handle older kernels that lack the per-CPU hash

97cc8f18 · Brendan Gregg · Alastair Robertson · 2ced3ad2 · 97cc8f18
Commit 97cc8f18 authored Mar 02, 2018 by Brendan Gregg Committed by Alastair Robertson Apr 29, 2018
Hide whitespace changes
Inline Side-by-side

Showing with 6 additions and 2 deletions

src/map.cpp src/map.cpp +6 -2

No files found.
--- a/src/map.cpp
+++ b/src/map.cpp
 #include <iostream>
 #include <unistd.h>
+#include <linux/version.h>
 #include "common.h"
 #include "libbpf.h"
@@ -21,8 +22,11 @@ Map::Map(const std::string &name, const SizedType &type, const MapKey &key)
    key_size = 8;
  enum bpf_map_type map_type;
-  if (type.type == Type::quantize || type.type == Type::count)
+  if ((type.type == Type::quantize || type.type == Type::count) &&
-    map_type = BPF_MAP_TYPE_PERCPU_HASH;
+      (LINUX_VERSION_CODE >= KERNEL_VERSION(4, 6, 0)))
+  {
+      map_type = BPF_MAP_TYPE_PERCPU_HASH;
+  }
  else
    map_type = BPF_MAP_TYPE_HASH;