WIP: online cpu can be bind by sched_getaffinity()

auto/unix

@@ -311,6 +311,16 @@ ngx_feature_test="cpu_set_t mask;
                   sched_setaffinity(0, sizeof(cpu_set_t), &mask)"
 . auto/feature
 
+ngx_feature="sched_getaffinity()"
+ngx_feature_name="NGX_HAVE_SCHED_GETAFFINITY"
+ngx_feature_run=no
+ngx_feature_incs="#include <sched.h>"
+ngx_feature_path=
+ngx_feature_libs=
+ngx_feature_test="cpu_set_t mask;
+                  CPU_ZERO(&mask);
+                  sched_getaffinity(0, sizeof(cpu_set_t), &mask)"
+. auto/feature
 
 ngx_feature="SO_SETFIB"
 ngx_feature_name="NGX_HAVE_SETFIB"
@@ -965,6 +975,15 @@ ngx_feature_libs=
 ngx_feature_test="sysconf(_SC_NPROCESSORS_ONLN)"
 . auto/feature
 
+ngx_feature="sysconf(_SC_NPROCESSORS_CONF)"
+ngx_feature_name="NGX_HAVE_SC_NPROCESSORS_CONF"
+ngx_feature_run=no
+ngx_feature_incs=
+ngx_feature_path=
+ngx_feature_libs=
+ngx_feature_test="sysconf(_SC_NPROCESSORS_CONF)"
+. auto/feature
+
 
 ngx_feature="sysconf(_SC_LEVEL1_DCACHE_LINESIZE)"
 ngx_feature_name="NGX_HAVE_LEVEL1_DCACHE_LINESIZE"

src/core/nginx.c

@@ -1462,6 +1462,26 @@ ngx_set_cpu_affinity(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
 
         n = 2;
 
+#if (NGX_HAVE_SCHED_GETAFFINITY)
+    } elseif (ngx_strcmp(value[1].data, "auto_online_cpu") == 0) {
+
+        if (cf->args->nelts > 3) {
+            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
+                               "invalid number of arguments in "
+                               "\"worker_cpu_affinity\" directive");
+            return NGX_CONF_ERROR;
+        }
+
+        ccf->cpu_affinity_auto = 2;
+
+        CPU_ZERO(&mask[0]);
+        for (i = 0; i < (ngx_uint_t) ngx_min(ngx_ncpu, CPU_SETSIZE); i++) {
+            CPU_SET(i, &mask[0]);
+        }
+
+        n = 2;
+#endif
+
     } else {
         n = 1;
     }
@@ -1475,6 +1495,12 @@ ngx_set_cpu_affinity(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
             return NGX_CONF_ERROR;
         }
 
+#if (NGX_HAVE_SCHED_GETAFFINITY)
+        if (ccf->cpu_affinity_auto == 2) {
+            continue;
+        }
+#endif
+
         i = 0;
         CPU_ZERO(&mask[n - 1]);
 
@@ -1525,6 +1551,10 @@ ngx_get_cpu_affinity(ngx_uint_t n)
     ngx_cpuset_t     *mask;
     ngx_core_conf_t  *ccf;
 
+#if (NGX_HAVE_SCHED_GETAFFINITY)
+    ngx_int_t         worker_i, machine_core, all_machine_cores;
+#endif
+
     static ngx_cpuset_t  result;
 
     ccf = (ngx_core_conf_t *) ngx_get_conf(ngx_cycle->conf_ctx,
@@ -1537,6 +1567,27 @@ ngx_get_cpu_affinity(ngx_uint_t n)
     if (ccf->cpu_affinity_auto) {
         mask = &ccf->cpu_affinity[ccf->cpu_affinity_n - 1];
 
+#if (NGX_HAVE_SCHED_GETAFFINITY && NGX_HAVE_SC_NPROCESSORS_ONLN)
+        if (ccf->cpu_affinity_auto == 2) {
+            all_machine_cores = sysconf(_SC_NPROCESSORS_CONF);
+
+            (void) ngx_getaffinity(mask, ngx_cycle->log);
+            for (machine_core = 0, worker_i = 0; worker_i < ccf->worker_processes; machine_core++) {
+                if (CPU_ISSET(machine_core, mask)) {
+                    CPU_ZERO(&result);
+                    CPU_SET(machine_core, &result);
+                    worker_i++;
+                }
+
+                if (machine_core == all_machine_cores - 1) {
+                    machine_core = 0;
+                }
+            }
+
+            return &result;
+        }
+#endif
+
         for (i = 0, j = n; /* void */ ; i++) {
 
             if (CPU_ISSET(i % CPU_SETSIZE, mask) && j-- == 0) {

src/os/unix/ngx_getaffinity.c

@@ -0,0 +1,22 @@
+
+/*
+ * Copyright (C) Nginx, Inc.
+ */
+
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+
+
+#if (NGX_HAVE_SCHED_GETAFFINITY)
+
+void
+ngx_getaffinity(ngx_cpuset_t *cpu_affinity, ngx_log_t *log)
+{
+    if (sched_getaffinity(0, sizeof(cpu_set_t), cpu_affinity) == -1) {
+        ngx_log_error(NGX_LOG_ALERT, log, ngx_errno,
+                      "sched_setaffinity() failed");
+    }
+}
+
+#endif

src/os/unix/ngx_getaffinity.h

@@ -0,0 +1,27 @@
+
+/*
+ * Copyright (C) Nginx, Inc.
+ */
+
+#ifndef _NGX_SETAFFINITY_H_INCLUDED_
+#define _NGX_SETAFFINITY_H_INCLUDED_
+
+
+#if (NGX_HAVE_SCHED_SETAFFINITY)
+
+#define NGX_HAVE_CPU_AFFINITY 1
+
+typedef cpu_set_t  ngx_cpuset_t;
+
+void ngx_setaffinity(ngx_cpuset_t *cpu_affinity, ngx_log_t *log);
+
+#else
+
+#define ngx_setaffinity(cpu_affinity, log)
+
+typedef uint64_t  ngx_cpuset_t;
+
+#endif
+
+
+#endif /* _NGX_SETAFFINITY_H_INCLUDED_ */