linux/include/net/phonet/pn_dev.h
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 <eric.dumazet@gmail.com>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Remi Denis-Courmont <remi.denis-courmont@nokia.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-02 15:26:28 -07:00

62 lines
1.9 KiB
C

/*
* File: pn_dev.h
*
* Phonet network device
*
* Copyright (C) 2008 Nokia Corporation.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*/
#ifndef PN_DEV_H
#define PN_DEV_H
struct phonet_device_list {
struct list_head list;
struct mutex lock;
};
struct phonet_device_list *phonet_device_list(struct net *net);
struct phonet_device {
struct list_head list;
struct net_device *netdev;
DECLARE_BITMAP(addrs, 64);
struct rcu_head rcu;
};
int phonet_device_init(void);
void phonet_device_exit(void);
int phonet_netlink_register(void);
struct net_device *phonet_device_get(struct net *net);
int phonet_address_add(struct net_device *dev, u8 addr);
int phonet_address_del(struct net_device *dev, u8 addr);
u8 phonet_address_get(struct net_device *dev, u8 addr);
int phonet_address_lookup(struct net *net, u8 addr);
void phonet_address_notify(int event, struct net_device *dev, u8 addr);
int phonet_route_add(struct net_device *dev, u8 daddr);
int phonet_route_del(struct net_device *dev, u8 daddr);
void rtm_phonet_notify(int event, struct net_device *dev, u8 dst);
struct net_device *phonet_route_get_rcu(struct net *net, u8 daddr);
struct net_device *phonet_route_output(struct net *net, u8 daddr);
#define PN_NO_ADDR 0xff
extern const struct file_operations pn_sock_seq_fops;
extern const struct file_operations pn_res_seq_fops;
#endif