xref: /openbmc/linux/kernel/tsacct.c (revision 04dc82e1)
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 
28 	BUILD_BUG_ON(TS_COMM_LEN < TASK_COMM_LEN);
29 
30 	/* calculate task elapsed time in nsec */
31 	delta = ktime_get_ns() - tsk->start_time;
32 	/* Convert to micro seconds */
33 	do_div(delta, NSEC_PER_USEC);
34 	stats->ac_etime = delta;
35 	/* Convert to seconds for btime */
36 	do_div(delta, USEC_PER_SEC);
37 	stats->ac_btime = get_seconds() - delta;
38 	if (thread_group_leader(tsk)) {
39 		stats->ac_exitcode = tsk->exit_code;
40 		if (tsk->flags & PF_FORKNOEXEC)
41 			stats->ac_flag |= AFORK;
42 	}
43 	if (tsk->flags & PF_SUPERPRIV)
44 		stats->ac_flag |= ASU;
45 	if (tsk->flags & PF_DUMPCORE)
46 		stats->ac_flag |= ACORE;
47 	if (tsk->flags & PF_SIGNALED)
48 		stats->ac_flag |= AXSIG;
49 	stats->ac_nice	 = task_nice(tsk);
50 	stats->ac_sched	 = tsk->policy;
51 	stats->ac_pid	 = task_pid_nr_ns(tsk, pid_ns);
52 	rcu_read_lock();
53 	tcred = __task_cred(tsk);
54 	stats->ac_uid	 = from_kuid_munged(user_ns, tcred->uid);
55 	stats->ac_gid	 = from_kgid_munged(user_ns, tcred->gid);
56 	stats->ac_ppid	 = pid_alive(tsk) ?
57 		task_tgid_nr_ns(rcu_dereference(tsk->real_parent), pid_ns) : 0;
58 	rcu_read_unlock();
59 
60 	task_cputime(tsk, &utime, &stime);
61 	stats->ac_utime = div_u64(utime, NSEC_PER_USEC);
62 	stats->ac_stime = div_u64(stime, NSEC_PER_USEC);
63 
64 	task_cputime_scaled(tsk, &utimescaled, &stimescaled);
65 	stats->ac_utimescaled = div_u64(utimescaled, NSEC_PER_USEC);
66 	stats->ac_stimescaled = div_u64(stimescaled, NSEC_PER_USEC);
67 
68 	stats->ac_minflt = tsk->min_flt;
69 	stats->ac_majflt = tsk->maj_flt;
70 
71 	strncpy(stats->ac_comm, tsk->comm, sizeof(stats->ac_comm));
72 }
73 
74 
75 #ifdef CONFIG_TASK_XACCT
76 
77 #define KB 1024
78 #define MB (1024*KB)
79 #define KB_MASK (~(KB-1))
80 /*
81  * fill in extended accounting fields
82  */
83 void xacct_add_tsk(struct taskstats *stats, struct task_struct *p)
84 {
85 	struct mm_struct *mm;
86 
87 	/* convert pages-nsec/1024 to Mbyte-usec, see __acct_update_integrals */
88 	stats->coremem = p->acct_rss_mem1 * PAGE_SIZE;
89 	do_div(stats->coremem, 1000 * KB);
90 	stats->virtmem = p->acct_vm_mem1 * PAGE_SIZE;
91 	do_div(stats->virtmem, 1000 * KB);
92 	mm = get_task_mm(p);
93 	if (mm) {
94 		/* adjust to KB unit */
95 		stats->hiwater_rss   = get_mm_hiwater_rss(mm) * PAGE_SIZE / KB;
96 		stats->hiwater_vm    = get_mm_hiwater_vm(mm)  * PAGE_SIZE / KB;
97 		mmput(mm);
98 	}
99 	stats->read_char	= p->ioac.rchar & KB_MASK;
100 	stats->write_char	= p->ioac.wchar & KB_MASK;
101 	stats->read_syscalls	= p->ioac.syscr & KB_MASK;
102 	stats->write_syscalls	= p->ioac.syscw & KB_MASK;
103 #ifdef CONFIG_TASK_IO_ACCOUNTING
104 	stats->read_bytes	= p->ioac.read_bytes & KB_MASK;
105 	stats->write_bytes	= p->ioac.write_bytes & KB_MASK;
106 	stats->cancelled_write_bytes = p->ioac.cancelled_write_bytes & KB_MASK;
107 #else
108 	stats->read_bytes	= 0;
109 	stats->write_bytes	= 0;
110 	stats->cancelled_write_bytes = 0;
111 #endif
112 }
113 #undef KB
114 #undef MB
115 
116 static void __acct_update_integrals(struct task_struct *tsk,
117 				    u64 utime, u64 stime)
118 {
119 	u64 time, delta;
120 
121 	if (!likely(tsk->mm))
122 		return;
123 
124 	time = stime + utime;
125 	delta = time - tsk->acct_timexpd;
126 
127 	if (delta < TICK_NSEC)
128 		return;
129 
130 	tsk->acct_timexpd = time;
131 	/*
132 	 * Divide by 1024 to avoid overflow, and to avoid division.
133 	 * The final unit reported to userspace is Mbyte-usecs,
134 	 * the rest of the math is done in xacct_add_tsk.
135 	 */
136 	tsk->acct_rss_mem1 += delta * get_mm_rss(tsk->mm) >> 10;
137 	tsk->acct_vm_mem1 += delta * tsk->mm->total_vm >> 10;
138 }
139 
140 /**
141  * acct_update_integrals - update mm integral fields in task_struct
142  * @tsk: task_struct for accounting
143  */
144 void acct_update_integrals(struct task_struct *tsk)
145 {
146 	u64 utime, stime;
147 	unsigned long flags;
148 
149 	local_irq_save(flags);
150 	task_cputime(tsk, &utime, &stime);
151 	__acct_update_integrals(tsk, utime, stime);
152 	local_irq_restore(flags);
153 }
154 
155 /**
156  * acct_account_cputime - update mm integral after cputime update
157  * @tsk: task_struct for accounting
158  */
159 void acct_account_cputime(struct task_struct *tsk)
160 {
161 	__acct_update_integrals(tsk, tsk->utime, tsk->stime);
162 }
163 
164 /**
165  * acct_clear_integrals - clear the mm integral fields in task_struct
166  * @tsk: task_struct whose accounting fields are cleared
167  */
168 void acct_clear_integrals(struct task_struct *tsk)
169 {
170 	tsk->acct_timexpd = 0;
171 	tsk->acct_rss_mem1 = 0;
172 	tsk->acct_vm_mem1 = 0;
173 }
174 #endif
175