shinys000114/linux
1
0
Fork 0
mirror of https://github.com/hardkernel/linux.git synced 2026-06-05 10:31:46 +09:00
Code Issues Packages Projects Releases Wiki Activity

rtnl: add helper to check if rtnl group has listeners

Browse Source 
[ Upstream commit c5e2a973448d958feb7881e4d875eac59fdeff3d ]

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.

When operations are done without the rtnl_lock, as in tc-flower, such
skb allocation, message fill and no-op broadcasting can happen in all
cores of the system, which contributes to system pressure and wastes
precious cpu cycles when no one will receive the built message.

Introduce this helper so rtnetlink operations can simply check if someone
is listening and then proceed if necessary.

Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Link: https://lore.kernel.org/r/20231208192847.714940-2-pctammela@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 369609fc6272 ("tc: Ensure we have enough buffer space when sending filter netlink notifications")
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Jamal Hadi Salim
2023-12-08 16:28:41 -03:00
committed by Greg Kroah-Hartman
parent f3ce4d3f87
commit 8ab0c35a95
1 changed files with 7 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
include/linux/rtnetlink.h
View File

@@ -138,4 +138,11 @@ 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 */