* [PATCH v2] sched/deadline: Fix the intention to re-evalute tick dependency for offline cpu
@ 2016-08-12 8:19 Wanpeng Li
2016-08-12 8:54 ` kbuild test robot
2016-08-12 8:57 ` kbuild test robot
0 siblings, 2 replies; 3+ messages in thread
From: Wanpeng Li @ 2016-08-12 8:19 UTC (permalink / raw)
To: linux-kernel, kvm
Cc: Wanpeng Li, Ingo Molnar, Peter Zijlstra, Juri Lelli, Luca Abeni,
Frederic Weisbecker
From: Wanpeng Li <wanpeng.li@hotmail.com>
The dl task will be replenished after dl task timer fire and start a
new period. It will be enqueued and to re-evaluate its dependency on
the tick in order to restart it. However, if cpu is hot-unplug,
irq_work_queue will splash since the target cpu is offline.
As a result:
WARNING: CPU: 2 PID: 0 at kernel/irq_work.c:69 irq_work_queue_on+0xad/0xe0
Call Trace:
dump_stack+0x99/0xd0
__warn+0xd1/0xf0
warn_slowpath_null+0x1d/0x20
irq_work_queue_on+0xad/0xe0
tick_nohz_full_kick_cpu+0x44/0x50
tick_nohz_dep_set_cpu+0x74/0xb0
enqueue_task_dl+0x226/0x480
activate_task+0x5c/0xa0
dl_task_timer+0x19b/0x2c0
? push_dl_task.part.31+0x190/0x190
This can be triggered by hot-unplug the full dynticks cpu which dl
task is running on.
We enqueue the dl task on the offline CPU, because we need to do
replenish for start_dl_timer(). So, as Juri pointed out, we would
need to do is calling replenish_dl_entity() directly, instead of
enqueue_task_dl(). pi_se shouldn't be a problem as the task shouldn't
be boosted if it was throttled.
This patch fix it by just replenish dl entity to avoid the intention
to re-evaluate tick dependency if the cpu is offline.
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@arm.com>
Cc: Luca Abeni <luca.abeni@unitn.it>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
---
v1 -> v2:
* replenish dl entity
kernel/sched/deadline.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index d091f4a..b141bd2 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -641,11 +641,15 @@ static enum hrtimer_restart dl_task_timer(struct hrtimer *timer)
goto unlock;
}
- enqueue_task_dl(rq, p, ENQUEUE_REPLENISH);
- if (dl_task(rq->curr))
- check_preempt_curr_dl(rq, p, 0);
- else
- resched_curr(rq);
+ if (unlikely(!rq->online))
+ replenish_dl_entity(dl_se, dl_se);
+ else {
+ enqueue_task_dl(rq, p, ENQUEUE_REPLENISH);
+ if (dl_task(rq->curr))
+ check_preempt_curr_dl(rq, p, 0);
+ else
+ resched_curr(rq);
+ }
#ifdef CONFIG_SMP
/*
--
1.9.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH v2] sched/deadline: Fix the intention to re-evalute tick dependency for offline cpu
2016-08-12 8:19 [PATCH v2] sched/deadline: Fix the intention to re-evalute tick dependency for offline cpu Wanpeng Li
@ 2016-08-12 8:54 ` kbuild test robot
2016-08-12 8:57 ` kbuild test robot
1 sibling, 0 replies; 3+ messages in thread
From: kbuild test robot @ 2016-08-12 8:54 UTC (permalink / raw)
To: Wanpeng Li
Cc: kbuild-all, linux-kernel, kvm, Wanpeng Li, Ingo Molnar,
Peter Zijlstra, Juri Lelli, Luca Abeni, Frederic Weisbecker
[-- Attachment #1: Type: text/plain, Size: 3091 bytes --]
Hi Wanpeng,
[auto build test ERROR on tip/sched/core]
[also build test ERROR on v4.8-rc1 next-20160811]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Wanpeng-Li/sched-deadline-Fix-the-intention-to-re-evalute-tick-dependency-for-offline-cpu/20160812-162528
config: x86_64-randconfig-x013-201632 (attached as .config)
compiler: gcc-6 (Debian 6.1.1-9) 6.1.1 20160705
reproduce:
# save the attached .config to linux build tree
make ARCH=x86_64
All error/warnings (new ones prefixed by >>):
In file included from include/uapi/linux/stddef.h:1:0,
from include/linux/stddef.h:4,
from include/uapi/linux/posix_types.h:4,
from include/uapi/linux/types.h:13,
from include/linux/types.h:5,
from include/uapi/linux/capability.h:16,
from include/linux/capability.h:15,
from include/linux/sched.h:15,
from kernel/sched/sched.h:2,
from kernel/sched/deadline.c:17:
kernel/sched/deadline.c: In function 'dl_task_timer':
>> kernel/sched/deadline.c:644:18: error: 'struct rq' has no member named 'online'
if (unlikely(!rq->online))
^
include/linux/compiler.h:139:45: note: in definition of macro 'unlikely'
# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
^
>> kernel/sched/deadline.c:644:18: error: 'struct rq' has no member named 'online'
if (unlikely(!rq->online))
^
include/linux/compiler.h:139:53: note: in definition of macro 'unlikely'
# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
^
>> kernel/sched/deadline.c:644:18: error: 'struct rq' has no member named 'online'
if (unlikely(!rq->online))
^
include/linux/compiler.h:112:47: note: in definition of macro 'likely_notrace'
#define likely_notrace(x) __builtin_expect(!!(x), 1)
^
include/linux/compiler.h:139:58: note: in expansion of macro '__branch_check__'
# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
^~~~~~~~~~~~~~~~
>> kernel/sched/deadline.c:644:6: note: in expansion of macro 'unlikely'
if (unlikely(!rq->online))
^~~~~~~~
vim +644 kernel/sched/deadline.c
638 */
639 if (!task_on_rq_queued(p)) {
640 replenish_dl_entity(dl_se, dl_se);
641 goto unlock;
642 }
643
> 644 if (unlikely(!rq->online))
645 replenish_dl_entity(dl_se, dl_se);
646 else {
647 enqueue_task_dl(rq, p, ENQUEUE_REPLENISH);
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
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^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH v2] sched/deadline: Fix the intention to re-evalute tick dependency for offline cpu
2016-08-12 8:19 [PATCH v2] sched/deadline: Fix the intention to re-evalute tick dependency for offline cpu Wanpeng Li
2016-08-12 8:54 ` kbuild test robot
@ 2016-08-12 8:57 ` kbuild test robot
1 sibling, 0 replies; 3+ messages in thread
From: kbuild test robot @ 2016-08-12 8:57 UTC (permalink / raw)
To: Wanpeng Li
Cc: kbuild-all, linux-kernel, kvm, Wanpeng Li, Ingo Molnar,
Peter Zijlstra, Juri Lelli, Luca Abeni, Frederic Weisbecker
[-- Attachment #1: Type: text/plain, Size: 8186 bytes --]
Hi Wanpeng,
[auto build test WARNING on tip/sched/core]
[also build test WARNING on v4.8-rc1 next-20160811]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Wanpeng-Li/sched-deadline-Fix-the-intention-to-re-evalute-tick-dependency-for-offline-cpu/20160812-162528
config: x86_64-randconfig-x019-201632 (attached as .config)
compiler: gcc-6 (Debian 6.1.1-9) 6.1.1 20160705
reproduce:
# save the attached .config to linux build tree
make ARCH=x86_64
All warnings (new ones prefixed by >>):
In file included from include/uapi/linux/stddef.h:1:0,
from include/linux/stddef.h:4,
from include/uapi/linux/posix_types.h:4,
from include/uapi/linux/types.h:13,
from include/linux/types.h:5,
from include/uapi/linux/capability.h:16,
from include/linux/capability.h:15,
from include/linux/sched.h:15,
from kernel/sched/sched.h:2,
from kernel/sched/deadline.c:17:
kernel/sched/deadline.c: In function 'dl_task_timer':
kernel/sched/deadline.c:644:18: error: 'struct rq' has no member named 'online'
if (unlikely(!rq->online))
^
include/linux/compiler.h:149:30: note: in definition of macro '__trace_if'
if (__builtin_constant_p(!!(cond)) ? !!(cond) : \
^~~~
>> kernel/sched/deadline.c:644:2: note: in expansion of macro 'if'
if (unlikely(!rq->online))
^~
kernel/sched/deadline.c:644:6: note: in expansion of macro 'unlikely'
if (unlikely(!rq->online))
^~~~~~~~
kernel/sched/deadline.c:644:18: error: 'struct rq' has no member named 'online'
if (unlikely(!rq->online))
^
include/linux/compiler.h:149:30: note: in definition of macro '__trace_if'
if (__builtin_constant_p(!!(cond)) ? !!(cond) : \
^~~~
>> kernel/sched/deadline.c:644:2: note: in expansion of macro 'if'
if (unlikely(!rq->online))
^~
kernel/sched/deadline.c:644:6: note: in expansion of macro 'unlikely'
if (unlikely(!rq->online))
^~~~~~~~
kernel/sched/deadline.c:644:18: error: 'struct rq' has no member named 'online'
if (unlikely(!rq->online))
^
include/linux/compiler.h:149:30: note: in definition of macro '__trace_if'
if (__builtin_constant_p(!!(cond)) ? !!(cond) : \
^~~~
>> kernel/sched/deadline.c:644:2: note: in expansion of macro 'if'
if (unlikely(!rq->online))
^~
include/linux/compiler.h:125:14: note: in expansion of macro 'likely_notrace'
______r = likely_notrace(x); \
^~~~~~~~~~~~~~
include/linux/compiler.h:139:58: note: in expansion of macro '__branch_check__'
# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
^~~~~~~~~~~~~~~~
kernel/sched/deadline.c:644:6: note: in expansion of macro 'unlikely'
if (unlikely(!rq->online))
^~~~~~~~
kernel/sched/deadline.c:644:18: error: 'struct rq' has no member named 'online'
if (unlikely(!rq->online))
^
include/linux/compiler.h:149:42: note: in definition of macro '__trace_if'
if (__builtin_constant_p(!!(cond)) ? !!(cond) : \
^~~~
>> kernel/sched/deadline.c:644:2: note: in expansion of macro 'if'
if (unlikely(!rq->online))
^~
kernel/sched/deadline.c:644:6: note: in expansion of macro 'unlikely'
if (unlikely(!rq->online))
^~~~~~~~
kernel/sched/deadline.c:644:18: error: 'struct rq' has no member named 'online'
if (unlikely(!rq->online))
^
include/linux/compiler.h:149:42: note: in definition of macro '__trace_if'
if (__builtin_constant_p(!!(cond)) ? !!(cond) : \
^~~~
>> kernel/sched/deadline.c:644:2: note: in expansion of macro 'if'
if (unlikely(!rq->online))
^~
kernel/sched/deadline.c:644:6: note: in expansion of macro 'unlikely'
if (unlikely(!rq->online))
^~~~~~~~
kernel/sched/deadline.c:644:18: error: 'struct rq' has no member named 'online'
if (unlikely(!rq->online))
^
include/linux/compiler.h:149:42: note: in definition of macro '__trace_if'
if (__builtin_constant_p(!!(cond)) ? !!(cond) : \
^~~~
>> kernel/sched/deadline.c:644:2: note: in expansion of macro 'if'
if (unlikely(!rq->online))
^~
include/linux/compiler.h:125:14: note: in expansion of macro 'likely_notrace'
______r = likely_notrace(x); \
^~~~~~~~~~~~~~
include/linux/compiler.h:139:58: note: in expansion of macro '__branch_check__'
# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
^~~~~~~~~~~~~~~~
kernel/sched/deadline.c:644:6: note: in expansion of macro 'unlikely'
if (unlikely(!rq->online))
^~~~~~~~
kernel/sched/deadline.c:644:18: error: 'struct rq' has no member named 'online'
if (unlikely(!rq->online))
^
include/linux/compiler.h:160:16: note: in definition of macro '__trace_if'
______r = !!(cond); \
^~~~
>> kernel/sched/deadline.c:644:2: note: in expansion of macro 'if'
if (unlikely(!rq->online))
^~
kernel/sched/deadline.c:644:6: note: in expansion of macro 'unlikely'
if (unlikely(!rq->online))
^~~~~~~~
kernel/sched/deadline.c:644:18: error: 'struct rq' has no member named 'online'
if (unlikely(!rq->online))
^
include/linux/compiler.h:160:16: note: in definition of macro '__trace_if'
______r = !!(cond); \
^~~~
>> kernel/sched/deadline.c:644:2: note: in expansion of macro 'if'
if (unlikely(!rq->online))
^~
kernel/sched/deadline.c:644:6: note: in expansion of macro 'unlikely'
if (unlikely(!rq->online))
^~~~~~~~
kernel/sched/deadline.c:644:18: error: 'struct rq' has no member named 'online'
if (unlikely(!rq->online))
^
include/linux/compiler.h:160:16: note: in definition of macro '__trace_if'
______r = !!(cond); \
^~~~
>> kernel/sched/deadline.c:644:2: note: in expansion of macro 'if'
if (unlikely(!rq->online))
^~
include/linux/compiler.h:125:14: note: in expansion of macro 'likely_notrace'
______r = likely_notrace(x); \
^~~~~~~~~~~~~~
include/linux/compiler.h:139:58: note: in expansion of macro '__branch_check__'
# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
^~~~~~~~~~~~~~~~
kernel/sched/deadline.c:644:6: note: in expansion of macro 'unlikely'
if (unlikely(!rq->online))
^~~~~~~~
vim +/if +644 kernel/sched/deadline.c
628 * schedule()
629 * deactivate_task()
630 * dequeue_task_dl()
631 * update_curr_dl()
632 * start_dl_timer()
633 * __dequeue_task_dl()
634 * prev->on_rq = 0;
635 *
636 * We can be both throttled and !queued. Replenish the counter
637 * but do not enqueue -- wait for our wakeup to do that.
638 */
639 if (!task_on_rq_queued(p)) {
640 replenish_dl_entity(dl_se, dl_se);
641 goto unlock;
642 }
643
> 644 if (unlikely(!rq->online))
645 replenish_dl_entity(dl_se, dl_se);
646 else {
647 enqueue_task_dl(rq, p, ENQUEUE_REPLENISH);
648 if (dl_task(rq->curr))
649 check_preempt_curr_dl(rq, p, 0);
650 else
651 resched_curr(rq);
652 }
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
[-- Attachment #2: .config.gz --]
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2016-08-12 8:19 [PATCH v2] sched/deadline: Fix the intention to re-evalute tick dependency for offline cpu Wanpeng Li
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2016-08-12 8:57 ` kbuild test robot
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