[PATCH 23/32] nohz/cpuset: Flush cputimes for getrusage() and times() syscalls

[Frederic Weisbecker]

Both syscalls need to iterate through the thread group to get
the cputimes. As some threads of the group may be running on
nohz cpuset, we need to flush the cputimes there.

Signed-off-by: Frederic Weisbecker <fweisbec at gmail.com>
Cc: Alessio Igor Bogani <abogani at kernel.org>
Cc: Andrew Morton <akpm at linux-foundation.org>
Cc: Avi Kivity <avi at redhat.com>
Cc: Chris Metcalf <cmetcalf at tilera.com>
Cc: Christoph Lameter <cl at linux.com>
Cc: Daniel Lezcano <daniel.lezcano at linaro.org>
Cc: Geoff Levand <geoff at infradead.org>
Cc: Gilad Ben Yossef <gilad at benyossef.com>
Cc: Ingo Molnar <mingo at kernel.org>
Cc: Max Krasnyansky <maxk at qualcomm.com>
Cc: Paul E. McKenney <paulmck at linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz at infradead.org>
Cc: Stephen Hemminger <shemminger at vyatta.com>
Cc: Steven Rostedt <rostedt at goodmis.org>
Cc: Sven-Thorsten Dietrich <thebigcorporation at gmail.com>
Cc: Thomas Gleixner <tglx at linutronix.de>
Cc: Zen Lin <zen at openhuawei.org>
---
 kernel/sys.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/kernel/sys.c b/kernel/sys.c
index 4070153..5b3e880 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -45,6 +45,7 @@
 #include <linux/syscalls.h>
 #include <linux/kprobes.h>
 #include <linux/user_namespace.h>
+#include <linux/cpuset.h>
 
 #include <linux/kmsg_dump.h>
 /* Move somewhere else to avoid recompiling? */
@@ -950,6 +951,8 @@ void do_sys_times(struct tms *tms)
 {
 	cputime_t tgutime, tgstime, cutime, cstime;
 
+	cpuset_nohz_flush_cputimes();
+
 	spin_lock_irq(&current->sighand->siglock);
 	thread_group_times(current, &tgutime, &tgstime);
 	cutime = current->signal->cutime;
@@ -1614,6 +1617,9 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
 		goto out;
 	}
 
+	/* For thread_group_times */
+	cpuset_nohz_flush_cputimes();
+
 	if (!lock_task_sighand(p, &flags))
 		return;
 
-- 
1.7.5.4