the-tree/kernel/tsacct.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * tsacct.c - System accounting over taskstats interface
0004  *
0005  * Copyright (C) Jay Lan,   <jlan@sgi.com>
0006  */
0007
0008 #include <linux/kernel.h>
0009 #include <linux/sched/signal.h>
0010 #include <linux/sched/mm.h>
0011 #include <linux/sched/cputime.h>
0012 #include <linux/tsacct_kern.h>
0013 #include <linux/acct.h>
0014 #include <linux/jiffies.h>
0015 #include <linux/mm.h>
0016
0017 /*
0018  * fill in basic accounting fields
0019  */
0020 void bacct_add_tsk(struct user_namespace *user_ns,
0021            struct pid_namespace *pid_ns,
0022            struct taskstats *stats, struct task_struct *tsk)
0023 {
0024     const struct cred *tcred;
0025     u64 utime, stime, utimescaled, stimescaled;
0026     u64 now_ns, delta;
0027     time64_t btime;
0028
0029     BUILD_BUG_ON(TS_COMM_LEN < TASK_COMM_LEN);
0030
0031     /* calculate task elapsed time in nsec */
0032     now_ns = ktime_get_ns();
0033     /* store whole group time first */
0034     delta = now_ns - tsk->group_leader->start_time;
0035     /* Convert to micro seconds */
0036     do_div(delta, NSEC_PER_USEC);
0037     stats->ac_tgetime = delta;
0038     delta = now_ns - tsk->start_time;
0039     do_div(delta, NSEC_PER_USEC);
0040     stats->ac_etime = delta;
0041     /* Convert to seconds for btime (note y2106 limit) */
0042     btime = ktime_get_real_seconds() - div_u64(delta, USEC_PER_SEC);
0043     stats->ac_btime = clamp_t(time64_t, btime, 0, U32_MAX);
0044     stats->ac_btime64 = btime;
0045
0046     if (tsk->flags & PF_EXITING)
0047         stats->ac_exitcode = tsk->exit_code;
0048     if (thread_group_leader(tsk) && (tsk->flags & PF_FORKNOEXEC))
0049         stats->ac_flag |= AFORK;
0050     if (tsk->flags & PF_SUPERPRIV)
0051         stats->ac_flag |= ASU;
0052     if (tsk->flags & PF_DUMPCORE)
0053         stats->ac_flag |= ACORE;
0054     if (tsk->flags & PF_SIGNALED)
0055         stats->ac_flag |= AXSIG;
0056     stats->ac_nice   = task_nice(tsk);
0057     stats->ac_sched  = tsk->policy;
0058     stats->ac_pid    = task_pid_nr_ns(tsk, pid_ns);
0059     stats->ac_tgid   = task_tgid_nr_ns(tsk, pid_ns);
0060     rcu_read_lock();
0061     tcred = __task_cred(tsk);
0062     stats->ac_uid    = from_kuid_munged(user_ns, tcred->uid);
0063     stats->ac_gid    = from_kgid_munged(user_ns, tcred->gid);
0064     stats->ac_ppid   = pid_alive(tsk) ?
0065         task_tgid_nr_ns(rcu_dereference(tsk->real_parent), pid_ns) : 0;
0066     rcu_read_unlock();
0067
0068     task_cputime(tsk, &utime, &stime);
0069     stats->ac_utime = div_u64(utime, NSEC_PER_USEC);
0070     stats->ac_stime = div_u64(stime, NSEC_PER_USEC);
0071
0072     task_cputime_scaled(tsk, &utimescaled, &stimescaled);
0073     stats->ac_utimescaled = div_u64(utimescaled, NSEC_PER_USEC);
0074     stats->ac_stimescaled = div_u64(stimescaled, NSEC_PER_USEC);
0075
0076     stats->ac_minflt = tsk->min_flt;
0077     stats->ac_majflt = tsk->maj_flt;
0078
0079     strncpy(stats->ac_comm, tsk->comm, sizeof(stats->ac_comm));
0080 }
0081
0082
0083 #ifdef CONFIG_TASK_XACCT
0084
0085 #define KB 1024
0086 #define MB (1024*KB)
0087 #define KB_MASK (~(KB-1))
0088 /*
0089  * fill in extended accounting fields
0090  */
0091 void xacct_add_tsk(struct taskstats *stats, struct task_struct *p)
0092 {
0093     struct mm_struct *mm;
0094
0095     /* convert pages-nsec/1024 to Mbyte-usec, see __acct_update_integrals */
0096     stats->coremem = p->acct_rss_mem1 * PAGE_SIZE;
0097     do_div(stats->coremem, 1000 * KB);
0098     stats->virtmem = p->acct_vm_mem1 * PAGE_SIZE;
0099     do_div(stats->virtmem, 1000 * KB);
0100     mm = get_task_mm(p);
0101     if (mm) {
0102         /* adjust to KB unit */
0103         stats->hiwater_rss   = get_mm_hiwater_rss(mm) * PAGE_SIZE / KB;
0104         stats->hiwater_vm    = get_mm_hiwater_vm(mm)  * PAGE_SIZE / KB;
0105         mmput(mm);
0106     }
0107     stats->read_char    = p->ioac.rchar & KB_MASK;
0108     stats->write_char   = p->ioac.wchar & KB_MASK;
0109     stats->read_syscalls    = p->ioac.syscr & KB_MASK;
0110     stats->write_syscalls   = p->ioac.syscw & KB_MASK;
0111 #ifdef CONFIG_TASK_IO_ACCOUNTING
0112     stats->read_bytes   = p->ioac.read_bytes & KB_MASK;
0113     stats->write_bytes  = p->ioac.write_bytes & KB_MASK;
0114     stats->cancelled_write_bytes = p->ioac.cancelled_write_bytes & KB_MASK;
0115 #else
0116     stats->read_bytes   = 0;
0117     stats->write_bytes  = 0;
0118     stats->cancelled_write_bytes = 0;
0119 #endif
0120 }
0121 #undef KB
0122 #undef MB
0123
0124 static void __acct_update_integrals(struct task_struct *tsk,
0125                     u64 utime, u64 stime)
0126 {
0127     u64 time, delta;
0128
0129     if (!likely(tsk->mm))
0130         return;
0131
0132     time = stime + utime;
0133     delta = time - tsk->acct_timexpd;
0134
0135     if (delta < TICK_NSEC)
0136         return;
0137
0138     tsk->acct_timexpd = time;
0139     /*
0140      * Divide by 1024 to avoid overflow, and to avoid division.
0141      * The final unit reported to userspace is Mbyte-usecs,
0142      * the rest of the math is done in xacct_add_tsk.
0143      */
0144     tsk->acct_rss_mem1 += delta * get_mm_rss(tsk->mm) >> 10;
0145     tsk->acct_vm_mem1 += delta * READ_ONCE(tsk->mm->total_vm) >> 10;
0146 }
0147
0148 /**
0149  * acct_update_integrals - update mm integral fields in task_struct
0150  * @tsk: task_struct for accounting
0151  */
0152 void acct_update_integrals(struct task_struct *tsk)
0153 {
0154     u64 utime, stime;
0155     unsigned long flags;
0156
0157     local_irq_save(flags);
0158     task_cputime(tsk, &utime, &stime);
0159     __acct_update_integrals(tsk, utime, stime);
0160     local_irq_restore(flags);
0161 }
0162
0163 /**
0164  * acct_account_cputime - update mm integral after cputime update
0165  * @tsk: task_struct for accounting
0166  */
0167 void acct_account_cputime(struct task_struct *tsk)
0168 {
0169     __acct_update_integrals(tsk, tsk->utime, tsk->stime);
0170 }
0171
0172 /**
0173  * acct_clear_integrals - clear the mm integral fields in task_struct
0174  * @tsk: task_struct whose accounting fields are cleared
0175  */
0176 void acct_clear_integrals(struct task_struct *tsk)
0177 {
0178     tsk->acct_timexpd = 0;
0179     tsk->acct_rss_mem1 = 0;
0180     tsk->acct_vm_mem1 = 0;
0181 }
0182 #endif