xref: /openbmc/linux/kernel/tsacct.c (revision b5f184fbdb03b4fcc1141de34dd5ec964ca5d99e)
1  // SPDX-License-Identifier: GPL-2.0-or-later
2  /*
3   * tsacct.c - System accounting over taskstats interface
4   *
5   * Copyright (C) Jay Lan,	<jlan@sgi.com>
6   */
7  
8  #include <linux/kernel.h>
9  #include <linux/sched/signal.h>
10  #include <linux/sched/mm.h>
11  #include <linux/sched/cputime.h>
12  #include <linux/tsacct_kern.h>
13  #include <linux/acct.h>
14  #include <linux/jiffies.h>
15  #include <linux/mm.h>
16  
17  /*
18   * fill in basic accounting fields
19   */
20  void bacct_add_tsk(struct user_namespace *user_ns,
21  		   struct pid_namespace *pid_ns,
22  		   struct taskstats *stats, struct task_struct *tsk)
23  {
24  	const struct cred *tcred;
25  	u64 utime, stime, utimescaled, stimescaled;
26  	u64 delta;
27  	time64_t btime;
28  
29  	BUILD_BUG_ON(TS_COMM_LEN < TASK_COMM_LEN);
30  
31  	/* calculate task elapsed time in nsec */
32  	delta = ktime_get_ns() - tsk->start_time;
33  	/* Convert to micro seconds */
34  	do_div(delta, NSEC_PER_USEC);
35  	stats->ac_etime = delta;
36  	/* Convert to seconds for btime (note y2106 limit) */
37  	btime = ktime_get_real_seconds() - div_u64(delta, USEC_PER_SEC);
38  	stats->ac_btime = clamp_t(time64_t, btime, 0, U32_MAX);
39  	stats->ac_btime64 = btime;
40  
41  	if (thread_group_leader(tsk)) {
42  		stats->ac_exitcode = tsk->exit_code;
43  		if (tsk->flags & PF_FORKNOEXEC)
44  			stats->ac_flag |= AFORK;
45  	}
46  	if (tsk->flags & PF_SUPERPRIV)
47  		stats->ac_flag |= ASU;
48  	if (tsk->flags & PF_DUMPCORE)
49  		stats->ac_flag |= ACORE;
50  	if (tsk->flags & PF_SIGNALED)
51  		stats->ac_flag |= AXSIG;
52  	stats->ac_nice	 = task_nice(tsk);
53  	stats->ac_sched	 = tsk->policy;
54  	stats->ac_pid	 = task_pid_nr_ns(tsk, pid_ns);
55  	rcu_read_lock();
56  	tcred = __task_cred(tsk);
57  	stats->ac_uid	 = from_kuid_munged(user_ns, tcred->uid);
58  	stats->ac_gid	 = from_kgid_munged(user_ns, tcred->gid);
59  	stats->ac_ppid	 = pid_alive(tsk) ?
60  		task_tgid_nr_ns(rcu_dereference(tsk->real_parent), pid_ns) : 0;
61  	rcu_read_unlock();
62  
63  	task_cputime(tsk, &utime, &stime);
64  	stats->ac_utime = div_u64(utime, NSEC_PER_USEC);
65  	stats->ac_stime = div_u64(stime, NSEC_PER_USEC);
66  
67  	task_cputime_scaled(tsk, &utimescaled, &stimescaled);
68  	stats->ac_utimescaled = div_u64(utimescaled, NSEC_PER_USEC);
69  	stats->ac_stimescaled = div_u64(stimescaled, NSEC_PER_USEC);
70  
71  	stats->ac_minflt = tsk->min_flt;
72  	stats->ac_majflt = tsk->maj_flt;
73  
74  	strncpy(stats->ac_comm, tsk->comm, sizeof(stats->ac_comm));
75  }
76  
77  
78  #ifdef CONFIG_TASK_XACCT
79  
80  #define KB 1024
81  #define MB (1024*KB)
82  #define KB_MASK (~(KB-1))
83  /*
84   * fill in extended accounting fields
85   */
86  void xacct_add_tsk(struct taskstats *stats, struct task_struct *p)
87  {
88  	struct mm_struct *mm;
89  
90  	/* convert pages-nsec/1024 to Mbyte-usec, see __acct_update_integrals */
91  	stats->coremem = p->acct_rss_mem1 * PAGE_SIZE;
92  	do_div(stats->coremem, 1000 * KB);
93  	stats->virtmem = p->acct_vm_mem1 * PAGE_SIZE;
94  	do_div(stats->virtmem, 1000 * KB);
95  	mm = get_task_mm(p);
96  	if (mm) {
97  		/* adjust to KB unit */
98  		stats->hiwater_rss   = get_mm_hiwater_rss(mm) * PAGE_SIZE / KB;
99  		stats->hiwater_vm    = get_mm_hiwater_vm(mm)  * PAGE_SIZE / KB;
100  		mmput(mm);
101  	}
102  	stats->read_char	= p->ioac.rchar & KB_MASK;
103  	stats->write_char	= p->ioac.wchar & KB_MASK;
104  	stats->read_syscalls	= p->ioac.syscr & KB_MASK;
105  	stats->write_syscalls	= p->ioac.syscw & KB_MASK;
106  #ifdef CONFIG_TASK_IO_ACCOUNTING
107  	stats->read_bytes	= p->ioac.read_bytes & KB_MASK;
108  	stats->write_bytes	= p->ioac.write_bytes & KB_MASK;
109  	stats->cancelled_write_bytes = p->ioac.cancelled_write_bytes & KB_MASK;
110  #else
111  	stats->read_bytes	= 0;
112  	stats->write_bytes	= 0;
113  	stats->cancelled_write_bytes = 0;
114  #endif
115  }
116  #undef KB
117  #undef MB
118  
119  static void __acct_update_integrals(struct task_struct *tsk,
120  				    u64 utime, u64 stime)
121  {
122  	u64 time, delta;
123  
124  	if (!likely(tsk->mm))
125  		return;
126  
127  	time = stime + utime;
128  	delta = time - tsk->acct_timexpd;
129  
130  	if (delta < TICK_NSEC)
131  		return;
132  
133  	tsk->acct_timexpd = time;
134  	/*
135  	 * Divide by 1024 to avoid overflow, and to avoid division.
136  	 * The final unit reported to userspace is Mbyte-usecs,
137  	 * the rest of the math is done in xacct_add_tsk.
138  	 */
139  	tsk->acct_rss_mem1 += delta * get_mm_rss(tsk->mm) >> 10;
140  	tsk->acct_vm_mem1 += delta * tsk->mm->total_vm >> 10;
141  }
142  
143  /**
144   * acct_update_integrals - update mm integral fields in task_struct
145   * @tsk: task_struct for accounting
146   */
147  void acct_update_integrals(struct task_struct *tsk)
148  {
149  	u64 utime, stime;
150  	unsigned long flags;
151  
152  	local_irq_save(flags);
153  	task_cputime(tsk, &utime, &stime);
154  	__acct_update_integrals(tsk, utime, stime);
155  	local_irq_restore(flags);
156  }
157  
158  /**
159   * acct_account_cputime - update mm integral after cputime update
160   * @tsk: task_struct for accounting
161   */
162  void acct_account_cputime(struct task_struct *tsk)
163  {
164  	__acct_update_integrals(tsk, tsk->utime, tsk->stime);
165  }
166  
167  /**
168   * acct_clear_integrals - clear the mm integral fields in task_struct
169   * @tsk: task_struct whose accounting fields are cleared
170   */
171  void acct_clear_integrals(struct task_struct *tsk)
172  {
173  	tsk->acct_timexpd = 0;
174  	tsk->acct_rss_mem1 = 0;
175  	tsk->acct_vm_mem1 = 0;
176  }
177  #endif
178