linux-stable/net
Eric Dumazet 29b4433d99 net: percpu net_device refcount
We tried very hard to remove all possible dev_hold()/dev_put() pairs in
network stack, using RCU conversions.

There is still an unavoidable device refcount change for every dst we
create/destroy, and this can slow down some workloads (routers or some
app servers, mmap af_packet)

We can switch to a percpu refcount implementation, now dynamic per_cpu
infrastructure is mature. On a 64 cpus machine, this consumes 256 bytes
per device.

On x86, dev_hold(dev) code :

before
        lock    incl 0x280(%ebx)
after:
        movl    0x260(%ebx),%eax
        incl    fs:(%eax)

Stress bench :

(Sending 160.000.000 UDP frames,
IP route cache disabled, dual E5540 @2.53GHz,
32bit kernel, FIB_TRIE)

Before:

real    1m1.662s
user    0m14.373s
sys     12m55.960s

After:

real    0m51.179s
user    0m15.329s
sys     10m15.942s

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-12 12:35:25 -07:00
..
9p Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-10-06 19:39:31 -07:00
802 net: return operator cleanup 2010-09-23 14:33:39 -07:00
8021q net: add a core netdev->rx_dropped counter 2010-10-05 14:47:55 -07:00
appletalk
atm Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-10-11 12:30:34 -07:00
ax25 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-09-09 22:27:33 -07:00
bluetooth Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-10-11 12:30:34 -07:00
bridge net dst: use a percpu_counter to track entries 2010-10-11 13:06:53 -07:00
caif Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-10-06 19:39:31 -07:00
can net: simplify flags for tx timestamping 2010-08-19 00:08:30 -07:00
core net: percpu net_device refcount 2010-10-12 12:35:25 -07:00
dcb
dccp dccp: cosmetics - warning format 2010-10-12 06:57:43 +02:00
decnet net dst: use a percpu_counter to track entries 2010-10-11 13:06:53 -07:00
dns_resolver DNS: If the DNS server returns an error, allow that to be cached [ver #2] 2010-08-11 17:11:28 +00:00
dsa phylib: available for any speed ethernet 2010-08-11 23:03:50 -07:00
econet net: return operator cleanup 2010-09-23 14:33:39 -07:00
ethernet net: return operator cleanup 2010-09-23 14:33:39 -07:00
ieee802154
ipv4 net dst: use a percpu_counter to track entries 2010-10-11 13:06:53 -07:00
ipv6 net dst: use a percpu_counter to track entries 2010-10-11 13:06:53 -07:00
ipx
irda irda: Fix heap memory corruption in iriap.c 2010-10-11 02:12:26 +02:00
iucv net: use __packed annotation 2010-06-03 03:21:52 -07:00
key net: return operator cleanup 2010-09-23 14:33:39 -07:00
l2tp net: constify some ppp/pptp structs 2010-09-21 18:04:47 -07:00
lapb
llc net/llc: storing negative error codes in unsigned short 2010-09-16 22:38:23 -07:00
mac80211 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next-2.6 into for-davem 2010-10-08 15:39:28 -04:00
netfilter ipvs: Use frag walker helper in SCTP proto support. 2010-10-05 00:27:05 -07:00
netlabel
netlink Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next-2.6 into for-davem 2010-10-08 15:39:28 -04:00
netrom
packet net: simplify flags for tx timestamping 2010-08-19 00:08:30 -07:00
phonet Phonet: mark the pipe controller as EXPERIMENTAL 2010-10-08 14:09:10 -07:00
rds Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-09-27 01:03:03 -07:00
rfkill net: return operator cleanup 2010-09-23 14:33:39 -07:00
rose Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-09-27 01:03:03 -07:00
rxrpc Add a dummy printk function for the maintenance of unused printks 2010-08-12 09:51:35 -07:00
sched neigh: Protect neigh->ha[] with a seqlock 2010-10-11 12:54:04 -07:00
sctp Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-10-04 11:56:38 -07:00
sunrpc Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-10-06 19:39:31 -07:00
tipc net: return operator cleanup 2010-09-23 14:33:39 -07:00
unix AF_UNIX: Implement SO_TIMESTAMP and SO_TIMETAMPNS on Unix sockets 2010-10-05 14:54:36 -07:00
wanrouter net: autoconvert trivial BKL users to private mutex 2010-07-12 20:21:47 -07:00
wimax
wireless Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next-2.6 into for-davem 2010-10-08 15:39:28 -04:00
x25 X.25 remove bkl in poll 2010-09-22 13:35:51 -07:00
xfrm xfrm: Allow different selector family in temporary state 2010-09-20 11:11:38 -07:00
compat.c From abbffa2aa9bd6f8df16d0d0a102af677510d8b9a Mon Sep 17 00:00:00 2001 2010-06-03 20:03:40 -07:00
Kconfig net: RPS needs to depend upon USE_GENERIC_SMP_HELPERS 2010-09-14 21:42:22 -07:00
Makefile DNS: Separate out CIFS DNS Resolver code 2010-08-05 17:17:51 +00:00
nonet.c
socket.c net: remove address space warnings in net/socket.c 2010-09-08 13:46:13 -07:00
sysctl_net.c
TUNABLE