diff mbox series

[RFC,v4,net-next,07/22] rtnl: add helper to check if group has listeners

Message ID 20230712153949.6894-8-jhs@mojatatu.com (mailing list archive)
State RFC
Delegated to: Netdev Maintainers
Headers show
Series Introducing P4TC | expand

Checks

Context Check Description
netdev/series_format fail Series longer than 15 patches (and no cover letter)
netdev/tree_selection success Clearly marked for net-next, async
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 4779 this patch: 4779
netdev/cc_maintainers warning 3 maintainers not CCed: victor@mojatatu.com pctammela@mojatatu.com liuhangbin@gmail.com
netdev/build_clang success Errors and warnings before: 2209 this patch: 2209
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 4952 this patch: 4952
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 11 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Jamal Hadi Salim July 12, 2023, 3:39 p.m. UTC 
As of today, rtnl code creates a new skb and unconditionally fills and
broadcasts it to the relevant group. For most operations this is okay
and doesn't waste resources in general.

For P4TC, it's interesting to know if the TC group has any listeners
when adding/updating/deleting table entries as we can optimize for the
most likely case it contains none. This not only improves our processing
speed, it also reduces pressure on the system memory as we completely
avoid the broadcast skb allocation.

Co-developed-by: Victor Nogueira <victor@mojatatu.com>
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Co-developed-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
---
 include/linux/rtnetlink.h | 7 +++++++
 1 file changed, 7 insertions(+)
diff mbox series

Patch

diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
index 971055e66..487e45f8a 100644
--- a/include/linux/rtnetlink.h
+++ b/include/linux/rtnetlink.h
@@ -142,4 +142,11 @@  extern int ndo_dflt_bridge_getlink(struct sk_buff *skb, u32 pid, u32 seq,
 
 extern void rtnl_offload_xstats_notify(struct net_device *dev);
 
+static inline int rtnl_has_listeners(const struct net *net, u32 group)
+{
+	struct sock *rtnl = net->rtnl;
+
+	return netlink_has_listeners(rtnl, group);
+}
+
 #endif	/* __LINUX_RTNETLINK_H */