1. 02 Nov, 2017 1 commit
    • Greg Kroah-Hartman's avatar
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      Greg Kroah-Hartman authored
      Many source files in the tree are missing licensing information, which
      makes it harder for compliance tools to determine the correct license.
      
      By default all files without license information are under the default
      license of the kernel, which is GPL version 2.
      
      Update the files which contain no license information with the 'GPL-2.0'
      SPDX license identifier.  The SPDX identifier is a legally binding
      shorthand, which can be used instead of the full boiler plate text.
      
      This patch is based on work done by Thomas Gleixner and Kate Stewart and
      Philippe Ombredanne.
      
      How this work was done:
      
      Patches were generated and checked against linux-4.14-rc6 for a subset of
      the use cases:
       - file had no licensing information it it.
       - file was a */uapi/* one with no licensing information in it,
       - file was a */uapi/* one with existing licensing information,
      
      Further patches will be generated in subsequent months to fix up cases
      where non-standard license headers were used, and references to license
      had to be inferred by heuristics based on keywords.
      
      The analysis to determine which SPDX License Identifier to be applied to
      a file was done in a spreadsheet of side by side results from of the
      output of two independent scanners (ScanCode & Windriver) producing SPDX
      tag:value files created by Philippe Ombredanne.  Philippe prepared the
      base worksheet, and did an initial spot review of a few 1000 files.
      
      The 4.13 kernel was the starting point of the analysis with 60,537 files
      assessed.  Kate Stewart did a file by file comparison of the scanner
      results in the spreadsheet to determine which SPDX license identifier(s)
      to be applied to the file. She confirmed any determination that was not
      immediately clear with lawyers working with the Linux Foundation.
      
      Criteria used to select files for SPDX license identifier tagging was:
       - Files considered eligible had to be source code files.
       - Make and config files were included as candidates if they contained >5
         lines of source
       - File already had some variant of a license header in it (even if <5
         lines).
      
      All documentation files were explicitly excluded.
      
      The following heuristics were used to determine which SPDX license
      identifiers to apply.
      
       - when both scanners couldn't find any license traces, file was
         considered to have no license information in it, and the top level
         COPYING file license applied.
      
         For non */uapi/* files that summary was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0                                              11139
      
         and resulted in the first patch in this series.
      
         If that file was a */uapi/* path one, it was "GPL-2.0 WITH
         Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0 WITH Linux-syscall-note                        930
      
         and resulted in the second patch in this series.
      
       - if a file had some form of licensing information in it, and was one
         of the */uapi/* ones, it was denoted with the Linux-syscall-note if
         any GPL family license was found in the file or had no licensing in
         it (per prior point).  Results summary:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|------
         GPL-2.0 WITH Linux-syscall-note                       270
         GPL-2.0+ WITH Linux-syscall-note                      169
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
         LGPL-2.1+ WITH Linux-syscall-note                      15
         GPL-1.0+ WITH Linux-syscall-note                       14
         ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
         LGPL-2.0+ WITH Linux-syscall-note                       4
         LGPL-2.1 WITH Linux-syscall-note                        3
         ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
         ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1
      
         and that resulted in the third patch in this series.
      
       - when the two scanners agreed on the detected license(s), that became
         the concluded license(s).
      
       - when there was disagreement between the two scanners (one detected a
         license but the other didn't, or they both detected different
         licenses) a manual inspection of the file occurred.
      
       - In most cases a manual inspection of the information in the file
         resulted in a clear resolution of the license that should apply (and
         which scanner probably needed to revisit its heuristics).
      
       - When it was not immediately clear, the license identifier was
         confirmed with lawyers working with the Linux Foundation.
      
       - If there was any question as to the appropriate license identifier,
         the file was flagged for further research and to be revisited later
         in time.
      
      In total, over 70 hours of logged manual review was done on the
      spreadsheet to determine the SPDX license identifiers to apply to the
      source files by Kate, Philippe, Thomas and, in some cases, confirmation
      by lawyers working with the Linux Foundation.
      
      Kate also obtained a third independent scan of the 4.13 code base from
      FOSSology, and compared selected files where the other two scanners
      disagreed against that SPDX file, to see if there was new insights.  The
      Windriver scanner is based on an older version of FOSSology in part, so
      they are related.
      
      Thomas did random spot checks in about 500 files from the spreadsheets
      for the uapi headers and agreed with SPDX license identifier in the
      files he inspected. For the non-uapi files Thomas did random spot checks
      in about 15000 files.
      
      In initial set of patches against 4.14-rc6, 3 files were found to have
      copy/paste license identifier errors, and have been fixed to reflect the
      correct identifier.
      
      Additionally Philippe spent 10 hours this week doing a detailed manual
      inspection and review of the 12,461 patched files from the initial patch
      version early this week with:
       - a full scancode scan run, collecting the matched texts, detected
         license ids and scores
       - reviewing anything where there was a license detected (about 500+
         files) to ensure that the applied SPDX license was correct
       - reviewing anything where there was no detection but the patch license
         was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
         SPDX license was correct
      
      This produced a worksheet with 20 files needing minor correction.  This
      worksheet was then exported into 3 different .csv files for the
      different types of files to be modified.
      
      These .csv files were then reviewed by Greg.  Thomas wrote a script to
      parse the csv files and add the proper SPDX tag to the file, in the
      format that the file expected.  This script was further refined by Greg
      based on the output to detect more types of files automatically and to
      distinguish between header and source .c files (which need different
      comment types.)  Finally Greg ran the script using the .csv files to
      generate the patches.
      Reviewed-by: default avatarKate Stewart <kstewart@linuxfoundation.org>
      Reviewed-by: default avatarPhilippe Ombredanne <pombredanne@nexb.com>
      Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b2441318
  2. 16 Nov, 2016 1 commit
  3. 29 Feb, 2016 1 commit
    • Peter Zijlstra's avatar
      locking/mcs: Fix mcs_spin_lock() ordering · 920c720a
      Peter Zijlstra authored
      Similar to commit b4b29f94 ("locking/osq: Fix ordering of node
      initialisation in osq_lock") the use of xchg_acquire() is
      fundamentally broken with MCS like constructs.
      
      Furthermore, it turns out we rely on the global transitivity of this
      operation because the unlock path observes the pointer with a
      READ_ONCE(), not an smp_load_acquire().
      
      This is non-critical because the MCS code isn't actually used and
      mostly serves as documentation, a stepping stone to the more complex
      things we've build on top of the idea.
      Reported-by: default avatarAndrea Parri <parri.andrea@gmail.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Will Deacon <will.deacon@arm.com>
      Fixes: 3552a07a ("locking/mcs: Use acquire/release semantics")
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      920c720a
  4. 06 Oct, 2015 1 commit
  5. 08 May, 2015 1 commit
    • Waiman Long's avatar
      locking/qspinlock: Introduce a simple generic 4-byte queued spinlock · a33fda35
      Waiman Long authored
      This patch introduces a new generic queued spinlock implementation that
      can serve as an alternative to the default ticket spinlock. Compared
      with the ticket spinlock, this queued spinlock should be almost as fair
      as the ticket spinlock. It has about the same speed in single-thread
      and it can be much faster in high contention situations especially when
      the spinlock is embedded within the data structure to be protected.
      
      Only in light to moderate contention where the average queue depth
      is around 1-3 will this queued spinlock be potentially a bit slower
      due to the higher slowpath overhead.
      
      This queued spinlock is especially suit to NUMA machines with a large
      number of cores as the chance of spinlock contention is much higher
      in those machines. The cost of contention is also higher because of
      slower inter-node memory traffic.
      
      Due to the fact that spinlocks are acquired with preemption disabled,
      the process will not be migrated to another CPU while it is trying
      to get a spinlock. Ignoring interrupt handling, a CPU can only be
      contending in one spinlock at any one time. Counting soft IRQ, hard
      IRQ and NMI, a CPU can only have a maximum of 4 concurrent lock waiting
      activities.  By allocating a set of per-cpu queue nodes and used them
      to form a waiting queue, we can encode the queue node address into a
      much smaller 24-bit size (including CPU number and queue node index)
      leaving one byte for the lock.
      
      Please note that the queue node is only needed when waiting for the
      lock. Once the lock is acquired, the queue node can be released to
      be used later.
      Signed-off-by: default avatarWaiman Long <Waiman.Long@hp.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Daniel J Blueman <daniel@numascale.com>
      Cc: David Vrabel <david.vrabel@citrix.com>
      Cc: Douglas Hatch <doug.hatch@hp.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Paolo Bonzini <paolo.bonzini@gmail.com>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Scott J Norton <scott.norton@hp.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: virtualization@lists.linux-foundation.org
      Cc: xen-devel@lists.xenproject.org
      Link: http://lkml.kernel.org/r/1429901803-29771-2-git-send-email-Waiman.Long@hp.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      a33fda35
  6. 24 Feb, 2015 1 commit
  7. 14 Jan, 2015 1 commit
  8. 13 Aug, 2014 1 commit
  9. 17 Jul, 2014 1 commit
    • Davidlohr Bueso's avatar
      arch, locking: Ciao arch_mutex_cpu_relax() · 3a6bfbc9
      Davidlohr Bueso authored
      The arch_mutex_cpu_relax() function, introduced by 34b133f8, is
      hacky and ugly. It was added a few years ago to address the fact
      that common cpu_relax() calls include yielding on s390, and thus
      impact the optimistic spinning functionality of mutexes. Nowadays
      we use this function well beyond mutexes: rwsem, qrwlock, mcs and
      lockref. Since the macro that defines the call is in the mutex header,
      any users must include mutex.h and the naming is misleading as well.
      
      This patch (i) renames the call to cpu_relax_lowlatency  ("relax, but
      only if you can do it with very low latency") and (ii) defines it in
      each arch's asm/processor.h local header, just like for regular cpu_relax
      functions. On all archs, except s390, cpu_relax_lowlatency is simply cpu_relax,
      and thus we can take it out of mutex.h. While this can seem redundant,
      I believe it is a good choice as it allows us to move out arch specific
      logic from generic locking primitives and enables future(?) archs to
      transparently define it, similarly to System Z.
      Signed-off-by: default avatarDavidlohr Bueso <davidlohr@hp.com>
      Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Anton Blanchard <anton@samba.org>
      Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Bharat Bhushan <r65777@freescale.com>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Chen Liqin <liqin.linux@gmail.com>
      Cc: Chris Metcalf <cmetcalf@tilera.com>
      Cc: Christian Borntraeger <borntraeger@de.ibm.com>
      Cc: Chris Zankel <chris@zankel.net>
      Cc: David Howells <dhowells@redhat.com>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
      Cc: Dominik Dingel <dingel@linux.vnet.ibm.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
      Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Helge Deller <deller@gmx.de>
      Cc: Hirokazu Takata <takata@linux-m32r.org>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: James E.J. Bottomley <jejb@parisc-linux.org>
      Cc: James Hogan <james.hogan@imgtec.com>
      Cc: Jason Wang <jasowang@redhat.com>
      Cc: Jesper Nilsson <jesper.nilsson@axis.com>
      Cc: Joe Perches <joe@perches.com>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: Joseph Myers <joseph@codesourcery.com>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
      Cc: Lennox Wu <lennox.wu@gmail.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mark Salter <msalter@redhat.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Matt Turner <mattst88@gmail.com>
      Cc: Max Filippov <jcmvbkbc@gmail.com>
      Cc: Michael Neuling <mikey@neuling.org>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Mikael Starvik <starvik@axis.com>
      Cc: Nicolas Pitre <nico@linaro.org>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Paul Burton <paul.burton@imgtec.com>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Qais Yousef <qais.yousef@imgtec.com>
      Cc: Qiaowei Ren <qiaowei.ren@intel.com>
      Cc: Rafael Wysocki <rafael.j.wysocki@intel.com>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Richard Kuo <rkuo@codeaurora.org>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Steven Miao <realmz6@gmail.com>
      Cc: Steven Rostedt <srostedt@redhat.com>
      Cc: Stratos Karafotis <stratosk@semaphore.gr>
      Cc: Tim Chen <tim.c.chen@linux.intel.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Vasily Kulikov <segoon@openwall.com>
      Cc: Vineet Gupta <vgupta@synopsys.com>
      Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com>
      Cc: Waiman Long <Waiman.Long@hp.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Wolfram Sang <wsa@the-dreams.de>
      Cc: adi-buildroot-devel@lists.sourceforge.net
      Cc: linux390@de.ibm.com
      Cc: linux-alpha@vger.kernel.org
      Cc: linux-am33-list@redhat.com
      Cc: linux-arm-kernel@lists.infradead.org
      Cc: linux-c6x-dev@linux-c6x.org
      Cc: linux-cris-kernel@axis.com
      Cc: linux-hexagon@vger.kernel.org
      Cc: linux-ia64@vger.kernel.org
      Cc: linux@lists.openrisc.net
      Cc: linux-m32r-ja@ml.linux-m32r.org
      Cc: linux-m32r@ml.linux-m32r.org
      Cc: linux-m68k@lists.linux-m68k.org
      Cc: linux-metag@vger.kernel.org
      Cc: linux-mips@linux-mips.org
      Cc: linux-parisc@vger.kernel.org
      Cc: linuxppc-dev@lists.ozlabs.org
      Cc: linux-s390@vger.kernel.org
      Cc: linux-sh@vger.kernel.org
      Cc: linux-xtensa@linux-xtensa.org
      Cc: sparclinux@vger.kernel.org
      Link: http://lkml.kernel.org/r/1404079773.2619.4.camel@buesod1.americas.hpqcorp.netSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      3a6bfbc9
  10. 16 Jul, 2014 2 commits
    • Jason Low's avatar
      locking/spinlocks/mcs: Convert osq lock to atomic_t to reduce overhead · 90631822
      Jason Low authored
      The cancellable MCS spinlock is currently used to queue threads that are
      doing optimistic spinning. It uses per-cpu nodes, where a thread obtaining
      the lock would access and queue the local node corresponding to the CPU that
      it's running on. Currently, the cancellable MCS lock is implemented by using
      pointers to these nodes.
      
      In this patch, instead of operating on pointers to the per-cpu nodes, we
      store the CPU numbers in which the per-cpu nodes correspond to in atomic_t.
      A similar concept is used with the qspinlock.
      
      By operating on the CPU # of the nodes using atomic_t instead of pointers
      to those nodes, this can reduce the overhead of the cancellable MCS spinlock
      by 32 bits (on 64 bit systems).
      Signed-off-by: default avatarJason Low <jason.low2@hp.com>
      Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
      Cc: Scott Norton <scott.norton@hp.com>
      Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
      Cc: Dave Chinner <david@fromorbit.com>
      Cc: Waiman Long <waiman.long@hp.com>
      Cc: Davidlohr Bueso <davidlohr@hp.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Tim Chen <tim.c.chen@linux.intel.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Aswin Chandramouleeswaran <aswin@hp.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Chris Mason <clm@fb.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Josef Bacik <jbacik@fusionio.com>
      Link: http://lkml.kernel.org/r/1405358872-3732-3-git-send-email-jason.low2@hp.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      90631822
    • Jason Low's avatar
      locking/spinlocks/mcs: Rename optimistic_spin_queue() to optimistic_spin_node() · 046a619d
      Jason Low authored
      Currently, the per-cpu nodes structure for the cancellable MCS spinlock is
      named "optimistic_spin_queue". However, in a follow up patch in the series
      we will be introducing a new structure that serves as the new "handle" for
      the lock. It would make more sense if that structure is named
      "optimistic_spin_queue". Additionally, since the current use of the
      "optimistic_spin_queue" structure are  "nodes", it might be better if we
      rename them to "node" anyway.
      
      This preparatory patch renames all current "optimistic_spin_queue"
      to "optimistic_spin_node".
      Signed-off-by: default avatarJason Low <jason.low2@hp.com>
      Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
      Cc: Scott Norton <scott.norton@hp.com>
      Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
      Cc: Dave Chinner <david@fromorbit.com>
      Cc: Waiman Long <waiman.long@hp.com>
      Cc: Davidlohr Bueso <davidlohr@hp.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Tim Chen <tim.c.chen@linux.intel.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Aswin Chandramouleeswaran <aswin@hp.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Chris Mason <clm@fb.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Josef Bacik <jbacik@fusionio.com>
      Link: http://lkml.kernel.org/r/1405358872-3732-2-git-send-email-jason.low2@hp.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      046a619d
  11. 11 Mar, 2014 2 commits
  12. 09 Feb, 2014 1 commit
    • Tim Chen's avatar
      locking/mcs: Allow architecture specific asm files to be used for contended case · ddf1d169
      Tim Chen authored
      This patch allows each architecture to add its specific assembly optimized
      arch_mcs_spin_lock_contended and arch_mcs_spinlock_uncontended for
      MCS lock and unlock functions.
      Signed-off-by: default avatarTim Chen <tim.c.chen@linux.intel.com>
      Cc: Scott J Norton <scott.norton@hp.com>
      Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
      Cc: AswinChandramouleeswaran <aswin@hp.com>
      Cc: George Spelvin <linux@horizon.com>
      Cc: Rik vanRiel <riel@redhat.com>
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: MichelLespinasse <walken@google.com>
      Cc: Peter Hurley <peter@hurleysoftware.com>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: Alex Shi <alex.shi@linaro.org>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Tim Chen <tim.c.chen@linux.intel.com>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: "Figo.zhang" <figo1802@gmail.com>
      Cc: "Paul E.McKenney" <paulmck@linux.vnet.ibm.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
      Cc: Waiman Long <waiman.long@hp.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Matthew R Wilcox <matthew.r.wilcox@intel.com>
      Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/1390347382.3138.67.camel@schen9-DESKSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      ddf1d169
  13. 28 Jan, 2014 3 commits