Track depth in cgroup tree, this is useful for things like
find_matching_se() where you need to get to a common parent of two
sched entities.

Keeping the depth avoids having to calculate it on the spot, which
saves a number of possible cache-misses.
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1328936700.2476.17.camel@laptopSigned-off-by: NIngo Molnar <mingo@kernel.org>

idle_balance() modifies the rq->idle_stamp field, making this information
shared across core.c and fair.c.

As we know if the cpu is going to idle or not with the previous patch, let's
encapsulate the rq->idle_stamp information in core.c by moving it up to the
caller.

The idle_balance() function returns true in case a balancing occured and the
cpu won't be idle, false if no balance happened and the cpu is going idle.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Cc: alex.shi@linaro.org
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1389949444-14821-3-git-send-email-daniel.lezcano@linaro.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

The scheduler main function 'schedule()' checks if there are no more tasks
on the runqueue. Then it checks if a task should be pulled in the current
runqueue in idle_balance() assuming it will go to idle otherwise.

But idle_balance() releases the rq->lock in order to look up the sched
domains and takes the lock again right after. That opens a window where
another cpu may put a task in our runqueue, so we won't go to idle but
we have filled the idle_stamp, thinking we will.

This patch closes the window by checking if the runqueue has been modified
but without pulling a task after taking the lock again, so we won't go to idle
right after in the __schedule() function.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Cc: alex.shi@linaro.org
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1389949444-14821-2-git-send-email-daniel.lezcano@linaro.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

The cpu parameter passed to idle_balance() is not needed as it could
be retrieved from 'struct rq.'
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Cc: alex.shi@linaro.org
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1389949444-14821-1-git-send-email-daniel.lezcano@linaro.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

As patch "sched: Move the priority specific bits into a new header file" exposes
the priority related macros in linux/sched/prio.h, we don't have to implement
task_nice() in kernel/sched/core.c any more.

This patch implements it in linux/sched/sched.h as static inline function,
saving the kernel stack and enhancing performance a bit.
Signed-off-by: NDongsheng Yang <yangds.fnst@cn.fujitsu.com>
Cc: clark.williams@gmail.com
Cc: rostedt@goodmis.org
Cc: raistlin@linux.it
Cc: juri.lelli@gmail.com
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1390878045-7096-1-git-send-email-yangds.fnst@cn.fujitsu.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Some macros in kernel/sched/sched.h about priority are
private to kernel/sched. But they are useful to other
parts of the core kernel.

This patch moves these macros from kernel/sched/sched.h to
include/linux/sched/prio.h so that they are available to
other subsystems.
Signed-off-by: NDongsheng Yang <yangds.fnst@cn.fujitsu.com>
Cc: raistlin@linux.it
Cc: juri.lelli@gmail.com
Cc: clark.williams@gmail.com
Cc: rostedt@goodmis.org
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/2b022810905b52d13238466807f4b2a691577180.1390859827.git.yangds.fnst@cn.fujitsu.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

When p is current and it's not of dl class, then there are no other
dl taks in the rq. If we had had pushable tasks in some other rq,
they would have been pushed earlier. So, skip "p == rq->curr" case.
Signed-off-by: NKirill Tkhai <ktkhai@parallels.com>
Acked-by: NJuri Lelli <juri.lelli@gmail.com>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140128072421.32315.25300.stgit@tkhaiSigned-off-by: NIngo Molnar <mingo@kernel.org>

After commit 9a46ad6d ("smp: make smp_call_function_many() use logic
similar to smp_call_function_single()"), cfd->cpumask is accessed only
in smp_call_function_many().  So there is no more need to copy it into
cfd->cpumask_ipi before putting csd into the list.  The cpumask_ipi
field is obsolete and can be removed.
Signed-off-by: NRoman Gushchin <klamm@yandex-team.ru>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Wang YanQing <udknight@gmail.com>
Cc: Xie XiuQi <xiexiuqi@huawei.com>
Cc: Shaohua Li <shli@fusionio.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Make smp_call_function_single and friends more efficient by using a
lockless list.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Cleanup suggested by Mel Gorman. Now the code contains some more
hints on what statistics go where.
Suggested-by: NMel Gorman <mgorman@suse.de>
Signed-off-by: NRik van Riel <riel@redhat.com>
Acked-by: NMel Gorman <mgorman@suse.de>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Chegu Vinod <chegu_vinod@hp.com>
Link: http://lkml.kernel.org/r/1390860228-21539-10-git-send-email-riel@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

We track both the node of the memory after a NUMA fault, and the node
of the CPU on which the fault happened. Rename the local variables in
task_numa_fault to make things more explicit.
Suggested-by: NMel Gorman <mgorman@suse.de>
Signed-off-by: NRik van Riel <riel@redhat.com>
Acked-by: NMel Gorman <mgorman@suse.de>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Chegu Vinod <chegu_vinod@hp.com>
Link: http://lkml.kernel.org/r/1390860228-21539-9-git-send-email-riel@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

The current code in task_numa_placement calculates the difference
between the old and the new value, but also temporarily stores half
of the old value in the per-process variables.

The NUMA balancing code looks at those per-process variables, and
having other tasks temporarily see halved statistics could lead to
unwanted numa migrations. This can be avoided by doing all the math
in local variables.

This change also simplifies the code a little.
Signed-off-by: NRik van Riel <riel@redhat.com>
Acked-by: NMel Gorman <mgorman@suse.de>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Chegu Vinod <chegu_vinod@hp.com>
Link: http://lkml.kernel.org/r/1390860228-21539-8-git-send-email-riel@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Tracing the code that decides the active nodes has made it abundantly clear
that the naive implementation of the faults_from code has issues.

Specifically, the garbage collector in some workloads will access orders
of magnitudes more memory than the threads that do all the active work.
This resulted in the node with the garbage collector being marked the only
active node in the group.

This issue is avoided if we weigh the statistics by CPU use of each task in
the numa group, instead of by how many faults each thread has occurred.

To achieve this, we normalize the number of faults to the fraction of faults
that occurred on each node, and then multiply that fraction by the fraction
of CPU time the task has used since the last time task_numa_placement was
invoked.

This way the nodes in the active node mask will be the ones where the tasks
from the numa group are most actively running, and the influence of eg. the
garbage collector and other do-little threads is properly minimized.

On a 4 node system, using CPU use statistics calculated over a longer interval
results in about 1% fewer page migrations with two 32-warehouse specjbb runs
on a 4 node system, and about 5% fewer page migrations, as well as 1% better
throughput, with two 8-warehouse specjbb runs, as compared with the shorter
term statistics kept by the scheduler.
Signed-off-by: NRik van Riel <riel@redhat.com>
Acked-by: NMel Gorman <mgorman@suse.de>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Chegu Vinod <chegu_vinod@hp.com>
Link: http://lkml.kernel.org/r/1390860228-21539-7-git-send-email-riel@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Use the active_nodes nodemask to make smarter decisions on NUMA migrations.

In order to maximize performance of workloads that do not fit in one NUMA
node, we want to satisfy the following criteria:

  1) keep private memory local to each thread

  2) avoid excessive NUMA migration of pages

  3) distribute shared memory across the active nodes, to
     maximize memory bandwidth available to the workload

This patch accomplishes that by implementing the following policy for
NUMA migrations:

  1) always migrate on a private fault

  2) never migrate to a node that is not in the set of active nodes
     for the numa_group

  3) always migrate from a node outside of the set of active nodes,
     to a node that is in that set

  4) within the set of active nodes in the numa_group, only migrate
     from a node with more NUMA page faults, to a node with fewer
     NUMA page faults, with a 25% margin to avoid ping-ponging

This results in most pages of a workload ending up on the actively
used nodes, with reduced ping-ponging of pages between those nodes.
Signed-off-by: NRik van Riel <riel@redhat.com>
Acked-by: NMel Gorman <mgorman@suse.de>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Chegu Vinod <chegu_vinod@hp.com>
Link: http://lkml.kernel.org/r/1390860228-21539-6-git-send-email-riel@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

The numa_faults_cpu statistics are used to maintain an active_nodes nodemask
per numa_group. This allows us to be smarter about when to do numa migrations.
Signed-off-by: NRik van Riel <riel@redhat.com>
Acked-by: NMel Gorman <mgorman@suse.de>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Chegu Vinod <chegu_vinod@hp.com>
Link: http://lkml.kernel.org/r/1390860228-21539-5-git-send-email-riel@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Track which nodes NUMA faults are triggered from, in other words
the CPUs on which the NUMA faults happened. This uses a similar
mechanism to what is used to track the memory involved in numa faults.

The next patches use this to build up a bitmap of which nodes a
workload is actively running on.
Signed-off-by: NRik van Riel <riel@redhat.com>
Acked-by: NMel Gorman <mgorman@suse.de>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Chegu Vinod <chegu_vinod@hp.com>
Link: http://lkml.kernel.org/r/1390860228-21539-4-git-send-email-riel@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

In order to get a more consistent naming scheme, making it clear
which fault statistics track memory locality, and which track
CPU locality, rename the memory fault statistics.
Suggested-by: NMel Gorman <mgorman@suse.de>
Signed-off-by: NRik van Riel <riel@redhat.com>
Acked-by: NMel Gorman <mgorman@suse.de>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Chegu Vinod <chegu_vinod@hp.com>
Link: http://lkml.kernel.org/r/1390860228-21539-3-git-send-email-riel@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Excessive migration of pages can hurt the performance of workloads
that span multiple NUMA nodes.  However, it turns out that the
p->numa_migrate_deferred knob is a really big hammer, which does
reduce migration rates, but does not actually help performance.

Now that the second stage of the automatic numa balancing code
has stabilized, it is time to replace the simplistic migration
deferral code with something smarter.
Signed-off-by: NRik van Riel <riel@redhat.com>
Acked-by: NMel Gorman <mgorman@suse.de>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Chegu Vinod <chegu_vinod@hp.com>
Link: http://lkml.kernel.org/r/1390860228-21539-2-git-send-email-riel@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Not all classes implement (or can implement) a useful get_rr_interval()
function, default to a 0 time-slice for them.

This fixes a crash reported by Tommi Rantala.
Reported-by: NTommi Rantala <tt.rantala@gmail.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Tommi Rantala <tt.rantala@gmail.com>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140127105413.GC11314@laptop.programming.kicks-ass.netSigned-off-by: NIngo Molnar <mingo@kernel.org>

Add in Documentation/scheduler/ some hints about the design
choices, the usage and the future possible developments of the
sched_dl scheduling class and of the SCHED_DEADLINE policy.
Reviewed-by: NHenrik Austad <henrik@austad.us>
Signed-off-by: NDario Faggioli <raistlin@linux.it>
Signed-off-by: NJuri Lelli <juri.lelli@gmail.com>
[ Re-wrote sections 2 and 3. ]
Signed-off-by: NLuca Abeni <luca.abeni@unitn.it>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1390821615-23247-1-git-send-email-juri.lelli@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Reduce data size a little.
Reduce checkpatch noise.

$ size kernel/softirq.o*
   text	   data	    bss	    dec	    hex	filename
  11554	   6013	   4008	  21575	   5447	kernel/softirq.o.new
  11474	   6093	   4008	  21575	   5447	kernel/softirq.o.old
Signed-off-by: NJoe Perches <joe@perches.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use a more current logging style.
Signed-off-by: NJoe Perches <joe@perches.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Possible speed improvement of __do_softirq() by using ffs() instead of
using a while loop with an & 1 test then single bit shift.
Signed-off-by: NJoe Perches <joe@perches.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

vsnprintf() may let 'r' larger than sizeof(buf), in this case, if 'r' is
also less than "vmcoreinfo_max_size - vmcoreinfo_size" (left size of
destination buffer), next memcpy() will read the unexpected addresses.
Signed-off-by: NChen Gang <gang.chen@asianux.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When khungtaskd detects hung tasks, it prints out
backtraces from a number of those tasks.

Limiting the number of backtraces being printed
out can result in the user not seeing the information
necessary to debug the issue. The hung_task_warnings
sysctl controls this feature.

This patch makes it possible for hung_task_warnings
to accept a special value to print an unlimited
number of backtraces when khungtaskd detects hung
tasks.

The special value is -1. To use this value it is
necessary to change types from ulong to int.
Signed-off-by: NAaron Tomlin <atomlin@redhat.com>
Reviewed-by: NRik van Riel <riel@redhat.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Cc: oleg@redhat.com
Link: http://lkml.kernel.org/r/1390239253-24030-3-git-send-email-atomlin@redhat.com
[ Build warning fix. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>

rcu_dereference_check_fdtable() looks very wrong,

1. rcu_my_thread_group_empty() was added by 844b9a87 "vfs: fix
   RCU-lockdep false positive due to /proc" but it doesn't really
   fix the problem. A CLONE_THREAD (without CLONE_FILES) task can
   hit the same race with get_files_struct().

   And otoh rcu_my_thread_group_empty() can suppress the correct
   warning if the caller is the CLONE_FILES (without CLONE_THREAD)
   task.

2. files->count == 1 check is not really right too. Even if this
   files_struct is not shared it is not safe to access it lockless
   unless the caller is the owner.

   Otoh, this check is sub-optimal. files->count == 0 always means
   it is safe to use it lockless even if files != current->files,
   but put_files_struct() has to take rcu_read_lock(). See the next
   patch.

This patch removes the buggy checks and turns fcheck_files() into
__fcheck_files() which uses rcu_dereference_raw(), the "unshared"
callers, fget_light() and fget_raw_light(), can use it to avoid
the warning from RCU-lockdep.

fcheck_files() is trivially reimplemented as rcu_lockdep_assert()
plus __fcheck_files().
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Add neg_one to the list of standard constraints - will be used by the next patch.
Signed-off-by: NAaron Tomlin <atomlin@redhat.com>
Acked-by: NRik van Riel <riel@redhat.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Cc: oleg@redhat.com
Link: http://lkml.kernel.org/r/1390239253-24030-2-git-send-email-atomlin@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Some code added to the debug_core module had KDB dependencies
that it shouldn't have.  Move the KDB dependent REASON back to
the caller to remove the dependency in the debug core code.

Update the call from the UV NMI handler to conform to the new
interface.
Signed-off-by: NMike Travis <travis@sgi.com>
Reviewed-by: NHedi Berriche <hedi@sgi.com>
Cc: Russ Anderson <rja@sgi.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Link: http://lkml.kernel.org/r/20140114162551.318251993@asylum.americas.sgi.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Right now we seem to be exporting the max data size contained inside
vmcoreinfo note.  But this does not include the size of meta data around
vmcore info data.  Like name of the note and starting and ending elf_note.

I think user space expects total size and that size is put in PT_NOTE elf
header.  Things seem to be fine so far because we are not using vmcoreinfo
note to the maximum capacity.  But as it starts filling up, to capacity,
at some point of time, problem will be visible.

I don't think user space will be broken with this change.  So there is no
need to introduce vmcoreinfo2.  This change is safe and backward
compatible.  More explanation on why this change is safe is below.

vmcoreinfo contains information about kernel which user space needs to
know to do things like filtering.  For example, various kernel config
options or information about size or offset of some data structures etc.
All this information is commmunicated to user space with an ELF note
present in ELF /proc/vmcore file.

Currently vmcoreinfo data size is 4096.  With some elf note meta data
around it, actual size is 4132 bytes.  But we are using barely 25% of that
size.  Rest is empty.  So even if we tell user space that size of ELf note
is 4096 and not 4132, nothing will be broken becase after around 1000
bytes, everything is zero anyway.

But once we start filling up the note to the capacity, and not report the
full size of note, bad things will start happening.  Either some data will
be lost or tools will be confused that they did not fine the zero note at
the end.

So I think this change is safe and should not break existing tools.
Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
Cc: Ken'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp>
Cc: Dan Aloni <da-x@monatomic.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

For general-purpose (i.e.  distro) kernel builds it makes sense to build
with CONFIG_KEXEC to allow end users to choose what kind of things they
want to do with kexec.  However, in the face of trying to lock down a
system with such a kernel, there needs to be a way to disable kexec_load
(much like module loading can be disabled).  Without this, it is too easy
for the root user to modify kernel memory even when CONFIG_STRICT_DEVMEM
and modules_disabled are set.  With this change, it is still possible to
load an image for use later, then disable kexec_load so the image (or lack
of image) can't be altered.

The intention is for using this in environments where "perfect"
enforcement is hard.  Without a verified boot, along with verified
modules, and along with verified kexec, this is trying to give a system a
better chance to defend itself (or at least grow the window of
discoverability) against attack in the face of a privilege escalation.

In my mind, I consider several boot scenarios:

1) Verified boot of read-only verified root fs loading fd-based
   verification of kexec images.
2) Secure boot of writable root fs loading signed kexec images.
3) Regular boot loading kexec (e.g. kcrash) image early and locking it.
4) Regular boot with no control of kexec image at all.

1 and 2 don't exist yet, but will soon once the verified kexec series has
landed.  4 is the state of things now.  The gap between 2 and 4 is too
large, so this change creates scenario 3, a middle-ground above 4 when 2
and 1 are not possible for a system.
Signed-off-by: NKees Cook <keescook@chromium.org>
Acked-by: NRik van Riel <riel@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Change do_signal_stop() and do_sigaction() to avoid next_thread() and use
while_each_thread() instead.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Reviewed-by: NSameer Nanda <snanda@chromium.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Change k_getrusage() to use while_each_thread(), no changes in the
compiled code.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Reviewed-by: NSameer Nanda <snanda@chromium.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We can kill either task->did_exec or PF_FORKNOEXEC, they are mutually
exclusive.  The patch kills ->did_exec because it has a single user.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

current->mm doesn't need a NULL check in dup_mm().  Becasue dup_mm() is
used only in copy_mm() and current->mm is checked whether it is NULL or
not in copy_mm() before calling dup_mm().
Signed-off-by: NDaeseok Youn <daeseok.youn@gmail.com>
Acked-by: NOleg Nesterov <oleg@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix errors reported by checkpatch.pl.  One error is parentheses, the other
is a whitespace issue.
Signed-off-by: NDaeseok Youn <daeseok.youn@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

dup_mm() is used only in kernel/fork.c
Signed-off-by: NDaeseok Youn <daeseok.youn@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

An earlier newline was missing and current print is from different task.
In this scenario flush the continuation line and store this line
seperatly.

This patch fix the below scenario of timestamp interleaving,
   [   28.154370 ] read_word_reg : reg[0x 3], reg[0x 4]  data [0x 642]
   [   28.155428 ] uart disconnect
   [   31.947341 ] dvfs[cpufreq.c<275>]:plug-in cpu<1> done
   [   28.155445 ] UART detached : send switch state 201
   [   32.014112 ] read_reg : reg[0x 3] data[0x21]

[akpm@linux-foundation.org: simplify and condense the code]
Signed-off-by: NArun KS <getarunks@gmail.com>
Signed-off-by: NArun KS <arun.ks@broadcom.com>
Cc: Joe Perches <joe@perches.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Kay Sievers <kay@vrfy.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a working sysctl to enable/disable automatic numa memory balancing
at runtime.

This allows us to track down performance problems with this feature and
is generally a good idea.

This was possible earlier through debugfs, but only with special
debugging options set.  Also fix the boot message.

[akpm@linux-foundation.org: s/sched_numa_balancing/sysctl_numa_balancing/]
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Acked-by: NMel Gorman <mgorman@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If trace_puts() is used very early in boot up, it can crash the machine
if it is called before the ring buffer is allocated. If a trace_printk()
is used with no arguments, then it will be converted into a trace_puts()
and suffer the same fate.

Cc: stable@vger.kernel.org # 3.10+
Fixes: 09ae7234 "tracing: Add trace_puts() for even faster trace_printk() tracing"
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

The code would assume sched_clock_stable() and switch to !stable
later, this switch brings a discontinuity in time.

The discontinuity on switching from stable to unstable was always
present, but previously we would set stable/unstable before
initializing TSC and usually stick to the one we start out with.

So the static_key bits brought an extra switch where there previously
wasn't one.

Things are further complicated by the fact that we cannot use
static_key as early as we usually call set_sched_clock_stable().

Fix things by tracking the stable state in a regular variable and only
set the static_key to the right state on sched_clock_init(), which is
ran right after late_time_init->tsc_init().

Before this we would not be using the TSC anyway.
Reported-and-Tested-by: NSasha Levin <sasha.levin@oracle.com>
Reported-by: dyoung@redhat.com
Fixes: 35af99e6 ("sched/clock, x86: Use a static_key for sched_clock_stable")
Cc: jacob.jun.pan@linux.intel.com
Cc: Mike Galbraith <bitbucket@online.de>
Cc: hpa@zytor.com
Cc: paulmck@linux.vnet.ibm.com
Cc: John Stultz <john.stultz@linaro.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: lenb@kernel.org
Cc: rjw@rjwysocki.net
Cc: Eliezer Tamir <eliezer.tamir@linux.intel.com>
Cc: rui.zhang@intel.com
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140122115918.GG3694@twins.programming.kicks-ass.netSigned-off-by: NIngo Molnar <mingo@kernel.org>