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| Started by | Wanpeng Li <kernellwp@gmail.com> |
|---|---|
| First post | 2017-02-22 09:00 +0100 |
| Last post | 2017-02-24 10:20 +0100 |
| Articles | 3 — 3 participants |
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[PATCH] sched/fair: Update rq clock before changing a task's CPU affinity Wanpeng Li <kernellwp@gmail.com> - 2017-02-22 09:00 +0100
Re: [PATCH] sched/fair: Update rq clock before changing a task's CPU affinity Matt Fleming <matt@codeblueprint.co.uk> - 2017-02-22 10:40 +0100
[tip:sched/urgent] sched/fair: Update rq clock before changing a task's CPU affinity tip-bot for Wanpeng Li <tipbot@zytor.com> - 2017-02-24 10:20 +0100
| From | Wanpeng Li <kernellwp@gmail.com> |
|---|---|
| Date | 2017-02-22 09:00 +0100 |
| Subject | [PATCH] sched/fair: Update rq clock before changing a task's CPU affinity |
| Message-ID | <tdA09-6IQ-5@gated-at.bofh.it> |
From: Wanpeng Li <wanpeng.li@hotmail.com>
------------[ cut here ]------------
WARNING: CPU: 6 PID: 81 at kernel/sched/sched.h:812 set_next_entity+0x11d/0x380
rq->clock_update_flags < RQCF_ACT_SKIP
CPU: 6 PID: 81 Comm: torture_shuffle Not tainted 4.10.0+ #1
Hardware name: LENOVO ThinkCentre M8500t-N000/SHARKBAY, BIOS FBKTC1AUS 02/16/2016
Call Trace:
dump_stack+0x85/0xc2
__warn+0xcb/0xf0
warn_slowpath_fmt+0x5f/0x80
set_next_entity+0x11d/0x380
set_curr_task_fair+0x2b/0x60
do_set_cpus_allowed+0x139/0x180
__set_cpus_allowed_ptr+0x113/0x260
set_cpus_allowed_ptr+0x10/0x20
torture_shuffle+0xfd/0x180
kthread+0x10f/0x150
? torture_shutdown_init+0x60/0x60
? kthread_create_on_node+0x60/0x60
ret_from_fork+0x31/0x40
---[ end trace dd94d92344cea9c6 ]---
This is triggered during boot when CONFIG_SCHED_DEBUG is enabled. The
task is running && !queued, so there is no rq clock update before calling
set_curr_task.
This patch fixes it by updating rq clock after holding rq->lock/pi_lock
just as what other dequeue + put_prev + enqueue + set_curr story does.
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
---
kernel/sched/core.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 34e2291..2c51bdf 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1087,6 +1087,7 @@ static int __set_cpus_allowed_ptr(struct task_struct *p,
int ret = 0;
rq = task_rq_lock(p, &rf);
+ update_rq_clock(rq);
if (p->flags & PF_KTHREAD) {
/*
--
2.7.4
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| From | Matt Fleming <matt@codeblueprint.co.uk> |
|---|---|
| Date | 2017-02-22 10:40 +0100 |
| Subject | Re: [PATCH] sched/fair: Update rq clock before changing a task's CPU affinity |
| Message-ID | <tdByW-7Zb-31@gated-at.bofh.it> |
| In reply to | #1585975 |
On Tue, 21 Feb, at 11:52:55PM, Wanpeng Li wrote: > From: Wanpeng Li <wanpeng.li@hotmail.com> > > ------------[ cut here ]------------ > WARNING: CPU: 6 PID: 81 at kernel/sched/sched.h:812 set_next_entity+0x11d/0x380 > rq->clock_update_flags < RQCF_ACT_SKIP > CPU: 6 PID: 81 Comm: torture_shuffle Not tainted 4.10.0+ #1 > Hardware name: LENOVO ThinkCentre M8500t-N000/SHARKBAY, BIOS FBKTC1AUS 02/16/2016 > Call Trace: > dump_stack+0x85/0xc2 > __warn+0xcb/0xf0 > warn_slowpath_fmt+0x5f/0x80 > set_next_entity+0x11d/0x380 > set_curr_task_fair+0x2b/0x60 > do_set_cpus_allowed+0x139/0x180 > __set_cpus_allowed_ptr+0x113/0x260 > set_cpus_allowed_ptr+0x10/0x20 > torture_shuffle+0xfd/0x180 > kthread+0x10f/0x150 > ? torture_shutdown_init+0x60/0x60 > ? kthread_create_on_node+0x60/0x60 > ret_from_fork+0x31/0x40 > ---[ end trace dd94d92344cea9c6 ]--- > > This is triggered during boot when CONFIG_SCHED_DEBUG is enabled. The > task is running && !queued, so there is no rq clock update before calling > set_curr_task. > > This patch fixes it by updating rq clock after holding rq->lock/pi_lock > just as what other dequeue + put_prev + enqueue + set_curr story does. > > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: Ingo Molnar <mingo@kernel.org> > Cc: Matt Fleming <matt@codeblueprint.co.uk> > Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> > --- > kernel/sched/core.c | 1 + > 1 file changed, 1 insertion(+) This looks correct. Thanks for doing it. Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
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| From | tip-bot for Wanpeng Li <tipbot@zytor.com> |
|---|---|
| Date | 2017-02-24 10:20 +0100 |
| Subject | [tip:sched/urgent] sched/fair: Update rq clock before changing a task's CPU affinity |
| Message-ID | <tekcF-6wz-11@gated-at.bofh.it> |
| In reply to | #1585975 |
Commit-ID: a499c3ead88ccf147fc50689e85a530ad923ce36
Gitweb: http://git.kernel.org/tip/a499c3ead88ccf147fc50689e85a530ad923ce36
Author: Wanpeng Li <wanpeng.li@hotmail.com>
AuthorDate: Tue, 21 Feb 2017 23:52:55 -0800
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Fri, 24 Feb 2017 08:58:33 +0100
sched/fair: Update rq clock before changing a task's CPU affinity
This is triggered during boot when CONFIG_SCHED_DEBUG is enabled:
------------[ cut here ]------------
WARNING: CPU: 6 PID: 81 at kernel/sched/sched.h:812 set_next_entity+0x11d/0x380
rq->clock_update_flags < RQCF_ACT_SKIP
CPU: 6 PID: 81 Comm: torture_shuffle Not tainted 4.10.0+ #1
Hardware name: LENOVO ThinkCentre M8500t-N000/SHARKBAY, BIOS FBKTC1AUS 02/16/2016
Call Trace:
dump_stack+0x85/0xc2
__warn+0xcb/0xf0
warn_slowpath_fmt+0x5f/0x80
set_next_entity+0x11d/0x380
set_curr_task_fair+0x2b/0x60
do_set_cpus_allowed+0x139/0x180
__set_cpus_allowed_ptr+0x113/0x260
set_cpus_allowed_ptr+0x10/0x20
torture_shuffle+0xfd/0x180
kthread+0x10f/0x150
? torture_shutdown_init+0x60/0x60
? kthread_create_on_node+0x60/0x60
ret_from_fork+0x31/0x40
---[ end trace dd94d92344cea9c6 ]---
The task is running && !queued, so there is no rq clock update before calling
set_curr_task().
This patch fixes it by updating rq clock after holding rq->lock/pi_lock
just as what other dequeue + put_prev + enqueue + set_curr story does.
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1487749975-5994-1-git-send-email-wanpeng.li@hotmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
kernel/sched/core.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 2d6e828..cc1e3e0 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1087,6 +1087,7 @@ static int __set_cpus_allowed_ptr(struct task_struct *p,
int ret = 0;
rq = task_rq_lock(p, &rf);
+ update_rq_clock(rq);
if (p->flags & PF_KTHREAD) {
/*
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