x86/smpboot: Fix announce_cpu() to printk() the last "OK" properly

When booting secondary CPUs, announce_cpu() is called to show which cpu has
been brought up. For example:

[    0.402751] smpboot: Booting Node   0, Processors  #1 #2 #3 #4 #5 OK
[    0.525667] smpboot: Booting Node   1, Processors  #6 #7 #8 #9 #10 #11 OK
[    0.755592] smpboot: Booting Node   0, Processors  #12 #13 #14 #15 #16 #17 OK
[    0.890495] smpboot: Booting Node   1, Processors  #18 #19 #20 #21 #22 #23

But the last "OK" is lost, because 'nr_cpu_ids-1' represents the maximum
possible cpu id. It should use the maximum present cpu id in case not all
CPUs booted up.

Signed-off-by: Libin <huawei.libin@huawei.com>
Cc: <guohanjun@huawei.com>
Cc: <wangyijing@huawei.com>
Cc: <fenghua.yu@intel.com>
Cc: <paul.gortmaker@windriver.com>
Link: http://lkml.kernel.org/r/1378378676-18276-1-git-send-email-huawei.libin@huawei.com
[ tweaked the changelog, removed unnecessary line break, tweaked the format to align the fields vertically. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
x86: Remove now-unused save_rest()

b3af11afe06a ("x86: get rid of pt_regs argument of iopl(2)")
dropped PTREGSCALL which was also the last user of save_rest.
Drop that now-unused function too.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Link: http://lkml.kernel.org/r/1378546750-19727-1-git-send-email-bp@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
timekeeping: Fix HRTICK related deadlock from ntp lock changes

Gerlando Falauto reported that when HRTICK is enabled, it is
possible to trigger system deadlocks. These were hard to
reproduce, as HRTICK has been broken in the past, but seemed
to be connected to the timekeeping_seq lock.

Since seqlock/seqcount's aren't supported w/ lockdep, I added
some extra spinlock based locking and triggered the following
lockdep output:

[   15.849182] ntpd/4062 is trying to acquire lock:
[   15.849765]  (&(&pool->lock)->rlock){..-...}, at: [<ffffffff810aa9b5>] __queue_work+0x145/0x480
[   15.850051]
[   15.850051] but task is already holding lock:
[   15.850051]  (timekeeper_lock){-.-.-.}, at: [<ffffffff810df6df>] do_adjtimex+0x7f/0x100

<snip>

[   15.850051] Chain exists of: &(&pool->lock)->rlock --> &p->pi_lock --> timekeeper_lock
[   15.850051]  Possible unsafe locking scenario:
[   15.850051]
[   15.850051]        CPU0                    CPU1
[   15.850051]        ----                    ----
[   15.850051]   lock(timekeeper_lock);
[   15.850051]                                lock(&p->pi_lock);
[   15.850051] lock(timekeeper_lock);
[   15.850051] lock(&(&pool->lock)->rlock);
[   15.850051]
[   15.850051]  *** DEADLOCK ***

The deadlock was introduced by 06c017fdd4dc48451a ("timekeeping:
Hold timekeepering locks in do_adjtimex and hardpps") in 3.10

This patch avoids this deadlock, by moving the call to
schedule_delayed_work() outside of the timekeeper lock
critical section.

Reported-by: Gerlando Falauto <gerlando.falauto@keymile.com>
Tested-by: Lin Ming <minggr@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: stable <stable@vger.kernel.org> #3.11, 3.10
Link: http://lkml.kernel.org/r/1378943457-27314-1-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
perf/x86/intel: Fix Silvermont offcore masks

Fengguang Wu reported:

> sparse warnings: (new ones prefixed by >>)
>
> >> arch/x86/kernel/cpu/perf_event_intel.c:901:9: sparse: constant 0x768005ffff is so big it is long
> >> arch/x86/kernel/cpu/perf_event_intel.c:902:9: sparse: constant 0x768005ffff is so big it is long
>
> vim +901 arch/x86/kernel/cpu/perf_event_intel.c
>
>    895	 },
>    896	};
>    897
>    898	static struct extra_reg intel_slm_extra_regs[] __read_mostly =
>    899	{
>    900		/* must define OFFCORE_RSP_X first, see intel_fixup_er() */
>  > 901		INTEL_UEVENT_EXTRA_REG(0x01b7, MSR_OFFCORE_RSP_0, 0x768005ffff, RSP_0),
>  > 902		INTEL_UEVENT_EXTRA_REG(0x02b7, MSR_OFFCORE_RSP_1, 0x768005ffff, RSP_1),
>    903		EVENT_EXTRA_END
>    904	};
>    905

Extend those constants to 64 bits.

Reported-by: fengguang.wu@intel.com
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20130909112636.GQ31370@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
sched/fair: Fix small race where child->se.parent,cfs_rq might point to invalid ones

There is a small race between copy_process() and cgroup_attach_task()
where child->se.parent,cfs_rq points to invalid (old) ones.

        parent doing fork()      | someone moving the parent to another cgroup
  -------------------------------+---------------------------------------------
    copy_process()
      + dup_task_struct()
        -> parent->se is copied to child->se.
           se.parent,cfs_rq of them point to old ones.

                                     cgroup_attach_task()
                                       + cgroup_task_migrate()
                                         -> parent->cgroup is updated.
                                       + cpu_cgroup_attach()
                                         + sched_move_task()
                                           + task_move_group_fair()
                                             +- set_task_rq()
                                                -> se.parent,cfs_rq of parent
                                                   are updated.

      + cgroup_fork()
        -> parent->cgroup is copied to child->cgroup. (*1)
      + sched_fork()
        + task_fork_fair()
          -> se.parent,cfs_rq of child are accessed
             while they point to old ones. (*2)

In the worst case, this bug can lead to "use-after-free" and cause a panic,
because it's new cgroup's refcount that is incremented at (*1),
so the old cgroup(and related data) can be freed before (*2).

In fact, a panic caused by this bug was originally caught in RHEL6.4.

    BUG: unable to handle kernel NULL pointer dereference at (null)
    IP: [<ffffffff81051e3e>] sched_slice+0x6e/0xa0
    [...]
    Call Trace:
     [<ffffffff81051f25>] place_entity+0x75/0xa0
     [<ffffffff81056a3a>] task_fork_fair+0xaa/0x160
     [<ffffffff81063c0b>] sched_fork+0x6b/0x140
     [<ffffffff8106c3c2>] copy_process+0x5b2/0x1450
     [<ffffffff81063b49>] ? wake_up_new_task+0xd9/0x130
     [<ffffffff8106d2f4>] do_fork+0x94/0x460
     [<ffffffff81072a9e>] ? sys_wait4+0xae/0x100
     [<ffffffff81009598>] sys_clone+0x28/0x30
     [<ffffffff8100b393>] stub_clone+0x13/0x20
     [<ffffffff8100b072>] ? system_call_fastpath+0x16/0x1b

Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/039601ceae06$733d3130$59b79390$@mxp.nes.nec.co.jp
Signed-off-by: Ingo Molnar <mingo@kernel.org>
sched/debug: Take PID namespace into account

Emmanuel reported that /proc/sched_debug didn't report the right PIDs
when using namespaces, cure this.

Reported-by: Emmanuel Deloget <emmanuel.deloget@efixo.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20130909110141.GM31370@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
sched/Documentation: Update sched-design-CFS.txt documentation

2bd2d6f2dc ("sched: Replace use of entity_key()") had remove the
entity_key() which function is to subtract a tasks vruntime by
its groups minvruntime as the rbtree key.
The phrase "there is a subtraction using rq->cfs.min_vruntime
to account for possible wraparounds" in documentation feels strange
and meaningless. So remove it.

Signed-off-by: Li Bin <huawei.libin@huawei.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1378706740-7500-1-git-send-email-huawei.libin@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
perf/x86/intel: Mark MEM_LOAD_UOPS_MISS_RETIRED as precise on SNB

On Intel SNB (SNB, SNB-EP), the event MEM_LOAD_UOPS_MISS_RETIRED
supports PEBS. It was missing for the SNB PEBS event constraint
table thereby preventing any measurement with PEBS for it.

This patch adds the event to the PEBS table for SNB.

WARNING: it should be noted that this event like a few others
are subject to the erratum BT241 for Xeon E5 (SNB-EP). As such,
the event may undercount when used with PEBS unless the
workaround is implemented. But without this patch and just the
workaround, the kernel would not allow precise sampling on this
event. BT241 is documented in:

  http://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/xeon-e5-family-spec-update.pdf

Signed-off-by: Stephane Eranian <eranian@google.com>
Cc: peterz@infradead.org
Cc: ak@linux.intel.com
Cc: zheng.z.yan@intel.com
Link: http://lkml.kernel.org/r/20130913201646.GA23981@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
x86/intel/lpss: Add pin control support to Intel low power subsystem

x86 chips with LPSS (low power subsystem) such as Lynxpoint and
Baytrail have SoC like peripheral support and controllable pins.

At the moment, Baytrail needs the pinctrl-baytrail driver to let
peripherals control their gpio resources, but more pincontrol
functions such as pin muxing and grouping are possible to add
later.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: http://lkml.kernel.org/r/1379080949-21734-1-git-send-email-mathias.nyman@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
sched: Fix comment for sched_info_depart

sched_info_depart seems to be only called from
sched_info_switch(), so only on involuntary task switch.

Fix the comment to match.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Link: http://lkml.kernel.org/r/20130916083036.GA1113@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
perf: Fix UAPI export of PERF_EVENT_IOC_ID

Without the following patch I have problems compiling code using
the new PERF_EVENT_IOC_ID ioctl().  It looks like u64 was used
instead of __u64

Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1309171450380.11444@vincent-weaver-1.um.maine.edu
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf fixes from Ingo Molnar:
 "Two small fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: Fix UAPI export of PERF_EVENT_IOC_ID
  perf/x86/intel: Fix Silvermont offcore masks
Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Ingo Molnar:
 "Misc fixes"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched: Fix comment for sched_info_depart
  sched/Documentation: Update sched-design-CFS.txt documentation
  sched/debug: Take PID namespace into account
  sched/fair: Fix small race where child->se.parent,cfs_rq might point to invalid ones
Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer fix from Ingo Molnar:
 "An NTP related lockup fix"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timekeeping: Fix HRTICK related deadlock from ntp lock changes
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Ingo Molnar:
 "Misc fixes"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/intel/lpss: Add pin control support to Intel low power subsystem
  perf/x86/intel: Mark MEM_LOAD_UOPS_MISS_RETIRED as precise on SNB
  x86: Remove now-unused save_rest()
  x86/smpboot: Fix announce_cpu() to printk() the last "OK" properly