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  1. Nov 04, 2015
    • Linus Torvalds's avatar
      Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · b02ac6b1
      Linus Torvalds authored
      Pull perf updates from Ingo Molnar:
       "Kernel side changes:
      
         - Improve accuracy of perf/sched clock on x86.  (Adrian Hunter)
      
         - Intel DS and BTS updates.  (Alexander Shishkin)
      
         - Intel cstate PMU support.  (Kan Liang)
      
         - Add group read support to perf_event_read().  (Peter Zijlstra)
      
         - Branch call hardware sampling support, implemented on x86 and
           PowerPC.  (Stephane Eranian)
      
         - Event groups transactional interface enhancements.  (Sukadev
           Bhattiprolu)
      
         - Enable proper x86/intel/uncore PMU support on multi-segment PCI
           systems.  (Taku Izumi)
      
         - ... misc fixes and cleanups.
      
        The perf tooling team was very busy again with 200+ commits, the full
        diff doesn't fit into lkml size limits.  Here's an (incomplete) list
        of the tooling highlights:
      
        New features:
      
         - Change the default event used in all tools (record/top): use the
           most precise "cycles" hw counter available, i.e...
      b02ac6b1
    • Linus Torvalds's avatar
      atomic: remove all traces of READ_ONCE_CTRL() and atomic*_read_ctrl() · 105ff3cb
      Linus Torvalds authored
      
      This seems to be a mis-reading of how alpha memory ordering works, and
      is not backed up by the alpha architecture manual.  The helper functions
      don't do anything special on any other architectures, and the arguments
      that support them being safe on other architectures also argue that they
      are safe on alpha.
      
      Basically, the "control dependency" is between a previous read and a
      subsequent write that is dependent on the value read.  Even if the
      subsequent write is actually done speculatively, there is no way that
      such a speculative write could be made visible to other cpu's until it
      has been committed, which requires validating the speculation.
      
      Note that most weakely ordered architectures (very much including alpha)
      do not guarantee any ordering relationship between two loads that depend
      on each other on a control dependency:
      
          read A
          if (val == 1)
              read B
      
      because the conditional may be predicted, and the "read B" may be
      speculatively moved up to before reading the value A.  So we require the
      user to insert a smp_rmb() between the two accesses to be correct:
      
          read A;
          if (A == 1)
              smp_rmb()
              read B
      
      Alpha is further special in that it can break that ordering even if the
      *address* of B depends on the read of A, because the cacheline that is
      read later may be stale unless you have a memory barrier in between the
      pointer read and the read of the value behind a pointer:
      
          read ptr
          read offset(ptr)
      
      whereas all other weakly ordered architectures guarantee that the data
      dependency (as opposed to just a control dependency) will order the two
      accesses.  As a result, alpha needs a "smp_read_barrier_depends()" in
      between those two reads for them to be ordered.
      
      The coontrol dependency that "READ_ONCE_CTRL()" and "atomic_read_ctrl()"
      had was a control dependency to a subsequent *write*, however, and
      nobody can finalize such a subsequent write without having actually done
      the read.  And were you to write such a value to a "stale" cacheline
      (the way the unordered reads came to be), that would seem to lose the
      write entirely.
      
      So the things that make alpha able to re-order reads even more
      aggressively than other weak architectures do not seem to be relevant
      for a subsequent write.  Alpha memory ordering may be strange, but
      there's no real indication that it is *that* strange.
      
      Also, the alpha architecture reference manual very explicitly talks
      about the definition of "Dependence Constraints" in section 5.6.1.7,
      where a preceding read dominates a subsequent write.
      
      Such a dependence constraint admittedly does not impose a BEFORE (alpha
      architecture term for globally visible ordering), but it does guarantee
      that there can be no "causal loop".  I don't see how you could avoid
      such a loop if another cpu could see the stored value and then impact
      the value of the first read.  Put another way: the read and the write
      could not be seen as being out of order wrt other cpus.
      
      So I do not see how these "x_ctrl()" functions can currently be necessary.
      
      I may have to eat my words at some point, but in the absense of clear
      proof that alpha actually needs this, or indeed even an explanation of
      how alpha could _possibly_ need it, I do not believe these functions are
      called for.
      
      And if it turns out that alpha really _does_ need a barrier for this
      case, that barrier still should not be "smp_read_barrier_depends()".
      We'd have to make up some new speciality barrier just for alpha, along
      with the documentation for why it really is necessary.
      
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Paul E McKenney <paulmck@us.ibm.com>
      Cc: Dmitry Vyukov <dvyukov@google.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      105ff3cb
    • Linus Torvalds's avatar
      Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · d63a9788
      Linus Torvalds authored
      Pull locking changes from Ingo Molnar:
       "The main changes in this cycle were:
      
         - More gradual enhancements to atomic ops: new atomic*_read_ctrl()
           ops, synchronize atomic_{read,set}() ordering requirements between
           architectures, add atomic_long_t bitops.  (Peter Zijlstra)
      
         - Add _{relaxed|acquire|release}() variants for inc/dec atomics and
           use them in various locking primitives: mutex, rtmutex, mcs, rwsem.
           This enables weakly ordered architectures (such as arm64) to make
           use of more locking related optimizations.  (Davidlohr Bueso)
      
         - Implement atomic[64]_{inc,dec}_relaxed() on ARM.  (Will Deacon)
      
         - Futex kernel data cache footprint micro-optimization.  (Rasmus
           Villemoes)
      
         - pvqspinlock runtime overhead micro-optimization.  (Waiman Long)
      
         - misc smaller fixlets"
      
      * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        ARM, locking/ato...
      d63a9788
    • Linus Torvalds's avatar
      Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 28142286
      Linus Torvalds authored
      Pull RCU changes from Ingo Molnar:
       "The main changes in this cycle were:
      
         - Improvements to expedited grace periods (Paul E McKenney)
      
         - Performance improvements to and locktorture tests for percpu-rwsem
           (Oleg Nesterov, Paul E McKenney)
      
         - Torture-test changes (Paul E McKenney, Davidlohr Bueso)
      
         - Documentation updates (Paul E McKenney)
      
         - Miscellaneous fixes (Paul E McKenney, Boqun Feng, Oleg Nesterov,
           Patrick Marlier)"
      
      * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (54 commits)
        fs/writeback, rcu: Don't use list_entry_rcu() for pointer offsetting in bdi_split_work_to_wbs()
        rcu: Better hotplug handling for synchronize_sched_expedited()
        rcu: Enable stall warnings for synchronize_rcu_expedited()
        rcu: Add tasks to expedited stall-warning messages
        rcu: Add online/offline info to expedited stall warning message
        rcu: Consolidate expedited CPU selecti...
      28142286
    • Linus Torvalds's avatar
      Merge branch 'core-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · f5a8160c
      Linus Torvalds authored
      Pull EFI changes from Ingo Molnar:
       "The main changes in this cycle were:
      
         - further EFI code generalization to make it more workable for ARM64
         - various extensions, such as 64-bit framebuffer address support,
           UEFI v2.5 EFI_PROPERTIES_TABLE support
         - code modularization simplifications and cleanups
         - new debugging parameters
         - various fixes and smaller additions"
      
      * 'core-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
        efi: Fix warning of int-to-pointer-cast on x86 32-bit builds
        efi: Use correct type for struct efi_memory_map::phys_map
        x86/efi: Fix kernel panic when CONFIG_DEBUG_VIRTUAL is enabled
        efi: Add "efi_fake_mem" boot option
        x86/efi: Rename print_efi_memmap() to efi_print_memmap()
        efi: Auto-load the efi-pstore module
        efi: Introduce EFI_NX_PE_DATA bit and set it from properties table
        efi: Add support for UEFIv2.5 Properties table
        efi: Add EFI_MEMORY_MORE_RELIABLE support to efi_md_typeattr_format()
        efifb: Add support for 64-bit frame buffer addresses
        efi/arm64: Clean up efi_get_fdt_params() interface
        arm64: Use core efi=debug instead of uefi_debug command line parameter
        efi/x86: Move efi=debug option parsing to core
        drivers/firmware: Make efi/esrt.c driver explicitly non-modular
        efi: Use the generic efi.memmap instead of 'memmap'
        acpi/apei: Use appropriate pgprot_t to map GHES memory
        arm64, acpi/apei: Implement arch_apei_get_mem_attributes()
        arm64/mm: Add PROT_DEVICE_nGnRnE and PROT_NORMAL_WT
        acpi, x86: Implement arch_apei_get_mem_attributes()
        efi, x86: Rearrange efi_mem_attributes()
        ...
      f5a8160c
    • Linus Torvalds's avatar
      Merge branch 'core-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 7eeef2ab
      Linus Torvalds authored
      Pull wchan kernel address hiding from Ingo Molnar:
       "This fixes a wchan related information leak in /proc/PID/stat.
      
        There's a bit of an ABI twist to it: instead of setting the wchan
        field to 0 (which is our usual technique) we set it conditionally to a
        0/1 flag to keep ABI compatibility with older procps versions that
        only fetches /proc/PID/wchan (symbolic names) if the absolute wchan
        address is nonzero"
      
      * 'core-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        fs/proc, core/debug: Don't expose absolute kernel addresses via wchan
      7eeef2ab
    • Linus Torvalds's avatar
      Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 6aa2fdb8
      Linus Torvalds authored
      Pull irq updates from Thomas Gleixner:
       "The irq departement delivers:
      
         - Rework the irqdomain core infrastructure to accomodate ACPI based
           systems.  This is required to support ARM64 without creating
           artificial device tree nodes.
      
         - Sanitize the ACPI based ARM GIC initialization by making use of the
           new firmware independent irqdomain core
      
         - Further improvements to the generic MSI management
      
         - Generalize the irq migration on CPU hotplug
      
         - Improvements to the threaded interrupt infrastructure
      
         - Allow the migration of "chained" low level interrupt handlers
      
         - Allow optional force masking of interrupts in disable_irq[_nosysnc]
      
         - Support for two new interrupt chips - Sigh!
      
         - A larger set of errata fixes for ARM gicv3
      
         - The usual pile of fixes, updates, improvements and cleanups all
           over the place"
      
      * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kerne...
      6aa2fdb8
    • Linus Torvalds's avatar
      Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 7b2a4306
      Linus Torvalds authored
      Pull timer updates from Thomas Gleixner:
       "The timer departement provides:
      
         - More y2038 work in the area of ntp and pps.
      
         - Optimization of posix cpu timers
      
         - New time related selftests
      
         - Some new clocksource drivers
      
         - The usual pile of fixes, cleanups and improvements"
      
      * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (25 commits)
        timeconst: Update path in comment
        timers/x86/hpet: Type adjustments
        clocksource/drivers/armada-370-xp: Implement ARM delay timer
        clocksource/drivers/tango_xtal: Add new timer for Tango SoCs
        clocksource/drivers/imx: Allow timer irq affinity change
        clocksource/drivers/exynos_mct: Use container_of() instead of this_cpu_ptr()
        clocksource/drivers/h8300_*: Remove unneeded memset()s
        clocksource/drivers/sh_cmt: Remove unneeded memset() in sh_cmt_setup()
        clocksource/drivers/em_sti: Remove unneeded memset()s
        clocksource/dr...
      7b2a4306
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm · 316dde2f
      Linus Torvalds authored
      Pull ARM updates from Russell King:
       "In this ARM merge, we remove more lines than we add.  Changes include:
      
         - Enable imprecise aborts early, so that bus errors aren't masked
           until later in the boot.  This has the side effect that boot
           loaders which provoke these aborts can cause the kernel to crash
           early in boot, so we install a handler to report this event around
           the site where these are enabled.
      
         - Remove the buggy but impossible to enable cmpxchg syscall code.
      
         - Add unwinding annotations to some assembly code.
      
         - Add support for atomic half-word exchange for ARMv6k+.
      
         - Reduce ioremap() alignment for SMP/LPAE cases where we don't need
           the large alignment.
      
         - Addition of an "optimal" 3G configuration for systems with 1G of
           RAM.
      
         - Increase vmalloc space by 128M.
      
         - Constify some SMP operations structures, which have never been
           writable.
      
         - Improve ARMs dma_mmap() support...
      316dde2f
    • Linus Torvalds's avatar
      Merge tag 'arc-4.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc · 2c2b8285
      Linus Torvalds authored
      Pull ARC updates from Vineet Gupta:
      
       - Support for new MM features in ARCv2 cores (THP, PAE40) Some generic
         THP bits are touched - all ACKed by Kirill
      
       - Platform framework updates to prepare for EZChip arrival (still in works)
      
       - ARC Public Mailing list setup finally (linux-snps-arc@lists.infraded.org)
      
      * tag 'arc-4.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: (42 commits)
        ARC: mm: PAE40 support
        ARC: mm: PAE40: tlbex.S: Explicitify the size of pte_t
        ARC: mm: PAE40: switch to using phys_addr_t for physical addresses
        ARC: mm: HIGHMEM: populate high memory from DT
        ARC: mm: HIGHMEM: kmap API implementation
        ARC: mm: preps ahead of HIGHMEM support #2
        ARC: mm: preps ahead of HIGHMEM support
        ARC: mm: use generic macros _BITUL()/_AC()
        ARC: mm: Improve Duplicate PD Fault handler
        MAINTAINERS: Add public mailing list for ARC
        ARC: Ensure DT mem base is same as what kernel is built wit...
      2c2b8285
    • Linus Torvalds's avatar
      Merge tag 'cris-for-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/jesper/cris · 0921f1ef
      Linus Torvalds authored
      Pull CRIS changes from Jesper Nilsson:
       "Mostly another batch of code removal due to move to standard
        frameworks for CRISv32, initial devicetree configuration for a couple
        of boards, and some small fixes for kgdb and time handling"
      
      * tag 'cris-for-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/jesper/cris:
        cris: Drop reference to get_cmos_time()
        CRIS: Drop code related to obsolete or unused kconfigs
        cris: time: Cleanup of persistent clock stuff
        cris: re-use helpers to dump data in hex format
        CRIS v32: remove old GPIO and LEDs code
        CRIS v32: remove I2C bitbanging driver
        CRIS v32: add ARTPEC-3 and P1343 device trees
        CRIS v32: dev88: add GPIO, LEDs, RTC, temp sensor
        CRIS: add dt-bindings symlink
        CRIS v32: increase NR_IRQS
        cris: arch-v10: kgdb: Add '__used' for static variable is_dyn_brkp
        cris: arch-v10: kgdb: Use BAR instead of DTP0 for register P12
        cris: kgdb: use native hex2bin
      0921f1ef
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/egtvedt/linux-avr32 · 15f93405
      Linus Torvalds authored
      Pull avr32 update from Hans-Christian Noren Egtvedt.
      
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/egtvedt/linux-avr32:
        avr32: atngw100: remove useless include
      15f93405
    • Linus Torvalds's avatar
      Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k · df91fba5
      Linus Torvalds authored
      Pull m68k update from Geert Uytterhoeven.
      
      * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
        m68k/sun3: Use %pM format specifier to print ethernet address
      df91fba5
    • Linus Torvalds's avatar
      Merge tag 'leds_for_4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds · e8a2a176
      Linus Torvalds authored
      Pull LED updates from Jacek Anaszewski:
      
       - Move the out-of-LED-tree led-sead3 driver to the LED subsystem.
      
       - Add 'invert' sysfs attribute to the heartbeat trigger.
      
       - Add Device Tree support to the leds-netxbig driver and add related DT
         nodes to the kirkwood-netxbig.dtsi and kirkwood-net5big.dts files.
         Remove static LED setup from the related board files.
      
       - Remove redundant brightness conversion operation from leds-netxbig.
      
       - Improve leds-bcm6328 driver: improve default-state handling, add more
         init configuration options, print invalid LED instead of warning only
         about maximum LED value.
      
       - Add a shutdown function for setting gpio-leds into off state when
         shutting down.
      
       - Fix DT flash timeout property naming in leds-aat1290.txt.
      
       - Switch to using devm prefixed version of led_classdev_register()
         (leds-cobalt-qube, leds-hp6xx, leds-ot200, leds-ipaq-micro,
         leds-netxbig, leds-loc...
      e8a2a176
  2. Nov 03, 2015