();
+    llama_init_backend(params.numa);
 
     llama_model * model;
     llama_context * ctx;

examples/quantize/quantize.cpp

@@ -180,7 +180,7 @@ int main(int argc, char ** argv) {
         usage(argv[0]);
     }
 
-    llama_init_backend();
+    llama_init_backend(false);
 
     // parse command line arguments
     const std::string fname_inp = argv[arg_idx];

examples/server/server.cpp

@@ -789,7 +789,7 @@ int main(int argc, char ** argv) {
         params.model_alias = params.model;
     }
 
-    llama_init_backend();
+    llama_init_backend(params.numa);
 
     LOG_INFO("build info", {
         { "build", BUILD_NUMBER },

examples/simple/simple.cpp

@@ -66,7 +66,7 @@ int main(int argc, char ** argv)
     // Init LLM :
     //---------------------------------
 
-    llama_init_backend();
+    llama_init_backend(params.numa);
 
     llama_model * model;
     llama_context * ctx;

ggml.c

@@ -91,6 +91,11 @@ static int sched_yield (void) {
 #include <stdatomic.h>
 
 typedef void* thread_ret_t;
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
 #endif
 
 // __FMA__ and __F16C__ are not defined in MSVC, however they are implied with AVX2/AVX512
@@ -119,6 +124,30 @@ typedef void* thread_ret_t;
 #define GGML_SOFT_MAX_UNROLL 4
 #define GGML_VEC_DOT_UNROLL  2
 
+//
+// logging
+//
+
+#if (GGML_DEBUG >= 1)
+#define GGML_PRINT_DEBUG(...) printf(__VA_ARGS__)
+#else
+#define GGML_PRINT_DEBUG(...)
+#endif
+
+#if (GGML_DEBUG >= 5)
+#define GGML_PRINT_DEBUG_5(...) printf(__VA_ARGS__)
+#else
+#define GGML_PRINT_DEBUG_5(...)
+#endif
+
+#if (GGML_DEBUG >= 10)
+#define GGML_PRINT_DEBUG_10(...) printf(__VA_ARGS__)
+#else
+#define GGML_PRINT_DEBUG_10(...)
+#endif
+
+#define GGML_PRINT(...) printf(__VA_ARGS__)
+
 #ifdef GGML_USE_ACCELERATE
 // uncomment to use vDSP for soft max computation
 // note: not sure if it is actually faster
@@ -459,7 +488,6 @@ void ggml_fp32_to_fp16_row(const float * x, ggml_fp16_t * y, size_t n) {
     }
 }
 
-
 //
 // timing
 //
@@ -522,6 +550,7 @@ int64_t ggml_cycles_per_ms(void) {
 #define ggml_perf_cycles_per_ms() 0
 #endif
 
+
 //
 // cache line
 //
@@ -3843,12 +3872,31 @@ struct ggml_context_container {
     struct ggml_context context;
 };
 
+//
+// NUMA support
+//
+
+#define GGML_NUMA_MAX_NODES 8
+#define GGML_NUMA_MAX_CPUS 512
+
+struct ggml_numa_node {
+    uint32_t cpus[GGML_NUMA_MAX_CPUS]; // hardware threads on this node
+    uint32_t n_cpus;
+};
+
+struct ggml_numa_nodes {
+    struct ggml_numa_node nodes[GGML_NUMA_MAX_NODES];
+    uint32_t n_nodes;
+    uint32_t total_cpus; // hardware threads on system
+};
+
 //
 // ggml state
 //
 
 struct ggml_state {
     struct ggml_context_container contexts[GGML_MAX_CONTEXTS];
+    struct ggml_numa_nodes numa;
 };
 
 // global state
@@ -3873,6 +3921,75 @@ inline static void ggml_critical_section_end(void) {
     atomic_fetch_sub(&g_state_barrier, 1);
 }
 
+void ggml_numa_init(void) {
+    if (g_state.numa.n_nodes > 0) {
+        fprintf(stderr, "ggml_numa_init: NUMA already initialized\n");
+
+        return;
+    }
+
+#ifdef __linux__
+    struct stat st;
+    char path[256];
+    int rv;
+
+    // enumerate nodes
+    while (g_state.numa.n_nodes < GGML_NUMA_MAX_NODES) {
+        rv = snprintf(path, sizeof(path), "/sys/devices/system/node/node%u", g_state.numa.n_nodes);
+        GGML_ASSERT(rv > 0 && (unsigned)rv < sizeof(path));
+        if (stat(path, &st) != 0) { break; }
+        ++g_state.numa.n_nodes;
+    }
+
+    // enumerate CPUs
+    while (g_state.numa.total_cpus < GGML_NUMA_MAX_CPUS) {
+        rv = snprintf(path, sizeof(path), "/sys/devices/system/cpu/cpu%u", g_state.numa.total_cpus);
+        GGML_ASSERT(rv > 0 && (unsigned)rv < sizeof(path));
+        if (stat(path, &st) != 0) { break; }
+        ++g_state.numa.total_cpus;
+    }
+
+    GGML_PRINT_DEBUG("found %u numa nodes, %u CPUs\n", g_state.numa.n_nodes, g_state.numa.total_cpus);
+
+    if (g_state.numa.n_nodes < 1 || g_state.numa.total_cpus < 1) {
+        g_state.numa.n_nodes = 0;
+        return;
+    }
+
+    for (uint32_t n = 0; n < g_state.numa.n_nodes; ++n) {
+        struct ggml_numa_node * node = &g_state.numa.nodes[n];
+        GGML_PRINT_DEBUG("CPUs on node %u:", n);
+        node->n_cpus = 0;
+        for (uint32_t c = 0; c < g_state.numa.total_cpus; ++c) {
+            rv = snprintf(path, sizeof(path), "/sys/devices/system/node/node%u/cpu%u", n, c);
+            GGML_ASSERT(rv > 0 && (unsigned)rv < sizeof(path));
+            if (stat(path, &st) == 0) {
+                node->cpus[node->n_cpus++] = c;
+                GGML_PRINT_DEBUG(" %u", c);
+            }
+        }
+        GGML_PRINT_DEBUG("\n");
+    }
+
+    if (ggml_is_numa()) {
+        FILE *fptr = fopen("/proc/sys/kernel/numa_balancing", "r");
+        if (fptr != NULL) {
+            char buf[42];
+            if (fgets(buf, sizeof(buf), fptr) && strncmp(buf, "0\n", sizeof(buf)) != 0) {
+                GGML_PRINT("WARNING: /proc/sys/kernel/numa_balancing is enabled, this has been observed to impair performance\n");
+            }
+            fclose(fptr);
+        }
+    }
+#else
+    // TODO
+#endif
+}
+
+bool ggml_is_numa(void) {
+    return g_state.numa.n_nodes > 1;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 
 void ggml_print_object(const struct ggml_object * obj) {
@@ -4129,6 +4246,10 @@ struct ggml_context * ggml_init(struct ggml_init_params params) {
 
             g_state = (struct ggml_state) {
                 /*.contexts =*/ { { 0 } },
+                /*.numa =*/ {
+                    .n_nodes = 0,
+                    .total_cpus = 0,
+                },
             };
 
             for (int i = 0; i < GGML_MAX_CONTEXTS; ++i) {
@@ -16504,68 +16625,172 @@ typedef pthread_t ggml_thread_t;
 
 #endif
 
+#ifdef __linux__
+void set_numa_thread_affinity(int thread_n, int n_threads) {
+    if (!ggml_is_numa()) {
+        return;
+    }
+
+    // run thread on node_num thread_n / (threads per node)
+    const int node_num = thread_n / ((n_threads + g_state.numa.n_nodes - 1) / g_state.numa.n_nodes);
+    struct ggml_numa_node * node = &g_state.numa.nodes[node_num];
+    size_t setsize = CPU_ALLOC_SIZE(g_state.numa.total_cpus);
+
+    cpu_set_t * cpus = CPU_ALLOC(g_state.numa.total_cpus);
+    CPU_ZERO_S(setsize, cpus);
+    for (size_t i = 0; i < node->n_cpus; ++i) {
+        CPU_SET_S(node->cpus[i], setsize, cpus);
+    }
+
+    int rv = pthread_setaffinity_np(pthread_self(), setsize, cpus);
+    if (rv) {
+            fprintf(stderr, "warning: pthread_setaffinity_np() failed: %s\n",
+                    strerror(rv));
+    }
+
+    CPU_FREE(cpus);
+}
+
+void clear_numa_thread_affinity(void) {
+    if (!ggml_is_numa()) {
+        return;
+    }
+
+    size_t setsize = CPU_ALLOC_SIZE(g_state.numa.total_cpus);
+
+    cpu_set_t * cpus = CPU_ALLOC(g_state.numa.total_cpus);
+    CPU_ZERO_S(setsize, cpus);
+    for (unsigned i = 0; i < g_state.numa.total_cpus; ++i) {
+        CPU_SET_S(i, setsize, cpus);
+    }
+
+    int rv = pthread_setaffinity_np(pthread_self(), setsize, cpus);
+    if (rv) {
+        fprintf(stderr, "warning: pthread_setaffinity_np() failed: %s\n",
+            strerror(rv));
+    }
+
+    CPU_FREE(cpus);
+}
+#else
+// TODO: Windows etc.
+// (the linux implementation may also work on BSD, someone should test)
+void set_numa_thread_affinity(int thread_n, int n_threads) { UNUSED(thread_n); UNUSED(n_threads);  }
+void clear_numa_thread_affinity(void) {}
+#endif
+
 struct ggml_compute_state_shared {
-    ggml_lock_t spin;
+    struct ggml_cgraph * cgraph;
+
+    int64_t perf_node_start_cycles;
+    int64_t perf_node_start_time_us;
 
     int n_threads;
 
     // synchronization primitives
-    atomic_int  n_ready;
-    atomic_bool has_work;
-    atomic_bool stop; // stop all threads
+    atomic_int n_active; // num active threads
+    atomic_int node_n;   // active graph node
 };
 
 struct ggml_compute_state {
     ggml_thread_t thrd;
-
-    struct ggml_compute_params params;
-    struct ggml_tensor * node;
-
+    int ith;
     struct ggml_compute_state_shared * shared;
 };
 
+static void ggml_graph_compute_perf_stats_node(struct ggml_tensor * node, const struct ggml_compute_state_shared * st) {
+    int64_t cycles_cur  = ggml_perf_cycles()  - st->perf_node_start_cycles;
+    int64_t time_us_cur = ggml_perf_time_us() - st->perf_node_start_time_us;
+
+    node->perf_runs++;
+    node->perf_cycles  += cycles_cur;
+    node->perf_time_us += time_us_cur;
+}
+
 static thread_ret_t ggml_graph_compute_thread(void * data) {
     struct ggml_compute_state * state = (struct ggml_compute_state *) data;
+    struct ggml_cgraph * cgraph = state->shared->cgraph;
 
     const int n_threads = state->shared->n_threads;
+    set_numa_thread_affinity(state->ith, n_threads);
+
+    int node_n = -1;
 
     while (true) {
-        if (atomic_fetch_add(&state->shared->n_ready, 1) == n_threads - 1) {
-            atomic_store(&state->shared->has_work, false);
-        } else {
-            while (atomic_load(&state->shared->has_work)) {
-                if (atomic_load(&state->shared->stop)) {
-                    return 0;
+        if (atomic_fetch_sub(&state->shared->n_active, 1) == 1) {
+            // all other threads are finished and spinning
+            // do finalize and init here so we don't have synchronize again
+            struct ggml_compute_params params = {
+                /*.type  =*/ GGML_TASK_FINALIZE,
+                /*.ith   =*/ 0,
+                /*.nth   =*/ 0,
+                /*.wsize =*/ cgraph->work ? ggml_nbytes(cgraph->work) : 0,
+                /*.wdata =*/ cgraph->work ? cgraph->work->data : NULL,
+            };
+
+            if (node_n != -1) {
+                /* FINALIZE */
+                struct ggml_tensor * node = state->shared->cgraph->nodes[node_n];
+                params.nth = node->n_tasks;
+                ggml_compute_forward(&params, node);
+                ggml_graph_compute_perf_stats_node(node, state->shared);
+            }
+
+            // distribute new work or execute it direct if 1T
+            while (++node_n < cgraph->n_nodes) {
+                GGML_PRINT_DEBUG_5("%s: %d/%d\n", __func__, node_n, cgraph->n_nodes);
+
+                struct ggml_tensor * node = cgraph->nodes[node_n];
+
+                state->shared->perf_node_start_cycles  = ggml_perf_cycles();
+                state->shared->perf_node_start_time_us = ggml_perf_time_us();
+
+                /* INIT */
+                params.type = GGML_TASK_INIT;
+                params.nth  = node->n_tasks;
+                ggml_compute_forward(&params, node);
+
+                if (node->n_tasks == 1) {
+                    // TODO: maybe push node_n to the atomic but if other threads see n_tasks is 1,
+                    // they do something more efficient than spinning (?)
+                    params.type = GGML_TASK_COMPUTE;
+                    ggml_compute_forward(&params, node);
+
+                    params.type = GGML_TASK_FINALIZE;
+                    ggml_compute_forward(&params, node);
+                    ggml_graph_compute_perf_stats_node(node, state->shared);
+                } else {
+                    break;
                 }
-                ggml_lock_lock  (&state->shared->spin);
-                ggml_lock_unlock(&state->shared->spin);
             }
-        }
 
-        atomic_fetch_sub(&state->shared->n_ready, 1);
-
-        // wait for work
-        while (!atomic_load(&state->shared->has_work)) {
-            if (atomic_load(&state->shared->stop)) {
-                return 0;
-            }
-            ggml_lock_lock  (&state->shared->spin);
-            ggml_lock_unlock(&state->shared->spin);
+            atomic_store(&state->shared->n_active, n_threads);
+            atomic_store(&state->shared->node_n,   node_n);
+        } else {
+            // wait for other threads to finish
+            const int last = node_n;
+            do {
+                sched_yield();
+                node_n = atomic_load(&state->shared->node_n);
+            } while (node_n == last);
         }
 
         // check if we should stop
-        if (atomic_load(&state->shared->stop)) {
-            break;
-        }
+        if (node_n >= cgraph->n_nodes) break;
 
-        if (state->node) {
-            if (state->params.ith < state->params.nth) {
-                ggml_compute_forward(&state->params, state->node);
-            }
+        /* COMPUTE */
+        struct ggml_tensor * node = cgraph->nodes[node_n];
 
-            state->node = NULL;
-        } else {
-            break;
+        struct ggml_compute_params params = {
+            /*.type  =*/ GGML_TASK_COMPUTE,
+            /*.ith   =*/ state->ith,
+            /*.nth   =*/ node->n_tasks,
+            /*.wsize =*/ cgraph->work ? ggml_nbytes(cgraph->work) : 0,
+            /*.wdata =*/ cgraph->work ? cgraph->work->data : NULL,
+        };
+
+        if (state->ith < node->n_tasks) {
+            ggml_compute_forward(&params, node);
         }
     }
 
@@ -16576,39 +16801,14 @@ void ggml_graph_compute(struct ggml_context * ctx, struct ggml_cgraph * cgraph)
     const int n_threads = cgraph->n_threads;
 
     struct ggml_compute_state_shared state_shared = {
-        /*.spin      =*/ GGML_LOCK_INITIALIZER,
-        /*.n_threads =*/ n_threads,
-        /*.n_ready   =*/ 0,
-        /*.has_work  =*/ false,
-        /*.stop      =*/ false,
+        /*.cgraph                  =*/ cgraph,
+        /*.perf_node_start_cycles  =*/ 0,
+        /*.perf_node_start_time_us =*/ 0,
+        /*.n_threads               =*/ n_threads,
+        /*.n_active                =*/ n_threads,
+        /*.node_n                  =*/ -1,
     };
-    struct ggml_compute_state * workers = n_threads > 1 ? alloca(sizeof(struct ggml_compute_state)*(n_threads - 1)) : NULL;
-
-    // create thread pool
-    if (n_threads > 1) {
-        ggml_lock_init(&state_shared.spin);
-
-        atomic_store(&state_shared.has_work, true);
-
-        for (int j = 0; j < n_threads - 1; j++) {
-            workers[j] = (struct ggml_compute_state) {
-                .thrd   = 0,
-                .params = {
-                    .type  = GGML_TASK_COMPUTE,
-                    .ith   = j + 1,
-                    .nth   = n_threads,
-                    .wsize = cgraph->work ? ggml_nbytes(cgraph->work) : 0,
-                    .wdata = cgraph->work ? cgraph->work->data : NULL,
-                },
-                .node   = NULL,
-                .shared = &state_shared,
-            };
-
-            int rc = ggml_thread_create(&workers[j].thrd, NULL, ggml_graph_compute_thread, &workers[j]);
-            GGML_ASSERT(rc == 0);
-            UNUSED(rc);
-        }
-    }
+    struct ggml_compute_state * workers = alloca(sizeof(struct ggml_compute_state)*n_threads);
 
     // initialize tasks + work buffer
     {
@@ -16752,7 +16952,7 @@ void ggml_graph_compute(struct ggml_context * ctx, struct ggml_cgraph * cgraph)
                     } break;
                 case GGML_OP_SCALE:
                     {
-                        node->n_tasks = n_threads;
+                        node->n_tasks = 1;
                     } break;
                 case GGML_OP_SET:
                 case GGML_OP_CONT:
@@ -16956,166 +17156,37 @@ void ggml_graph_compute(struct ggml_context * ctx, struct ggml_cgraph * cgraph)
         }
     }
 
+    // create thread pool
+    if (n_threads > 1) {
+        for (int j = 1; j < n_threads; ++j) {
+            workers[j] = (struct ggml_compute_state) {
+                .thrd   = 0,
+                .ith = j,
+                .shared = &state_shared,
+            };
+
+            const int rc = ggml_thread_create(&workers[j].thrd, NULL, ggml_graph_compute_thread, &workers[j]);
+            GGML_ASSERT(rc == 0);
+        }
+    }
+    workers[0].ith = 0;
+    workers[0].shared = &state_shared;
+
     const int64_t perf_start_cycles  = ggml_perf_cycles();
     const int64_t perf_start_time_us = ggml_perf_time_us();
 
-    for (int i = 0; i < cgraph->n_nodes; i++) {
-        GGML_PRINT_DEBUG_5("%s: %d/%d\n", __func__, i, cgraph->n_nodes);
+    // this is a work thread too
+    ggml_graph_compute_thread(&workers[0]);
 
-        struct ggml_tensor * node = cgraph->nodes[i];
-
-        // TODO: this could be used to avoid unnecessary computations, but it needs to be improved
-        //if (node->grad == NULL && node->perf_runs > 0) {
-        //    continue;
-        //}
-
-        const int64_t perf_node_start_cycles  = ggml_perf_cycles();
-        const int64_t perf_node_start_time_us = ggml_perf_time_us();
-
-        // INIT
-        struct ggml_compute_params params = {
-            /*.type  =*/ GGML_TASK_INIT,
-            /*.ith   =*/ 0,
-            /*.nth   =*/ node->n_tasks,
-            /*.wsize =*/ cgraph->work ? ggml_nbytes(cgraph->work) : 0,
-            /*.wdata =*/ cgraph->work ? cgraph->work->data : NULL,
-        };
-
-        ggml_compute_forward(&params, node);
-
-        // COMPUTE
-        if (node->n_tasks > 1) {
-            if (atomic_fetch_add(&state_shared.n_ready, 1) == n_threads - 1) {
-                atomic_store(&state_shared.has_work, false);
-            }
-
-            while (atomic_load(&state_shared.has_work)) {
-                ggml_lock_lock  (&state_shared.spin);
-                ggml_lock_unlock(&state_shared.spin);
-            }
-
-            // launch thread pool
-            for (int j = 0; j < n_threads - 1; j++) {
-                workers[j].params = (struct ggml_compute_params) {
-                    .type  = GGML_TASK_COMPUTE,
-                    .ith   = j + 1,
-                    .nth   = node->n_tasks,
-                    .wsize = cgraph->work ? ggml_nbytes(cgraph->work) : 0,
-                    .wdata = cgraph->work ? cgraph->work->data : NULL,
-                };
-                workers[j].node = node;
-            }
-
-            atomic_fetch_sub(&state_shared.n_ready, 1);
-
-            while (atomic_load(&state_shared.n_ready) > 0) {
-                ggml_lock_lock  (&state_shared.spin);
-                ggml_lock_unlock(&state_shared.spin);
-            }
-
-            atomic_store(&state_shared.has_work, true);
-        }
-
-        params.type = GGML_TASK_COMPUTE;
-        ggml_compute_forward(&params, node);
-
-        // wait for thread pool
-        if (node->n_tasks > 1) {
-            if (atomic_fetch_add(&state_shared.n_ready, 1) == n_threads - 1) {
-                atomic_store(&state_shared.has_work, false);
-            }
-
-            while (atomic_load(&state_shared.has_work)) {
-                ggml_lock_lock  (&state_shared.spin);
-                ggml_lock_unlock(&state_shared.spin);
-            }
-
-            atomic_fetch_sub(&state_shared.n_ready, 1);
-
-            while (atomic_load(&state_shared.n_ready) != 0) {
-                ggml_lock_lock  (&state_shared.spin);
-                ggml_lock_unlock(&state_shared.spin);
-            }
-        }
-
-        // FINALIZE
-        if (node->n_tasks > 1) {
-            if (atomic_fetch_add(&state_shared.n_ready, 1) == n_threads - 1) {
-                atomic_store(&state_shared.has_work, false);
-            }
-
-            while (atomic_load(&state_shared.has_work)) {
-                ggml_lock_lock  (&state_shared.spin);
-                ggml_lock_unlock(&state_shared.spin);
-            }
-
-            // launch thread pool
-            for (int j = 0; j < n_threads - 1; j++) {
-                workers[j].params = (struct ggml_compute_params) {
-                    .type  = GGML_TASK_FINALIZE,
-                    .ith   = j + 1,
-                    .nth   = node->n_tasks,
-                    .wsize = cgraph->work ? ggml_nbytes(cgraph->work) : 0,
-                    .wdata = cgraph->work ? cgraph->work->data : NULL,
-                };
-                workers[j].node = node;
-            }
-
-            atomic_fetch_sub(&state_shared.n_ready, 1);
-
-            while (atomic_load(&state_shared.n_ready) > 0) {
-                ggml_lock_lock  (&state_shared.spin);
-                ggml_lock_unlock(&state_shared.spin);
-            }
-
-            atomic_store(&state_shared.has_work, true);
-        }
-
-        params.type = GGML_TASK_FINALIZE;
-        ggml_compute_forward(&params, node);
-
-        // wait for thread pool
-        if (node->n_tasks > 1) {
-            if (atomic_fetch_add(&state_shared.n_ready, 1) == n_threads - 1) {
-                atomic_store(&state_shared.has_work, false);
-            }
-
-            while (atomic_load(&state_shared.has_work)) {
-                ggml_lock_lock  (&state_shared.spin);
-                ggml_lock_unlock(&state_shared.spin);
-            }
-
-            atomic_fetch_sub(&state_shared.n_ready, 1);
-
-            while (atomic_load(&state_shared.n_ready) != 0) {
-                ggml_lock_lock  (&state_shared.spin);
-                ggml_lock_unlock(&state_shared.spin);
-            }
-        }
-
-        // performance stats (node)
-        {
-            int64_t perf_cycles_cur  = ggml_perf_cycles()  - perf_node_start_cycles;
-            int64_t perf_time_us_cur = ggml_perf_time_us() - perf_node_start_time_us;
-
-            node->perf_runs++;
-            node->perf_cycles  += perf_cycles_cur;
-            node->perf_time_us += perf_time_us_cur;
-        }
-    }
+    // don't leave affinity set on the main thread
+    clear_numa_thread_affinity();
 
     // join thread pool
     if (n_threads > 1) {
-        atomic_store(&state_shared.stop, true);
-        atomic_store(&state_shared.has_work, true);
-
-        for (int j = 0; j < n_threads - 1; j++) {
-            int rc = ggml_thread_join(workers[j].thrd, NULL);
+        for (int j = 1; j < n_threads; j++) {
+            const int rc = ggml_thread_join(workers[j].thrd, NULL);
             GGML_ASSERT(rc == 0);
-            UNUSED(rc);
         }
-
-        ggml_lock_destroy(&state_shared.spin);
     }
 
     // performance stats (graph)

ggml.h

@@ -469,6 +469,9 @@ extern "C" {
     GGML_API int64_t ggml_cycles(void);
     GGML_API int64_t ggml_cycles_per_ms(void);
 
+    GGML_API void    ggml_numa_init(void); // call once for better performance on NUMA systems
+    GGML_API bool    ggml_is_numa(void); // true if init detected that system has >1 NUMA node
+
     GGML_API void    ggml_print_object (const struct ggml_object * obj);
     GGML_API void    ggml_print_objects(const struct ggml_context * ctx);
 

llama-util.h

@@ -172,12 +172,14 @@ struct llama_mmap {
 #ifdef _POSIX_MAPPED_FILES
     static constexpr bool SUPPORTED = true;
 
-    llama_mmap(struct llama_file * file, size_t prefetch = (size_t) -1 /* -1 = max value */) {
+    llama_mmap(struct llama_file * file, size_t prefetch = (size_t) -1 /* -1 = max value */, bool numa = false) {
         size = file->size;
         int fd = fileno(file->fp);
         int flags = MAP_SHARED;
+        // prefetch/readahead impairs performance on NUMA systems
+        if (numa) { prefetch = 0; }
 #ifdef __linux__
-        flags |= MAP_POPULATE;
+        if (prefetch) { flags |= MAP_POPULATE; }
 #endif
         addr = mmap(NULL, file->size, PROT_READ, flags, fd, 0);
         if (addr == MAP_FAILED) {
@@ -191,6 +193,14 @@ struct llama_mmap {
                         strerror(errno));
             }
         }
+        if (numa) {
+            // advise the kernel not to use readahead
+            // (because the next page might not belong on the same node)
+            if (madvise(addr, file->size, MADV_RANDOM)) {
+                fprintf(stderr, "warning: madvise(.., MADV_RANDOM) failed: %s\n",
+                        strerror(errno));
+            }
+        }
     }
 
     ~llama_mmap() {
@@ -199,7 +209,9 @@ struct llama_mmap {
 #elif defined(_WIN32)
     static constexpr bool SUPPORTED = true;
 
-    llama_mmap(struct llama_file * file, bool prefetch = true) {
+    llama_mmap(struct llama_file * file, bool prefetch = true, bool numa = false) {
+        (void) numa;
+
         size = file->size;
 
         HANDLE hFile = (HANDLE) _get_osfhandle(_fileno(file->fp));
@@ -244,8 +256,10 @@ struct llama_mmap {
 #else
     static constexpr bool SUPPORTED = false;
 
-    llama_mmap(struct llama_file *, bool prefetch = true) {
-        (void)prefetch;
+    llama_mmap(struct llama_file *, bool prefetch = true, bool numa = false) {
+        (void) prefetch;
+        (void) numa;
+
         throw std::runtime_error(std::string("mmap not supported"));
     }
 #endif

llama.cpp

@@ -774,7 +774,7 @@ struct llama_model_loader {
         }
 
         if (use_mmap) {
-            mapping.reset(new llama_mmap(&file_loaders.at(0)->file, prefetch_size));
+            mapping.reset(new llama_mmap(&file_loaders.at(0)->file, prefetch_size, ggml_is_numa()));
             if (lmlock) {
                 lmlock->init(mapping->addr);
             }
@@ -977,7 +977,7 @@ bool llama_mlock_supported() {
     return llama_mlock::SUPPORTED;
 }
 
-void llama_init_backend() {
+void llama_init_backend(bool numa) {
     ggml_time_init();
 
     // needed to initialize f16 tables
@@ -986,6 +986,10 @@ void llama_init_backend() {
         struct ggml_context * ctx = ggml_init(params);
         ggml_free(ctx);
     }
+
+    if (numa) {
+        ggml_numa_init();
+    }
 }
 
 int64_t llama_time_us() {
@@ -2899,7 +2903,7 @@ int llama_apply_lora_from_file_internal(const struct llama_model & model, const
 
         // maybe this should in llama_model_loader
         if (model_loader->use_mmap) {
-            model_loader->mapping.reset(new llama_mmap(&model_loader->file_loaders.at(0)->file, /* prefetch */ 0));
+            model_loader->mapping.reset(new llama_mmap(&model_loader->file_loaders.at(0)->file, /* prefetch */ 0, ggml_is_numa()));
         }
     }
 

llama.h

@@ -140,8 +140,9 @@ extern "C" {
 
     // TODO: not great API - very likely to change
     // Initialize the llama + ggml backend
+    // If numa is true, use NUMA optimizations
     // Call once at the start of the program
-    LLAMA_API void llama_init_backend();
+    LLAMA_API void llama_init_backend(bool numa);
 
     LLAMA_API int64_t llama_time_us();