Some numbers like nr_running and nr_uninterruptible are fundamentally
unsigned since its impossible to have a negative amount of tasks, yet
we still print them as signed to easily recognise the underflow
condition.

rq->nr_uninterruptible has 'special' accounting and can in fact very
easily become negative on a per-cpu basis.

It was noted that since the P() macro assumes things are long long and
the promotion of unsigned 'int/long' to long long on 32bit doesn't
sign extend we print silly large numbers instead of the easier to read
signed numbers.

Therefore extend the P() macro to not require the sign extention.
Reported-by: NDiwakar Tundlam <dtundlam@nvidia.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-gk5tm8t2n4ix2vkpns42uqqp@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Since there's a PID space limit of 30bits (see
futex.h:FUTEX_TID_MASK) and allocating that many tasks (assuming a
lower bound of 2 pages per task) would still take 8T of memory it
seems reasonable to say that unsigned int is sufficient for
rq->nr_running.

When we do get anywhere near that amount of tasks I suspect other
things would go funny, load-balancer load computations would really
need to be hoisted to 128bit etc.

So save a few bytes and convert rq->nr_running and friends to
unsigned int.
Suggested-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-y3tvyszjdmbibade5bw8zl81@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Currently we don't utilize the sched_switch field anymore.

But, simply removing sched_switch field from the middle of the
sched_stat output will break tools.

So, to stay compatible we hardcode it to zero and remove the
field from the scheduler data structures.

Update the schedstat documentation accordingly.
Signed-off-by: NRakib Mullick <rakib.mullick@gmail.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1327422836.27181.5.camel@localhost.localdomainSigned-off-by: NIngo Molnar <mingo@elte.hu>

There's too many sched*.[ch] files in kernel/, give them their own
directory.

(No code changed, other than Makefile glue added.)
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Since once needs to do something at conferences and fixing compile
warnings doesn't actually require much if any attention I decided
to break up the sched.c #include "*.c" fest.

This further modularizes the scheduler code.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-x0fcd3mnp8f9c99grcpewmhi@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>

Neil Brown pointed out that lock_depth somehow escaped the BKL
removal work.  Let's get rid of it now.

Note that the perf scripting utilities still have a bunch of
code for dealing with common_lock_depth in tracepoints; I have
left that in place in case anybody wants to use that code with
older kernels.
Suggested-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20110422111910.456c0e84@bike.lwn.netSigned-off-by: NIngo Molnar <mingo@elte.hu>

Provide a generic p->on_rq because the p->se.on_rq semantics are
unfavourable for lockless wakeups but needed for sched_fair.

In particular, p->on_rq is only cleared when we actually dequeue the
task in schedule() and not on any random dequeue as done by things
like __migrate_task() and __sched_setscheduler().

This also allows us to remove p->se usage from !sched_fair code.
Reviewed-by: NFrank Rowand <frank.rowand@am.sony.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110405152728.949545047@chello.nl

Use the buddy mechanism to implement yield_task_fair.  This
allows us to skip onto the next highest priority se at every
level in the CFS tree, unless doing so would introduce gross
unfairness in CPU time distribution.

We order the buddy selection in pick_next_entity to check
yield first, then last, then next.  We need next to be able
to override yield, because it is possible for the "next" and
"yield" task to be different processen in the same sub-tree
of the CFS tree.  When they are, we need to go into that
sub-tree regardless of the "yield" hint, and pick the correct
entity once we get to the right level.
Signed-off-by: NRik van Riel <riel@redhat.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110201095103.3a79e92a@annuminas.surriel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Now rq->rq_sched_info.bkl_count is not used for rq, scroll
rq->bkl_count into it. Thus we can save some space for rq.
Signed-off-by: NYong Zhang <yong.zhang0@gmail.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1294991859-13246-1-git-send-email-yong.zhang0@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Add autogroup name to cfs_rq and tasks information to /proc/sched_debug.
Signed-off-by: NBharata B Rao <bharata@linux.vnet.ibm.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110111101257.GF4772@in.ibm.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Displaying of group names in /proc/sched_debug was dropped in autogroup
patches. Add group names while displaying cfs_rq and tasks information.
Signed-off-by: NBharata B Rao <bharata@linux.vnet.ibm.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110111101153.GE4772@in.ibm.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

A recurring complaint from CFS users is that parallel kbuild has
a negative impact on desktop interactivity.  This patch
implements an idea from Linus, to automatically create task
groups.  Currently, only per session autogroups are implemented,
but the patch leaves the way open for enhancement.

Implementation: each task's signal struct contains an inherited
pointer to a refcounted autogroup struct containing a task group
pointer, the default for all tasks pointing to the
init_task_group.  When a task calls setsid(), a new task group
is created, the process is moved into the new task group, and a
reference to the preveious task group is dropped.  Child
processes inherit this task group thereafter, and increase it's
refcount.  When the last thread of a process exits, the
process's reference is dropped, such that when the last process
referencing an autogroup exits, the autogroup is destroyed.

At runqueue selection time, IFF a task has no cgroup assignment,
its current autogroup is used.

Autogroup bandwidth is controllable via setting it's nice level
through the proc filesystem:

  cat /proc/<pid>/autogroup

Displays the task's group and the group's nice level.

  echo <nice level> > /proc/<pid>/autogroup

Sets the task group's shares to the weight of nice <level> task.
Setting nice level is rate limited for !admin users due to the
abuse risk of task group locking.

The feature is enabled from boot by default if
CONFIG_SCHED_AUTOGROUP=y is selected, but can be disabled via
the boot option noautogroup, and can also be turned on/off on
the fly via:

  echo [01] > /proc/sys/kernel/sched_autogroup_enabled

... which will automatically move tasks to/from the root task group.
Signed-off-by: NMike Galbraith <efault@gmx.de>
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Markus Trippelsdorf <markus@trippelsdorf.de>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Paul Turner <pjt@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
[ Removed the task_group_path() debug code, and fixed !EVENTFD build failure. ]
Signed-off-by: NIngo Molnar <mingo@elte.hu>
LKML-Reference: <1290281700.28711.9.camel@maggy.simson.net>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Add more clock information to /proc/sched_debug, Thomas wanted to see
the sched_clock_stable state.
Requested-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

By tracking a per-cpu load-avg for each cfs_rq and folding it into a
global task_group load on each tick we can rework tg_shares_up to be
strictly per-cpu.

This should improve cpu-cgroup performance for smp systems
significantly.

[ Paul: changed to use queueing cfs_rq + bug fixes ]
Signed-off-by: NPaul Turner <pjt@google.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101115234937.580480400@google.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The sched_child_runs_first value in /proc/sched_debug is
currently displayed using a macro meant to split ns time values.
This patch uses the correct macro to display it as a plain
decimal value.
Signed-off-by: NJosh Hunt <johunt@akamai.com>
Cc: peterz@infradead.org
Cc: juhlenko@akamai.com
Cc: efault@gmx.de
LKML-Reference: <1279567876-25418-1-git-send-email-johunt@akamai.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Trivial, use get_nr_threads() helper to read signal->count which we are
going to change.

Like other callers, proc_sched_show_task() doesn't need the exactly
precise nr_threads.

David said:

: Note that get_nr_threads() isn't completely equivalent (it can return 0
: where proc_sched_show_task() will display a 1).  But I don't think this
: should be a problem.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Acked-by: NRoland McGrath <roland@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With CONFIG_PROVE_RCU=y, a warning can be triggered:

  $ cat /proc/sched_debug

...
kernel/cgroup.c:1649 invoked rcu_dereference_check() without protection!
...

Both cgroup_path() and task_group() should be called with either
rcu_read_lock or cgroup_mutex held.

The rcu_dereference_check() does include cgroup_lock_is_held(), so we
know that this lock is not held.  Therefore, in a CONFIG_PREEMPT kernel,
to say nothing of a CONFIG_PREEMPT_RT kernel, the original code could
have ended up copying a string out of the freelist.

This patch inserts RCU read-side primitives needed to prevent this
scenario.
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

This is left over from commit 7c941438 ("sched: Remove USER_SCHED"")
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Acked-by: NDhaval Giani <dhaval.giani@gmail.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: David Howells <dhowells@redhat.com>
LKML-Reference: <4BA9A05F.7010407@cn.fujitsu.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Latencytop clearing sum_exec_runtime via proc_sched_set_task() breaks
task_times().  Other places in kernel use nvcsw and nivcsw, which are
being cleared as well,  Clear task statistics only.
Reported-by: NTörök Edwin <edwintorok@gmail.com>
Signed-off-by: NMike Galbraith <efault@gmx.de>
Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1269940193.19286.14.camel@marge.simson.net>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Both avg_overlap and avg_wakeup had an inherent problem in that their accuracy
was detrimentally affected by cross-cpu wakeups, this because we are missing
the necessary call to update_curr().  This can't be fixed without increasing
overhead in our already too fat fastpath.

Additionally, with recent load balancing changes making us prefer to place tasks
in an idle cache domain (which is good for compute bound loads), communicating
tasks suffer when a sync wakeup, which would enable affine placement, is turned
into a non-sync wakeup by SYNC_LESS.  With one task on the runqueue, wake_affine()
rejects the affine wakeup request, leaving the unfortunate where placed, taking
frequent cache misses.

Remove it, and recover some fastpath cycles.
Signed-off-by: NMike Galbraith <efault@gmx.de>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1268301121.6785.30.camel@marge.simson.net>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Testing the load which led to this heuristic (nfs4 kbuild) shows that it has
outlived it's usefullness.  With intervening load balancing changes, I cannot
see any difference with/without, so recover there fastpath cycles.
Signed-off-by: NMike Galbraith <efault@gmx.de>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1268301062.6785.29.camel@marge.simson.net>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Put all statistic fields of sched_entity in one struct, sched_statistics,
and embed it into sched_entity.

This change allows to memset the sched_statistics to 0 when needed (for
instance when forking), avoiding bugs of non initialized fields.
Signed-off-by: NLucas De Marchi <lucas.de.marchi@gmail.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1268275065-18542-1-git-send-email-lucas.de.marchi@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Convert locks which cannot be sleeping locks in preempt-rt to
raw_spinlocks.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
Acked-by: NIngo Molnar <mingo@elte.hu>

This build warning:

 kernel/sched.c: In function 'set_task_cpu':
 kernel/sched.c:2070: warning: unused variable 'old_rq'

Made me realize that the forced2_migrations stat looks pretty
pointless (and a misnomer) - remove it.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

As scaling now takes place on all kind of cpu add/remove events a user
that configures values via proc should be able to configure if his set
values are still rescaled or kept whatever happens.

As the comments state that log2 was just a second guess that worked the
interface is not just designed for on/off, but to choose a scaling type.
Currently this allows none, log and linear, but more important it allwos
us to keep the interface even if someone has an even better idea how to
scale the values.
Signed-off-by: NChristian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1259579808-11357-3-git-send-email-ehrhardt@linux.vnet.ibm.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

WAKEUP_RUNNING was an experiment, not sure why that ever ended up being
merged...
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Rate limit newidle to migration_cost. It's a win for all
stages of sysbench oltp tests.
Signed-off-by: NMike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Create a new wakeup preemption mode, preempt towards tasks that run
shorter on avg. It sets next buddy to be sure we actually run the task
we preempted for.

Test results:

 root@twins:~# while :; do :; done &
 [1] 6537
 root@twins:~# while :; do :; done &
 [2] 6538
 root@twins:~# while :; do :; done &
 [3] 6539
 root@twins:~# while :; do :; done &
 [4] 6540

 root@twins:/home/peter# ./latt -c4 sleep 4
 Entries: 48 (clients=4)

 Averages:
 ------------------------------
        Max          4750 usec
        Avg           497 usec
        Stdev         737 usec

 root@twins:/home/peter# echo WAKEUP_RUNNING > /debug/sched_features

 root@twins:/home/peter# ./latt -c4 sleep 4
 Entries: 48 (clients=4)

 Averages:
 ------------------------------
        Max            14 usec
        Avg             5 usec
        Stdev           3 usec

Disabled by default - needs more testing.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NMike Galbraith <efault@gmx.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
LKML-Reference: <new-submission>

For counting how long an application has been waiting for
(disk) IO, there currently is only the HZ sample driven
information available, while for all other counters in this
class, a high resolution version is available via
CONFIG_SCHEDSTATS.

In order to make an improved bootchart tool possible, we also
need a higher resolution version of the iowait time.

This patch below adds this scheduler statistic to the kernel.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4A64B813.1080506@linux.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

There are some points which refer the per-cpu value "runqueues" directly.
sched.c provides nice abstraction, such as cpu_rq() and this_rq(),
so we should use these macros when looking runqueues.
Signed-off-by: NHitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
LKML-Reference: <20090617.222055.374768827975756908.mitake@dcl.info.waseda.ac.jp>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup, new schedstat ABI

Since they are used on in statistics and are always set to zero, the
following fields from struct rq have been removed: yld_exp_empty,
yld_act_empty and yld_both_empty.

Both Sched Debug and SCHEDSTAT_VERSION versions has also been
incremented since ABIs have been changed.

The schedtop tool has been updated to properly handle new version of
schedstat:

   http://rt.wiki.kernel.org/index.php/Schedtop_utilitySigned-off-by: NLuis Henriques <henrix@sapo.pt>
Acked-by: NGregory Haskins <ghaskins@novell.com>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
LKML-Reference: <20090324221002.GA10061@hades.domain.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The jiffies value was being printed for each CPU, which does not seem to make
sense.  Moved jiffies to system section.
Signed-off-by: NLuis Henriques <henrix@sapo.pt>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
LKML-Reference: <20090318000425.GA2228@hades.domain.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Introduce a new avg_wakeup statistic.

avg_wakeup is a measure of how frequently a task wakes up other tasks, it
represents the average time between wakeups, with a limit of avg_runtime
for when it doesn't wake up anybody.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NMike Galbraith <efault@gmx.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: avoid accessing NULL tg.css->cgroup

In commit 0a0db8f5, I removed checking
NULL tg.css->cgroup, but I realized I was wrong when I found reading
/proc/sched_debug can race with cgroup_create().
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: extend information in /proc/sched_debug

This patch adds uid information in sched_debug for CONFIG_USER_SCHED
Signed-off-by: NArun R Bharadwaj <arun@linux.vnet.ibm.com>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Luis Henriques reported that with CONFIG_PREEMPT=y + CONFIG_PREEMPT_DEBUG=y +
CONFIG_SCHED_DEBUG=y + CONFIG_LATENCYTOP=y enabled, the following warning
triggers when using latencytop:

> [  775.663239] BUG: using smp_processor_id() in preemptible [00000000] code: latencytop/6585
> [  775.663303] caller is native_sched_clock+0x3a/0x80
> [  775.663314] Pid: 6585, comm: latencytop Tainted: G        W 2.6.28-rc4-00355-g9c7c3546 #1
> [  775.663322] Call Trace:
> [  775.663343]  [<ffffffff803a94e4>] debug_smp_processor_id+0xe4/0xf0
> [  775.663356]  [<ffffffff80213f7a>] native_sched_clock+0x3a/0x80
> [  775.663368]  [<ffffffff80213e19>] sched_clock+0x9/0x10
> [  775.663381]  [<ffffffff8024550d>] proc_sched_show_task+0x8bd/0x10e0
> [  775.663395]  [<ffffffff8034466e>] sched_show+0x3e/0x80
> [  775.663408]  [<ffffffff8031039b>] seq_read+0xdb/0x350
> [  775.663421]  [<ffffffff80368776>] ? security_file_permission+0x16/0x20
> [  775.663435]  [<ffffffff802f4198>] vfs_read+0xc8/0x170
> [  775.663447]  [<ffffffff802f4335>] sys_read+0x55/0x90
> [  775.663460]  [<ffffffff8020c67a>] system_call_fastpath+0x16/0x1b
> ...

This breakage was caused by me via:

  7cbaef9c: sched: optimize sched_clock() a bit

Change the calls to cpu_clock().
Reported-by: NLuis Henriques <henrix@sapo.pt>

Impact: extend /proc/sched_debug info

Since the statistics of a group entity isn't exported directly from the
kernel, it becomes difficult to obtain some of the group statistics.
For example, the current method to obtain exec time of a group entity
is not always accurate. One has to read the exec times of all
the tasks(/proc/<pid>/sched) in the group and add them. This method
fails (or becomes difficult) if we want to collect stats of a group over
a duration where tasks get created and terminated.

This patch makes it easier to obtain group stats by directly including
them in /proc/sched_debug. Stats like group exec time would help user
programs (like LTP) to accurately measure the group fairness.

An example output of group stats from /proc/sched_debug:

cfs_rq[3]:/3/a/1
  .exec_clock                    : 89.598007
  .MIN_vruntime                  : 0.000001
  .min_vruntime                  : 256300.970506
  .max_vruntime                  : 0.000001
  .spread                        : 0.000000
  .spread0                       : -25373.372248
  .nr_running                    : 0
  .load                          : 0
  .yld_exp_empty                 : 0
  .yld_act_empty                 : 0
  .yld_both_empty                : 0
  .yld_count                     : 4474
  .sched_switch                  : 0
  .sched_count                   : 40507
  .sched_goidle                  : 12686
  .ttwu_count                    : 15114
  .ttwu_local                    : 11950
  .bkl_count                     : 67
  .nr_spread_over                : 0
  .shares                        : 0
  .se->exec_start                : 113676.727170
  .se->vruntime                  : 1592.612714
  .se->sum_exec_runtime          : 89.598007
  .se->wait_start                : 0.000000
  .se->sleep_start               : 0.000000
  .se->block_start               : 0.000000
  .se->sleep_max                 : 0.000000
  .se->block_max                 : 0.000000
  .se->exec_max                  : 1.000282
  .se->slice_max                 : 1.999750
  .se->wait_max                  : 54.981093
  .se->wait_sum                  : 217.610521
  .se->wait_count                : 50
  .se->load.weight               : 2
Signed-off-by: NBharata B Rao <bharata@linux.vnet.ibm.com>
Acked-by: NSrivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Acked-by: NDhaval Giani <dhaval@linux.vnet.ibm.com>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: clean up and fix debug info printout

While looking over the sched_debug code I noticed that we printed the rq
schedstats for every cfs_rq, ammend this.

Also change nr_spead_over into an int, and fix a little buglet in
min_vruntime printing.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup

cfs->tg is initialized in init_tg_cfs_entry() with tg != NULL, and
will never be invalidated to NULL. And the underlying cgroup of a
valid task_group is always valid.

Same for rt->tg.
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: change /proc/sched/debug from rw-r--r-- to r--r--r--

/proc/sched_debug is read-only.
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>