v4.19.13 snapshot.
diff --git a/kernel/tsacct.c b/kernel/tsacct.c
new file mode 100644
index 0000000..370724b
--- /dev/null
+++ b/kernel/tsacct.c
@@ -0,0 +1,185 @@
+/*
+ * tsacct.c - System accounting over taskstats interface
+ *
+ * Copyright (C) Jay Lan, <jlan@sgi.com>
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/sched/signal.h>
+#include <linux/sched/mm.h>
+#include <linux/sched/cputime.h>
+#include <linux/tsacct_kern.h>
+#include <linux/acct.h>
+#include <linux/jiffies.h>
+#include <linux/mm.h>
+
+/*
+ * fill in basic accounting fields
+ */
+void bacct_add_tsk(struct user_namespace *user_ns,
+ struct pid_namespace *pid_ns,
+ struct taskstats *stats, struct task_struct *tsk)
+{
+ const struct cred *tcred;
+ u64 utime, stime, utimescaled, stimescaled;
+ u64 delta;
+
+ BUILD_BUG_ON(TS_COMM_LEN < TASK_COMM_LEN);
+
+ /* calculate task elapsed time in nsec */
+ delta = ktime_get_ns() - tsk->start_time;
+ /* Convert to micro seconds */
+ do_div(delta, NSEC_PER_USEC);
+ stats->ac_etime = delta;
+ /* Convert to seconds for btime */
+ do_div(delta, USEC_PER_SEC);
+ stats->ac_btime = get_seconds() - delta;
+ if (thread_group_leader(tsk)) {
+ stats->ac_exitcode = tsk->exit_code;
+ if (tsk->flags & PF_FORKNOEXEC)
+ stats->ac_flag |= AFORK;
+ }
+ if (tsk->flags & PF_SUPERPRIV)
+ stats->ac_flag |= ASU;
+ if (tsk->flags & PF_DUMPCORE)
+ stats->ac_flag |= ACORE;
+ if (tsk->flags & PF_SIGNALED)
+ stats->ac_flag |= AXSIG;
+ stats->ac_nice = task_nice(tsk);
+ stats->ac_sched = tsk->policy;
+ stats->ac_pid = task_pid_nr_ns(tsk, pid_ns);
+ rcu_read_lock();
+ tcred = __task_cred(tsk);
+ stats->ac_uid = from_kuid_munged(user_ns, tcred->uid);
+ stats->ac_gid = from_kgid_munged(user_ns, tcred->gid);
+ stats->ac_ppid = pid_alive(tsk) ?
+ task_tgid_nr_ns(rcu_dereference(tsk->real_parent), pid_ns) : 0;
+ rcu_read_unlock();
+
+ task_cputime(tsk, &utime, &stime);
+ stats->ac_utime = div_u64(utime, NSEC_PER_USEC);
+ stats->ac_stime = div_u64(stime, NSEC_PER_USEC);
+
+ task_cputime_scaled(tsk, &utimescaled, &stimescaled);
+ stats->ac_utimescaled = div_u64(utimescaled, NSEC_PER_USEC);
+ stats->ac_stimescaled = div_u64(stimescaled, NSEC_PER_USEC);
+
+ stats->ac_minflt = tsk->min_flt;
+ stats->ac_majflt = tsk->maj_flt;
+
+ strncpy(stats->ac_comm, tsk->comm, sizeof(stats->ac_comm));
+}
+
+
+#ifdef CONFIG_TASK_XACCT
+
+#define KB 1024
+#define MB (1024*KB)
+#define KB_MASK (~(KB-1))
+/*
+ * fill in extended accounting fields
+ */
+void xacct_add_tsk(struct taskstats *stats, struct task_struct *p)
+{
+ struct mm_struct *mm;
+
+ /* convert pages-nsec/1024 to Mbyte-usec, see __acct_update_integrals */
+ stats->coremem = p->acct_rss_mem1 * PAGE_SIZE;
+ do_div(stats->coremem, 1000 * KB);
+ stats->virtmem = p->acct_vm_mem1 * PAGE_SIZE;
+ do_div(stats->virtmem, 1000 * KB);
+ mm = get_task_mm(p);
+ if (mm) {
+ /* adjust to KB unit */
+ stats->hiwater_rss = get_mm_hiwater_rss(mm) * PAGE_SIZE / KB;
+ stats->hiwater_vm = get_mm_hiwater_vm(mm) * PAGE_SIZE / KB;
+ mmput(mm);
+ }
+ stats->read_char = p->ioac.rchar & KB_MASK;
+ stats->write_char = p->ioac.wchar & KB_MASK;
+ stats->read_syscalls = p->ioac.syscr & KB_MASK;
+ stats->write_syscalls = p->ioac.syscw & KB_MASK;
+#ifdef CONFIG_TASK_IO_ACCOUNTING
+ stats->read_bytes = p->ioac.read_bytes & KB_MASK;
+ stats->write_bytes = p->ioac.write_bytes & KB_MASK;
+ stats->cancelled_write_bytes = p->ioac.cancelled_write_bytes & KB_MASK;
+#else
+ stats->read_bytes = 0;
+ stats->write_bytes = 0;
+ stats->cancelled_write_bytes = 0;
+#endif
+}
+#undef KB
+#undef MB
+
+static void __acct_update_integrals(struct task_struct *tsk,
+ u64 utime, u64 stime)
+{
+ u64 time, delta;
+
+ if (!likely(tsk->mm))
+ return;
+
+ time = stime + utime;
+ delta = time - tsk->acct_timexpd;
+
+ if (delta < TICK_NSEC)
+ return;
+
+ tsk->acct_timexpd = time;
+ /*
+ * Divide by 1024 to avoid overflow, and to avoid division.
+ * The final unit reported to userspace is Mbyte-usecs,
+ * the rest of the math is done in xacct_add_tsk.
+ */
+ tsk->acct_rss_mem1 += delta * get_mm_rss(tsk->mm) >> 10;
+ tsk->acct_vm_mem1 += delta * tsk->mm->total_vm >> 10;
+}
+
+/**
+ * acct_update_integrals - update mm integral fields in task_struct
+ * @tsk: task_struct for accounting
+ */
+void acct_update_integrals(struct task_struct *tsk)
+{
+ u64 utime, stime;
+ unsigned long flags;
+
+ local_irq_save(flags);
+ task_cputime(tsk, &utime, &stime);
+ __acct_update_integrals(tsk, utime, stime);
+ local_irq_restore(flags);
+}
+
+/**
+ * acct_account_cputime - update mm integral after cputime update
+ * @tsk: task_struct for accounting
+ */
+void acct_account_cputime(struct task_struct *tsk)
+{
+ __acct_update_integrals(tsk, tsk->utime, tsk->stime);
+}
+
+/**
+ * acct_clear_integrals - clear the mm integral fields in task_struct
+ * @tsk: task_struct whose accounting fields are cleared
+ */
+void acct_clear_integrals(struct task_struct *tsk)
+{
+ tsk->acct_timexpd = 0;
+ tsk->acct_rss_mem1 = 0;
+ tsk->acct_vm_mem1 = 0;
+}
+#endif