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![Nicolas Dichtel](/assets/img/avatar_default.png)
When a lot of netdevices are created, one of the bottleneck is the creation of proc entries. This serie aims to accelerate this part. The current implementation for the directories in /proc is using a single linked list. This is slow when handling directories with large numbers of entries (eg netdevice-related entries when lots of tunnels are opened). This patch replaces this linked list by a red-black tree. Here are some numbers: dummy30000.batch contains 30 000 times 'link add type dummy'. Before the patch: $ time ip -b dummy30000.batch real 2m31.950s user 0m0.440s sys 2m21.440s $ time rmmod dummy real 1m35.764s user 0m0.000s sys 1m24.088s After the patch: $ time ip -b dummy30000.batch real 2m0.874s user 0m0.448s sys 1m49.720s $ time rmmod dummy real 1m13.988s user 0m0.000s sys 1m1.008s The idea of improving this part was suggested by Thierry Herbelot. [akpm@linux-foundation.org: initialise proc_root.subdir at compile time] Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: David S. Miller <davem@davemloft.net> Cc: Thierry Herbelot <thierry.herbelot@6wind.com>. Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
233 lines
4.3 KiB
C
233 lines
4.3 KiB
C
/*
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* linux/fs/proc/net.c
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*
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* Copyright (C) 2007
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*
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* Author: Eric Biederman <ebiederm@xmission.com>
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*
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* proc net directory handling functions
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*/
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#include <asm/uaccess.h>
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#include <linux/errno.h>
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#include <linux/time.h>
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#include <linux/proc_fs.h>
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#include <linux/stat.h>
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#include <linux/slab.h>
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#include <linux/init.h>
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#include <linux/sched.h>
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#include <linux/module.h>
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#include <linux/bitops.h>
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#include <linux/mount.h>
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#include <linux/nsproxy.h>
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#include <net/net_namespace.h>
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#include <linux/seq_file.h>
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#include "internal.h"
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static inline struct net *PDE_NET(struct proc_dir_entry *pde)
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{
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return pde->parent->data;
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}
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static struct net *get_proc_net(const struct inode *inode)
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{
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return maybe_get_net(PDE_NET(PDE(inode)));
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}
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int seq_open_net(struct inode *ino, struct file *f,
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const struct seq_operations *ops, int size)
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{
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struct net *net;
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struct seq_net_private *p;
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BUG_ON(size < sizeof(*p));
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net = get_proc_net(ino);
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if (net == NULL)
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return -ENXIO;
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p = __seq_open_private(f, ops, size);
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if (p == NULL) {
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put_net(net);
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return -ENOMEM;
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}
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#ifdef CONFIG_NET_NS
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p->net = net;
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#endif
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return 0;
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}
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EXPORT_SYMBOL_GPL(seq_open_net);
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int single_open_net(struct inode *inode, struct file *file,
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int (*show)(struct seq_file *, void *))
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{
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int err;
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struct net *net;
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err = -ENXIO;
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net = get_proc_net(inode);
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if (net == NULL)
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goto err_net;
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err = single_open(file, show, net);
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if (err < 0)
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goto err_open;
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return 0;
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err_open:
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put_net(net);
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err_net:
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return err;
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}
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EXPORT_SYMBOL_GPL(single_open_net);
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int seq_release_net(struct inode *ino, struct file *f)
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{
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struct seq_file *seq;
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seq = f->private_data;
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put_net(seq_file_net(seq));
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seq_release_private(ino, f);
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return 0;
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}
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EXPORT_SYMBOL_GPL(seq_release_net);
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int single_release_net(struct inode *ino, struct file *f)
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{
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struct seq_file *seq = f->private_data;
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put_net(seq->private);
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return single_release(ino, f);
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}
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EXPORT_SYMBOL_GPL(single_release_net);
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static struct net *get_proc_task_net(struct inode *dir)
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{
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struct task_struct *task;
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struct nsproxy *ns;
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struct net *net = NULL;
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rcu_read_lock();
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task = pid_task(proc_pid(dir), PIDTYPE_PID);
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if (task != NULL) {
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task_lock(task);
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ns = task->nsproxy;
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if (ns != NULL)
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net = get_net(ns->net_ns);
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task_unlock(task);
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}
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rcu_read_unlock();
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return net;
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}
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static struct dentry *proc_tgid_net_lookup(struct inode *dir,
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struct dentry *dentry, unsigned int flags)
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{
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struct dentry *de;
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struct net *net;
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de = ERR_PTR(-ENOENT);
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net = get_proc_task_net(dir);
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if (net != NULL) {
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de = proc_lookup_de(net->proc_net, dir, dentry);
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put_net(net);
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}
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return de;
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}
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static int proc_tgid_net_getattr(struct vfsmount *mnt, struct dentry *dentry,
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struct kstat *stat)
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{
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struct inode *inode = dentry->d_inode;
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struct net *net;
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net = get_proc_task_net(inode);
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generic_fillattr(inode, stat);
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if (net != NULL) {
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stat->nlink = net->proc_net->nlink;
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put_net(net);
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}
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return 0;
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}
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const struct inode_operations proc_net_inode_operations = {
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.lookup = proc_tgid_net_lookup,
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.getattr = proc_tgid_net_getattr,
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};
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static int proc_tgid_net_readdir(struct file *file, struct dir_context *ctx)
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{
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int ret;
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struct net *net;
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ret = -EINVAL;
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net = get_proc_task_net(file_inode(file));
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if (net != NULL) {
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ret = proc_readdir_de(net->proc_net, file, ctx);
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put_net(net);
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}
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return ret;
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}
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const struct file_operations proc_net_operations = {
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.llseek = generic_file_llseek,
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.read = generic_read_dir,
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.iterate = proc_tgid_net_readdir,
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};
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static __net_init int proc_net_ns_init(struct net *net)
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{
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struct proc_dir_entry *netd, *net_statd;
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int err;
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err = -ENOMEM;
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netd = kzalloc(sizeof(*netd) + 4, GFP_KERNEL);
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if (!netd)
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goto out;
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netd->subdir = RB_ROOT;
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netd->data = net;
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netd->nlink = 2;
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netd->namelen = 3;
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netd->parent = &proc_root;
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memcpy(netd->name, "net", 4);
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err = -EEXIST;
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net_statd = proc_net_mkdir(net, "stat", netd);
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if (!net_statd)
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goto free_net;
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net->proc_net = netd;
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net->proc_net_stat = net_statd;
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return 0;
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free_net:
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kfree(netd);
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out:
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return err;
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}
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static __net_exit void proc_net_ns_exit(struct net *net)
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{
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remove_proc_entry("stat", net->proc_net);
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kfree(net->proc_net);
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}
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static struct pernet_operations __net_initdata proc_net_ns_ops = {
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.init = proc_net_ns_init,
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.exit = proc_net_ns_exit,
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};
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int __init proc_net_init(void)
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{
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proc_symlink("net", NULL, "self/net");
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return register_pernet_subsys(&proc_net_ns_ops);
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}
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