1. 18 6月, 2019 22 次提交
    • A
      perf evsel: Make perf_evsel__name() accept a NULL argument · fdbdd7e8
      Arnaldo Carvalho de Melo 提交于
      In which case it simply returns "unknown", like when it can't figure out
      the evsel->name value.
      
      This makes this code more robust and fixes a problem in 'perf trace'
      where a NULL evsel was being passed to a routine that only used the
      evsel for printing its name when a invalid syscall id was passed.
      Reported-by: NLeo Yan <leo.yan@linaro.org>
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Link: https://lkml.kernel.org/n/tip-f30ztaasku3z935cn3ak3h53@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      fdbdd7e8
    • A
      perf trace: Fixup pointer arithmetic when consuming augmented syscall args · 016f327c
      Arnaldo Carvalho de Melo 提交于
      We can't just add the consumed bytes to the arg->augmented.args member,
      as it is not void *, so it will access (consumed * sizeof(struct augmented_arg))
      in the next augmented arg, totally wrong, cast the member to void pointe
      before adding the number of bytes consumed, duh.
      
      With this and hardcoding handling the 'renameat' and 'renameat2'
      syscalls in the tools/perf/examples/bpf/augmented_raw_syscalls.c eBPF
      proggie, we get:
      
      	mv/24388 renameat2(AT_FDCWD, "/tmp/build/perf/util/.bpf-event.o.tmp", AT_FDCWD, "/tmp/build/perf/util/.bpf-event.o.cmd", RENAME_NOREPLACE) = 0
      	mv/24394 renameat2(AT_FDCWD, "/tmp/build/perf/util/.perf-hooks.o.tmp", AT_FDCWD, "/tmp/build/perf/util/.perf-hooks.o.cmd", RENAME_NOREPLACE) = 0
      	mv/24398 renameat2(AT_FDCWD, "/tmp/build/perf/util/.pmu-bison.o.tmp", AT_FDCWD, "/tmp/build/perf/util/.pmu-bison.o.cmd", RENAME_NOREPLACE) = 0
      	mv/24401 renameat2(AT_FDCWD, "/tmp/build/perf/util/.expr-bison.o.tmp", AT_FDCWD, "/tmp/build/perf/util/.expr-bison.o.cmd", RENAME_NOREPLACE) = 0
      	mv/24406 renameat2(AT_FDCWD, "/tmp/build/perf/util/.pmu.o.tmp", AT_FDCWD, "/tmp/build/perf/util/.pmu.o.cmd", RENAME_NOREPLACE) = 0
      	mv/24407 renameat2(AT_FDCWD, "/tmp/build/perf/util/.pmu-flex.o.tmp", AT_FDCWD, "/tmp/build/perf/util/.pmu-flex.o.cmd", RENAME_NOREPLACE) = 0
      	mv/24416 renameat2(AT_FDCWD, "/tmp/build/perf/util/.parse-events-flex.o.tmp", AT_FDCWD, "/tmp/build/perf/util/.parse-events-flex.o.cmd", RENAME_NOREPLACE) = 0
      
      I.e. it works with two string args in the same syscall.
      
      Now back to taming the verifier...
      
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Fixes: 8195168e ("perf trace: Consume the augmented_raw_syscalls payload")
      Link: https://lkml.kernel.org/n/tip-n1w59lpxks6m1le7fpo6rmyw@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      016f327c
    • J
      perf pmu: Fix uncore PMU alias list for ARM64 · 599ee18f
      John Garry 提交于
      In commit 292c34c1 ("perf pmu: Fix core PMU alias list for X86
      platform"), we fixed the issue of CPU events being aliased to uncore
      events.
      
      Fix this same issue for ARM64, since the said commit left the (broken)
      behaviour untouched for ARM64.
      Signed-off-by: NJohn Garry <john.garry@huawei.com>
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Ben Hutchings <ben@decadent.org.uk>
      Cc: Hendrik Brueckner <brueckner@linux.ibm.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Kan Liang <kan.liang@linux.intel.com>
      Cc: Mark Rutland <mark.rutland@arm.com>
      Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Shaokun Zhang <zhangshaokun@hisilicon.com>
      Cc: Thomas Richter <tmricht@linux.ibm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: linux-arm-kernel@lists.infradead.org
      Cc: linuxarm@huawei.com
      Cc: stable@vger.kernel.org
      Fixes: 292c34c1 ("perf pmu: Fix core PMU alias list for X86 platform")
      Link: http://lkml.kernel.org/r/1560521283-73314-2-git-send-email-john.garry@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      599ee18f
    • A
      perf tests: Add missing SPDX headers · 5875cf4c
      Arnaldo Carvalho de Melo 提交于
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Andi Kleen <ak@linux.intel.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Wang Nan <wangnan0@huawei.com>
      Link: https://lkml.kernel.org/n/tip-p0kg493z2m8qizjbdefzip1i@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      5875cf4c
    • A
      tools build feature tests: Add missing SPDX headers · 5e2156d8
      Arnaldo Carvalho de Melo 提交于
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Link: https://lkml.kernel.org/n/tip-3h6fa866w6ao0wsbyqz9nrm8@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      5e2156d8
    • A
      perf trace: Streamline validation of select syscall names list · 99f26f85
      Arnaldo Carvalho de Melo 提交于
      Rename the 'i' variable to 'nr_used' and use set 'nr_allocated' since
      the start of this function, leaving the final assignment of the longer
      named trace->ev_qualifier_ids.nr state to 'nr_used' at the end of the
      function.
      
      No change in behaviour intended.
      
      Cc: Leo Yan <leo.yan@linaro.org>
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
      Cc: Mike Leach <mike.leach@linaro.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
      Link: https://lkml.kernel.org/n/tip-kpgyn8xjdjgt0timrrnniquv@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      99f26f85
    • A
      perf trace: Fix exclusion of not available syscall names from selector list · a4066d64
      Arnaldo Carvalho de Melo 提交于
      We were just skipping the syscalls not available in a particular
      architecture without reflecting this in the number of entries in the
      ev_qualifier_ids.nr variable, fix it.
      
      This was done with the most minimalistic way, reusing the index variable
      'i', a followup patch will further clean this by making 'i' renamed to
      'nr_used' and using 'nr_allocated' in a few more places.
      Reported-by: NLeo Yan <leo.yan@linaro.org>
      Tested-by: NLeo Yan <leo.yan@linaro.org>
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
      Cc: Mike Leach <mike.leach@linaro.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
      Fixes: 04c41bcb ("perf trace: Skip unknown syscalls when expanding strace like syscall groups")
      Link: https://lkml.kernel.org/r/20190613181514.GC1402@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      a4066d64
    • A
      tools build: Check if gettid() is available before providing helper · 4541a8bb
      Arnaldo Carvalho de Melo 提交于
      Laura reported that the perf build failed in fedora when we got a glibc
      that provides gettid(), which I reproduced using fedora rawhide with the
      glibc-devel-2.29.9000-26.fc31.x86_64 package.
      
      Add a feature check to avoid providing a gettid() helper in such
      systems.
      
      On a fedora rawhide system with this patch applied we now get:
      
        [root@7a5f55352234 perf]# grep gettid /tmp/build/perf/FEATURE-DUMP
        feature-gettid=1
        [root@7a5f55352234 perf]# cat /tmp/build/perf/feature/test-gettid.make.output
        [root@7a5f55352234 perf]# ldd /tmp/build/perf/feature/test-gettid.bin
                linux-vdso.so.1 (0x00007ffc6b1f6000)
                libc.so.6 => /lib64/libc.so.6 (0x00007f04e0a74000)
                /lib64/ld-linux-x86-64.so.2 (0x00007f04e0c47000)
        [root@7a5f55352234 perf]# nm /tmp/build/perf/feature/test-gettid.bin | grep -w gettid
                         U gettid@@GLIBC_2.30
        [root@7a5f55352234 perf]#
      
      While on a fedora:29 system:
      
        [acme@quaco perf]$ grep gettid /tmp/build/perf/FEATURE-DUMP
        feature-gettid=0
        [acme@quaco perf]$ cat /tmp/build/perf/feature/test-gettid.make.output
        test-gettid.c: In function ‘main’:
        test-gettid.c:8:9: error: implicit declaration of function ‘gettid’; did you mean ‘getgid’? [-Werror=implicit-function-declaration]
          return gettid();
                 ^~~~~~
                 getgid
        cc1: all warnings being treated as errors
        [acme@quaco perf]$
      Reported-by: NLaura Abbott <labbott@redhat.com>
      Tested-by: NLaura Abbott <labbott@redhat.com>
      Acked-by: NJiri Olsa <jolsa@kernel.org>
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Florian Weimer <fweimer@redhat.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Stephane Eranian <eranian@google.com>
      Link: https://lkml.kernel.org/n/tip-yfy3ch53agmklwu9o7rlgf9c@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      4541a8bb
    • A
      perf intel-pt: Add callchain to synthesized PEBS sample · e01f0ef5
      Adrian Hunter 提交于
      Like other synthesized events, if there is also an Intel PT branch
      trace, then a call stack can also be synthesized.  Add that.
      Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Link: http://lkml.kernel.org/r/20190610072803.10456-12-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      e01f0ef5
    • A
      perf intel-pt: Add memory information to synthesized PEBS sample · 975846ed
      Adrian Hunter 提交于
      Add memory information from PEBS data in the Intel PT trace to the
      synthesized PEBS sample. This provides sample types PERF_SAMPLE_ADDR,
      PERF_SAMPLE_WEIGHT, and PERF_SAMPLE_TRANSACTION, but not
      PERF_SAMPLE_DATA_SRC.
      Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Link: http://lkml.kernel.org/r/20190610072803.10456-11-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      975846ed
    • A
      perf intel-pt: Add LBR information to synthesized PEBS sample · aa62afd7
      Adrian Hunter 提交于
      Add LBR information from PEBS data in the Intel PT trace to the
      synthesized PEBS sample.
      Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Link: http://lkml.kernel.org/r/20190610072803.10456-10-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      aa62afd7
    • A
      perf intel-pt: Add XMM registers to synthesized PEBS sample · 143d34a6
      Adrian Hunter 提交于
      Add XMM register information from PEBS data in the Intel PT trace to the
      synthesized PEBS sample.
      Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Link: http://lkml.kernel.org/r/20190610072803.10456-9-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      143d34a6
    • A
      perf intel-pt: Add gp registers to synthesized PEBS sample · 9e9a618a
      Adrian Hunter 提交于
      Add general purpose register information from PEBS data in the Intel PT
      trace to the synthesized PEBS sample.
      Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Link: http://lkml.kernel.org/r/20190610072803.10456-8-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      9e9a618a
    • A
      perf intel-pt: Synthesize PEBS sample basic information · 9d0bc53e
      Adrian Hunter 提交于
      Synthesize a PEBS sample using basic information (ip, timestamp) only.
      Other PEBS information will be added in later patches.
      Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Link: http://lkml.kernel.org/r/20190610072803.10456-7-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      9d0bc53e
    • A
      perf intel-pt: Factor out common sample preparation for re-use · 0dfded34
      Adrian Hunter 提交于
      Factor out common sample preparation for re-use when synthesizing PEBS
      samples.
      Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Link: http://lkml.kernel.org/r/20190610072803.10456-6-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      0dfded34
    • A
      perf intel-pt: Prepare to synthesize PEBS samples · e62ca655
      Adrian Hunter 提交于
      Add infrastructure to prepare for synthesizing PEBS samples but leave
      the actual synthesis to later patches.
      Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Link: http://lkml.kernel.org/r/20190610072803.10456-5-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      e62ca655
    • A
      perf intel-pt: Add decoder support for PEBS via PT · 4c35595e
      Adrian Hunter 提交于
      PEBS data is encoded in Block Item Packets (BIP). Populate a new structure
      intel_pt_blk_items with the values and, upon a Block End Packet (BEP),
      report them as a new Intel PT sample type INTEL_PT_BLK_ITEMS.
      Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Link: http://lkml.kernel.org/r/20190610072803.10456-4-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      4c35595e
    • A
      perf intel-pt: Add Intel PT packet decoder test · a0db77bf
      Adrian Hunter 提交于
      Add Intel PT packet decoder test. This test feeds byte sequences to the
      Intel PT packet decoder and checks the results. Changes to the packet
      context are also checked.
      
      Committer testing:
      
        # perf test "Intel PT"
        65: Intel PT packet decoder                               : Ok
        # perf test -v "Intel PT"
        65: Intel PT packet decoder                               :
        --- start ---
        test child forked, pid 6360
        Decoded ok: 00                                                PAD
        Decoded ok: 04                                                TNT N (1)
        Decoded ok: 06                                                TNT T (1)
        Decoded ok: 80                                                TNT NNNNNN (6)
        Decoded ok: fe                                                TNT TTTTTT (6)
        Decoded ok: 02 a3 02 00 00 00 00 00                           TNT N (1)
        Decoded ok: 02 a3 03 00 00 00 00 00                           TNT T (1)
        Decoded ok: 02 a3 00 00 00 00 00 80                           TNT NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN (47)
        Decoded ok: 02 a3 ff ff ff ff ff ff                           TNT TTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTT (47)
        Decoded ok: 0d                                                TIP no ip
        Decoded ok: 2d 01 02                                          TIP 0x201
        Decoded ok: 4d 01 02 03 04                                    TIP 0x4030201
        Decoded ok: 6d 01 02 03 04 05 06                              TIP 0x60504030201
        Decoded ok: 8d 01 02 03 04 05 06                              TIP 0x60504030201
        Decoded ok: cd 01 02 03 04 05 06 07 08                        TIP 0x807060504030201
        Decoded ok: 11                                                TIP.PGE no ip
        Decoded ok: 31 01 02                                          TIP.PGE 0x201
        Decoded ok: 51 01 02 03 04                                    TIP.PGE 0x4030201
        Decoded ok: 71 01 02 03 04 05 06                              TIP.PGE 0x60504030201
        Decoded ok: 91 01 02 03 04 05 06                              TIP.PGE 0x60504030201
        Decoded ok: d1 01 02 03 04 05 06 07 08                        TIP.PGE 0x807060504030201
        Decoded ok: 01                                                TIP.PGD no ip
        Decoded ok: 21 01 02                                          TIP.PGD 0x201
        Decoded ok: 41 01 02 03 04                                    TIP.PGD 0x4030201
        Decoded ok: 61 01 02 03 04 05 06                              TIP.PGD 0x60504030201
        Decoded ok: 81 01 02 03 04 05 06                              TIP.PGD 0x60504030201
        Decoded ok: c1 01 02 03 04 05 06 07 08                        TIP.PGD 0x807060504030201
        Decoded ok: 1d                                                FUP no ip
        Decoded ok: 3d 01 02                                          FUP 0x201
        Decoded ok: 5d 01 02 03 04                                    FUP 0x4030201
        Decoded ok: 7d 01 02 03 04 05 06                              FUP 0x60504030201
        Decoded ok: 9d 01 02 03 04 05 06                              FUP 0x60504030201
        Decoded ok: dd 01 02 03 04 05 06 07 08                        FUP 0x807060504030201
        Decoded ok: 02 43 02 04 06 08 0a 0c                           PIP 0x60504030201 (NR=0)
        Decoded ok: 02 43 03 04 06 08 0a 0c                           PIP 0x60504030201 (NR=1)
        Decoded ok: 99 00                                             MODE.Exec 16
        Decoded ok: 99 01                                             MODE.Exec 64
        Decoded ok: 99 02                                             MODE.Exec 32
        Decoded ok: 99 20                                             MODE.TSX TXAbort:0 InTX:0
        Decoded ok: 99 21                                             MODE.TSX TXAbort:0 InTX:1
        Decoded ok: 99 22                                             MODE.TSX TXAbort:1 InTX:0
        Decoded ok: 02 83                                             TraceSTOP
        Decoded ok: 02 03 12 00                                       CBR 0x12
        Decoded ok: 19 01 02 03 04 05 06 07                           TSC 0x7060504030201
        Decoded ok: 59 12                                             MTC 0x12
        Decoded ok: 02 73 00 00 00 00 00                              TMA CTC 0x0 FC 0x0
        Decoded ok: 02 73 01 02 00 00 00                              TMA CTC 0x201 FC 0x0
        Decoded ok: 02 73 00 00 00 ff 01                              TMA CTC 0x0 FC 0x1ff
        Decoded ok: 02 73 80 c0 00 ff 01                              TMA CTC 0xc080 FC 0x1ff
        Decoded ok: 03                                                CYC 0x0
        Decoded ok: 0b                                                CYC 0x1
        Decoded ok: fb                                                CYC 0x1f
        Decoded ok: 07 02                                             CYC 0x20
        Decoded ok: ff fe                                             CYC 0xfff
        Decoded ok: 07 01 02                                          CYC 0x1000
        Decoded ok: ff ff fe                                          CYC 0x7ffff
        Decoded ok: 07 01 01 02                                       CYC 0x80000
        Decoded ok: ff ff ff fe                                       CYC 0x3ffffff
        Decoded ok: 07 01 01 01 02                                    CYC 0x4000000
        Decoded ok: ff ff ff ff fe                                    CYC 0x1ffffffff
        Decoded ok: 07 01 01 01 01 02                                 CYC 0x200000000
        Decoded ok: ff ff ff ff ff fe                                 CYC 0xffffffffff
        Decoded ok: 07 01 01 01 01 01 02                              CYC 0x10000000000
        Decoded ok: ff ff ff ff ff ff fe                              CYC 0x7fffffffffff
        Decoded ok: 07 01 01 01 01 01 01 02                           CYC 0x800000000000
        Decoded ok: ff ff ff ff ff ff ff fe                           CYC 0x3fffffffffffff
        Decoded ok: 07 01 01 01 01 01 01 01 02                        CYC 0x40000000000000
        Decoded ok: ff ff ff ff ff ff ff ff fe                        CYC 0x1fffffffffffffff
        Decoded ok: 07 01 01 01 01 01 01 01 01 02                     CYC 0x2000000000000000
        Decoded ok: ff ff ff ff ff ff ff ff ff 0e                     CYC 0xffffffffffffffff
        Decoded ok: 02 c8 01 02 03 04 05                              VMCS 0x504030201
        Decoded ok: 02 f3                                             OVF
        Decoded ok: 02 f3                                             OVF
        Decoded ok: 02 f3                                             OVF
        Decoded ok: 02 82 02 82 02 82 02 82 02 82 02 82 02 82 02 82   PSB
        Decoded ok: 02 82 02 82 02 82 02 82 02 82 02 82 02 82 02 82   PSB
        Decoded ok: 02 82 02 82 02 82 02 82 02 82 02 82 02 82 02 82   PSB
        Decoded ok: 02 23                                             PSBEND
        Decoded ok: 02 c3 88 01 02 03 04 05 06 07 00                  MNT 0x7060504030201
        Decoded ok: 02 12 01 02 03 04                                 PTWRITE 0x4030201 IP:0
        Decoded ok: 02 32 01 02 03 04 05 06 07 08                     PTWRITE 0x807060504030201 IP:0
        Decoded ok: 02 92 01 02 03 04                                 PTWRITE 0x4030201 IP:1
        Decoded ok: 02 b2 01 02 03 04 05 06 07 08                     PTWRITE 0x807060504030201 IP:1
        Decoded ok: 02 62                                             EXSTOP IP:0
        Decoded ok: 02 e2                                             EXSTOP IP:1
        Decoded ok: 02 c2 00 00 00 00 00 00 00 00                     MWAIT 0x0 Hints 0x0 Extensions 0x0
        Decoded ok: 02 c2 01 02 03 04 05 06 07 08                     MWAIT 0x807060504030201 Hints 0x1 Extensions 0x1
        Decoded ok: 02 c2 ff 02 03 04 07 06 07 08                     MWAIT 0x8070607040302ff Hints 0xff Extensions 0x3
        Decoded ok: 02 22 00 00                                       PWRE 0x0 HW:0 CState:0 Sub-CState:0
        Decoded ok: 02 22 01 02                                       PWRE 0x201 HW:0 CState:0 Sub-CState:2
        Decoded ok: 02 22 80 34                                       PWRE 0x3480 HW:1 CState:3 Sub-CState:4
        Decoded ok: 02 22 00 56                                       PWRE 0x5600 HW:0 CState:5 Sub-CState:6
        Decoded ok: 02 a2 00 00 00 00 00                              PWRX 0x0 Last CState:0 Deepest CState:0 Wake Reason 0x0
        Decoded ok: 02 a2 01 02 03 04 05                              PWRX 0x504030201 Last CState:0 Deepest CState:1 Wake Reason 0x2
        Decoded ok: 02 a2 ff ff ff ff ff                              PWRX 0xffffffffff Last CState:15 Deepest CState:15 Wake Reason 0xf
        Decoded ok: 02 63 00                                          BBP SZ 8-byte Type 0x0
        Decoded ok: 02 63 80                                          BBP SZ 4-byte Type 0x0
        Decoded ok: 02 63 1f                                          BBP SZ 8-byte Type 0x1f
        Decoded ok: 02 63 9f                                          BBP SZ 4-byte Type 0x1f
        Decoded ok: 04 00 00 00 00                                    BIP ID 0x00 Value 0x0
        Decoded ok: fc 00 00 00 00                                    BIP ID 0x1f Value 0x0
        Decoded ok: 04 01 02 03 04                                    BIP ID 0x00 Value 0x4030201
        Decoded ok: fc 01 02 03 04                                    BIP ID 0x1f Value 0x4030201
        Decoded ok: 04 00 00 00 00 00 00 00 00                        BIP ID 0x00 Value 0x0
        Decoded ok: fc 00 00 00 00 00 00 00 00                        BIP ID 0x1f Value 0x0
        Decoded ok: 04 01 02 03 04 05 06 07 08                        BIP ID 0x00 Value 0x807060504030201
        Decoded ok: fc 01 02 03 04 05 06 07 08                        BIP ID 0x1f Value 0x807060504030201
        Decoded ok: 02 33                                             BEP IP:0
        Decoded ok: 02 b3                                             BEP IP:1
        Decoded ok: 02 33                                             BEP IP:0
        Decoded ok: 02 b3                                             BEP IP:1
        test child finished with 0
        ---- end ----
        Intel PT packet decoder: Ok
        #
      Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
      Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Link: http://lkml.kernel.org/r/20190610072803.10456-3-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      a0db77bf
    • A
      perf intel-pt: Add new packets for PEBS via PT · edff7809
      Adrian Hunter 提交于
      Add 3 new packets to supports PEBS via PT, namely Block Begin Packet
      (BBP), Block Item Packet (BIP) and Block End Packet (BEP). PEBS data is
      encoded into multiple BIP packets that come between BBP and BEP. The BEP
      packet might be associated with a FUP packet. That is indicated by using
      a separate packet type (INTEL_PT_BEP_IP) similar to other packets types
      with the _IP suffix.
      
      Refer to the Intel SDM for more information about PEBS via PT:
      
        https://software.intel.com/en-us/articles/intel-sdm
        May 2019 version: Vol. 3B 18.5.5.2 PEBS output to Intel® Processor Trace
      
      Decoding of BIP packets conflicts with single-byte TNT packets. Since
      BIP packets only occur in the context of a block (i.e. between BBP and
      BEP), that context must be recorded and passed to the packet decoder.
      Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Link: http://lkml.kernel.org/r/20190610072803.10456-2-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      edff7809
    • M
      perf: cs-etm: Optimize option setup for CPU-wide sessions · 374d910f
      Mathieu Poirier 提交于
      Call function cs_etm_set_option() once with all relevant options set
      rather than multiple times to avoid going through the list of CPU more
      than once.
      Suggested-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
      Signed-off-by: NMathieu Poirier <mathieu.poirier@linaro.org>
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: linux-arm-kernel@lists.infradead.org
      Link: http://lkml.kernel.org/r/20190611204528.20093-1-mathieu.poirier@linaro.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      374d910f
    • R
      perf tests arm64: Compile tests unconditionally · 010e3e8f
      Raphael Gault 提交于
      In order to subsequently add more tests for the arm64 architecture we
      compile the tests target for arm64 systematically.
      
      Further explanation provided by Mark Rutland:
      
      Given prior questions regarding this commit, it's probably worth
      spelling things out more explicitly, e.g.
      
        Currently we only build the arm64/tests directory if
        CONFIG_DWARF_UNWIND is selected, which is fine as the only test we
        have is arm64/tests/dwarf-unwind.o.
      
        So that we can add more tests to the test directory, let's
        unconditionally build the directory, but conditionally build
        dwarf-unwind.o depending on CONFIG_DWARF_UNWIND.
      
        There should be no functional change as a result of this patch.
      Signed-off-by: NRaphael Gault <raphael.gault@arm.com>
      Acked-by: NMark Rutland <mark.rutland@arm.com>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: linux-arm-kernel@lists.infradead.org
      Link: http://lkml.kernel.org/r/20190611125315.18736-2-raphael.gault@arm.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      010e3e8f
    • I
      Merge tag 'perf-core-for-mingo-5.3-20190611' of... · 3ce5aceb
      Ingo Molnar 提交于
      Merge tag 'perf-core-for-mingo-5.3-20190611' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core
      
      Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:
      
      perf record:
      
        Alexey Budankov:
      
        - Allow mixing --user-regs with --call-graph=dwarf, making sure that
          the minimal set of registers for DWARF unwinding is present in the
          set of user registers requested to be present in each sample, while
          warning the user that this may make callchains unreliable if more
          that the minimal set of registers is needed to unwind.
      
        yuzhoujian:
      
        - Add support to collect callchains from kernel or user space only,
          IOW allow setting the perf_event_attr.exclude_callchain_{kernel,user}
          bits from the command line.
      
      perf trace:
      
        Arnaldo Carvalho de Melo:
      
        - Remove x86_64 specific syscall numbers from the augmented_raw_syscalls
          BPF in-kernel collector of augmented raw_syscalls:sys_{enter,exit}
          payloads, use instead the syscall numbers obtainer either by the
          arch specific syscalltbl generators or from audit-libs.
      
        - Allow 'perf trace' to ask for the number of bytes to collect for
          string arguments, for now ask for PATH_MAX, i.e. the whole
          pathnames, which ends up being just a way to speficy which syscall
          args are pathnames and thus should be read using bpf_probe_read_str().
      
        - Skip unknown syscalls when expanding strace like syscall groups.
          This helps using the 'string' group of syscalls to work in arm64,
          where some of the syscalls present in x86_64 that deal with
          strings, for instance 'access', are deprecated and this should not
          be asked for tracing.
      
        Leo Yan:
      
        - Exit when failing to build eBPF program.
      
      perf config:
      
        Arnaldo Carvalho de Melo:
      
        - Bail out when a handler returns failure for a key-value pair. This
          helps with cases where processing a key-value pair is not just a
          matter of setting some tool specific knob, involving, for instance
          building a BPF program to then attach to the list of events 'perf
          trace' will use, e.g. augmented_raw_syscalls.c.
      
      perf.data:
      
        Kan Liang:
      
        - Read and store die ID information available in new Intel processors
          in CPUID.1F in the CPU topology written in the perf.data header.
      
      perf stat:
      
        Kan Liang:
      
        - Support per-die aggregation.
      
      Documentation:
      
        Arnaldo Carvalho de Melo:
      
        - Update perf.data documentation about the CPU_TOPOLOGY, MEM_TOPOLOGY,
          CLOCKID and DIR_FORMAT headers.
      
        Song Liu:
      
        - Add description of headers HEADER_BPF_PROG_INFO and HEADER_BPF_BTF.
      
        Leo Yan:
      
        - Update default value for llvm.clang-bpf-cmd-template in 'man perf-config'.
      
      JVMTI:
      
        Jiri Olsa:
      
        - Address gcc string overflow warning for strncpy()
      
      core:
      
        - Remove superfluous nthreads system_wide setup in perf_evsel__alloc_fd().
      
      Intel PT:
      
        Adrian Hunter:
      
        - Add support for samples to contain IPC ratio, collecting cycles
          information from CYC packets, showing the IPC info periodically, because
          Intel PT does not update the cycle count on every branch or instruction,
          the incremental values will often be zero.  When there are values, they
          will be the number of instructions and number of cycles since the last
          update, and thus represent the average IPC since the last IPC value.
      
          E.g.:
      
          # perf record --cpu 1 -m200000 -a -e intel_pt/cyc/u sleep 0.0001
          rounding mmap pages size to 1024M (262144 pages)
          [ perf record: Woken up 0 times to write data ]
          [ perf record: Captured and wrote 2.208 MB perf.data ]
          # perf script --insn-trace --xed -F+ipc,-dso,-cpu,-tid
          #
          <SNIP + add line numbering to make sense of IPC counts e.g.: (18/3)>
          1   cc1 63501.650479626: 7f5219ac27bf _int_free+0x3f   jnz 0x7f5219ac2af0       IPC: 0.81 (36/44)
          2   cc1 63501.650479626: 7f5219ac27c5 _int_free+0x45   cmp $0x1f, %rbp
          3   cc1 63501.650479626: 7f5219ac27c9 _int_free+0x49   jbe 0x7f5219ac2b00
          4   cc1 63501.650479626: 7f5219ac27cf _int_free+0x4f   test $0x8, %al
          5   cc1 63501.650479626: 7f5219ac27d1 _int_free+0x51   jnz 0x7f5219ac2b00
          6   cc1 63501.650479626: 7f5219ac27d7 _int_free+0x57   movq  0x13c58a(%rip), %rcx
          7   cc1 63501.650479626: 7f5219ac27de _int_free+0x5e   mov %rdi, %r12
          8   cc1 63501.650479626: 7f5219ac27e1 _int_free+0x61   movq  %fs:(%rcx), %rax
          9   cc1 63501.650479626: 7f5219ac27e5 _int_free+0x65   test %rax, %rax
         10   cc1 63501.650479626: 7f5219ac27e8 _int_free+0x68   jz 0x7f5219ac2821
         11   cc1 63501.650479626: 7f5219ac27ea _int_free+0x6a   leaq  -0x11(%rbp), %rdi
         12   cc1 63501.650479626: 7f5219ac27ee _int_free+0x6e   mov %rdi, %rsi
         13   cc1 63501.650479626: 7f5219ac27f1 _int_free+0x71   shr $0x4, %rsi
         14   cc1 63501.650479626: 7f5219ac27f5 _int_free+0x75   cmpq  %rsi, 0x13caf4(%rip)
         15   cc1 63501.650479626: 7f5219ac27fc _int_free+0x7c   jbe 0x7f5219ac2821
         16   cc1 63501.650479626: 7f5219ac2821 _int_free+0xa1   cmpq  0x13f138(%rip), %rbp
         17   cc1 63501.650479626: 7f5219ac2828 _int_free+0xa8   jnbe 0x7f5219ac28d8
         18   cc1 63501.650479626: 7f5219ac28d8 _int_free+0x158  testb  $0x2, 0x8(%rbx)
         19   cc1 63501.650479628: 7f5219ac28dc _int_free+0x15c  jnz 0x7f5219ac2ab0       IPC: 6.00 (18/3)
          <SNIP>
      
        - Allow using time ranges with Intel PT, i.e. these features, already
          present but not optimially usable with Intel PT, should be now:
      
              Select the second 10% time slice:
      
              $ perf script --time 10%/2
      
              Select from 0% to 10% time slice:
      
              $ perf script --time 0%-10%
      
              Select the first and second 10% time slices:
      
              $ perf script --time 10%/1,10%/2
      
              Select from 0% to 10% and 30% to 40% slices:
      
              $ perf script --time 0%-10%,30%-40%
      
      cs-etm (ARM):
      
        Mathieu Poirier:
      
        - Add support for CPU-wide trace scenarios.
      
      s390:
      
        Thomas Richter:
      
        - Fix missing kvm module load for s390.
      
        - Fix OOM error in TUI mode on s390
      
        - Support s390 diag event display when doing analysis on !s390
          architectures.
      Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      3ce5aceb
  2. 17 6月, 2019 11 次提交
  3. 14 6月, 2019 3 次提交
  4. 11 6月, 2019 4 次提交
    • A
      perf trace: Skip unknown syscalls when expanding strace like syscall groups · 04c41bcb
      Arnaldo Carvalho de Melo 提交于
      We have $INSTALL_DIR/share/perf-core/strace/groups/string files with
      syscalls that should be selected when 'string' is used, meaning, in this
      case, syscalls that receive as one of its arguments a string, like a
      pathname.
      
      But those were first selected and tested on x86_64, and end up failing
      in architectures where some of those syscalls are not available, like
      the 'access' syscall on arm64, which makes using 'perf trace -e string'
      in such archs to fail.
      
      Since this the routine doing the validation is used only when reading
      such files, do not fail when some syscall is not found in the
      syscalltbl, instead just use pr_debug() to register that in case people
      are suspicious of problems.
      
      Now using 'perf trace -e string' should work on arm64, selecting only
      the syscalls that have a string and are available on that architecture.
      Reported-by: NLeo Yan <leo.yan@linaro.org>
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Alexei Starovoitov <ast@kernel.org>
      Cc: Daniel Borkmann <daniel@iogearbox.net>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Martin KaFai Lau <kafai@fb.com>
      Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
      Cc: Mike Leach <mike.leach@linaro.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Song Liu <songliubraving@fb.com>
      Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
      Cc: Yonghong Song <yhs@fb.com>
      Link: https://lkml.kernel.org/r/20190610184754.GU21245@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      04c41bcb
    • T
      perf report: Support s390 diag event display on x86 · 180ca71c
      Thomas Richter 提交于
      Perf report fails to display s390 specific event numbered bd000
      on an x86 platform. For example on s390 this works without error:
      
      [root@m35lp76 perf]# uname -m
      s390x
      [root@m35lp76 perf]# ./perf record -e rbd000 -- find / >/dev/null
      [ perf record: Woken up 3 times to write data ]
      [ perf record: Captured and wrote 0.549 MB perf.data ]
      [root@m35lp76 perf]# ./perf report -D --stdio  > /dev/null
      [root@m35lp76 perf]#
      
      Transfering this perf.data file to an x86 platform and executing
      the same report command produces:
      
      [root@f29 perf]# uname -m
      x86_64
      [root@f29 perf]# ./perf report -i ~/perf.data.m35lp76 --stdio
      interpreting bpf_prog_info from systems with endianity is not yet supported
      interpreting btf from systems with endianity is not yet supported
      0x8c890 [0x8]: failed to process type: 68
      Error:
      failed to process sample
      
      Event bd000 generates auxiliary data which is stored in big endian
      format in the perf data file.
      This error is caused by missing endianess handling on the x86 platform
      when the data is displayed. Fix this by handling s390 auxiliary event
      data depending on the local platform endianness.
      
      Output after on x86:
      
      [root@f29 perf]# ./perf report -D -i ~/perf.data.m35lp76 --stdio > /dev/null
      interpreting bpf_prog_info from systems with endianity is not yet supported
      interpreting btf from systems with endianity is not yet supported
      [root@f29 perf]#
      
      Committer notes:
      
      Fix build breakage on older systems, such as CentOS:6 where using
      nesting calls to the endian.h macros end up redefining local variables:
      
        util/s390-cpumsf.c: In function 's390_cpumsf_trailer_show':
        util/s390-cpumsf.c:333: error: declaration of '__v' shadows a previous local
        util/s390-cpumsf.c:333: error: shadowed declaration is here
        util/s390-cpumsf.c:333: error: declaration of '__x' shadows a previous local
        util/s390-cpumsf.c:333: error: shadowed declaration is here
        util/s390-cpumsf.c:334: error: declaration of '__v' shadows a previous local
        util/s390-cpumsf.c:334: error: shadowed declaration is here
        util/s390-cpumsf.c:334: error: declaration of '__x' shadows a previous local
        util/s390-cpumsf.c:334: error: shadowed declaration is here
      
        [perfbuilder@455a63ef60dc perf]$ gcc -v |& tail -1
        gcc version 4.4.7 20120313 (Red Hat 4.4.7-23) (GCC)
        [perfbuilder@455a63ef60dc perf]$
      
      Since there are several uses of
      
        be64toh(te->flags)
      
      Introduce a variable to hold that and then use it, avoiding this case
      that causes the above problems:
      
        -       local.bsdes = be16toh((be64toh(te->flags) >> 16 & 0xffff));
        +       local.bsdes = be16toh((flags >> 16 & 0xffff));
      
      Its the same construct used in s390_cpumsf_diag_show() where we have a
      'word' variable that is used just once, s390_cpumsf_basic_show() has
      lots of uses and also uses a variable to hold the result of be16toh().
      
      Some of those temp variables needed to be converted from 'unsigned long'
      to 'unsigned long long' so as to build on 32-bit arches such as
      debian:experimental-x-mipsel, the android NDK ones and
      fedora:24-x-ARC-uClibc.
      Signed-off-by: NThomas Richter <tmricht@linux.ibm.com>
      Reviewed-by: NHendrik Brueckner <brueckner@linux.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Link: http://lkml.kernel.org/r/20190522064325.25596-1-tmricht@linux.ibm.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      180ca71c
    • T
      perf report: Fix OOM error in TUI mode on s390 · 8a07aa4e
      Thomas Richter 提交于
      Debugging a OOM error using the TUI interface revealed this issue
      on s390:
      
      [tmricht@m83lp54 perf]$ cat /proc/kallsyms |sort
      ....
      00000001119b7158 B radix_tree_node_cachep
      00000001119b8000 B __bss_stop
      00000001119b8000 B _end
      000003ff80002850 t autofs_mount	[autofs4]
      000003ff80002868 t autofs_show_options	[autofs4]
      000003ff80002a98 t autofs_evict_inode	[autofs4]
      ....
      
      There is a huge gap between the last kernel symbol
      __bss_stop/_end and the first kernel module symbol
      autofs_mount (from autofs4 module).
      
      After reading the kernel symbol table via functions:
      
       dso__load()
       +--> dso__load_kernel_sym()
            +--> dso__load_kallsyms()
      	   +--> __dso_load_kallsyms()
      	        +--> symbols__fixup_end()
      
      the symbol __bss_stop has a start address of 1119b8000 and
      an end address of 3ff80002850, as can be seen by this debug statement:
      
        symbols__fixup_end __bss_stop start:0x1119b8000 end:0x3ff80002850
      
      The size of symbol __bss_stop is 0x3fe6e64a850 bytes!
      It is the last kernel symbol and fills up the space until
      the first kernel module symbol.
      
      This size kills the TUI interface when executing the following
      code:
      
        process_sample_event()
          hist_entry_iter__add()
            hist_iter__report_callback()
              hist_entry__inc_addr_samples()
                symbol__inc_addr_samples(symbol = __bss_stop)
                  symbol__cycles_hist()
                     annotated_source__alloc_histograms(...,
      				                symbol__size(sym),
      		                                ...)
      
      This function allocates memory to save sample histograms.
      The symbol_size() marco is defined as sym->end - sym->start, which
      results in above value of 0x3fe6e64a850 bytes and
      the call to calloc() in annotated_source__alloc_histograms() fails.
      
      The histgram memory allocation might fail, make this failure
      no-fatal and continue processing.
      
      Output before:
      [tmricht@m83lp54 perf]$ ./perf --debug stderr=1 report -vvvvv \
      					      -i ~/slow.data 2>/tmp/2
      [tmricht@m83lp54 perf]$ tail -5 /tmp/2
        __symbol__inc_addr_samples(875): ENOMEM! sym->name=__bss_stop,
      		start=0x1119b8000, addr=0x2aa0005eb08, end=0x3ff80002850,
      		func: 0
      problem adding hist entry, skipping event
      0x938b8 [0x8]: failed to process type: 68 [Cannot allocate memory]
      [tmricht@m83lp54 perf]$
      
      Output after:
      [tmricht@m83lp54 perf]$ ./perf --debug stderr=1 report -vvvvv \
      					      -i ~/slow.data 2>/tmp/2
      [tmricht@m83lp54 perf]$ tail -5 /tmp/2
         symbol__inc_addr_samples map:0x1597830 start:0x110730000 end:0x3ff80002850
         symbol__hists notes->src:0x2aa2a70 nr_hists:1
         symbol__inc_addr_samples sym:unlink_anon_vmas src:0x2aa2a70
         __symbol__inc_addr_samples: addr=0x11094c69e
         0x11094c670 unlink_anon_vmas: period++ [addr: 0x11094c69e, 0x2e, evidx=0]
         	=> nr_samples: 1, period: 526008
      [tmricht@m83lp54 perf]$
      
      There is no error about failed memory allocation and the TUI interface
      shows all entries.
      Signed-off-by: NThomas Richter <tmricht@linux.ibm.com>
      Reviewed-by: NHendrik Brueckner <brueckner@linux.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
      Link: http://lkml.kernel.org/r/90cb5607-3e12-5167-682d-978eba7dafa8@linux.ibm.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      8a07aa4e
    • T
      perf test 6: Fix missing kvm module load for s390 · 53fe307d
      Thomas Richter 提交于
      Command
      
         # perf test -Fv 6
      
      fails with error
      
         running test 100 'kvm-s390:kvm_s390_create_vm' failed to parse
          event 'kvm-s390:kvm_s390_create_vm', err -1, str 'unknown tracepoint'
          event syntax error: 'kvm-s390:kvm_s390_create_vm'
                               \___ unknown tracepoint
      
      when the kvm module is not loaded or not built in.
      
      Fix this by adding a valid function which tests if the module
      is loaded. Loaded modules (or builtin KVM support) have a
      directory named
        /sys/kernel/debug/tracing/events/kvm-s390
      for this tracepoint.
      
      Check for existence of this directory.
      Signed-off-by: NThomas Richter <tmricht@linux.ibm.com>
      Reviewed-by: NChristian Borntraeger <borntraeger@de.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
      Link: http://lkml.kernel.org/r/20190604053504.43073-1-tmricht@linux.ibm.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      53fe307d