linux/net/core
Eric Dumazet 4381548237 net: sock_def_readable() and friends RCU conversion
sk_callback_lock rwlock actually protects sk->sk_sleep pointer, so we
need two atomic operations (and associated dirtying) per incoming
packet.

RCU conversion is pretty much needed :

1) Add a new structure, called "struct socket_wq" to hold all fields
that will need rcu_read_lock() protection (currently: a
wait_queue_head_t and a struct fasync_struct pointer).

[Future patch will add a list anchor for wakeup coalescing]

2) Attach one of such structure to each "struct socket" created in
sock_alloc_inode().

3) Respect RCU grace period when freeing a "struct socket_wq"

4) Change sk_sleep pointer in "struct sock" by sk_wq, pointer to "struct
socket_wq"

5) Change sk_sleep() function to use new sk->sk_wq instead of
sk->sk_sleep

6) Change sk_has_sleeper() to wq_has_sleeper() that must be used inside
a rcu_read_lock() section.

7) Change all sk_has_sleeper() callers to :
  - Use rcu_read_lock() instead of read_lock(&sk->sk_callback_lock)
  - Use wq_has_sleeper() to eventually wakeup tasks.
  - Use rcu_read_unlock() instead of read_unlock(&sk->sk_callback_lock)

8) sock_wake_async() is modified to use rcu protection as well.

9) Exceptions :
  macvtap, drivers/net/tun.c, af_unix use integrated "struct socket_wq"
instead of dynamically allocated ones. They dont need rcu freeing.

Some cleanups or followups are probably needed, (possible
sk_callback_lock conversion to a spinlock for example...).

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-01 15:00:15 -07:00
..
datagram.c net: speedup udp receive path 2010-04-28 14:35:48 -07:00
dev_addr_lists.c net: include linux/proc_fs.h in dev_addr_lists.c 2010-04-07 16:46:36 -07:00
dev.c net: batch skb dequeueing from softnet input_pkt_queue 2010-04-27 15:11:49 -07:00
drop_monitor.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
dst.c dst: don't inline dst_ifdown 2010-04-13 03:32:44 -07:00
ethtool.c Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-04-11 14:53:53 -07:00
fib_rules.c net: fib_rules: mark arguments to fib_rules_register const and __net_initdata 2010-04-26 16:02:04 +02:00
filter.c net: Socket filter ancilliary data access for skb->dev->type 2010-04-22 16:05:44 -07:00
flow.c flow: delayed deletion of flow cache entries 2010-04-07 03:43:20 -07:00
gen_estimator.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
gen_stats.c pkt_sched: gen_estimator: Dont report fake rate estimators 2009-10-07 01:07:42 -07:00
iovec.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
kmap_skb.h [PATCH] severing skbuff.h -> highmem.h 2006-12-04 02:00:29 -05:00
link_watch.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
Makefile net: convert multicast list to list_head 2010-04-03 14:22:15 -07:00
neighbour.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
net_namespace.c net: disallow to use net_assign_generic externally 2010-04-27 15:49:02 -07:00
net-sysfs.c rps: static functions 2010-04-19 14:40:57 -07:00
net-sysfs.h netns: Fix device renaming for sysfs 2008-05-02 17:00:58 -07:00
net-traces.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
netevent.c [NET]: net/core/netevent.c should #include <net/netevent.h> 2007-07-05 17:40:27 -07:00
netpoll.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
pktgen.c pktgen node allocation 2010-03-21 20:33:36 -07:00
request_sock.c net: convert BUG_TRAP to generic WARN_ON 2008-07-25 21:43:18 -07:00
rtnetlink.c Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/kaber/ipmr-2.6 2010-04-27 12:57:39 -07:00
scm.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
skbuff.c net: Remove two unnecessary exports (skbuff). 2010-04-20 22:39:53 -07:00
sock.c net: sock_def_readable() and friends RCU conversion 2010-05-01 15:00:15 -07:00
stream.c net: sock_def_readable() and friends RCU conversion 2010-05-01 15:00:15 -07:00
sysctl_net_core.c rfs: Receive Flow Steering 2010-04-16 16:01:27 -07:00
user_dma.c net/core/user_dma.c: Use frag list abstraction interfaces. 2009-06-09 00:19:10 -07:00
utils.c printk: Remove ratelimit.h from kernel.h 2009-09-22 16:18:09 +02:00