vlib: revert automatic core pinning changes

This reverts commit 71c32a898941e32b5d4f865b50fbe775560c582d.

Type: fix

Reason for revert: vnet pinning is not considered in this patch.
This causes keywords 'workers' and 'skip-cores' to be broken,
as well as keyword 'main-core auto' introduced in this patch.
If this patch is ever reconsidered, it must account for vnet
pinning fix in commit https://gerrit.fd.io/r/c/vpp/+/40711.

Change-Id: I1f3154a6c7e830b100f824375aa00e95b192f7f3
Signed-off-by: hsandid <halsandi@cisco.com>

src/vlib/threads.c

@@ -182,9 +182,7 @@ vlib_thread_init (vlib_main_t * vm)
   u32 n_vlib_mains = 1;
   u32 first_index = 1;
   u32 i;
-  pid_t pid;
-  uword *avail_cpu, *affinity_cpu;
-  uword n_cpus;
+  uword *avail_cpu;
   u32 stats_num_worker_threads_dir_index;
 
   stats_num_worker_threads_dir_index =
@@ -195,39 +193,16 @@ vlib_thread_init (vlib_main_t * vm)
   tm->cpu_core_bitmap = os_get_online_cpu_core_bitmap ();
   tm->cpu_socket_bitmap = os_get_online_cpu_node_bitmap ();
 
-  /* get bitmap of active cpu cores vpp has affinity to */
-  pid = getpid ();
-  tm->cpu_affinity_bitmap = os_get_cpu_affinity_bitmap (pid);
-
-  /* if fetching affinity fails, return online cpu core bmp */
-  if (tm->cpu_affinity_bitmap == 0)
-    tm->cpu_affinity_bitmap = os_get_online_cpu_core_bitmap ();
-
   avail_cpu = clib_bitmap_dup (tm->cpu_core_bitmap);
-  affinity_cpu = clib_bitmap_dup (tm->cpu_affinity_bitmap);
 
   /* skip cores */
-  n_cpus = clib_bitmap_count_set_bits (avail_cpu);
-  if (tm->skip_cores >= n_cpus)
-    return clib_error_return (0, "skip-core greater than available cpus");
-  n_cpus = clib_bitmap_count_set_bits (affinity_cpu);
-  if (tm->skip_cores >= n_cpus)
-    return clib_error_return (0, "skip-core greater than affinity cpus");
-
   for (i = 0; i < tm->skip_cores; i++)
     {
-      uword c;
-      c = clib_bitmap_first_set (avail_cpu);
+      uword c = clib_bitmap_first_set (avail_cpu);
       if (c == ~0)
 	return clib_error_return (0, "no available cpus to skip");
 
       avail_cpu = clib_bitmap_set (avail_cpu, c, 0);
-
-      c = clib_bitmap_first_set (affinity_cpu);
-      if (c == ~0)
-	return clib_error_return (0, "no available env cpus to skip");
-
-      affinity_cpu = clib_bitmap_set (affinity_cpu, c, 0);
     }
 
   /* grab cpu for main thread */
@@ -237,17 +212,6 @@ vlib_thread_init (vlib_main_t * vm)
 	return clib_error_return (0, "cpu %u is not available to be used"
 				  " for the main thread", tm->main_lcore);
       avail_cpu = clib_bitmap_set (avail_cpu, tm->main_lcore, 0);
-      affinity_cpu = clib_bitmap_set (affinity_cpu, tm->main_lcore, 0);
-    }
-  /* if auto enabled, grab first cpu vpp has affinity to for main thread */
-  else if (tm->use_main_core_auto)
-    {
-      uword c = clib_bitmap_first_set (affinity_cpu);
-      if (c != ~0)
-	tm->main_lcore = c;
-
-      avail_cpu = clib_bitmap_set (avail_cpu, tm->main_lcore, 0);
-      affinity_cpu = clib_bitmap_set (affinity_cpu, tm->main_lcore, 0);
     }
 
   /* assume that there is socket 0 only if there is no data from sysfs */
@@ -332,23 +296,13 @@ vlib_thread_init (vlib_main_t * vm)
 	}
       else
 	{
-	  /* for automatic pinning, use cpu affinity list */
-	  uword n_env_cpu = 0;
-	  n_env_cpu = clib_bitmap_count_set_bits (affinity_cpu);
-
-	  if (n_env_cpu < tr->count)
-	    return clib_error_return (0,
-				      "no available cpus to be used for"
-				      " the '%s' thread #%u",
-				      tr->name, n_env_cpu);
-
 	  for (j = 0; j < tr->count; j++)
 	    {
 	      /* Do not use CPU 0 by default - leave it to the host and IRQs */
-	      uword avail_c0 = clib_bitmap_get (affinity_cpu, 0);
-	      affinity_cpu = clib_bitmap_set (affinity_cpu, 0, 0);
+	      uword avail_c0 = clib_bitmap_get (avail_cpu, 0);
+	      avail_cpu = clib_bitmap_set (avail_cpu, 0, 0);
 
-	      uword c = clib_bitmap_first_set (affinity_cpu);
+	      uword c = clib_bitmap_first_set (avail_cpu);
 	      /* Use CPU 0 as a last resort */
 	      if (c == ~0 && avail_c0)
 		{
@@ -362,15 +316,14 @@ vlib_thread_init (vlib_main_t * vm)
 					  " the '%s' thread #%u",
 					  tr->name, tr->count);
 
-	      affinity_cpu = clib_bitmap_set (affinity_cpu, 0, avail_c0);
-	      affinity_cpu = clib_bitmap_set (affinity_cpu, c, 0);
+	      avail_cpu = clib_bitmap_set (avail_cpu, 0, avail_c0);
+	      avail_cpu = clib_bitmap_set (avail_cpu, c, 0);
 	      tr->coremask = clib_bitmap_set (tr->coremask, c, 1);
 	    }
 	}
     }
 
   clib_bitmap_free (avail_cpu);
-  clib_bitmap_free (affinity_cpu);
 
   tm->n_vlib_mains = n_vlib_mains;
   vlib_stats_set_gauge (stats_num_worker_threads_dir_index, n_vlib_mains - 1);
@@ -1176,7 +1129,6 @@ cpu_config (vlib_main_t * vm, unformat_input_t * input)
   tm->sched_policy = ~0;
   tm->sched_priority = ~0;
   tm->main_lcore = ~0;
-  tm->use_main_core_auto = 0;
 
   tr = tm->next;
 
@@ -1192,8 +1144,6 @@ cpu_config (vlib_main_t * vm, unformat_input_t * input)
 	tm->use_pthreads = 1;
       else if (unformat (input, "thread-prefix %v", &tm->thread_prefix))
 	;
-      else if (unformat (input, "main-core auto"))
-	tm->use_main_core_auto = 1;
       else if (unformat (input, "main-core %u", &tm->main_lcore))
 	;
       else if (unformat (input, "skip-cores %u", &tm->skip_cores))
@@ -1252,13 +1202,6 @@ cpu_config (vlib_main_t * vm, unformat_input_t * input)
 	break;
     }
 
-  if (tm->main_lcore != ~0 && tm->use_main_core_auto)
-    {
-      return clib_error_return (
-	0, "cannot set both 'main-core %u' and 'main-core auto'",
-	tm->main_lcore);
-    }
-
   if (tm->sched_priority != ~0)
     {
       if (tm->sched_policy == SCHED_FIFO || tm->sched_policy == SCHED_RR)

src/vlib/threads.h

@@ -255,8 +255,6 @@ typedef struct
 
   int use_pthreads;
 
-  int use_main_core_auto;
-
   /* Number of vlib_main / vnet_main clones */
   u32 n_vlib_mains;
 
@@ -284,9 +282,6 @@ typedef struct
   /* Bitmap of available CPU sockets (NUMA nodes) */
   uword *cpu_socket_bitmap;
 
-  /* Bitmap of CPU affinity for VPP process */
-  uword *cpu_affinity_bitmap;
-
   /* Worker handoff queues */
   vlib_frame_queue_main_t *frame_queue_mains;
 

src/vppinfra/unix-misc.c

@@ -49,7 +49,6 @@
 
 #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 */
@@ -278,36 +277,6 @@ 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 ()
 {

src/vppinfra/unix.h

@@ -56,9 +56,6 @@ clib_error_t *unix_proc_file_contents (char *file, u8 ** result);
 /* Retrieve bitmap of online cpu cures */
 clib_bitmap_t *os_get_online_cpu_core_bitmap ();
 
-/* Retrieve bitmap of cpus vpp has affinity to */
-clib_bitmap_t *os_get_cpu_affinity_bitmap (int pid);
-
 /* Retrieve bitmap of online cpu nodes (sockets) */
 clib_bitmap_t *os_get_online_cpu_node_bitmap ();