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    Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 6c8a53c9
    Linus Torvalds authored
    Pull perf changes from Ingo Molnar:
     "Core kernel changes:
    
       - One of the more interesting features in this cycle is the ability
         to attach eBPF programs (user-defined, sandboxed bytecode executed
         by the kernel) to kprobes.
    
         This allows user-defined instrumentation on a live kernel image
         that can never crash, hang or interfere with the kernel negatively.
         (Right now it's limited to root-only, but in the future we might
         allow unprivileged use as well.)
    
         (Alexei Starovoitov)
    
       - Another non-trivial feature is per event clockid support: this
         allows, amongst other things, the selection of different clock
         sources for event timestamps traced via perf.
    
         This feature is sought by people who'd like to merge perf generated
         events with external events that were measured with different
         clocks:
    
           - cluster wide profiling
    
           - for system wide tracing with user-space events,
    
           - JIT profiling events
    
         etc.  Matching perf tooling support is added as well, available via
         the -k, --clockid <clockid> parameter to perf record et al.
    
         (Peter Zijlstra)
    
      Hardware enablement kernel changes:
    
       - x86 Intel Processor Trace (PT) support: which is a hardware tracer
         on steroids, available on Broadwell CPUs.
    
         The hardware trace stream is directly output into the user-space
         ring-buffer, using the 'AUX' data format extension that was added
         to the perf core to support hardware constraints such as the
         necessity to have the tracing buffer physically contiguous.
    
         This patch-set was developed for two years and this is the result.
         A simple way to make use of this is to use BTS tracing, the PT
         driver emulates BTS output - available via the 'intel_bts' PMU.
         More explicit PT specific tooling support is in the works as well -
         will probably be ready by 4.2.
    
         (Alexander Shishkin, Peter Zijlstra)
    
       - x86 Intel Cache QoS Monitoring (CQM) support: this is a hardware
         feature of Intel Xeon CPUs that allows the measurement and
         allocation/partitioning of caches to individual workloads.
    
         These kernel changes expose the measurement side as a new PMU
         driver, which exposes various QoS related PMU events.  (The
         partitioning change is work in progress and is planned to be merged
         as a cgroup extension.)
    
         (Matt Fleming, Peter Zijlstra; CPU feature detection by Peter P
         Waskiewicz Jr)
    
       - x86 Intel Haswell LBR call stack support: this is a new Haswell
         feature that allows the hardware recording of call chains, plus
         tooling support.  To activate this feature you have to enable it
         via the new 'lbr' call-graph recording option:
    
            perf record --call-graph lbr
            perf report
    
         or:
    
            perf top --call-graph lbr
    
         This hardware feature is a lot faster than stack walk or dwarf
         based unwinding, but has some limitations:
    
           - It reuses the current LBR facility, so LBR call stack and
             branch record can not be enabled at the same time.
    
           - It is only available for user-space callchains.
    
         (Yan, Zheng)
    
       - x86 Intel Broadwell CPU support and various event constraints and
         event table fixes for earlier models.
    
         (Andi Kleen)
    
       - x86 Intel HT CPUs event scheduling workarounds.  This is a complex
         CPU bug affecting the SNB,IVB,HSW families that results in counter
         value corruption.  The mitigation code is automatically enabled and
         is transparent.
    
         (Maria Dimakopoulou, Stephane Eranian)
    
      The perf tooling side had a ton of changes in this cycle as well, so
      I'm only able to list the user visible changes here, in addition to
      the tooling changes outlined above:
    
      User visible changes affecting all tools:
    
          - Improve support of compressed kernel modules (Jiri Olsa)
          - Save DSO loading errno to better report errors (Arnaldo Carvalho de Melo)
          - Bash completion for subcommands (Yunlong Song)
          - Add 'I' event modifier for perf_event_attr.exclude_idle bit (Jiri Olsa)
          - Support missing -f to override perf.data file ownership. (Yunlong Song)
          - Show the first event with an invalid filter (David Ahern, Arnaldo Carvalho de Melo)
    
      User visible changes in individual tools:
    
        'perf data':
    
            New tool for converting perf.data to other formats, initially
            for the CTF (Common Trace Format) from LTTng (Jiri Olsa,
            Sebastian Siewior)
    
        'perf diff':
    
            Add --kallsyms option (David Ahern)
    
        'perf list':
    
            Allow listing events with 'tracepoint' prefix (Yunlong Song)
    
            Sort the output of the command (Yunlong Song)
    
        'perf kmem':
    
            Respect -i option (Jiri Olsa)
    
            Print big numbers using thousands' group (Namhyung Kim)
    
            Allow -v option (Namhyung Kim)
    
            Fix alignment of slab result table (Namhyung Kim)
    
        'perf probe':
    
            Support multiple probes on different binaries on the same command line (Masami Hiramatsu)
    
            Support unnamed union/structure members data collection. (Masami Hiramatsu)
    
            Check kprobes blacklist when adding new events. (Masami Hiramatsu)
    
        'perf record':
    
            Teach 'perf record' about perf_event_attr.clockid (Peter Zijlstra)
    
            Support recording running/enabled time (Andi Kleen)
    
        'perf sched':
    
            Improve the performance of 'perf sched replay' on high CPU core count machines (Yunlong Song)
    
        'perf report' and 'perf top':
    
            Allow annotating entries in callchains in the hists browser (Arnaldo Carvalho de Melo)
    
            Indicate which callchain entries are annotated in the
            TUI hists browser (Arnaldo Carvalho de Melo)
    
            Add pid/tid filtering to 'report' and 'script' commands (David Ahern)
    
            Consider PERF_RECORD_ events with cpumode == 0 in 'perf top', removing one
            cause of long term memory usage buildup, i.e. not processing PERF_RECORD_EXIT
            events (Arnaldo Carvalho de Melo)
    
        'perf stat':
    
            Report unsupported events properly (Suzuki K. Poulose)
    
            Output running time and run/enabled ratio in CSV mode (Andi Kleen)
    
        'perf trace':
    
            Handle legacy syscalls tracepoints (David Ahern, Arnaldo Carvalho de Melo)
    
            Only insert blank duration bracket when tracing syscalls (Arnaldo Carvalho de Melo)
    
            Filter out the trace pid when no threads are specified (Arnaldo Carvalho de Melo)
    
            Dump stack on segfaults (Arnaldo Carvalho de Melo)
    
            No need to explicitely enable evsels for workload started from perf, let it
            be enabled via perf_event_attr.enable_on_exec, removing some events that take
            place in the 'perf trace' before a workload is really started by it.
            (Arnaldo Carvalho de Melo)
    
            Allow mixing with tracepoints and suppressing plain syscalls. (Arnaldo Carvalho de Melo)
    
      There's also been a ton of infrastructure work done, such as the
      split-out of perf's build system into tools/build/ and other changes -
      see the shortlog and changelog for details"
    
    * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (358 commits)
      perf/x86/intel/pt: Clean up the control flow in pt_pmu_hw_init()
      perf evlist: Fix type for references to data_head/tail
      perf probe: Check the orphaned -x option
      perf probe: Support multiple probes on different binaries
      perf buildid-list: Fix segfault when show DSOs with hits
      perf tools: Fix cross-endian analysis
      perf tools: Fix error path to do closedir() when synthesizing threads
      perf tools: Fix synthesizing fork_event.ppid for non-main thread
      perf tools: Add 'I' event modifier for exclude_idle bit
      perf report: Don't call map__kmap if map is NULL.
      perf tests: Fix attr tests
      perf probe: Fix ARM 32 building error
      perf tools: Merge all perf_event_attr print functions
      perf record: Add clockid parameter
      perf sched replay: Use replay_repeat to calculate the runavg of cpu usage instead of the default value 10
      perf sched replay: Support using -f to override perf.data file ownership
      perf sched replay: Fix the EMFILE error caused by the limitation of the maximum open files
      perf sched replay: Handle the dead halt of sem_wait when create_tasks() fails for any task
      perf sched replay: Fix the segmentation fault problem caused by pr_err in threads
      perf sched replay: Realloc the memory of pid_to_task stepwise to adapt to the different pid_max configurations
      ...
    6c8a53c9