Eric Dumazet e67f88dd12 net: dont hold rtnl mutex during netlink dump callbacks ...

Four years ago, Patrick made a change to hold rtnl mutex during netlink
dump callbacks.

I believe it was a wrong move. This slows down concurrent dumps, making
good old /proc/net/ files faster than rtnetlink in some situations.

This occurred to me because one "ip link show dev ..." was _very_ slow
on a workload adding/removing network devices in background.

All dump callbacks are able to use RCU locking now, so this patch does
roughly a revert of commits :

1c2d670f36 : [RTNETLINK]: Hold rtnl_mutex during netlink dump callbacks
6313c1e099 : [RTNETLINK]: Remove unnecessary locking in dump callbacks

This let writers fight for rtnl mutex and readers going full speed.

It also takes care of phonet : phonet_route_get() is now called from rcu
read section. I renamed it to phonet_route_get_rcu()

Signed-off-by: Eric Dumazet <[email protected]>
Cc: Patrick McHardy <[email protected]>
Cc: Remi Denis-Courmont <[email protected]>
Acked-by: Stephen Hemminger <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

2011-05-02 15:26:28 -07:00

..

gprs.h

Phonet: implement GPRS virtual interface over PEP socket

2008-10-05 11:16:16 -07:00

pep.h

Phonet: allocate sock from accept syscall rather than soft IRQ

2011-03-09 11:59:32 -08:00

phonet.h

Phonet: implement per-socket destination/peer address

2011-02-25 11:19:35 -08:00

pn_dev.h

net: dont hold rtnl mutex during netlink dump callbacks

2011-05-02 15:26:28 -07:00