vlib: improve automatic core pinning

[vpp.git] / src / vppinfra / unix-misc.c

diff --git a/src/vppinfra/unix-misc.c b/src/vppinfra/unix-misc.c
index e0591ff..4dbc5ce 100644 (file)
--- a/src/vppinfra/unix-misc.c
+++ b/src/vppinfra/unix-misc.c
@@ -46,6 +46,7 @@
 
 #include <sys/stat.h>
 #include <sys/types.h>
+#include <sys/syscall.h>
 #include <sys/uio.h>           /* writev */
 #include <fcntl.h>
 #include <stdio.h>             /* for sprintf */
@@ -274,6 +275,36 @@ os_get_online_cpu_core_bitmap ()
 #endif
 }
 
+__clib_export clib_bitmap_t *
+os_get_cpu_affinity_bitmap (int pid)
+{
+#if __linux
+  int index, ret;
+  cpu_set_t cpuset;
+  uword *affinity_cpus;
+
+  clib_bitmap_alloc (affinity_cpus, sizeof (cpu_set_t));
+  clib_bitmap_zero (affinity_cpus);
+
+  __CPU_ZERO_S (sizeof (cpu_set_t), &cpuset);
+
+  ret = syscall (SYS_sched_getaffinity, 0, sizeof (cpu_set_t), &cpuset);
+
+  if (ret < 0)
+    {
+      clib_bitmap_free (affinity_cpus);
+      return 0;
+    }
+
+  for (index = 0; index < sizeof (cpu_set_t); index++)
+    if (__CPU_ISSET_S (index, sizeof (cpu_set_t), &cpuset))
+      clib_bitmap_set (affinity_cpus, index, 1);
+  return affinity_cpus;
+#else
+  return 0;
+#endif
+}
+
 __clib_export clib_bitmap_t *
 os_get_online_cpu_node_bitmap ()
 {