1. 08 Jul, 2013 19 commits
  2. 05 Jul, 2013 2 commits
  3. 02 Jul, 2013 19 commits
    • Linus Torvalds's avatar
      Merge branch 'x86-uv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 7c6809ff
      Linus Torvalds authored
      Pull x86 UV update from Ingo Molnar:
       "There's a single commit in this tree, which adds support for a new SGI
        UV GRU (Global Reference Unit - fast NUMA messaging ASIC) hardware
        feature to scale up and beyond: an optional distributed mode that will
        allow per-node address mapping of local GRU space, as opposed to
        mapping all GRU hardware to the same contiguous high space"
      
      * 'x86-uv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        x86/UV: Add GRU distributed mode mappings
      7c6809ff
    • Linus Torvalds's avatar
      Merge branch 'x86-tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 96a3d998
      Linus Torvalds authored
      Pull x86 tracing updates from Ingo Molnar:
       "This tree adds IRQ vector tracepoints that are named after the handler
        and which output the vector #, based on a zero-overhead approach that
        relies on changing the IDT entries, by Seiji Aguchi.
      
        The new tracepoints look like this:
      
         # perf list | grep -i irq_vector
          irq_vectors:local_timer_entry                      [Tracepoint event]
          irq_vectors:local_timer_exit                       [Tracepoint event]
          irq_vectors:reschedule_entry                       [Tracepoint event]
          irq_vectors:reschedule_exit                        [Tracepoint event]
          irq_vectors:spurious_apic_entry                    [Tracepoint event]
          irq_vectors:spurious_apic_exit                     [Tracepoint event]
          irq_vectors:error_apic_entry                       [Tracepoint event]
          irq_vectors:error_apic_exit                        [Tracepoint event]
         [...]"
      
      * 'x86-tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        x86/tracing: Add config option checking to the definitions of mce handlers
        trace,x86: Do not call local_irq_save() in load_current_idt()
        trace,x86: Move creation of irq tracepoints from apic.c to irq.c
        x86, trace: Add irq vector tracepoints
        x86: Rename variables for debugging
        x86, trace: Introduce entering/exiting_irq()
        tracing: Add DEFINE_EVENT_FN() macro
      96a3d998
    • Linus Torvalds's avatar
      Merge branch 'x86-ras-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 3045f94a
      Linus Torvalds authored
      Pull x86 RAS update from Ingo Molnar:
       "The changes in this tree are:
      
         - ACPI APEI (ACPI Platform Error Interface) improvements, by Chen
           Gong
         - misc MCE fixes/cleanups"
      
      * 'x86-ras-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        x86/mce: Update MCE severity condition check
        mce: acpi/apei: Add comments to clarify usage of the various bitfields in the MCA subsystem
        ACPI/APEI: Update einj documentation for param1/param2
        ACPI/APEI: Add parameter check before error injection
        ACPI, APEI, EINJ: Fix error return code in einj_init()
        x86, mce: Fix "braodcast" typo
      3045f94a
    • Linus Torvalds's avatar
      Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 52e8ad90
      Linus Torvalds authored
      Pull x86 platform updates from Ingo Molnar:
       "Two changes:
      
         - A Kconfig dependency fix/cleanup
      
         - Introduce the 'make kvmconfig' KVM configuration helper utility
           that turns the current .config into a KVM-bootable config.  Useful
           for debugging specific native kernel configs that have no KVM
           config options enabled on VM setups."
      
      * 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        x86/platform: Make X86_GOLDFISH depend on X86_EXTENDED_PLATFORM
        x86/platform: Add kvmconfig to the phony targets
        x86, platform, kvm, kconfig: Turn existing .config's into KVM-capable configs
      52e8ad90
    • Linus Torvalds's avatar
      Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 1982269a
      Linus Torvalds authored
      Pull x86 mm changes from Ingo Molnar:
       "Misc improvements:
      
         - Fix /proc/mtrr reporting
         - Fix ioremap printout
         - Remove the unused pvclock fixmap entry on 32-bit
         - misc cleanups"
      
      * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        x86/ioremap: Correct function name output
        x86: Fix /proc/mtrr with base/size more than 44bits
        ix86: Don't waste fixmap entries
        x86/mm: Drop unneeded include <asm/*pgtable, page*_types.h>
        x86_64: Correct phys_addr in cleanup_highmap comment
      1982269a
    • Linus Torvalds's avatar
      Merge branch 'x86-microcode-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · fdd78889
      Linus Torvalds authored
      Pull x86 microcode loading update from Ingo Molnar:
       "Two main changes that improve microcode loading on AMD CPUs:
      
         - Add support for all-in-one binary microcode files that concatenate
           the microcode images of multiple processor families, by Jacob Shin
      
         - Add early microcode loading (embedded in the initrd) support, also
           by Jacob Shin"
      
      * 'x86-microcode-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        x86, microcode, amd: Another early loading fixup
        x86, microcode, amd: Allow multiple families' bin files appended together
        x86, microcode, amd: Make find_ucode_in_initrd() __init
        x86, microcode, amd: Fix warnings and errors on with CONFIG_MICROCODE=m
        x86, microcode, amd: Early microcode patch loading support for AMD
        x86, microcode, amd: Refactor functions to prepare for early loading
        x86, microcode: Vendor abstract out save_microcode_in_initrd()
        x86, microcode, intel: Correct typo in printk
      fdd78889
    • Linus Torvalds's avatar
      Merge branch 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · d652df0b
      Linus Torvalds authored
      Pull x86 FPU changes from Ingo Molnar:
       "There are two bigger changes in this tree:
      
         - Add an [early-use-]safe static_cpu_has() variant and other
           robustness improvements, including the new X86_DEBUG_STATIC_CPU_HAS
           configurable debugging facility, motivated by recent obscure FPU
           code bugs, by Borislav Petkov
      
         - Reimplement FPU detection code in C and drop the old asm code, by
           Peter Anvin."
      
      * 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        x86, fpu: Use static_cpu_has_safe before alternatives
        x86: Add a static_cpu_has_safe variant
        x86: Sanity-check static_cpu_has usage
        x86, cpu: Add a synthetic, always true, cpu feature
        x86: Get rid of ->hard_math and all the FPU asm fu
      d652df0b
    • Linus Torvalds's avatar
      Merge branch 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 4d6f843a
      Linus Torvalds authored
      Pull x86 EFI changes from Ingo Molnar:
       "Two fixes that should in principle increase robustness of our
        interaction with the EFI firmware, and a cleanup"
      
      * 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        x86, efi: retry ExitBootServices() on failure
        efi: Convert runtime services function ptrs
        UEFI: Don't pass boot services regions to SetVirtualAddressMap()
      4d6f843a
    • Linus Torvalds's avatar
      Merge branch 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 55a0d3ff
      Linus Torvalds authored
      Pull x86 debug update from Ingo Molnar:
       "Misc debuggability improvements:
      
         - Optimize the x86 CPU register printout a bit
         - Expose the tboot TXT log via debugfs
         - Small do_debug() cleanup"
      
      * 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        x86/tboot: Provide debugfs interfaces to access TXT log
        x86: Remove weird PTR_ERR() in do_debug
        x86/debug: Only print out DR registers if they are not power-on defaults
      55a0d3ff
    • Linus Torvalds's avatar
      Merge branch 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 35c23d5d
      Linus Torvalds authored
      Pull x86 cpu updates from Ingo Molnar:
       "Two changes:
      
         - Extend 32-bit double fault debugging aid to 64-bit
         - Fix a build warning"
      
      * 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        x86/intel/cacheinfo: Shut up last long-standing warning
        x86: Extend #DF debugging aid to 64-bit
      35c23d5d
    • Linus Torvalds's avatar
      Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 57935b26
      Linus Torvalds authored
      Pull x86 cleanups from Ingo Molnar:
       "Misc x86 cleanups"
      
      * 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        x86, reloc: Use xorl instead of xorq in relocate_kernel_64.S
        x86, cleanups: Remove extra tab in __flush_tlb_one()
        x86/mce: Remove check for CONFIG_X86_MCE_P4THERMAL
      57935b26
    • Linus Torvalds's avatar
      Merge branch 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 5f16a8cf
      Linus Torvalds authored
      Pull x86 boot build fix from Ingo Molnar:
       "Small fixlet for the build process"
      
      * 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        x86/boot: Close opened file descriptor
      5f16a8cf
    • Linus Torvalds's avatar
      Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 002e44bf
      Linus Torvalds authored
      Pull asm/x86 changes from Ingo Molnar:
       "Misc changes, with a bigger processor-flags cleanup/reorganization by
        Peter Anvin"
      
      * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        x86, asm, cleanup: Replace open-coded control register values with symbolic
        x86, processor-flags: Fix the datatypes and add bit number defines
        x86: Rename X86_CR4_RDWRGSFS to X86_CR4_FSGSBASE
        x86, flags: Rename X86_EFLAGS_BIT1 to X86_EFLAGS_FIXED
        linux/const.h: Add _BITUL() and _BITULL()
        x86/vdso: Convert use of typedef ctl_table to struct ctl_table
        x86: __force_order doesn't need to be an actual variable
      002e44bf
    • Linus Torvalds's avatar
      Merge branch 'sched-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · e13053f5
      Linus Torvalds authored
      Pull voluntary preemption fixes from Ingo Molnar:
       "This tree contains a speedup which is achieved through better
        might_sleep()/might_fault() preemption point annotations for uaccess
        functions, by Michael S Tsirkin:
      
        1. The only reason uaccess routines might sleep is if they fault.
           Make this explicit for all architectures.
      
        2. A voluntary preemption point in uaccess functions means compiler
           can't inline them efficiently, this breaks assumptions that they
           are very fast and small that e.g.  net code seems to make.  Remove
           this preemption point so behaviour matches with what callers
           assume.
      
        3. Accesses (e.g through socket ops) to kernel memory with KERNEL_DS
           like net/sunrpc does will never sleep.  Remove an unconditinal
           might_sleep() in the might_fault() inline in kernel.h (used when
           PROVE_LOCKING is not set).
      
        4. Accesses with pagefault_disable() return EFAULT but won't cause
           caller to sleep.  Check for that and thus avoid might_sleep() when
           PROVE_LOCKING is set.
      
        These changes offer a nice speedup for CONFIG_PREEMPT_VOLUNTARY=y
        kernels, here's a network bandwidth measurement between a virtual
        machine and the host:
      
         before:
              incoming: 7122.77   Mb/s
              outgoing: 8480.37   Mb/s
      
         after:
              incoming: 8619.24   Mb/s   [ +21.0% ]
              outgoing: 9455.42   Mb/s   [ +11.5% ]
      
        I kept these changes in a separate tree, separate from scheduler
        changes, because it's a mixed MM and scheduler topic"
      
      * 'sched-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        mm, sched: Allow uaccess in atomic with pagefault_disable()
        mm, sched: Drop voluntary schedule from might_fault()
        x86: uaccess s/might_sleep/might_fault/
        tile: uaccess s/might_sleep/might_fault/
        powerpc: uaccess s/might_sleep/might_fault/
        mn10300: uaccess s/might_sleep/might_fault/
        microblaze: uaccess s/might_sleep/might_fault/
        m32r: uaccess s/might_sleep/might_fault/
        frv: uaccess s/might_sleep/might_fault/
        arm64: uaccess s/might_sleep/might_fault/
        asm-generic: uaccess s/might_sleep/might_fault/
      e13053f5
    • Linus Torvalds's avatar
      Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 2d722f6d
      Linus Torvalds authored
      Pull scheduler updates from Ingo Molnar:
       "The main changes:
      
         - load-calculation cleanups and improvements, by Alex Shi
         - various nohz related tidying up of statisics, by Frederic
           Weisbecker
         - factor out /proc functions to kernel/sched/proc.c, by Paul
           Gortmaker
         - simplify the RT policy scheduler, by Kirill Tkhai
         - various fixes and cleanups"
      
      * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (42 commits)
        sched/debug: Remove CONFIG_FAIR_GROUP_SCHED mask
        sched/debug: Fix formatting of /proc/<PID>/sched
        sched: Fix typo in struct sched_avg member description
        sched/fair: Fix typo describing flags in enqueue_entity
        sched/debug: Add load-tracking statistics to task
        sched: Change get_rq_runnable_load() to static and inline
        sched/tg: Remove tg.load_weight
        sched/cfs_rq: Change atomic64_t removed_load to atomic_long_t
        sched/tg: Use 'unsigned long' for load variable in task group
        sched: Change cfs_rq load avg to unsigned long
        sched: Consider runnable load average in move_tasks()
        sched: Compute runnable load avg in cpu_load and cpu_avg_load_per_task
        sched: Update cpu load after task_tick
        sched: Fix sleep time double accounting in enqueue entity
        sched: Set an initial value of runnable avg for new forked task
        sched: Move a few runnable tg variables into CONFIG_SMP
        Revert "sched: Introduce temporary FAIR_GROUP_SCHED dependency for load-tracking"
        sched: Don't mix use of typedef ctl_table and struct ctl_table
        sched: Remove WARN_ON(!sd) from init_sched_groups_power()
        sched: Fix memory leakage in build_sched_groups()
        ...
      2d722f6d
    • Linus Torvalds's avatar
      Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · f0bb4c0a
      Linus Torvalds authored
      Pull perf updates from Ingo Molnar:
       "Kernel improvements:
      
         - watchdog driver improvements by Li Zefan
         - Power7 CPI stack events related improvements by Sukadev Bhattiprolu
         - event multiplexing via hrtimers and other improvements by Stephane
           Eranian
         - kernel stack use optimization by Andrew Hunter
         - AMD IOMMU uncore PMU support by Suravee Suthikulpanit
         - NMI handling rate-limits by Dave Hansen
         - various hw_breakpoint fixes by Oleg Nesterov
         - hw_breakpoint overflow period sampling and related signal handling
           fixes by Jiri Olsa
         - Intel Haswell PMU support by Andi Kleen
      
        Tooling improvements:
      
         - Reset SIGTERM handler in workload child process, fix from David
           Ahern.
         - Makefile reorganization, prep work for Kconfig patches, from Jiri
           Olsa.
         - Add automated make test suite, from Jiri Olsa.
         - Add --percent-limit option to 'top' and 'report', from Namhyung
           Kim.
         - Sorting improvements, from Namhyung Kim.
         - Expand definition of sysfs format attribute, from Michael Ellerman.
      
        Tooling fixes:
      
         - 'perf tests' fixes from Jiri Olsa.
         - Make Power7 CPI stack events available in sysfs, from Sukadev
           Bhattiprolu.
         - Handle death by SIGTERM in 'perf record', fix from David Ahern.
         - Fix printing of perf_event_paranoid message, from David Ahern.
         - Handle realloc failures in 'perf kvm', from David Ahern.
         - Fix divide by 0 in variance, from David Ahern.
         - Save parent pid in thread struct, from David Ahern.
         - Handle JITed code in shared memory, from Andi Kleen.
         - Fixes for 'perf diff', from Jiri Olsa.
         - Remove some unused struct members, from Jiri Olsa.
         - Add missing liblk.a dependency for python/perf.so, fix from Jiri
           Olsa.
         - Respect CROSS_COMPILE in liblk.a, from Rabin Vincent.
         - No need to do locking when adding hists in perf report, only 'top'
           needs that, from Namhyung Kim.
         - Fix alignment of symbol column in in the hists browser (top,
           report) when -v is given, from NAmhyung Kim.
         - Fix 'perf top' -E option behavior, from Namhyung Kim.
         - Fix bug in isupper() and islower(), from Sukadev Bhattiprolu.
         - Fix compile errors in bp_signal 'perf test', from Sukadev
           Bhattiprolu.
      
        ... and more things"
      
      * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (102 commits)
        perf/x86: Disable PEBS-LL in intel_pmu_pebs_disable()
        perf/x86: Fix shared register mutual exclusion enforcement
        perf/x86/intel: Support full width counting
        x86: Add NMI duration tracepoints
        perf: Drop sample rate when sampling is too slow
        x86: Warn when NMI handlers take large amounts of time
        hw_breakpoint: Introduce "struct bp_cpuinfo"
        hw_breakpoint: Simplify *register_wide_hw_breakpoint()
        hw_breakpoint: Introduce cpumask_of_bp()
        hw_breakpoint: Simplify the "weight" usage in toggle_bp_slot() paths
        hw_breakpoint: Simplify list/idx mess in toggle_bp_slot() paths
        perf/x86/intel: Add mem-loads/stores support for Haswell
        perf/x86/intel: Support Haswell/v4 LBR format
        perf/x86/intel: Move NMI clearing to end of PMI handler
        perf/x86/intel: Add Haswell PEBS support
        perf/x86/intel: Add simple Haswell PMU support
        perf/x86/intel: Add Haswell PEBS record support
        perf/x86/intel: Fix sparse warning
        perf/x86/amd: AMD IOMMU Performance Counter PERF uncore PMU implementation
        perf/x86/amd: Add IOMMU Performance Counter resource management
        ...
      f0bb4c0a
    • Linus Torvalds's avatar
      Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · a4883ef6
      Linus Torvalds authored
      Pull core irq changes from Ingo Molnar:
       "The main changes:
      
        - generic-irqchip driver additions, cleanups and fixes
      
        - 3 new irqchip drivers: ARMv7-M NVIC, TB10x and Marvell Orion SoCs
      
        - irq_get_trigger_type() simplification and cross-arch cleanup
      
        - various cleanups, simplifications
      
        - documentation updates"
      
      * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (26 commits)
        softirq: Use _RET_IP_
        genirq: Add the generic chip to the genirq docbook
        genirq: generic-chip: Export some irq_gc_ functions
        genirq: Fix can_request_irq() for IRQs without an action
        irqchip: exynos-combiner: Staticize combiner_init
        irqchip: Add support for ARMv7-M NVIC
        irqchip: Add TB10x interrupt controller driver
        irqdomain: Use irq_get_trigger_type() to get IRQ flags
        MIPS: octeon: Use irq_get_trigger_type() to get IRQ flags
        arm: orion: Use irq_get_trigger_type() to get IRQ flags
        mfd: stmpe: use irq_get_trigger_type() to get IRQ flags
        mfd: twl4030-irq: Use irq_get_trigger_type() to get IRQ flags
        gpio: mvebu: Use irq_get_trigger_type() to get IRQ flags
        genirq: Add irq_get_trigger_type() to get IRQ flags
        genirq: Irqchip: document gcflags arg of irq_alloc_domain_generic_chips
        genirq: Set irq thread to RT priority on creation
        irqchip: Add support for Marvell Orion SoCs
        genirq: Add kerneldoc for irq_disable.
        genirq: irqchip: Add mask to block out invalid irqs
        genirq: Generic chip: Add linear irq domain support
        ...
      a4883ef6
    • Linus Torvalds's avatar
      Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · ab3d681e
      Linus Torvalds authored
      Pull RCU updates from Ingo Molnar:
       "The major changes:
      
        - Simplify RCU's grace-period and callback processing based on the new
          numbering for callbacks.
      
        - Removal of TINY_PREEMPT_RCU in favor of TREE_PREEMPT_RCU for
          single-CPU low-latency systems.
      
        - SRCU-related changes and fixes.
      
        - Miscellaneous fixes, including converting a few remaining printk()
          calls to pr_*().
      
        - Documentation updates"
      
      * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits)
        rcu: Shrink TINY_RCU by reworking CPU-stall ifdefs
        rcu: Shrink TINY_RCU by moving exit_rcu()
        rcu: Remove TINY_PREEMPT_RCU tracing documentation
        rcu: Consolidate rcutiny_plugin.h ifdefs
        rcu: Remove rcu_preempt_note_context_switch()
        rcu: Remove the CONFIG_TINY_RCU ifdefs in rcutiny.h
        rcu: Remove check_cpu_stall_preempt()
        rcu: Simplify RCU_TINY RCU callback invocation
        rcu: Remove rcu_preempt_process_callbacks()
        rcu: Remove rcu_preempt_remove_callbacks()
        rcu: Remove rcu_preempt_check_callbacks()
        rcu: Remove show_tiny_preempt_stats()
        rcu: Remove TINY_PREEMPT_RCU
        powerpc,kvm: fix imbalance srcu_read_[un]lock()
        rcu: Remove srcu_read_lock_raw() and srcu_read_unlock_raw().
        rcu: Apply Dave Jones's NOCB Kconfig help feedback
        rcu: Merge adjacent identical ifdefs
        rcu: Drive quiescent-state-forcing delay from HZ
        rcu: Remove "Experimental" flags
        kthread: Add kworker kthreads to OS-jitter documentation
        ...
      ab3d681e
    • Linus Torvalds's avatar
      Merge branch 'core-mutexes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 0c46d68d
      Linus Torvalds authored
      Pull WW mutex support from Ingo Molnar:
       "This tree adds support for wound/wait style locks, which the graphics
        guys would like to make use of in the TTM graphics subsystem.
      
        Wound/wait mutexes are used when other multiple lock acquisitions of a
        similar type can be done in an arbitrary order.  The deadlock handling
        used here is called wait/wound in the RDBMS literature: The older
        tasks waits until it can acquire the contended lock.  The younger
        tasks needs to back off and drop all the locks it is currently
        holding, ie the younger task is wounded.
      
        See this LWN.net description of W/W mutexes:
      
           https://lwn.net/Articles/548909/
      
        The comments there outline specific usecases for this facility (which
        have already been implemented for the DRM tree).
      
        Also see Documentation/ww-mutex-design.txt for more details"
      
      * 'core-mutexes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        locking-selftests: Handle unexpected failures more strictly
        mutex: Add more w/w tests to test EDEADLK path handling
        mutex: Add more tests to lib/locking-selftest.c
        mutex: Add w/w tests to lib/locking-selftest.c
        mutex: Add w/w mutex slowpath debugging
        mutex: Add support for wound/wait style locks
        arch: Make __mutex_fastpath_lock_retval return whether fastpath succeeded or not
      0c46d68d