linux/net/sunrpc/sunrpc_syms.c

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/*
* linux/net/sunrpc/sunrpc_syms.c
*
* Symbols exported by the sunrpc module.
*
* Copyright (C) 1997 Olaf Kirch <okir@monad.swb.de>
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/uio.h>
#include <linux/unistd.h>
#include <linux/init.h>
#include <linux/sunrpc/sched.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/svc.h>
#include <linux/sunrpc/svcsock.h>
#include <linux/sunrpc/auth.h>
#include <linux/workqueue.h>
#include <linux/sunrpc/rpc_pipe_fs.h>
#include <linux/sunrpc/xprtsock.h>
#include "netns.h"
netns: make struct pernet_operations::id unsigned int 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>
2016-11-17 09:58:21 +08:00
unsigned int sunrpc_net_id;
EXPORT_SYMBOL_GPL(sunrpc_net_id);
static __net_init int sunrpc_init_net(struct net *net)
{
int err;
struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
err = rpc_proc_init(net);
if (err)
goto err_proc;
err = ip_map_cache_create(net);
if (err)
goto err_ipmap;
err = unix_gid_cache_create(net);
if (err)
goto err_unixgid;
err = rpc_pipefs_init_net(net);
if (err)
goto err_pipefs;
INIT_LIST_HEAD(&sn->all_clients);
spin_lock_init(&sn->rpc_client_lock);
spin_lock_init(&sn->rpcb_clnt_lock);
return 0;
err_pipefs:
unix_gid_cache_destroy(net);
err_unixgid:
ip_map_cache_destroy(net);
err_ipmap:
rpc_proc_exit(net);
err_proc:
return err;
}
static __net_exit void sunrpc_exit_net(struct net *net)
{
rpc_pipefs_exit_net(net);
unix_gid_cache_destroy(net);
ip_map_cache_destroy(net);
rpc_proc_exit(net);
}
static struct pernet_operations sunrpc_net_ops = {
.init = sunrpc_init_net,
.exit = sunrpc_exit_net,
.id = &sunrpc_net_id,
.size = sizeof(struct sunrpc_net),
};
static int __init
init_sunrpc(void)
{
int err = rpc_init_mempool();
if (err)
goto out;
err = rpcauth_init_module();
if (err)
goto out2;
cache_initialize();
err = register_pernet_subsys(&sunrpc_net_ops);
if (err)
goto out3;
err = register_rpc_pipefs();
if (err)
goto out4;
sunrpc_debugfs_init();
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
rpc_register_sysctl();
#endif
svc_init_xprt_sock(); /* svc sock transport */
init_socket_xprt(); /* clnt sock transport */
return 0;
out4:
unregister_pernet_subsys(&sunrpc_net_ops);
out3:
rpcauth_remove_module();
out2:
rpc_destroy_mempool();
out:
return err;
}
static void __exit
cleanup_sunrpc(void)
{
rpcauth_remove_module();
cleanup_socket_xprt();
svc_cleanup_xprt_sock();
sunrpc_debugfs_exit();
unregister_rpc_pipefs();
rpc_destroy_mempool();
unregister_pernet_subsys(&sunrpc_net_ops);
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
rpc_unregister_sysctl();
#endif
rcu_barrier(); /* Wait for completion of call_rcu()'s */
}
MODULE_LICENSE("GPL");
fs_initcall(init_sunrpc); /* Ensure we're initialised before nfs */
module_exit(cleanup_sunrpc);