[PATCH v1] netdev: Make 100 percents packets sampled when sampling rate is 1.
From: Wenyu Zhang <hidden>
Date: 2015-08-03 07:12:16
Subsystem:
networking [general], openvswitch, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Aaron Conole, Eelco Chaudron, Ilya Maximets, Linus Torvalds
When sampling rate is 1, the sampling probability is UINT32_MAX. The packet should be sampled even the prandom32() generate the number of UINT32_MAX. And none packet need be sampled when the probability is 0. Signed-off-by: Wenyu Zhang <redacted> --- net/openvswitch/actions.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c
index cf04c2f..03acb09 100644
--- a/net/openvswitch/actions.c
+++ b/net/openvswitch/actions.c@@ -669,9 +669,11 @@ static int sample(struct datapath *dp, struct sk_buff *skb, for (a = nla_data(attr), rem = nla_len(attr); rem > 0; a = nla_next(a, &rem)) { + uint32_t probability; switch (nla_type(a)) { case OVS_SAMPLE_ATTR_PROBABILITY: - if (prandom_u32() >= nla_get_u32(a)) + probability = nla_get_u32(a); + if (!probability || probability > nla_get_u32(a)) return 0; break;
--
1.7.9.5