Subject: [PATCH net-next 4/9] samples/bpf: make map creation more verbose

From: Alexei Starovoitov <[email-masked]>
Date: Sun, 6 Mar 2016 17:58:32 -0800

map creation is typically the first one to fail when rlimits are
too low, not enough memory, etc
Make this failure scenario more verbose

Signed-off-by: Alexei Starovoitov <[email-masked]>
---
 samples/bpf/bpf_load.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/samples/bpf/bpf_load.c b/samples/bpf/bpf_load.c
index da86a8e0a95a..816bca5760a0 100644
--- a/samples/bpf/bpf_load.c
+++ b/samples/bpf/bpf_load.c
@@ -158,8 +158,11 @@ static int load_maps(struct bpf_map_def *maps, int len)
 					   maps[i].key_size,
 					   maps[i].value_size,
 					   maps[i].max_entries);
-		if (map_fd[i] < 0)
+		if (map_fd[i] < 0) {
+			printf("failed to create a map: %d %s\n",
+			       errno, strerror(errno));
 			return 1;
+		}
 
 		if (maps[i].type == BPF_MAP_TYPE_PROG_ARRAY)
 			prog_array_fd = map_fd[i];
-- 
2.6.5