signal: re-add dead task accumulation stats.
We're going to split the process wide cpu accounting into two parts:
- clocks; which can take all the time they want since they run
from user context.
- timers; which need constant time tracing but can affort the overhead
because they're default off -- and rare.
The clock readout will go back to a full sum of the thread group, for this
we need to re-add the exit stats that were removed in the initial itimer
rework (f06febc9: timers: fix itimer/many thread hang).
Furthermore, since that full sum can be rather slow for large thread groups
and we have the complete dead task stats, revert the do_notify_parent time
computation.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 2127e95..2e0646a 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -559,7 +559,7 @@
* Live threads maintain their own counters and add to these
* in __exit_signal, except for the group leader.
*/
- cputime_t cutime, cstime;
+ cputime_t utime, stime, cutime, cstime;
cputime_t gtime;
cputime_t cgtime;
unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
@@ -568,6 +568,14 @@
struct task_io_accounting ioac;
/*
+ * Cumulative ns of schedule CPU time fo dead threads in the
+ * group, not including a zombie group leader, (This only differs
+ * from jiffies_to_ns(utime + stime) if sched_clock uses something
+ * other than jiffies.)
+ */
+ unsigned long long sum_sched_runtime;
+
+ /*
* We don't bother to synchronize most readers of this at all,
* because there is no reader checking a limit that actually needs
* to get both rlim_cur and rlim_max atomically, and either one
diff --git a/kernel/exit.c b/kernel/exit.c
index f80dec3..efd30cc 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -118,6 +118,8 @@
* We won't ever get here for the group leader, since it
* will have been the last reference on the signal_struct.
*/
+ sig->utime = cputime_add(sig->utime, task_utime(tsk));
+ sig->stime = cputime_add(sig->stime, task_stime(tsk));
sig->gtime = cputime_add(sig->gtime, task_gtime(tsk));
sig->min_flt += tsk->min_flt;
sig->maj_flt += tsk->maj_flt;
@@ -126,6 +128,7 @@
sig->inblock += task_io_get_inblock(tsk);
sig->oublock += task_io_get_oublock(tsk);
task_io_accounting_add(&sig->ioac, &tsk->ioac);
+ sig->sum_sched_runtime += tsk->se.sum_exec_runtime;
sig = NULL; /* Marker for below. */
}
diff --git a/kernel/fork.c b/kernel/fork.c
index 242a706..e8e854a 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -851,13 +851,14 @@
sig->tty_old_pgrp = NULL;
sig->tty = NULL;
- sig->cutime = sig->cstime = cputime_zero;
+ sig->utime = sig->stime = sig->cutime = sig->cstime = cputime_zero;
sig->gtime = cputime_zero;
sig->cgtime = cputime_zero;
sig->nvcsw = sig->nivcsw = sig->cnvcsw = sig->cnivcsw = 0;
sig->min_flt = sig->maj_flt = sig->cmin_flt = sig->cmaj_flt = 0;
sig->inblock = sig->oublock = sig->cinblock = sig->coublock = 0;
task_io_accounting_init(&sig->ioac);
+ sig->sum_sched_runtime = 0;
taskstats_tgid_init(sig);
task_lock(current->group_leader);
diff --git a/kernel/signal.c b/kernel/signal.c
index b6b3676..2a74fe87 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1367,7 +1367,6 @@
struct siginfo info;
unsigned long flags;
struct sighand_struct *psig;
- struct task_cputime cputime;
int ret = sig;
BUG_ON(sig == -1);
@@ -1397,9 +1396,10 @@
info.si_uid = __task_cred(tsk)->uid;
rcu_read_unlock();
- thread_group_cputime(tsk, &cputime);
- info.si_utime = cputime_to_jiffies(cputime.utime);
- info.si_stime = cputime_to_jiffies(cputime.stime);
+ info.si_utime = cputime_to_clock_t(cputime_add(tsk->utime,
+ tsk->signal->utime));
+ info.si_stime = cputime_to_clock_t(cputime_add(tsk->stime,
+ tsk->signal->stime));
info.si_status = tsk->exit_code & 0x7f;
if (tsk->exit_code & 0x80)
