xref: /openbmc/linux/kernel/tsacct.c (revision f3539c12)
1 /*
2  * tsacct.c - System accounting over taskstats interface
3  *
4  * Copyright (C) Jay Lan,	<jlan@sgi.com>
5  *
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  */
18 
19 #include <linux/kernel.h>
20 #include <linux/sched.h>
21 #include <linux/tsacct_kern.h>
22 #include <linux/acct.h>
23 #include <linux/jiffies.h>
24 #include <linux/mm.h>
25 
26 /*
27  * fill in basic accounting fields
28  */
29 void bacct_add_tsk(struct user_namespace *user_ns,
30 		   struct pid_namespace *pid_ns,
31 		   struct taskstats *stats, struct task_struct *tsk)
32 {
33 	const struct cred *tcred;
34 	cputime_t utime, stime, utimescaled, stimescaled;
35 	u64 delta;
36 
37 	BUILD_BUG_ON(TS_COMM_LEN < TASK_COMM_LEN);
38 
39 	/* calculate task elapsed time in nsec */
40 	delta = ktime_get_ns() - tsk->start_time;
41 	/* Convert to micro seconds */
42 	do_div(delta, NSEC_PER_USEC);
43 	stats->ac_etime = delta;
44 	/* Convert to seconds for btime */
45 	do_div(delta, USEC_PER_SEC);
46 	stats->ac_btime = get_seconds() - delta;
47 	if (thread_group_leader(tsk)) {
48 		stats->ac_exitcode = tsk->exit_code;
49 		if (tsk->flags & PF_FORKNOEXEC)
50 			stats->ac_flag |= AFORK;
51 	}
52 	if (tsk->flags & PF_SUPERPRIV)
53 		stats->ac_flag |= ASU;
54 	if (tsk->flags & PF_DUMPCORE)
55 		stats->ac_flag |= ACORE;
56 	if (tsk->flags & PF_SIGNALED)
57 		stats->ac_flag |= AXSIG;
58 	stats->ac_nice	 = task_nice(tsk);
59 	stats->ac_sched	 = tsk->policy;
60 	stats->ac_pid	 = task_pid_nr_ns(tsk, pid_ns);
61 	rcu_read_lock();
62 	tcred = __task_cred(tsk);
63 	stats->ac_uid	 = from_kuid_munged(user_ns, tcred->uid);
64 	stats->ac_gid	 = from_kgid_munged(user_ns, tcred->gid);
65 	stats->ac_ppid	 = pid_alive(tsk) ?
66 		task_tgid_nr_ns(rcu_dereference(tsk->real_parent), pid_ns) : 0;
67 	rcu_read_unlock();
68 
69 	task_cputime(tsk, &utime, &stime);
70 	stats->ac_utime = cputime_to_usecs(utime);
71 	stats->ac_stime = cputime_to_usecs(stime);
72 
73 	task_cputime_scaled(tsk, &utimescaled, &stimescaled);
74 	stats->ac_utimescaled = cputime_to_usecs(utimescaled);
75 	stats->ac_stimescaled = cputime_to_usecs(stimescaled);
76 
77 	stats->ac_minflt = tsk->min_flt;
78 	stats->ac_majflt = tsk->maj_flt;
79 
80 	strncpy(stats->ac_comm, tsk->comm, sizeof(stats->ac_comm));
81 }
82 
83 
84 #ifdef CONFIG_TASK_XACCT
85 
86 #define KB 1024
87 #define MB (1024*KB)
88 #define KB_MASK (~(KB-1))
89 /*
90  * fill in extended accounting fields
91  */
92 void xacct_add_tsk(struct taskstats *stats, struct task_struct *p)
93 {
94 	struct mm_struct *mm;
95 
96 	/* convert pages-nsec/1024 to Mbyte-usec, see __acct_update_integrals */
97 	stats->coremem = p->acct_rss_mem1 * PAGE_SIZE;
98 	do_div(stats->coremem, 1000 * KB);
99 	stats->virtmem = p->acct_vm_mem1 * PAGE_SIZE;
100 	do_div(stats->virtmem, 1000 * KB);
101 	mm = get_task_mm(p);
102 	if (mm) {
103 		/* adjust to KB unit */
104 		stats->hiwater_rss   = get_mm_hiwater_rss(mm) * PAGE_SIZE / KB;
105 		stats->hiwater_vm    = get_mm_hiwater_vm(mm)  * PAGE_SIZE / KB;
106 		mmput(mm);
107 	}
108 	stats->read_char	= p->ioac.rchar & KB_MASK;
109 	stats->write_char	= p->ioac.wchar & KB_MASK;
110 	stats->read_syscalls	= p->ioac.syscr & KB_MASK;
111 	stats->write_syscalls	= p->ioac.syscw & KB_MASK;
112 #ifdef CONFIG_TASK_IO_ACCOUNTING
113 	stats->read_bytes	= p->ioac.read_bytes & KB_MASK;
114 	stats->write_bytes	= p->ioac.write_bytes & KB_MASK;
115 	stats->cancelled_write_bytes = p->ioac.cancelled_write_bytes & KB_MASK;
116 #else
117 	stats->read_bytes	= 0;
118 	stats->write_bytes	= 0;
119 	stats->cancelled_write_bytes = 0;
120 #endif
121 }
122 #undef KB
123 #undef MB
124 
125 static void __acct_update_integrals(struct task_struct *tsk,
126 				    cputime_t utime, cputime_t stime)
127 {
128 	cputime_t time, dtime;
129 	u64 delta;
130 
131 	if (!likely(tsk->mm))
132 		return;
133 
134 	time = stime + utime;
135 	dtime = time - tsk->acct_timexpd;
136 	/* Avoid division: cputime_t is often in nanoseconds already. */
137 	delta = cputime_to_nsecs(dtime);
138 
139 	if (delta < TICK_NSEC)
140 		return;
141 
142 	tsk->acct_timexpd = time;
143 	/*
144 	 * Divide by 1024 to avoid overflow, and to avoid division.
145 	 * The final unit reported to userspace is Mbyte-usecs,
146 	 * the rest of the math is done in xacct_add_tsk.
147 	 */
148 	tsk->acct_rss_mem1 += delta * get_mm_rss(tsk->mm) >> 10;
149 	tsk->acct_vm_mem1 += delta * tsk->mm->total_vm >> 10;
150 }
151 
152 /**
153  * acct_update_integrals - update mm integral fields in task_struct
154  * @tsk: task_struct for accounting
155  */
156 void acct_update_integrals(struct task_struct *tsk)
157 {
158 	cputime_t utime, stime;
159 	unsigned long flags;
160 
161 	local_irq_save(flags);
162 	task_cputime(tsk, &utime, &stime);
163 	__acct_update_integrals(tsk, utime, stime);
164 	local_irq_restore(flags);
165 }
166 
167 /**
168  * acct_account_cputime - update mm integral after cputime update
169  * @tsk: task_struct for accounting
170  */
171 void acct_account_cputime(struct task_struct *tsk)
172 {
173 	__acct_update_integrals(tsk, tsk->utime, tsk->stime);
174 }
175 
176 /**
177  * acct_clear_integrals - clear the mm integral fields in task_struct
178  * @tsk: task_struct whose accounting fields are cleared
179  */
180 void acct_clear_integrals(struct task_struct *tsk)
181 {
182 	tsk->acct_timexpd = 0;
183 	tsk->acct_rss_mem1 = 0;
184 	tsk->acct_vm_mem1 = 0;
185 }
186 #endif
187