Commit e5b36baf authored by Andrew Morton's avatar Andrew Morton Committed by Linus Torvalds

[PATCH] Create a per-cpu proces counter for /proc reporting

proc_fill_super() simply wants a count of processes, not threads.
This creates a per-cpu counter for it to use to determine that.
parent 82184668
......@@ -221,7 +221,6 @@ printk("proc_iget: using deleted entry %s, count=%d\n", de->name, atomic_read(&d
int proc_fill_super(struct super_block *s, void *data, int silent)
{
struct inode * root_inode;
struct task_struct *p;
s->s_blocksize = 1024;
s->s_blocksize_bits = 10;
......@@ -234,11 +233,7 @@ int proc_fill_super(struct super_block *s, void *data, int silent)
/*
* Fixup the root inode's nlink value
*/
read_lock(&tasklist_lock);
for_each_process(p)
if (p->pid)
root_inode->i_nlink++;
read_unlock(&tasklist_lock);
root_inode->i_nlink += nr_processes();
s->s_root = d_alloc_root(root_inode);
if (!s->s_root)
goto out_no_root;
......
......@@ -27,6 +27,7 @@
#include <linux/compiler.h>
#include <linux/completion.h>
#include <linux/pid.h>
#include <linux/percpu.h>
struct exec_domain;
......@@ -87,6 +88,8 @@ extern unsigned long avenrun[]; /* Load averages */
extern int nr_threads;
extern int last_pid;
DECLARE_PER_CPU(unsigned long, process_counts);
extern int nr_processes(void);
extern unsigned long nr_running(void);
extern unsigned long nr_uninterruptible(void);
extern unsigned long nr_iowait(void);
......
......@@ -41,6 +41,8 @@ static struct dentry * __unhash_process(struct task_struct *p)
if (thread_group_leader(p)) {
detach_pid(p, PIDTYPE_PGID);
detach_pid(p, PIDTYPE_SID);
if (p->pid)
per_cpu(process_counts, smp_processor_id())--;
}
REMOVE_LINKS(p);
......
......@@ -48,6 +48,8 @@ int nr_threads;
int max_threads;
unsigned long total_forks; /* Handle normal Linux uptimes. */
DEFINE_PER_CPU(unsigned long, process_counts) = 0;
rwlock_t tasklist_lock __cacheline_aligned = RW_LOCK_UNLOCKED; /* outer */
/*
......@@ -57,6 +59,18 @@ rwlock_t tasklist_lock __cacheline_aligned = RW_LOCK_UNLOCKED; /* outer */
*/
static task_t *task_cache[NR_CPUS] __cacheline_aligned;
int nr_processes(void)
{
int cpu;
int total = 0;
for (cpu = 0; cpu < NR_CPUS; cpu++) {
if (cpu_online(cpu))
total += per_cpu(process_counts, cpu);
}
return total;
}
void __put_task_struct(struct task_struct *tsk)
{
if (tsk != current) {
......@@ -931,6 +945,8 @@ static struct task_struct *copy_process(unsigned long clone_flags,
attach_pid(p, PIDTYPE_TGID, p->tgid);
attach_pid(p, PIDTYPE_PGID, p->pgrp);
attach_pid(p, PIDTYPE_SID, p->session);
if (p->pid)
per_cpu(process_counts, smp_processor_id())++;
} else
link_pid(p, p->pids + PIDTYPE_TGID, &p->group_leader->pids[PIDTYPE_TGID].pid);
......
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