1. 20 Apr, 2016 34 commits
  2. 12 Apr, 2016 6 commits
    • Greg Kroah-Hartman's avatar
      Linux 4.5.1 · d5441f92
      Greg Kroah-Hartman authored
      d5441f92
    • Andi Kleen's avatar
      perf/x86/intel: Fix PEBS data source interpretation on Nehalem/Westmere · 73d45efd
      Andi Kleen authored
      commit e17dc653 upstream.
      
      Jiri reported some time ago that some entries in the PEBS data source table
      in perf do not agree with the SDM. We investigated and the bits
      changed for Sandy Bridge, but the SDM was not updated.
      
      perf already implements the bits correctly for Sandy Bridge
      and later. This patch patches it up for Nehalem and Westmere.
      Signed-off-by: default avatarAndi Kleen <ak@linux.intel.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: jolsa@kernel.org
      Link: http://lkml.kernel.org/r/1456871124-15985-1-git-send-email-andi@firstfloor.orgSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      73d45efd
    • Jiri Olsa's avatar
      perf/x86/intel: Use PAGE_SIZE for PEBS buffer size on Core2 · 1b3b7e5e
      Jiri Olsa authored
      commit e72daf3f upstream.
      
      Using PAGE_SIZE buffers makes the WRMSR to PERF_GLOBAL_CTRL in
      intel_pmu_enable_all() mysteriously hang on Core2. As a workaround, we
      don't do this.
      
      The hard lockup is easily triggered by running 'perf test attr'
      repeatedly. Most of the time it gets stuck on sample session with
      small periods.
      
        # perf test attr -vv
        14: struct perf_event_attr setup                             :
        --- start ---
        ...
          'PERF_TEST_ATTR=/tmp/tmpuEKz3B /usr/bin/perf record -o /tmp/tmpuEKz3B/perf.data -c 123 kill >/dev/null 2>&1' ret 1
      Reported-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Reviewed-by: default avatarAndi Kleen <ak@linux.intel.com>
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Kan Liang <kan.liang@intel.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Vince Weaver <vincent.weaver@maine.edu>
      Cc: Wang Nan <wangnan0@huawei.com>
      Link: http://lkml.kernel.org/r/20160301190352.GA8355@krava.redhat.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      1b3b7e5e
    • Kan Liang's avatar
      perf/x86/intel: Fix PEBS warning by only restoring active PMU in pmi · ff8f5b41
      Kan Liang authored
      commit c3d266c8 upstream.
      
      This patch tries to fix a PEBS warning found in my stress test. The
      following perf command can easily trigger the pebs warning or spurious
      NMI error on Skylake/Broadwell/Haswell platforms:
      
        sudo perf record -e 'cpu/umask=0x04,event=0xc4/pp,cycles,branches,ref-cycles,cache-misses,cache-references' --call-graph fp -b -c1000 -a
      
      Also the NMI watchdog must be enabled.
      
      For this case, the events number is larger than counter number. So
      perf has to do multiplexing.
      
      In perf_mux_hrtimer_handler, it does perf_pmu_disable(), schedule out
      old events, rotate_ctx, schedule in new events and finally
      perf_pmu_enable().
      
      If the old events include precise event, the MSR_IA32_PEBS_ENABLE
      should be cleared when perf_pmu_disable().  The MSR_IA32_PEBS_ENABLE
      should keep 0 until the perf_pmu_enable() is called and the new event is
      precise event.
      
      However, there is a corner case which could restore PEBS_ENABLE to
      stale value during the above period. In perf_pmu_disable(), GLOBAL_CTRL
      will be set to 0 to stop overflow and followed PMI. But there may be
      pending PMI from an earlier overflow, which cannot be stopped. So even
      GLOBAL_CTRL is cleared, the kernel still be possible to get PMI. At
      the end of the PMI handler, __intel_pmu_enable_all() will be called,
      which will restore the stale values if old events haven't scheduled
      out.
      
      Once the stale pebs value is set, it's impossible to be corrected if
      the new events are non-precise. Because the pebs_enabled will be set
      to 0. x86_pmu.enable_all() will ignore the MSR_IA32_PEBS_ENABLE
      setting. As a result, the following NMI with stale PEBS_ENABLE
      trigger pebs warning.
      
      The pending PMI after enabled=0 will become harmless if the NMI handler
      does not change the state. This patch checks cpuc->enabled in pmi and
      only restore the state when PMU is active.
      
      Here is the dump:
      
        Call Trace:
         <NMI>  [<ffffffff813c3a2e>] dump_stack+0x63/0x85
         [<ffffffff810a46f2>] warn_slowpath_common+0x82/0xc0
         [<ffffffff810a483a>] warn_slowpath_null+0x1a/0x20
         [<ffffffff8100fe2e>] intel_pmu_drain_pebs_nhm+0x2be/0x320
         [<ffffffff8100caa9>] intel_pmu_handle_irq+0x279/0x460
         [<ffffffff810639b6>] ? native_write_msr_safe+0x6/0x40
         [<ffffffff811f290d>] ? vunmap_page_range+0x20d/0x330
         [<ffffffff811f2f11>] ?  unmap_kernel_range_noflush+0x11/0x20
         [<ffffffff8148379f>] ? ghes_copy_tofrom_phys+0x10f/0x2a0
         [<ffffffff814839c8>] ? ghes_read_estatus+0x98/0x170
         [<ffffffff81005a7d>] perf_event_nmi_handler+0x2d/0x50
         [<ffffffff810310b9>] nmi_handle+0x69/0x120
         [<ffffffff810316f6>] default_do_nmi+0xe6/0x100
         [<ffffffff810317f2>] do_nmi+0xe2/0x130
         [<ffffffff817aea71>] end_repeat_nmi+0x1a/0x1e
         [<ffffffff810639b6>] ? native_write_msr_safe+0x6/0x40
         [<ffffffff810639b6>] ? native_write_msr_safe+0x6/0x40
         [<ffffffff810639b6>] ? native_write_msr_safe+0x6/0x40
         <<EOE>>  <IRQ>  [<ffffffff81006df8>] ?  x86_perf_event_set_period+0xd8/0x180
         [<ffffffff81006eec>] x86_pmu_start+0x4c/0x100
         [<ffffffff8100722d>] x86_pmu_enable+0x28d/0x300
         [<ffffffff811994d7>] perf_pmu_enable.part.81+0x7/0x10
         [<ffffffff8119cb70>] perf_mux_hrtimer_handler+0x200/0x280
         [<ffffffff8119c970>] ?  __perf_install_in_context+0xc0/0xc0
         [<ffffffff8110f92d>] __hrtimer_run_queues+0xfd/0x280
         [<ffffffff811100d8>] hrtimer_interrupt+0xa8/0x190
         [<ffffffff81199080>] ?  __perf_read_group_add.part.61+0x1a0/0x1a0
         [<ffffffff81051bd8>] local_apic_timer_interrupt+0x38/0x60
         [<ffffffff817af01d>] smp_apic_timer_interrupt+0x3d/0x50
         [<ffffffff817ad15c>] apic_timer_interrupt+0x8c/0xa0
         <EOI>  [<ffffffff81199080>] ?  __perf_read_group_add.part.61+0x1a0/0x1a0
         [<ffffffff81123de5>] ?  smp_call_function_single+0xd5/0x130
         [<ffffffff81123ddb>] ?  smp_call_function_single+0xcb/0x130
         [<ffffffff81199080>] ?  __perf_read_group_add.part.61+0x1a0/0x1a0
         [<ffffffff8119765a>] event_function_call+0x10a/0x120
         [<ffffffff8119c660>] ? ctx_resched+0x90/0x90
         [<ffffffff811971e0>] ? cpu_clock_event_read+0x30/0x30
         [<ffffffff811976d0>] ? _perf_event_disable+0x60/0x60
         [<ffffffff8119772b>] _perf_event_enable+0x5b/0x70
         [<ffffffff81197388>] perf_event_for_each_child+0x38/0xa0
         [<ffffffff811976d0>] ? _perf_event_disable+0x60/0x60
         [<ffffffff811a0ffd>] perf_ioctl+0x12d/0x3c0
         [<ffffffff8134d855>] ? selinux_file_ioctl+0x95/0x1e0
         [<ffffffff8124a3a1>] do_vfs_ioctl+0xa1/0x5a0
         [<ffffffff81036d29>] ? sched_clock+0x9/0x10
         [<ffffffff8124a919>] SyS_ioctl+0x79/0x90
         [<ffffffff817ac4b2>] entry_SYSCALL_64_fastpath+0x1a/0xa4
        ---[ end trace aef202839fe9a71d ]---
        Uhhuh. NMI received for unknown reason 2d on CPU 2.
        Do you have a strange power saving mode enabled?
      Signed-off-by: default avatarKan Liang <kan.liang@intel.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Vince Weaver <vincent.weaver@maine.edu>
      Link: http://lkml.kernel.org/r/1457046448-6184-1-git-send-email-kan.liang@intel.com
      [ Fixed various typos and other small details. ]
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      ff8f5b41
    • Kan Liang's avatar
      perf/x86/intel/uncore: Remove SBOX support for BDX-DE · e5b6971c
      Kan Liang authored
      commit 6cb2f1d9 upstream.
      
      BDX-DE and BDX-EP share the same uncore code path. But there is no sbox
      in BDX-DE. This patch remove SBOX support for BDX-DE.
      Signed-off-by: default avatarKan Liang <kan.liang@intel.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: <tonyb@cybernetics.com>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Tony Battersby <tonyb@cybernetics.com>
      Cc: Vince Weaver <vincent.weaver@maine.edu>
      Link: http://lkml.kernel.org/r/37D7C6CF3E00A74B8858931C1DB2F0770589D336@SHSMSX103.ccr.corp.intel.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      e5b6971c
    • Stephane Eranian's avatar
      perf/x86/pebs: Add workaround for broken OVFL status on HSW+ · 41585808
      Stephane Eranian authored
      commit 8077eca0 upstream.
      
      This patch fixes an issue with the GLOBAL_OVERFLOW_STATUS bits on
      Haswell, Broadwell and Skylake processors when using PEBS.
      
      The SDM stipulates that when the PEBS iterrupt threshold is crossed,
      an interrupt is posted and the kernel is interrupted. The kernel will
      find GLOBAL_OVF_SATUS bit 62 set indicating there are PEBS records to
      drain. But the bits corresponding to the actual counters should NOT be
      set. The kernel follows the SDM and assumes that all PEBS events are
      processed in the drain_pebs() callback. The kernel then checks for
      remaining overflows on any other (non-PEBS) events and processes these
      in the for_each_bit_set(&status) loop.
      
      As it turns out, under certain conditions on HSW and later processors,
      on PEBS buffer interrupt, bit 62 is set but the counter bits may be
      set as well. In that case, the kernel drains PEBS and generates
      SAMPLES with the EXACT tag, then it processes the counter bits, and
      generates normal (non-EXACT) SAMPLES.
      
      I ran into this problem by trying to understand why on HSW sampling on
      a PEBS event was sometimes returning SAMPLES without the EXACT tag.
      This should not happen on user level code because HSW has the
      eventing_ip which always point to the instruction that caused the
      event.
      
      The workaround in this patch simply ensures that the bits for the
      counters used for PEBS events are cleared after the PEBS buffer has
      been drained. With this fix 100% of the PEBS samples on my user code
      report the EXACT tag.
      
      Before:
        $ perf record -e cpu/event=0xd0,umask=0x81/upp ./multichase
        $ perf report -D | fgrep SAMPLES
        PERF_RECORD_SAMPLE(IP, 0x2): 11775/11775: 0x406de5 period: 73469 addr: 0 exact=Y
                                 \--- EXACT tag is missing
      
      After:
        $ perf record -e cpu/event=0xd0,umask=0x81/upp ./multichase
        $ perf report -D | fgrep SAMPLES
        PERF_RECORD_SAMPLE(IP, 0x4002): 11775/11775: 0x406de5 period: 73469 addr: 0 exact=Y
                                 \--- EXACT tag is set
      
      The problem tends to appear more often when multiple PEBS events are used.
      Signed-off-by: default avatarStephane Eranian <eranian@google.com>
      Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Vince Weaver <vincent.weaver@maine.edu>
      Cc: adrian.hunter@intel.com
      Cc: kan.liang@intel.com
      Cc: namhyung@kernel.org
      Link: http://lkml.kernel.org/r/1457034642-21837-3-git-send-email-eranian@google.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      41585808