diff --git a/auto/sched b/auto/sched
new file mode 100644
index 000000000..a6a4499b3
--- /dev/null
+++ b/auto/sched
@@ -0,0 +1,19 @@
+# Copyright (C) Andrew Clayton
+# Copyright (C) NGINX, Inc.
+
+
+nxt_feature="Linux sched_getaffinity()"
+nxt_feature_name=NXT_HAVE_LINUX_SCHED_GETAFFINITY
+nxt_feature_run=no
+nxt_feature_incs=
+nxt_feature_libs=
+nxt_feature_test="#define _GNU_SOURCE
+                  #include <sched.h>
+
+                  int main(void) {
+                      cpu_set_t set;
+
+                      sched_getaffinity(0, sizeof(set), &set);
+                      return 0;
+                  }"
+. auto/feature
diff --git a/configure b/configure
index 4ad0dcdc3..6929d41da 100755
--- a/configure
+++ b/configure
@@ -135,6 +135,7 @@ fi
 . auto/cgroup
 . auto/isolation
 . auto/capability
+. auto/sched
 
 
 case "$NXT_SYSTEM_PLATFORM" in
diff --git a/src/nxt_lib.c b/src/nxt_lib.c
index aba07dda4..de23ce0ab 100644
--- a/src/nxt_lib.c
+++ b/src/nxt_lib.c
@@ -32,7 +32,7 @@ const char *malloc_conf = "junk:true";
 nxt_int_t
 nxt_lib_start(const char *app, char **argv, char ***envp)
 {
-    int           n;
+    int           n = 0;
     nxt_int_t     flags;
     nxt_bool_t    update;
     nxt_thread_t  *thread;
@@ -87,13 +87,32 @@ nxt_lib_start(const char *app, char **argv, char ***envp)
 #ifdef _SC_NPROCESSORS_ONLN
     /* Linux, FreeBSD, Solaris, MacOSX. */
     n = sysconf(_SC_NPROCESSORS_ONLN);
+#endif
+
+#if (NXT_HAVE_LINUX_SCHED_GETAFFINITY)
+    if (n > 0) {
+        int        err;
+        size_t     size;
+        cpu_set_t  *set;
+
+        set = CPU_ALLOC(n);
+        if (set == NULL) {
+            return NXT_ERROR;
+        }
+
+        size = CPU_ALLOC_SIZE(n);
+
+        err = sched_getaffinity(0, size, set);
+        if (err == 0) {
+            n = CPU_COUNT_S(size, set);
+        }
+
+        CPU_FREE(set);
+    }
 
 #elif (NXT_HPUX)
     n = mpctl(MPC_GETNUMSPUS, NULL, NULL);
 
-#else
-    n = 0;
-
 #endif
 
     nxt_debug(&nxt_main_task, "ncpu: %d", n);