mirror of
https://github.com/torvalds/linux.git
synced 2024-11-27 06:31:52 +00:00
c7d03a00b5
Make struct pernet_operations::id unsigned.
There are 2 reasons to do so:
1)
This field is really an index into an zero based array and
thus is unsigned entity. Using negative value is out-of-bound
access by definition.
2)
On x86_64 unsigned 32-bit data which are mixed with pointers
via array indexing or offsets added or subtracted to pointers
are preffered to signed 32-bit data.
"int" being used as an array index needs to be sign-extended
to 64-bit before being used.
void f(long *p, int i)
{
g(p[i]);
}
roughly translates to
movsx rsi, esi
mov rdi, [rsi+...]
call g
MOVSX is 3 byte instruction which isn't necessary if the variable is
unsigned because x86_64 is zero extending by default.
Now, there is net_generic() function which, you guessed it right, uses
"int" as an array index:
static inline void *net_generic(const struct net *net, int id)
{
...
ptr = ng->ptr[id - 1];
...
}
And this function is used a lot, so those sign extensions add up.
Patch snipes ~1730 bytes on allyesconfig kernel (without all junk
messing with code generation):
add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)
Unfortunately some functions actually grow bigger.
This is a semmingly random artefact of code generation with register
allocator being used differently. gcc decides that some variable
needs to live in new r8+ registers and every access now requires REX
prefix. Or it is shifted into r12, so [r12+0] addressing mode has to be
used which is longer than [r8]
However, overall balance is in negative direction:
add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)
function old new delta
nfsd4_lock 3886 3959 +73
tipc_link_build_proto_msg 1096 1140 +44
mac80211_hwsim_new_radio 2776 2808 +32
tipc_mon_rcv 1032 1058 +26
svcauth_gss_legacy_init 1413 1429 +16
tipc_bcbase_select_primary 379 392 +13
nfsd4_exchange_id 1247 1260 +13
nfsd4_setclientid_confirm 782 793 +11
...
put_client_renew_locked 494 480 -14
ip_set_sockfn_get 730 716 -14
geneve_sock_add 829 813 -16
nfsd4_sequence_done 721 703 -18
nlmclnt_lookup_host 708 686 -22
nfsd4_lockt 1085 1063 -22
nfs_get_client 1077 1050 -27
tcf_bpf_init 1106 1076 -30
nfsd4_encode_fattr 5997 5930 -67
Total: Before=154856051, After=154854321, chg -0.00%
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
179 lines
4.5 KiB
C
179 lines
4.5 KiB
C
/*
|
|
* net/tipc/core.c: TIPC module code
|
|
*
|
|
* Copyright (c) 2003-2006, 2013, Ericsson AB
|
|
* Copyright (c) 2005-2006, 2010-2013, Wind River Systems
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions are met:
|
|
*
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. Neither the names of the copyright holders nor the names of its
|
|
* contributors may be used to endorse or promote products derived from
|
|
* this software without specific prior written permission.
|
|
*
|
|
* Alternatively, this software may be distributed under the terms of the
|
|
* GNU General Public License ("GPL") version 2 as published by the Free
|
|
* Software Foundation.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
|
|
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
* POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
|
|
|
#include "core.h"
|
|
#include "name_table.h"
|
|
#include "subscr.h"
|
|
#include "bearer.h"
|
|
#include "net.h"
|
|
#include "socket.h"
|
|
#include "bcast.h"
|
|
|
|
#include <linux/module.h>
|
|
|
|
/* configurable TIPC parameters */
|
|
unsigned int tipc_net_id __read_mostly;
|
|
int sysctl_tipc_rmem[3] __read_mostly; /* min/default/max */
|
|
|
|
static int __net_init tipc_init_net(struct net *net)
|
|
{
|
|
struct tipc_net *tn = net_generic(net, tipc_net_id);
|
|
int err;
|
|
|
|
tn->net_id = 4711;
|
|
tn->own_addr = 0;
|
|
tn->mon_threshold = TIPC_DEF_MON_THRESHOLD;
|
|
get_random_bytes(&tn->random, sizeof(int));
|
|
INIT_LIST_HEAD(&tn->node_list);
|
|
spin_lock_init(&tn->node_list_lock);
|
|
|
|
err = tipc_sk_rht_init(net);
|
|
if (err)
|
|
goto out_sk_rht;
|
|
|
|
err = tipc_nametbl_init(net);
|
|
if (err)
|
|
goto out_nametbl;
|
|
|
|
INIT_LIST_HEAD(&tn->dist_queue);
|
|
err = tipc_topsrv_start(net);
|
|
if (err)
|
|
goto out_subscr;
|
|
|
|
err = tipc_bcast_init(net);
|
|
if (err)
|
|
goto out_bclink;
|
|
|
|
return 0;
|
|
|
|
out_bclink:
|
|
tipc_bcast_stop(net);
|
|
out_subscr:
|
|
tipc_nametbl_stop(net);
|
|
out_nametbl:
|
|
tipc_sk_rht_destroy(net);
|
|
out_sk_rht:
|
|
return err;
|
|
}
|
|
|
|
static void __net_exit tipc_exit_net(struct net *net)
|
|
{
|
|
tipc_topsrv_stop(net);
|
|
tipc_net_stop(net);
|
|
tipc_bcast_stop(net);
|
|
tipc_nametbl_stop(net);
|
|
tipc_sk_rht_destroy(net);
|
|
}
|
|
|
|
static struct pernet_operations tipc_net_ops = {
|
|
.init = tipc_init_net,
|
|
.exit = tipc_exit_net,
|
|
.id = &tipc_net_id,
|
|
.size = sizeof(struct tipc_net),
|
|
};
|
|
|
|
static int __init tipc_init(void)
|
|
{
|
|
int err;
|
|
|
|
pr_info("Activated (version " TIPC_MOD_VER ")\n");
|
|
|
|
sysctl_tipc_rmem[0] = RCVBUF_MIN;
|
|
sysctl_tipc_rmem[1] = RCVBUF_DEF;
|
|
sysctl_tipc_rmem[2] = RCVBUF_MAX;
|
|
|
|
err = tipc_netlink_start();
|
|
if (err)
|
|
goto out_netlink;
|
|
|
|
err = tipc_netlink_compat_start();
|
|
if (err)
|
|
goto out_netlink_compat;
|
|
|
|
err = tipc_socket_init();
|
|
if (err)
|
|
goto out_socket;
|
|
|
|
err = tipc_register_sysctl();
|
|
if (err)
|
|
goto out_sysctl;
|
|
|
|
err = register_pernet_subsys(&tipc_net_ops);
|
|
if (err)
|
|
goto out_pernet;
|
|
|
|
err = tipc_bearer_setup();
|
|
if (err)
|
|
goto out_bearer;
|
|
|
|
pr_info("Started in single node mode\n");
|
|
return 0;
|
|
out_bearer:
|
|
unregister_pernet_subsys(&tipc_net_ops);
|
|
out_pernet:
|
|
tipc_unregister_sysctl();
|
|
out_sysctl:
|
|
tipc_socket_stop();
|
|
out_socket:
|
|
tipc_netlink_compat_stop();
|
|
out_netlink_compat:
|
|
tipc_netlink_stop();
|
|
out_netlink:
|
|
pr_err("Unable to start in single node mode\n");
|
|
return err;
|
|
}
|
|
|
|
static void __exit tipc_exit(void)
|
|
{
|
|
tipc_bearer_cleanup();
|
|
unregister_pernet_subsys(&tipc_net_ops);
|
|
tipc_netlink_stop();
|
|
tipc_netlink_compat_stop();
|
|
tipc_socket_stop();
|
|
tipc_unregister_sysctl();
|
|
|
|
pr_info("Deactivated\n");
|
|
}
|
|
|
|
module_init(tipc_init);
|
|
module_exit(tipc_exit);
|
|
|
|
MODULE_DESCRIPTION("TIPC: Transparent Inter Process Communication");
|
|
MODULE_LICENSE("Dual BSD/GPL");
|
|
MODULE_VERSION(TIPC_MOD_VER);
|