2024-06-03 18:58:48

by Adrián Moreno

Subject: [PATCH net-next v2 3/9] net: psample: skip packet copy if no listeners

If nobody is listening on the multicast group, generating the sample,
which involves copying packet data, seems completely unnecessary.

Return fast in this case.

Signed-off-by: Adrian Moreno <[email protected]>
---
net/psample/psample.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/net/psample/psample.c b/net/psample/psample.c
index b37488f426bc..1c76f3e48dcd 100644
--- a/net/psample/psample.c
+++ b/net/psample/psample.c
@@ -376,6 +376,10 @@ void psample_sample_packet(struct psample_group *group, struct sk_buff *skb,
void *data;
int ret;

+ if (!genl_has_listeners(&psample_nl_family, group->net,
+ PSAMPLE_NL_MCGRP_SAMPLE))
+ return;
+
meta_len = (in_ifindex ? nla_total_size(sizeof(u16)) : 0) +
(out_ifindex ? nla_total_size(sizeof(u16)) : 0) +
(md->out_tc_valid ? nla_total_size(sizeof(u16)) : 0) +
--
2.45.1

2024-06-14 16:15:49

by Simon Horman

Subject: Re: [PATCH net-next v2 3/9] net: psample: skip packet copy if no listeners

On Mon, Jun 03, 2024 at 08:56:37PM +0200, Adrian Moreno wrote:
> If nobody is listening on the multicast group, generating the sample,
> which involves copying packet data, seems completely unnecessary.
>
> Return fast in this case.
>
> Signed-off-by: Adrian Moreno <[email protected]>

Reviewed-by: Simon Horman <[email protected]>