Commit Graph

1025 Commits

Author SHA1 Message Date
Linus Torvalds f3c233d75e Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull ntp fix from Ingo Molnar:
 "An adjtimex interface regression fix for 32-bit systems"

[ A check that was added in a previous commit is really only a concern
  for 64bit systems, but was applied to both 32 and 64bit systems, which
  results in breaking 32bit systems.

  Thus the fix here is to make the check only apply to 64bit systems ]

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  ntp: Fixup adjtimex freq validation on 32-bit systems
2015-02-21 11:05:22 -08:00
John Stultz 29183a70b0 ntp: Fixup adjtimex freq validation on 32-bit systems
Additional validation of adjtimex freq values to avoid
potential multiplication overflows were added in commit
5e5aeb4367 (time: adjtimex: Validate the ADJ_FREQUENCY values)

Unfortunately the patch used LONG_MAX/MIN instead of
LLONG_MAX/MIN, which was fine on 64-bit systems, but being
much smaller on 32-bit systems caused false positives
resulting in most direct frequency adjustments to fail w/
EINVAL.

ntpd only does direct frequency adjustments at startup, so
the issue was not as easily observed there, but other time
sync applications like ptpd and chrony were more effected by
the bug.

See bugs:

  https://bugzilla.kernel.org/show_bug.cgi?id=92481
  https://bugzilla.redhat.com/show_bug.cgi?id=1188074

This patch changes the checks to use LLONG_MAX for
clarity, and additionally the checks are disabled
on 32-bit systems since LLONG_MAX/PPM_SCALE is always
larger then the 32-bit long freq value, so multiplication
overflows aren't possible there.

Reported-by: Josh Boyer <jwboyer@fedoraproject.org>
Reported-by: George Joseph <george.joseph@fairview5.com>
Tested-by: George Joseph <george.joseph@fairview5.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org> # v3.19+
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Link: http://lkml.kernel.org/r/1423553436-29747-1-git-send-email-john.stultz@linaro.org
[ Prettified the changelog and the comments a bit. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-18 14:50:10 +01:00
Linus Torvalds 99fa0ad92c Suspend-to-idle timer quiescing support for v3.20-rc1
Till now suspend-to-idle has not been able to save much more energy
 than runtime PM because of timer interrupts that periodically bring
 CPUs out of idle while they are waiting for a wakeup interrupt.  Of
 course, the timer interrupts are not wakeup ones, so the handling of
 them can be deferred until a real wakeup interrupt happens, but at
 the same time we don't want to mass-expire timers at that point.
 
 The solution is to suspend the entire timekeeping when the last CPU
 is entering an idle state and resume it when the first CPU goes out
 of idle.  That has to be done with care, though, so as to avoid
 accessing suspended clocksources etc. end we need extra support
 from idle drivers for that.
 
 This series of commits adds support for quiescing timers during
 suspend-to-idle and adds the requisite callbacks to intel_idle
 and the ACPI cpuidle driver.
 
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Merge tag 'suspend-to-idle-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull suspend-to-idle updates from Rafael Wysocki:
 "Suspend-to-idle timer quiescing support for v3.20-rc1

  Until now suspend-to-idle has not been able to save much more energy
  than runtime PM because of timer interrupts that periodically bring
  CPUs out of idle while they are waiting for a wakeup interrupt.  Of
  course, the timer interrupts are not wakeup ones, so the handling of
  them can be deferred until a real wakeup interrupt happens, but at the
  same time we don't want to mass-expire timers at that point.

  The solution is to suspend the entire timekeeping when the last CPU is
  entering an idle state and resume it when the first CPU goes out of
  idle.  That has to be done with care, though, so as to avoid accessing
  suspended clocksources etc.  end we need extra support from idle
  drivers for that.

  This series of commits adds support for quiescing timers during
  suspend-to-idle and adds the requisite callbacks to intel_idle and the
  ACPI cpuidle driver"

* tag 'suspend-to-idle-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI / idle: Implement ->enter_freeze callback routine
  intel_idle: Add ->enter_freeze callbacks
  PM / sleep: Make it possible to quiesce timers during suspend-to-idle
  timekeeping: Make it safe to use the fast timekeeper while suspended
  timekeeping: Pass readout base to update_fast_timekeeper()
  PM / sleep: Re-implement suspend-to-idle handling
2015-02-17 14:17:51 -08:00
Rafael J. Wysocki 124cf9117c PM / sleep: Make it possible to quiesce timers during suspend-to-idle
The efficiency of suspend-to-idle depends on being able to keep CPUs
in the deepest available idle states for as much time as possible.
Ideally, they should only be brought out of idle by system wakeup
interrupts.

However, timer interrupts occurring periodically prevent that from
happening and it is not practical to chase all of the "misbehaving"
timers in a whack-a-mole fashion.  A much more effective approach is
to suspend the local ticks for all CPUs and the entire timekeeping
along the lines of what is done during full suspend, which also
helps to keep suspend-to-idle and full suspend reasonably similar.

The idea is to suspend the local tick on each CPU executing
cpuidle_enter_freeze() and to make the last of them suspend the
entire timekeeping.  That should prevent timer interrupts from
triggering until an IO interrupt wakes up one of the CPUs.  It
needs to be done with interrupts disabled on all of the CPUs,
though, because otherwise the suspended clocksource might be
accessed by an interrupt handler which might lead to fatal
consequences.

Unfortunately, the existing ->enter callbacks provided by cpuidle
drivers generally cannot be used for implementing that, because some
of them re-enable interrupts temporarily and some idle entry methods
cause interrupts to be re-enabled automatically on exit.  Also some
of these callbacks manipulate local clock event devices of the CPUs
which really shouldn't be done after suspending their ticks.

To overcome that difficulty, introduce a new cpuidle state callback,
->enter_freeze, that will be guaranteed (1) to keep interrupts
disabled all the time (and return with interrupts disabled) and (2)
not to touch the CPU timer devices.  Modify cpuidle_enter_freeze() to
look for the deepest available idle state with ->enter_freeze present
and to make the CPU execute that callback with suspended tick (and the
last of the online CPUs to execute it with suspended timekeeping).

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2015-02-15 19:40:09 +01:00
Rafael J. Wysocki 060407aed5 timekeeping: Make it safe to use the fast timekeeper while suspended
Theoretically, ktime_get_mono_fast_ns() may be executed after
timekeeping has been suspended (or before it is resumed) which
in turn may lead to undefined behavior, for example, when the
clocksource read from timekeeping_get_ns() called by it is
not accessible at that time.

Prevent that from happening by setting up a dummy readout base for
the fast timekeeper during timekeeping_suspend() such that it will
always return the same number of cycles.

After the last timekeeping_update() in timekeeping_suspend() the
clocksource is read and the result is stored as cycles_at_suspend.
The readout base from the current timekeeper is copied onto the
dummy and the ->read pointer of the dummy is set to a routine
unconditionally returning cycles_at_suspend.  Next, the dummy is
passed to update_fast_timekeeper().

Then, ktime_get_mono_fast_ns() will work until the subsequent
timekeeping_resume() and the proper readout base for the fast
timekeeper will be restored by the timekeeping_update() called
right after clearing timekeeping_suspended.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: John Stultz <john.stultz@linaro.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2015-02-15 19:39:40 +01:00
Tejun Heo ffda22c1f3 time: use %*pb[l] to print bitmaps including cpumasks and nodemasks
printk and friends can now format bitmaps using '%*pb[l]'.  cpumask
and nodemask also provide cpumask_pr_args() and nodemask_pr_args()
respectively which can be used to generate the two printf arguments
necessary to format the specified cpu/nodemask.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13 21:21:37 -08:00
Rafael J. Wysocki affe3e85ae timekeeping: Pass readout base to update_fast_timekeeper()
Modify update_fast_timekeeper() to take a struct tk_read_base
pointer as its argument (instead of a struct timekeeper pointer)
and update its kerneldoc comment to reflect that.

That will allow a struct tk_read_base that is not part of a
struct timekeeper to be passed to it in the next patch.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: John Stultz <john.stultz@linaro.org>
2015-02-13 23:49:36 +01:00
Andy Lutomirski f56141e3e2 all arches, signal: move restart_block to struct task_struct
If an attacker can cause a controlled kernel stack overflow, overwriting
the restart block is a very juicy exploit target.  This is because the
restart_block is held in the same memory allocation as the kernel stack.

Moving the restart block to struct task_struct prevents this exploit by
making the restart_block harder to locate.

Note that there are other fields in thread_info that are also easy
targets, at least on some architectures.

It's also a decent simplification, since the restart code is more or less
identical on all architectures.

[james.hogan@imgtec.com: metag: align thread_info::supervisor_stack]
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: David Miller <davem@davemloft.net>
Acked-by: Richard Weinberger <richard@nod.at>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Tested-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12 18:54:12 -08:00
Linus Torvalds c5ce28df0e Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller:

 1) More iov_iter conversion work from Al Viro.

    [ The "crypto: switch af_alg_make_sg() to iov_iter" commit was
      wrong, and this pull actually adds an extra commit on top of the
      branch I'm pulling to fix that up, so that the pre-merge state is
      ok.   - Linus ]

 2) Various optimizations to the ipv4 forwarding information base trie
    lookup implementation.  From Alexander Duyck.

 3) Remove sock_iocb altogether, from CHristoph Hellwig.

 4) Allow congestion control algorithm selection via routing metrics.
    From Daniel Borkmann.

 5) Make ipv4 uncached route list per-cpu, from Eric Dumazet.

 6) Handle rfs hash collisions more gracefully, also from Eric Dumazet.

 7) Add xmit_more support to r8169, e1000, and e1000e drivers.  From
    Florian Westphal.

 8) Transparent Ethernet Bridging support for GRO, from Jesse Gross.

 9) Add BPF packet actions to packet scheduler, from Jiri Pirko.

10) Add support for uniqu flow IDs to openvswitch, from Joe Stringer.

11) New NetCP ethernet driver, from Muralidharan Karicheri and Wingman
    Kwok.

12) More sanely handle out-of-window dupacks, which can result in
    serious ACK storms.  From Neal Cardwell.

13) Various rhashtable bug fixes and enhancements, from Herbert Xu,
    Patrick McHardy, and Thomas Graf.

14) Support xmit_more in be2net, from Sathya Perla.

15) Group Policy extensions for vxlan, from Thomas Graf.

16) Remove Checksum Offload support for vxlan, from Tom Herbert.

17) Like ipv4, support lockless transmit over ipv6 UDP sockets.  From
    Vlad Yasevich.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1494+1 commits)
  crypto: fix af_alg_make_sg() conversion to iov_iter
  ipv4: Namespecify TCP PMTU mechanism
  i40e: Fix for stats init function call in Rx setup
  tcp: don't include Fast Open option in SYN-ACK on pure SYN-data
  openvswitch: Only set TUNNEL_VXLAN_OPT if VXLAN-GBP metadata is set
  ipv6: Make __ipv6_select_ident static
  ipv6: Fix fragment id assignment on LE arches.
  bridge: Fix inability to add non-vlan fdb entry
  net: Mellanox: Delete unnecessary checks before the function call "vunmap"
  cxgb4: Add support in cxgb4 to get expansion rom version via ethtool
  ethtool: rename reserved1 memeber in ethtool_drvinfo for expansion ROM version
  net: dsa: Remove redundant phy_attach()
  IB/mlx4: Reset flow support for IB kernel ULPs
  IB/mlx4: Always use the correct port for mirrored multicast attachments
  net/bonding: Fix potential bad memory access during bonding events
  tipc: remove tipc_snprintf
  tipc: nl compat add noop and remove legacy nl framework
  tipc: convert legacy nl stats show to nl compat
  tipc: convert legacy nl net id get to nl compat
  tipc: convert legacy nl net id set to nl compat
  ...
2015-02-10 20:01:30 -08:00
Linus Torvalds 0ba97bc4b4 Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Ingo Molnar:
 "The main changes in this cycle were:

   - rework hrtimer expiry calculation in hrtimer_interrupt(): the
     previous code had a subtle bug where expiry caching would miss an
     expiry, resulting in occasional bogus (late) expiry of hrtimers.

   - continuing Y2038 fixes

   - ktime division optimization

   - misc smaller fixes and cleanups"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  hrtimer: Make __hrtimer_get_next_event() static
  rtc: Convert rtc_set_ntp_time() to use timespec64
  rtc: Remove redundant rtc_valid_tm() from rtc_hctosys()
  rtc: Modify rtc_hctosys() to address y2038 issues
  rtc: Update rtc-dev to use y2038-safe time interfaces
  rtc: Update interface.c to use y2038-safe time interfaces
  time: Expose get_monotonic_boottime64 for in-kernel use
  time: Expose getboottime64 for in-kernel uses
  ktime: Optimize ktime_divns for constant divisors
  hrtimer: Prevent stale expiry time in hrtimer_interrupt()
  ktime.h: Introduce ktime_ms_delta
2015-02-09 16:33:07 -08:00
John Stultz 2d926c15d6 hrtimer: Fix incorrect tai offset calculation for non high-res timer systems
I noticed some CLOCK_TAI timer test failures on one of my
less-frequently used configurations. And after digging in I
found in 76f4108892 (Cleanup hrtimer accessors to the
timekepeing state), the hrtimer_get_softirq_time tai offset
calucation was incorrectly rewritten, as the tai offset we
return shold be from CLOCK_MONOTONIC, and not CLOCK_REALTIME.

This results in CLOCK_TAI timers expiring early on non-highres
capable machines.

This patch fixes the issue, calculating the tai time properly
from the monotonic base.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable <stable@vger.kernel.org> # 3.17+
Link: http://lkml.kernel.org/r/1423097126-10236-1-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-02-05 08:39:37 +01:00
David S. Miller 95f873f2ff Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	arch/arm/boot/dts/imx6sx-sdb.dts
	net/sched/cls_bpf.c

Two simple sets of overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-27 16:59:56 -08:00
Linus Torvalds b73f0c8f4b Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Thomas Gleixner:
 "A set of small fixes:

   - regression fix for exynos_mct clocksource

   - trivial build fix for kona clocksource

   - functional one liner fix for the sh_tmu clocksource

   - two validation fixes to prevent (root only) data corruption in the
     kernel via settimeofday and adjtimex.  Tagged for stable"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  time: adjtimex: Validate the ADJ_FREQUENCY values
  time: settimeofday: Validate the values of tv from user
  clocksource: sh_tmu: Set cpu_possible_mask to fix SMP broadcast
  clocksource: kona: fix __iomem annotation
  clocksource: exynos_mct: Fix bitmask regression for exynos4_mct_write
2015-01-25 17:47:34 -08:00
kbuild test robot 4ebbda5251 hrtimer: Make __hrtimer_get_next_event() static
kernel/time/hrtimer.c:444:9: sparse: symbol '__hrtimer_get_next_event' was not declared. Should it be static?

Fixes: 9bc7491906 hrtimer: Prevent stale expiry time in hrtimer_interrupt()
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Cc: kbuild-all@01.org
Link: http://lkml.kernel.org/r/20150123121206.GA4766@snb
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-01-24 10:53:36 +01:00
Thomas Gleixner fe31fca35d Couple of items for 3.20
* ktime division optimization
 * Expose a few more y2038-safe timekeeping interfaces
 * RTC core changes to address y2038
 
 Signed-off-by: John Stultz <john.stultz@linaro.org>
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Merge tag 'fortglx-3.20-time' of https://git.linaro.org/people/john.stultz/linux into timers/core

Pull time updates from John Stultz for 3.20:

 * ktime division optimization
 * Expose a few more y2038-safe timekeeping interfaces
 * RTC core changes to address y2038
2015-01-24 10:11:12 +01:00
Xunlei Pang 9a4a445e30 rtc: Convert rtc_set_ntp_time() to use timespec64
rtc_set_ntp_time() uses timespec which is y2038-unsafe,
so modify to use timespec64 which is y2038-safe, then
replace rtc_time_to_tm() with rtc_time64_to_tm().

Also adjust all its call sites(only NTP uses it) accordingly.

Cc: pang.xunlei <pang.xunlei@linaro.org>
Cc: Arnd Bergmann <arnd.bergmann@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2015-01-23 17:21:57 -08:00
John Stultz d08c0cdd26 time: Expose getboottime64 for in-kernel uses
Adds a timespec64 based getboottime64() implementation
that can be used as we convert internal users of
getboottime away from using timespecs.

Cc: pang.xunlei <pang.xunlei@linaro.org>
Cc: Arnd Bergmann <arnd.bergmann@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2015-01-23 17:21:54 -08:00
Nicolas Pitre 8b618628b2 ktime: Optimize ktime_divns for constant divisors
At least on ARM, do_div() is optimized to turn constant divisors into
an inline multiplication by the reciprocal value at compile time.
However this optimization is missed entirely whenever ktime_divns() is
used and the slow out-of-line division code is used all the time.

Let ktime_divns() use do_div() inline whenever the divisor is constant
and small enough.  This will make things like ktime_to_us() and
ktime_to_ms() much faster.

Cc: Arnd Bergmann <arnd.bergmann@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Nicolas Pitre <nico@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2015-01-23 17:21:31 -08:00
Thomas Gleixner 9bc7491906 hrtimer: Prevent stale expiry time in hrtimer_interrupt()
hrtimer_interrupt() has the following subtle issue:

hrtimer_interrupt()
  lock(cpu_base);
  expires_next = KTIME_MAX;

  expire_timers(CLOCK_MONOTONIC);
  expires = get_next_timer(CLOCK_MONOTONIC);
  if (expires < expires_next)
    expires_next = expires;

  expire_timers(CLOCK_REALTIME);
    unlock(cpu_base);
    wakeup()
    hrtimer_start(CLOCK_MONOTONIC, newtimer);
    lock(cpu_base();  
  expires = get_next_timer(CLOCK_REALTIME);
  if (expires < expires_next)
    expires_next = expires;

So because we already evaluated the next expiring timer of
CLOCK_MONOTONIC we ignore that the expiry time of newtimer might be
earlier than the overall next expiry time in hrtimer_interrupt().

To solve this, remove the caching of the next expiry value from
hrtimer_interrupt() and reevaluate all active clock bases for the next
expiry value. To avoid another code duplication, create a shared
evaluation function and use it for hrtimer_get_next_event(),
hrtimer_force_reprogram() and hrtimer_interrupt().

There is another subtlety in this mechanism:

While hrtimer_interrupt() is running, we want to avoid to touch the
hardware device because we will reprogram it anyway at the end of
hrtimer_interrupt(). This works nicely for hrtimers which get rearmed
via the HRTIMER_RESTART mechanism, because we drop out when the
callback on that CPU is running. But that fails, if a new timer gets
enqueued like in the example above.

This has another implication: While hrtimer_interrupt() is running we
refuse remote enqueueing of timers - see hrtimer_interrupt() and
hrtimer_check_target().

hrtimer_interrupt() tries to prevent this by setting cpu_base->expires
to KTIME_MAX, but that fails if a new timer gets queued.

Prevent both the hardware access and the remote enqueue
explicitely. We can loosen the restriction on the remote enqueue now
due to reevaluation of the next expiry value, but that needs a
seperate patch.

Folded in a fix from Vignesh Radhakrishnan.

Reported-and-tested-by: Stanislav Fomichev <stfomichev@yandex-team.ru>
Based-on-patch-by: Stanislav Fomichev <stfomichev@yandex-team.ru>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: vigneshr@codeaurora.org
Cc: john.stultz@linaro.org
Cc: viresh.kumar@linaro.org
Cc: fweisbec@gmail.com
Cc: cl@linux.com
Cc: stuart.w.hayes@gmail.com
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1501202049190.5526@nanos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-01-23 12:13:20 +01:00
Thomas Gleixner 5fbaba8603 Merge branch 'fortglx/3.19-stable/time' of https://git.linaro.org/people/john.stultz/linux into timers/urgent
Pull urgent fixes from John Stultz:

  Two urgent fixes for user triggerable time related overflow issues
2015-01-22 12:28:02 +01:00
Sasha Levin 5e5aeb4367 time: adjtimex: Validate the ADJ_FREQUENCY values
Verify that the frequency value from userspace is valid and makes sense.

Unverified values can cause overflows later on.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
[jstultz: Fix up bug for negative values and drop redunent cap check]
Signed-off-by: John Stultz <john.stultz@linaro.org>
2015-01-07 09:50:32 -08:00
Sasha Levin 6ada1fc0e1 time: settimeofday: Validate the values of tv from user
An unvalidated user input is multiplied by a constant, which can result in
an undefined behaviour for large values. While this is validated later,
we should avoid triggering undefined behaviour.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
[jstultz: include trivial milisecond->microsecond correction noticed
by Andy]
Signed-off-by: John Stultz <john.stultz@linaro.org>
2015-01-07 09:49:14 -08:00
Richard Cochran 2eebdde652 timecounter: keep track of accumulated fractional nanoseconds
The current timecounter implementation will drop a variable amount
of resolution, depending on the magnitude of the time delta. In
other words, reading the clock too often or too close to a time
stamp conversion will introduce errors into the time values. This
patch fixes the issue by introducing a fractional nanosecond field
that accumulates the low order bits.

Reported-by: Janusz Użycki <j.uzycki@elproma.com.pl>
Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-30 18:29:27 -05:00
Richard Cochran 74d23cc704 time: move the timecounter/cyclecounter code into its own file.
The timecounter code has almost nothing to do with the clocksource
code. Let it live in its own file. This will help isolate the
timecounter users from the clocksource users in the source tree.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-30 18:29:25 -05:00
Linus Torvalds 4bb9374e0b Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull NOHZ update from Thomas Gleixner:
 "Remove the call into the nohz idle code from the fake 'idle' thread in
  the powerclamp driver along with the export of those functions which
  was smuggeled in via the thermal tree.  People have tried to hack
  around it in the nohz core code, but it just violates all rightful
  assumptions of that code about the only valid calling context (i.e.
  the proper idle task).

  The powerclamp trainwreck will still work, it just wont get the
  benefit of long idle sleeps"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tick/powerclamp: Remove tick_nohz_idle abuse
2014-12-19 13:29:20 -08:00
Thomas Gleixner a5fd9733a3 tick/powerclamp: Remove tick_nohz_idle abuse
commit 4dbd27711c "tick: export nohz tick idle symbols for module
use" was merged via the thermal tree without an explicit ack from the
relevant maintainers.

The exports are abused by the intel powerclamp driver which implements
a fake idle state from a sched FIFO task. This causes all kinds of
wreckage in the NOHZ core code which rightfully assumes that
tick_nohz_idle_enter/exit() are only called from the idle task itself.

Recent changes in the NOHZ core lead to a failure of the powerclamp
driver and now people try to hack completely broken and backwards
workarounds into the NOHZ core code. This is completely unacceptable
and just papers over the real problem. There are way more subtle
issues lurking around the corner.

The real solution is to fix the powerclamp driver by rewriting it with
a sane concept, but that's beyond the scope of this.

So the only solution for now is to remove the calls into the core NOHZ
code from the powerclamp trainwreck along with the exports. 

Fixes: d6d71ee4a1 "PM: Introduce Intel PowerClamp Driver"
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Pan Jacob jun <jacob.jun.pan@intel.com>
Cc: LKP <lkp@01.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1412181110110.17382@nanos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-12-19 14:05:52 +01:00
Linus Torvalds 988adfdffd Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux
Pull drm updates from Dave Airlie:
 "Highlights:

   - AMD KFD driver merge

     This is the AMD HSA interface for exposing a lowlevel interface for
     GPGPU use.  They have an open source userspace built on top of this
     interface, and the code looks as good as it was going to get out of
     tree.

   - Initial atomic modesetting work

     The need for an atomic modesetting interface to allow userspace to
     try and send a complete set of modesetting state to the driver has
     arisen, and been suffering from neglect this past year.  No more,
     the start of the common code and changes for msm driver to use it
     are in this tree.  Ongoing work to get the userspace ioctl finished
     and the code clean will probably wait until next kernel.

   - DisplayID 1.3 and tiled monitor exposed to userspace.

     Tiled monitor property is now exposed for userspace to make use of.

   - Rockchip drm driver merged.

   - imx gpu driver moved out of staging

  Other stuff:

   - core:
        panel - MIPI DSI + new panels.
        expose suggested x/y properties for virtual GPUs

   - i915:
        Initial Skylake (SKL) support
        gen3/4 reset work
        start of dri1/ums removal
        infoframe tracking
        fixes for lots of things.

   - nouveau:
        tegra k1 voltage support
        GM204 modesetting support
        GT21x memory reclocking work

   - radeon:
        CI dpm fixes
        GPUVM improvements
        Initial DPM fan control

   - rcar-du:
        HDMI support added
        removed some support for old boards
        slave encoder driver for Analog Devices adv7511

   - exynos:
        Exynos4415 SoC support

   - msm:
        a4xx gpu support
        atomic helper conversion

   - tegra:
        iommu support
        universal plane support
        ganged-mode DSI support

   - sti:
        HDMI i2c improvements

   - vmwgfx:
        some late fixes.

   - qxl:
        use suggested x/y properties"

* 'drm-next' of git://people.freedesktop.org/~airlied/linux: (969 commits)
  drm: sti: fix module compilation issue
  drm/i915: save/restore GMBUS freq across suspend/resume on gen4
  drm: sti: correctly cleanup CRTC and planes
  drm: sti: add HQVDP plane
  drm: sti: add cursor plane
  drm: sti: enable auxiliary CRTC
  drm: sti: fix delay in VTG programming
  drm: sti: prepare sti_tvout to support auxiliary crtc
  drm: sti: use drm_crtc_vblank_{on/off} instead of drm_vblank_{on/off}
  drm: sti: fix hdmi avi infoframe
  drm: sti: remove event lock while disabling vblank
  drm: sti: simplify gdp code
  drm: sti: clear all mixer control
  drm: sti: remove gpio for HDMI hot plug detection
  drm: sti: allow to change hdmi ddc i2c adapter
  drm/doc: Document drm_add_modes_noedid() usage
  drm/i915: Remove '& 0xffff' from the mask given to WA_REG()
  drm/i915: Invert the mask and val arguments in wa_add() and WA_REG()
  drm: Zero out DRM object memory upon cleanup
  drm/i915/bdw: Fix the write setting up the WIZ hashing mode
  ...
2014-12-15 15:52:01 -08:00
Linus Torvalds a7cb7bb664 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree update from Jiri Kosina:
 "Usual stuff: documentation updates, printk() fixes, etc"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (24 commits)
  intel_ips: fix a type in error message
  cpufreq: cpufreq-dt: Move newline to end of error message
  ps3rom: fix error return code
  treewide: fix typo in printk and Kconfig
  ARM: dts: bcm63138: change "interupts" to "interrupts"
  Replace mentions of "list_struct" to "list_head"
  kernel: trace: fix printk message
  scsi: mpt2sas: fix ioctl in comment
  zbud, zswap: change module author email
  clocksource: Fix 'clcoksource' typo in comment
  arm: fix wording of "Crotex" in CONFIG_ARCH_EXYNOS3 help
  gpio: msm-v1: make boolean argument more obvious
  usb: Fix typo in usb-serial-simple.c
  PCI: Fix comment typo 'COMFIG_PM_OPS'
  powerpc: Fix comment typo 'CONIFG_8xx'
  powerpc: Fix comment typos 'CONFiG_ALTIVEC'
  clk: st: Spelling s/stucture/structure/
  isci: Spelling s/stucture/structure/
  usb: gadget: zero: Spelling s/infrastucture/infrastructure/
  treewide: Fix company name in module descriptions
  ...
2014-12-12 10:08:06 -08:00
Linus Torvalds eedb3d3304 Merge branch 'for-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
Pull percpu updates from Tejun Heo:
 "Nothing interesting.  A patch to convert the remaining __get_cpu_var()
  users, another to fix non-critical off-by-one in an assertion and a
  cosmetic conversion to lockless_dereference() in percpu-ref.

  The back-merge from mainline is to receive lockless_dereference()"

* 'for-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  percpu: Replace smp_read_barrier_depends() with lockless_dereference()
  percpu: Convert remaining __get_cpu_var uses in 3.18-rcX
  percpu: off by one in BUG_ON()
2014-12-11 18:36:26 -08:00
Linus Torvalds d82012695e Merge branch 'timers-2038-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull more 2038 timer work from Thomas Gleixner:
 "Two more patches for the ongoing 2038 work:

   - New accessors to clock MONOTONIC and REALTIME seconds

  This is a seperate branch as Arnd has follow up work depending on
  this"

* 'timers-2038-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timekeeping: Provide y2038 safe accessor to the seconds portion of CLOCK_REALTIME
  timekeeping: Provide fast accessor to the seconds part of CLOCK_MONOTONIC
2014-12-10 10:13:28 -08:00
Linus Torvalds a157508c97 Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer core updates from Thomas Gleixner:
 "The time(r) departement provides:

   - more infrastructure work on the year 2038 issue

   - a few fixes in the Armada SoC timers

   - the usual pile of fixlets and improvements"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource: armada-370-xp: Use the reference clock on A375 SoC
  watchdog: orion: Use the reference clock on Armada 375 SoC
  clocksource: armada-370-xp: Add missing clock enable
  time: Fix sign bug in NTP mult overflow warning
  time: Remove timekeeping_inject_sleeptime()
  rtc: Update suspend/resume timing to use 64bit time
  rtc/lib: Provide y2038 safe rtc_tm_to_time()/rtc_time_to_tm() replacement
  time: Fixup comments to reflect usage of timespec64
  time: Expose get_monotonic_coarse64() for in-kernel uses
  time: Expose getrawmonotonic64 for in-kernel uses
  time: Provide y2038 safe mktime() replacement
  time: Provide y2038 safe timekeeping_inject_sleeptime() replacement
  time: Provide y2038 safe do_settimeofday() replacement
  time: Complete NTP adjustment threshold judging conditions
  time: Avoid possible NTP adjustment mult overflow.
  time: Rename udelay_test.c to test_udelay.c
  clocksource: sirf: Remove hard-coded clock rate
2014-12-10 08:18:32 -08:00
Linus Torvalds c30110608c Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU updates from Ingo Molnar:
 "These are the main changes in this cycle:

    - Streamline RCU's use of per-CPU variables, shifting from "cpu"
      arguments to functions to "this_"-style per-CPU variable
      accessors.

    - signal-handling RCU updates.

    - real-time updates.

    - torture-test updates.

    - miscellaneous fixes.

    - documentation updates"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (34 commits)
  rcu: Fix FIXME in rcu_tasks_kthread()
  rcu: More info about potential deadlocks with rcu_read_unlock()
  rcu: Optimize cond_resched_rcu_qs()
  rcu: Add sparse check for RCU_INIT_POINTER()
  documentation: memory-barriers.txt: Correct example for reorderings
  documentation: Add atomic_long_t to atomic_ops.txt
  documentation: Additional restriction for control dependencies
  documentation: Document RCU self test boot params
  rcutorture: Fix rcu_torture_cbflood() memory leak
  rcutorture: Remove obsolete kversion param in kvm.sh
  rcutorture: Remove stale test configurations
  rcutorture: Enable RCU self test in configs
  rcutorture: Add early boot self tests
  torture: Run Linux-kernel binary out of results directory
  cpu: Avoid puts_pending overflow
  rcu: Remove "cpu" argument to rcu_cleanup_after_idle()
  rcu: Remove "cpu" argument to rcu_prepare_for_idle()
  rcu: Remove "cpu" argument to rcu_needs_cpu()
  rcu: Remove "cpu" argument to rcu_note_context_switch()
  rcu: Remove "cpu" argument to rcu_preempt_check_callbacks()
  ...
2014-12-09 20:23:19 -08:00
Daniel Vetter 7bd0e226e3 drm/i915: compute wait_ioctl timeout correctly
We've lost the +1 required for correct timeouts in

commit 5ed0bdf21a
Author: Thomas Gleixner <tglx@linutronix.de>
Date:   Wed Jul 16 21:05:06 2014 +0000

    drm: i915: Use nsec based interfaces

    Use ktime_get_raw_ns() and get rid of the back and forth timespec
    conversions.

    Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
    Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
    Signed-off-by: John Stultz <john.stultz@linaro.org>

So fix this up by reinstating our handrolled _timeout function. While
at it bother with handling MAX_JIFFIES.

v2: Convert to usecs (we don't care about the accuracy anyway) first
to avoid overflow issues Dave Gordon spotted.

v3: Drop the explicit MAX_JIFFY_OFFSET check, usecs_to_jiffies should
take care of that already. It might be a bit too enthusiastic about it
though.

v4: Chris has a much nicer color, so use his implementation.

This requires to export nsec_to_jiffies from time.c.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Dave Gordon <david.s.gordon@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=82749
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Acked-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
2014-12-05 15:20:24 +02:00
John Stultz cb2aa63469 time: Fix sign bug in NTP mult overflow warning
In commit 6067dc5a8c ("time: Avoid possible NTP adjustment
mult overflow") a new check was added to watch for adjustments
that could cause a mult overflow.

Unfortunately the check compares a signed with unsigned value
and ignored the case where the adjustment was negative, which
causes spurious warn-ons on some systems (and seems like it
would result in problematic time adjustments there as well, due
to the early return).

Thus this patch adds a check to make sure the adjustment is
positive before we check for an overflow, and resovles the issue
in my testing.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Debugged-by: pang.xunlei <pang.xunlei@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/1416890145-30048-1-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-11-25 07:18:34 +01:00
Tejun Heo cceb9bd633 Merge branch 'master' into for-3.19
Pull in to receive 54ef6df3f3 ("rcu: Provide counterpart to
rcu_dereference() for non-RCU situations").

Signed-off-by: Tejun Heo <tj@kernel.org>
2014-11-22 09:32:08 -05:00
John Stultz 5322e4c264 time: Fixup comments to reflect usage of timespec64
Fix up a few comments that weren't updated when the
functions were converted to use timespec64 structures.

Acked-by: Arnd Bergmann <arnd.bergmann@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-11-21 11:59:59 -08:00
John Stultz 334334b5f5 time: Expose get_monotonic_coarse64() for in-kernel uses
Adds a timespec64 based get_monotonic_coarse64() implementation
that can be used as we convert internal users of
get_monotonic_coarse away from using timespecs.

Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-11-21 11:59:59 -08:00
John Stultz cdba2ec538 time: Expose getrawmonotonic64 for in-kernel uses
Adds a timespec64 based getrawmonotonic64() implementation
that can be used as we convert internal users of
getrawmonotonic away from using timespecs.

Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-11-21 11:59:58 -08:00
pang.xunlei 90b6ce9c40 time: Provide y2038 safe mktime() replacement
As part of addressing "y2038 problem" for in-kernel uses, this
patch adds safe mktime64() using time64_t.

After this patch, mktime() is deprecated and all its call sites
will be fixed using mktime64(), after that it can be removed.

Signed-off-by: pang.xunlei <pang.xunlei@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-11-21 11:59:58 -08:00
pang.xunlei 04d9089086 time: Provide y2038 safe timekeeping_inject_sleeptime() replacement
As part of addressing "y2038 problem" for in-kernel uses, this
patch adds timekeeping_inject_sleeptime64() using timespec64.

After this patch, timekeeping_inject_sleeptime() is deprecated
and all its call sites will be fixed using the new interface,
after that it can be removed.

NOTE: timekeeping_inject_sleeptime() is safe actually, but we
want to eliminate timespec eventually, so comes this patch.

Signed-off-by: pang.xunlei <pang.xunlei@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-11-21 11:59:57 -08:00
pang.xunlei 21f7eca555 time: Provide y2038 safe do_settimeofday() replacement
The kernel uses 32-bit signed value(time_t) for seconds elapsed
1970-01-01:00:00:00, thus it will overflow at 2038-01-19 03:14:08
on 32-bit systems. This is widely known as the y2038 problem.

As part of addressing "y2038 problem" for in-kernel uses, this patch
adds safe do_settimeofday64() using timespec64.

After this patch, do_settimeofday() is deprecated and all its call
sites will be fixed using do_settimeofday64(), after that it can be
removed.

Signed-off-by: pang.xunlei <pang.xunlei@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-11-21 11:59:57 -08:00
pang.xunlei 659bc17b80 time: Complete NTP adjustment threshold judging conditions
The clocksource mult-adjustment threshold is [mult-maxadj, mult+maxadj],
timekeeping_adjust() only deals with the upper threshold, but misses the
lower threshold.

This patch adds the lower threshold judging condition.

Signed-off-by: pang.xunlei <pang.xunlei@linaro.org>
[jstultz: Minor fix for > 80 char line]
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-11-21 11:59:56 -08:00
pang.xunlei 6067dc5a8c time: Avoid possible NTP adjustment mult overflow.
Ideally, __clocksource_updatefreq_scale, selects the largest shift
value possible for a clocksource. This results in the mult memember of
struct clocksource being particularly large, although not so large
that NTP would adjust the clock to cause it to overflow.

That said, nothing actually prohibits an overflow from occuring, its
just that it "shouldn't" occur.

So while very unlikely, and so far never observed, the value of
(cs->mult+cs->maxadj) may have a chance to reach very near 0xFFFFFFFF,
so there is a possibility it may overflow when doing NTP positive
adjustment

See the following detail: When NTP slewes the clock, kernel goes
through update_wall_time()->...->timekeeping_apply_adjustment():
	tk->tkr.mult += mult_adj;

Since there is no guard against it, its possible tk->tkr.mult may
overflow during this operation.

This patch avoids any possible mult overflow by judging the overflow
case before adding mult_adj to mult, also adds the WARNING message
when capturing such case.

Signed-off-by: pang.xunlei <pang.xunlei@linaro.org>
[jstultz: Reworded commit message]
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-11-21 11:59:56 -08:00
John Stultz fd866e2b11 time: Rename udelay_test.c to test_udelay.c
Kees requested that this test module be renamed for consistency sake,
so this patch renames the udelay_test.c file (recently added to
tip/timers/core for 3.17) to test_udelay.c

Cc: Kees Cook <keescook@chromium.org>
Cc: Greg KH <greg@kroah.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Linux-Next <linux-next@vger.kernel.org>
Cc: David Riley <davidriley@chromium.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-11-21 11:59:55 -08:00
Jiri Kosina a02001086b Merge Linus' tree to be be to apply submitted patches to newer code than
current trivial.git base
2014-11-20 14:42:02 +01:00
Ingo Molnar d360b78f99 Merge branch 'rcu/next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull RCU updates from Paul E. McKenney:

 - Streamline RCU's use of per-CPU variables, shifting from "cpu"
   arguments to functions to "this_"-style per-CPU variable accessors.

 - Signal-handling RCU updates.

 - Real-time updates.

 - Torture-test updates.

 - Miscellaneous fixes.

 - Documentation updates.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-11-20 08:57:58 +01:00
Peter Zijlstra 23cfa361f3 sched/cputime: Fix cpu_timer_sample_group() double accounting
While looking over the cpu-timer code I found that we appear to add
the delta for the calling task twice, through:

  cpu_timer_sample_group()
    thread_group_cputimer()
      thread_group_cputime()
        times->sum_exec_runtime += task_sched_runtime();

    *sample = cputime.sum_exec_runtime + task_delta_exec();

Which would make the sample run ahead, making the sleep short.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20141112113737.GI10476@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-11-16 10:04:18 +01:00
Paul E. McKenney aa6da5140b rcu: Remove "cpu" argument to rcu_needs_cpu()
The "cpu" argument to rcu_needs_cpu() is always the current CPU, so drop
it.  This in turn allows the "cpu" argument to rcu_cpu_has_callbacks()
to be removed, which allows the uses of "cpu" in both functions to be
replaced with a this_cpu_ptr().  Again, the anticipated cross-CPU uses
of these functions has been replaced by NO_HZ_FULL.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
2014-11-03 19:20:43 -08:00
Paul E. McKenney c3377c2da6 rcu: Remove "cpu" argument to rcu_check_callbacks()
The "cpu" argument was kept around on the off-chance that RCU might
offload scheduler-clock interrupts.  However, this offload approach
has been replaced by NO_HZ_FULL, which offloads -all- RCU processing
from qualifying CPUs.  It is therefore time to remove the "cpu" argument
to rcu_check_callbacks(), which this commit does.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
2014-11-03 19:20:11 -08:00
Christoph Lameter 56e4dea81a percpu: Convert remaining __get_cpu_var uses in 3.18-rcX
During the 3.18 merge period additional __get_cpu_var uses were
added. The patch converts these to this_cpu_ptr().

Signed-off-by: Christoph Lameter <cl@linux.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
2014-10-29 11:18:18 -04:00