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* [patch] sched,cgroup_sched: fix up task_groups list
@ 2012-08-06 15:32 Mike Galbraith
  2012-08-06 19:04 ` Peter Zijlstra
  0 siblings, 1 reply; 6+ messages in thread
From: Mike Galbraith @ 2012-08-06 15:32 UTC (permalink / raw)
  To: LKML; +Cc: Peter Zijlstra


Thinko happened during sched migration to kernel/sched, fix it up.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Cc: stable@kernel.org # v3.3+
---
 kernel/sched/core.c  |    1 +
 kernel/sched/sched.h |    2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -7246,6 +7246,7 @@ int in_sched_functions(unsigned long add
 
 #ifdef CONFIG_CGROUP_SCHED
 struct task_group root_task_group;
+LIST_HEAD(task_groups);
 #endif
 
 DECLARE_PER_CPU(cpumask_var_t, load_balance_tmpmask);
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -80,7 +80,7 @@ extern struct mutex sched_domains_mutex;
 struct cfs_rq;
 struct rt_rq;
 
-static LIST_HEAD(task_groups);
+extern struct list_head task_groups;
 
 struct cfs_bandwidth {
 #ifdef CONFIG_CFS_BANDWIDTH



^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [patch] sched,cgroup_sched: fix up task_groups list
  2012-08-06 15:32 [patch] sched,cgroup_sched: fix up task_groups list Mike Galbraith
@ 2012-08-06 19:04 ` Peter Zijlstra
  2012-08-06 20:09   ` Mike Galbraith
  0 siblings, 1 reply; 6+ messages in thread
From: Peter Zijlstra @ 2012-08-06 19:04 UTC (permalink / raw)
  To: Mike Galbraith; +Cc: LKML

On Mon, 2012-08-06 at 17:32 +0200, Mike Galbraith wrote:
> Thinko happened during sched migration to kernel/sched, fix it up.

what's the effect.. that is what broke and why are we backporting this
to -stable?

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [patch] sched,cgroup_sched: fix up task_groups list
  2012-08-06 19:04 ` Peter Zijlstra
@ 2012-08-06 20:09   ` Mike Galbraith
  2012-08-06 20:41     ` Peter Zijlstra
  0 siblings, 1 reply; 6+ messages in thread
From: Mike Galbraith @ 2012-08-06 20:09 UTC (permalink / raw)
  To: Peter Zijlstra; +Cc: LKML

On Mon, 2012-08-06 at 21:04 +0200, Peter Zijlstra wrote: 
> On Mon, 2012-08-06 at 17:32 +0200, Mike Galbraith wrote:
> > Thinko happened during sched migration to kernel/sched, fix it up.
> 
> what's the effect.. that is what broke and why are we backporting this
> to -stable?

The effect is that for_each_rt_rq() doesn't work, because it's not the
same task_groups list that groups were added to, it's an empty list, so
__enable/disable_runtime() and print_rt_stats() don't work, and you
can't see rt task groups.

-Mike


^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [patch] sched,cgroup_sched: fix up task_groups list
  2012-08-06 20:09   ` Mike Galbraith
@ 2012-08-06 20:41     ` Peter Zijlstra
  2012-08-07  3:00       ` Mike Galbraith
  0 siblings, 1 reply; 6+ messages in thread
From: Peter Zijlstra @ 2012-08-06 20:41 UTC (permalink / raw)
  To: Mike Galbraith; +Cc: LKML

On Mon, 2012-08-06 at 22:09 +0200, Mike Galbraith wrote:
> On Mon, 2012-08-06 at 21:04 +0200, Peter Zijlstra wrote: 
> > On Mon, 2012-08-06 at 17:32 +0200, Mike Galbraith wrote:
> > > Thinko happened during sched migration to kernel/sched, fix it up.
> > 
> > what's the effect.. that is what broke and why are we backporting this
> > to -stable?
> 
> The effect is that for_each_rt_rq() doesn't work, because it's not the
> same task_groups list that groups were added to, it's an empty list, so
> __enable/disable_runtime() and print_rt_stats() don't work, and you
> can't see rt task groups.

It seems to me this makes for excellent changelog material ;-)

^ permalink raw reply	[flat|nested] 6+ messages in thread
* Re: [patch] sched,cgroup_sched: fix up task_groups list
  2012-08-06 20:41     ` Peter Zijlstra
@ 2012-08-07  3:00       ` Mike Galbraith
  2012-08-13 16:51         ` [tip:sched/urgent] sched,cgroup: Fix " tip-bot for Mike Galbraith
  0 siblings, 1 reply; 6+ messages in thread
From: Mike Galbraith @ 2012-08-07  3:00 UTC (permalink / raw)
  To: Peter Zijlstra; +Cc: LKML

On Mon, 2012-08-06 at 22:41 +0200, Peter Zijlstra wrote: 
> On Mon, 2012-08-06 at 22:09 +0200, Mike Galbraith wrote:
> > On Mon, 2012-08-06 at 21:04 +0200, Peter Zijlstra wrote: 
> > > On Mon, 2012-08-06 at 17:32 +0200, Mike Galbraith wrote:
> > > > Thinko happened during sched migration to kernel/sched, fix it up.
> > > 
> > > what's the effect.. that is what broke and why are we backporting this
> > > to -stable?
> > 
> > The effect is that for_each_rt_rq() doesn't work, because it's not the
> > same task_groups list that groups were added to, it's an empty list, so
> > __enable/disable_runtime() and print_rt_stats() don't work, and you
> > can't see rt task groups.
> 
> It seems to me this makes for excellent changelog material ;-)

You do have a point there.  Back when I was looking for why the hell rt
task groups went missing, it was "<facepalm> well _duh_" upon finding
the why, and changelog seemed self evident ;-)

sched,cgroup_sched: fix up task_groups list

With multiple instances of task_groups, for_each_rt_rq() is a noop,
no task groups having been added to the rt.c list instance.  This
renders __enable/disable_runtime() and print_rt_stats() noop, the
user (non) visible effect being that rt task groups are missing in
/proc/sched_debug.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Cc: stable@kernel.org # v3.3+
---
 kernel/sched/core.c  |    1 +
 kernel/sched/sched.h |    2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -7246,6 +7246,7 @@ int in_sched_functions(unsigned long add
 
 #ifdef CONFIG_CGROUP_SCHED
 struct task_group root_task_group;
+LIST_HEAD(task_groups);
 #endif
 
 DECLARE_PER_CPU(cpumask_var_t, load_balance_tmpmask);
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -80,7 +80,7 @@ extern struct mutex sched_domains_mutex;
 struct cfs_rq;
 struct rt_rq;
 
-static LIST_HEAD(task_groups);
+extern struct list_head task_groups;
 
 struct cfs_bandwidth {
 #ifdef CONFIG_CFS_BANDWIDTH



^ permalink raw reply	[flat|nested] 6+ messages in thread
* [tip:sched/urgent] sched,cgroup: Fix up task_groups list
  2012-08-07  3:00       ` Mike Galbraith
@ 2012-08-13 16:51         ` tip-bot for Mike Galbraith
  0 siblings, 0 replies; 6+ messages in thread
From: tip-bot for Mike Galbraith @ 2012-08-13 16:51 UTC (permalink / raw)
  To: linux-tip-commits; +Cc: linux-kernel, hpa, mingo, a.p.zijlstra, efault, tglx

Commit-ID:  35cf4e50b16331def6cfcbee11e49270b6db07f5
Gitweb:     http://git.kernel.org/tip/35cf4e50b16331def6cfcbee11e49270b6db07f5
Author:     Mike Galbraith <efault@gmx.de>
AuthorDate: Tue, 7 Aug 2012 05:00:13 +0200
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Mon, 13 Aug 2012 18:41:54 +0200

sched,cgroup: Fix up task_groups list

With multiple instances of task_groups, for_each_rt_rq() is a noop,
no task groups having been added to the rt.c list instance.  This
renders __enable/disable_runtime() and print_rt_stats() noop, the
user (non) visible effect being that rt task groups are missing in
/proc/sched_debug.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Cc: stable@kernel.org # v3.3+
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1344308413.6846.7.camel@marge.simpson.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 kernel/sched/core.c  |    1 +
 kernel/sched/sched.h |    2 +-
 2 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index e2c5841..6aa212f 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -7252,6 +7252,7 @@ int in_sched_functions(unsigned long addr)
 
 #ifdef CONFIG_CGROUP_SCHED
 struct task_group root_task_group;
+LIST_HEAD(task_groups);
 #endif
 
 DECLARE_PER_CPU(cpumask_var_t, load_balance_tmpmask);
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 531411b..f6714d0 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -80,7 +80,7 @@ extern struct mutex sched_domains_mutex;
 struct cfs_rq;
 struct rt_rq;
 
-static LIST_HEAD(task_groups);
+extern struct list_head task_groups;
 
 struct cfs_bandwidth {
 #ifdef CONFIG_CFS_BANDWIDTH

^ permalink raw reply related	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2012-08-13 16:51 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2012-08-06 15:32 [patch] sched,cgroup_sched: fix up task_groups list Mike Galbraith
2012-08-06 19:04 ` Peter Zijlstra
2012-08-06 20:09   ` Mike Galbraith
2012-08-06 20:41     ` Peter Zijlstra
2012-08-07  3:00       ` Mike Galbraith
2012-08-13 16:51         ` [tip:sched/urgent] sched,cgroup: Fix " tip-bot for Mike Galbraith

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