This is a note to let you know that I've just added the patch titled
s390/cputime: fix guest/irq/softirq times after CPU hotplug
to the 4.13-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
s390-cputime-fix-guest-irq-softirq-times-after-cpu-hotplug.patch
and it can be found in the queue-4.13 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From b7662eef14caf4f582d453d45395825b5a8f594c Mon Sep 17 00:00:00 2001
From: Christian Borntraeger <borntraeger@xxxxxxxxxx>
Date: Wed, 4 Oct 2017 14:46:17 +0200
Subject: s390/cputime: fix guest/irq/softirq times after CPU hotplug
From: Christian Borntraeger <borntraeger@xxxxxxxxxx>
commit b7662eef14caf4f582d453d45395825b5a8f594c upstream.
On CPU hotplug some cpu stats contain bogus values:
$ cat /proc/stat
cpu 0 0 49 1280 0 0 0 3 0 0
cpu0 0 0 49 618 0 0 0 3 0 0
cpu1 0 0 0 662 0 0 0 0 0 0
[...]
$ echo 0 > /sys/devices/system/cpu/cpu1/online
$ echo 1 > /sys/devices/system/cpu/cpu1/online
$ cat /proc/stat
cpu 0 0 49 3200 0 450359962737 450359962737 3 0 0
cpu0 0 0 49 1956 0 0 0 3 0 0
cpu1 0 0 0 1244 0 450359962737 450359962737 0 0 0
[...]
pcpu_attach_task() needs the same assignments as vtime_task_switch.
Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
Fixes: b7394a5f4ce9 ("sched/cputime, s390: Implement delayed accounting of system time")
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/s390/kernel/smp.c | 3 +++
1 file changed, 3 insertions(+)
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -293,7 +293,10 @@ static void pcpu_attach_task(struct pcpu
lc->lpp = LPP_MAGIC;
lc->current_pid = tsk->pid;
lc->user_timer = tsk->thread.user_timer;
+ lc->guest_timer = tsk->thread.guest_timer;
lc->system_timer = tsk->thread.system_timer;
+ lc->hardirq_timer = tsk->thread.hardirq_timer;
+ lc->softirq_timer = tsk->thread.softirq_timer;
lc->steal_timer = 0;
}
Patches currently in stable-queue which might be from borntraeger@xxxxxxxxxx are
queue-4.13/s390-cputime-fix-guest-irq-softirq-times-after-cpu-hotplug.patch