linux/net/core
Eric Dumazet 93aaae2e01 filter: optimize sk_run_filter
Remove pc variable to avoid arithmetic to compute fentry at each filter
instruction. Jumps directly manipulate fentry pointer.

As the last instruction of filter[] is guaranteed to be a RETURN, and
all jumps are before the last instruction, we dont need to check filter
bounds (number of instructions in filter array) at each iteration, so we
remove it from sk_run_filter() params.

On x86_32 remove f_k var introduced in commit 57fe93b374
(filter: make sure filters dont read uninitialized memory)

Note : We could use a CONFIG_ARCH_HAS_{FEW|MANY}_REGISTERS in order to
avoid too many ifdefs in this code.

This helps compiler to use cpu registers to hold fentry and A
accumulator.

On x86_32, this saves 401 bytes, and more important, sk_run_filter()
runs much faster because less register pressure (One less conditional
branch per BPF instruction)

# size net/core/filter.o net/core/filter_pre.o
   text    data     bss     dec     hex filename
   2948       0       0    2948     b84 net/core/filter.o
   3349       0       0    3349     d15 net/core/filter_pre.o

on x86_64 :
# size net/core/filter.o net/core/filter_pre.o
   text    data     bss     dec     hex filename
   5173       0       0    5173    1435 net/core/filter.o
   5224       0       0    5224    1468 net/core/filter_pre.o

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-19 09:49:59 -08:00
..
datagram.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2010-10-23 11:47:02 -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: Export netif_get_vlan_features(). 2010-11-15 20:15:03 -08:00
drop_monitor.c drop_monitor: use genl_register_family_with_ops() 2010-07-26 20:59:42 -07:00
dst.c net/dst: dst_dev_event() called after other notifiers 2010-11-09 12:17:16 -08:00
ethtool.c ethtool: Add support for vlan accleration. 2010-10-21 01:26:54 -07:00
fib_rules.c fib_rules: __rcu annotates ctarget 2010-10-27 11:37:32 -07:00
filter.c filter: optimize sk_run_filter 2010-11-19 09:49:59 -08:00
flow.c net: return operator cleanup 2010-09-23 14:33:39 -07:00
gen_estimator.c pkt_sched: remov unnecessary bh_disable 2010-09-10 12:47:59 -07:00
gen_stats.c net/core: EXPORT_SYMBOL cleanups 2010-07-12 12:57:55 -07:00
iovec.c net: Limit socket I/O iovec total length to INT_MAX. 2010-10-28 11:47:52 -07:00
kmap_skb.h
link_watch.c net/core: EXPORT_SYMBOL cleanups 2010-07-12 12:57:55 -07:00
Makefile net: support time stamping in phy devices. 2010-07-18 19:15:26 -07:00
neighbour.c net/neighbour: cancel_delayed_work() + flush_scheduled_work() -> cancel_delayed_work_sync() 2010-10-21 04:25:48 -07:00
net_namespace.c net_ns: add __rcu annotations 2010-10-25 14:18:27 -07:00
net-sysfs.c net: zero kobject in rx_queue_release 2010-11-17 12:27:46 -08:00
net-sysfs.h net: Allow changing number of RX queues after device allocation 2010-09-27 22:09:49 -07:00
net-traces.c netdev: Add tracepoints to netdev layer 2010-09-07 17:51:33 +02:00
netevent.c net/core: EXPORT_SYMBOL cleanups 2010-07-12 12:57:55 -07:00
netpoll.c netpoll: Revert napi_poll fix for bonding driver 2010-10-20 01:44:30 -07:00
pktgen.c net: add priority field to pktgen 2010-11-18 10:43:07 -08:00
request_sock.c
rtnetlink.c rtnetlink: Link address family API 2010-11-17 11:28:24 -08:00
scm.c net/core: EXPORT_SYMBOL cleanups 2010-07-12 12:57:55 -07:00
skbuff.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2010-10-23 11:47:02 -07:00
sock.c net: avoid limits overflow 2010-11-10 12:12:00 -08:00
stream.c net: Fix the condition passed to sk_wait_event() 2010-10-03 20:41:32 -07:00
sysctl_net_core.c rps: add __rcu annotations 2010-10-25 14:18:27 -07:00
timestamping.c filter: optimize sk_run_filter 2010-11-19 09:49:59 -08:00
user_dma.c net/core/user_dma.c: Use frag list abstraction interfaces. 2009-06-09 00:19:10 -07:00
utils.c net: return operator cleanup 2010-09-23 14:33:39 -07:00