linux/net
Alexey Dobriyan 6af2d5fff2 netns: fix net_generic() "id - 1" bloat
net_generic() function is both a) inline and b) used ~600 times.

It has the following code inside

		...
	ptr = ng->ptr[id - 1];
		...

"id" is never compile time constant so compiler is forced to subtract 1.
And those decrements or LEA [r32 - 1] instructions add up.

We also start id'ing from 1 to catch bugs where pernet sybsystem id
is not initialized and 0. This is quite pointless idea (nothing will
work or immediate interference with first registered subsystem) in
general but it hints what needs to be done for code size reduction.

Namely, overlaying allocation of pointer array and fixed part of
structure in the beginning and using usual base-0 addressing.

Ids are just cookies, their exact values do not matter, so lets start
with 3 on x86_64.

Code size savings (oh boy): -4.2 KB

As usual, ignore the initial compiler stupidity part of the table.

	add/remove: 0/0 grow/shrink: 12/670 up/down: 89/-4297 (-4208)
	function                                     old     new   delta
	tipc_nametbl_insert_publ                    1250    1270     +20
	nlmclnt_lookup_host                          686     703     +17
	nfsd4_encode_fattr                          5930    5941     +11
	nfs_get_client                              1050    1061     +11
	register_pernet_operations                   333     342      +9
	tcf_mirred_init                              843     849      +6
	tcf_bpf_init                                1143    1149      +6
	gss_setup_upcall                             990     994      +4
	idmap_name_to_id                             432     434      +2
	ops_init                                     274     275      +1
	nfsd_inject_forget_client                    259     260      +1
	nfs4_alloc_client                            612     613      +1
	tunnel_key_walker                            164     163      -1

		...

	tipc_bcbase_select_primary                   392     360     -32
	mac80211_hwsim_new_radio                    2808    2767     -41
	ipip6_tunnel_ioctl                          2228    2186     -42
	tipc_bcast_rcv                               715     672     -43
	tipc_link_build_proto_msg                   1140    1089     -51
	nfsd4_lock                                  3851    3796     -55
	tipc_mon_rcv                                1012     956     -56
	Total: Before=156643951, After=156639743, chg -0.00%

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-03 15:59:58 -05:00
..
6lowpan 6lowpan: ndisc: no overreact if no short address is available 2016-09-19 20:19:34 +02:00
9p IB/core: add support to create a unsafe global rkey to ib_create_pd 2016-09-23 13:47:44 -04:00
802 net: use core MTU range checking in misc drivers 2016-10-20 14:51:10 -04:00
8021q netns: make struct pernet_operations::id unsigned int 2016-11-18 10:59:15 -05:00
appletalk appletalk: use IS_ENABLED() instead of checking for built-in or module 2016-09-10 21:19:10 -07:00
atm net: remove MTU limits on a few ether_setup callers 2016-10-21 13:57:50 -04:00
ax25
batman-adv Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-11-22 13:27:16 -05:00
bluetooth Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-11-26 23:42:21 -05:00
bridge bridge: mcast: add MLDv2 querier support 2016-11-21 13:16:58 -05:00
caif netns: make struct pernet_operations::id unsigned int 2016-11-18 10:59:15 -05:00
can can: bcm: fix support for CAN FD frames 2016-11-23 15:22:18 +01:00
ceph libceph: initialize last_linger_id with a large integer 2016-11-10 20:13:08 +01:00
core netns: fix net_generic() "id - 1" bloat 2016-12-03 15:59:58 -05:00
dcb
dccp Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-03 12:29:53 -05:00
decnet net: fix sleeping for sk_wait_event() 2016-11-14 13:17:21 -05:00
dns_resolver
dsa Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-03 12:29:53 -05:00
ethernet net: make default TX queue length a defined constant 2016-11-07 20:15:55 -05:00
hsr Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-10-30 12:42:58 -04:00
ieee802154 genetlink: mark families as __ro_after_init 2016-10-27 16:16:09 -04:00
ipv4 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-03 12:29:53 -05:00
ipv6 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-03 12:29:53 -05:00
ipx
irda genetlink: mark families as __ro_after_init 2016-10-27 16:16:09 -04:00
iucv Subject: [PATCH] af_iucv: drop skbs rejected by filter 2016-10-12 01:56:04 -04:00
kcm Merge branch 'work.splice_read' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-07 15:36:58 -07:00
key netns: make struct pernet_operations::id unsigned int 2016-11-18 10:59:15 -05:00
l2tp Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-03 12:29:53 -05:00
l3mdev net: ipv6: Remove l3mdev_get_saddr6 2016-09-10 23:12:53 -07:00
lapb
llc net: fix sleeping for sk_wait_event() 2016-11-14 13:17:21 -05:00
mac80211 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-11-22 13:27:16 -05:00
mac802154 mac802154: use rate limited warnings for malformed frames 2016-09-19 20:19:34 +02:00
mpls lwt: Remove unused len field 2016-10-23 17:45:01 -04:00
ncsi net/ncsi: Improve HNCDSC AEN handler 2016-10-20 11:23:08 -04:00
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-03 12:29:53 -05:00
netlabel genetlink: mark families as __ro_after_init 2016-10-27 16:16:09 -04:00
netlink Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-03 12:29:53 -05:00
netrom
nfc genetlink: mark families as __ro_after_init 2016-10-27 16:16:09 -04:00
openvswitch Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-03 12:29:53 -05:00
packet Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-03 12:29:53 -05:00
phonet netns: make struct pernet_operations::id unsigned int 2016-11-18 10:59:15 -05:00
qrtr
rds Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-03 12:29:53 -05:00
rfkill
rose
rxrpc udp: do fwd memory scheduling on dequeue 2016-11-07 13:24:41 -05:00
sched Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-03 12:29:53 -05:00
sctp sctp: use new rhlist interface on sctp transport rhashtable 2016-11-16 23:22:17 -05:00
strparser strparser: Propagate correct error code in strp_recv() 2016-10-12 01:51:49 -04:00
sunrpc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-11-22 13:27:16 -05:00
switchdev Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-10-30 12:42:58 -04:00
tipc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-03 12:29:53 -05:00
unix Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-11-22 13:27:16 -05:00
vmw_vsock VSOCK: add loopback to virtio_transport 2016-11-24 11:53:15 -05:00
wimax genetlink: mark families as __ro_after_init 2016-10-27 16:16:09 -04:00
wireless wireless-drivers-next patches for 4.10 2016-11-27 20:26:59 -05:00
x25 net: x25: remove null checks on arrays calling_ae and called_ae 2016-09-09 18:13:30 -07:00
xfrm Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-03 12:29:53 -05:00
compat.c
Kconfig bpf: BPF for lightweight tunnel infrastructure 2016-12-02 10:51:49 -05:00
Makefile strparser: Stream parser for messages 2016-08-17 19:36:23 -04:00
socket.c tcp: SOF_TIMESTAMPING_OPT_STATS option for SO_TIMESTAMPING 2016-11-30 10:04:25 -05:00
sysctl_net.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2016-10-06 09:52:23 -07:00