linux.git/tools/perf/util/header.c, branch v4.11

perf tools: Replace _SC_NPROCESSORS_CONF with max_present_cpu in cpu_topology_map

2017-02-17T15:56:35+00:00

There are 2 problems wrt. cpu_topology_map on systems with sparse CPUs:

1. offline/absent CPUs will have their socket_id and core_id set to -1
   which triggers:
   "socket_id number is too big.You may need to upgrade the perf tool."

2. size of cpu_topology_map (perf_env.cpu[]) is allocated based on
   _SC_NPROCESSORS_CONF, but can be indexed with CPU ids going above.
   Users of perf_env.cpu[] are using CPU id as index. This can lead
   to read beyond what was allocated:
   ==19991== Invalid read of size 4
   ==19991==    at 0x490CEB: check_cpu_topology (topology.c:69)
   ==19991==    by 0x490CEB: test_session_topology (topology.c:106)
   ...

For example:
  _SC_NPROCESSORS_CONF == 16
  available: 2 nodes (0-1)
  node 0 cpus: 0 6 8 10 16 22 24 26
  node 0 size: 12004 MB
  node 0 free: 9470 MB
  node 1 cpus: 1 7 9 11 23 25 27
  node 1 size: 12093 MB
  node 1 free: 9406 MB
  node distances:
  node   0   1
    0:  10  20
    1:  20  10

This patch changes HEADER_NRCPUS.nr_cpus_available from _SC_NPROCESSORS_CONF
to max_present_cpu and updates any user of cpu_topology_map to iterate
with nr_cpus_avail.

As a consequence HEADER_CPU_TOPOLOGY core_id and socket_id lists get longer,
but maintain compatibility with pre-patch state - index to cpu_topology_map is
CPU id.

  perf test 36 -v
  36: Session topology                           :
  --- start ---
  test child forked, pid 22211
  templ file: /tmp/perf-test-gmdX5i
  CPU 0, core 0, socket 0
  CPU 1, core 0, socket 1
  CPU 6, core 10, socket 0
  CPU 7, core 10, socket 1
  CPU 8, core 1, socket 0
  CPU 9, core 1, socket 1
  CPU 10, core 9, socket 0
  CPU 11, core 9, socket 1
  CPU 16, core 0, socket 0
  CPU 22, core 10, socket 0
  CPU 23, core 10, socket 1
  CPU 24, core 1, socket 0
  CPU 25, core 1, socket 1
  CPU 26, core 9, socket 0
  CPU 27, core 9, socket 1
  test child finished with 0
  ---- end ----
  Session topology: Ok

Signed-off-by: Jan Stancek 
Cc: Alexander Shishkin 
Cc: Jiri Olsa 
Cc: Masami Hiramatsu 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/d7c05c6445fca74a8442c2c73cfffd349c52c44f.1487146877.git.jstancek@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo

perf header: Make build_cpu_topology skip offline/absent CPUs

2017-02-17T15:37:04+00:00

When build_cpu_topo() encounters offline/absent CPUs, it fails to find any
sysfs entries and returns failure.

This leads to build_cpu_topology() and write_cpu_topology() failing as
well.

Because HEADER_CPU_TOPOLOGY has not been written, read leaves cpu_topology_map
NULL and we get NULL ptr deref at:

  ...
   cmd_test
    __cmd_test
     test_and_print
      run_test
       test_session_topology
        check_cpu_topology

  36: Session topology                           :
  --- start ---
  test child forked, pid 14902
  templ file: /tmp/perf-test-4CKocW
  failed to write feature HEADER_CPU_TOPOLOGY
  perf: Segmentation fault
  Obtained 9 stack frames.
  ./perf(sighandler_dump_stack+0x41) [0x5095f1]
  /lib64/libc.so.6(+0x35250) [0x7f4b7c3c9250]
  ./perf(test_session_topology+0x1db) [0x490ceb]
  ./perf() [0x475b68]
  ./perf(cmd_test+0x5b9) [0x4763c9]
  ./perf() [0x4945a3]
  ./perf(main+0x69f) [0x427e8f]
  /lib64/libc.so.6(__libc_start_main+0xf5) [0x7f4b7c3b5b35]
  ./perf() [0x427fb9]
  test child interrupted
  ---- end ----
  Session topology: FAILED!

This patch makes build_cpu_topology() skip offline/absent CPUs, by checking
their presence against cpu_map built from online CPUs.

Signed-off-by: Jan Stancek 
Acked-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Masami Hiramatsu 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/a271b770175524f4961d4903af33798358a4a518.1487146877.git.jstancek@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo

perf header: Fix handling of PERF_EVENT_UPDATE__SCALE

2017-02-09T01:06:18+00:00

In commit daeecbc0c431 ("perf tools: Add event_update event scale type"), the
handling of PERF_EVENT_UPDATE__SCALE cast struct event_update_event->data to a
pointer to event_update_event_scale, uses some field from this casted struct
and then ends up falling through to the handling of another event type,
PERF_EVENT_UPDATE__CPUS were it casts that ev->data to yet another type, oops,
fix it by inserting the missing break.

Noticed when building perf using gcc 7 on Fedora Rawhide:

  util/header.c: In function 'perf_event__process_event_update':
  util/header.c:3207:16: error: this statement may fall through [-Werror=implicit-fallthrough=]
     evsel->scale = ev_scale->scale;
     ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~
  util/header.c:3208:2: note: here
    case PERF_EVENT_UPDATE__CPUS:
    ^~~~

This wasn't noticed because probably PERF_EVENT_UPDATE__CPUS comes after
PERF_EVENT_UPDATE__SCALE, so we would just create a bogus evsel->own_cpus when
processing a PERF_EVENT_UPDATE__SCALE to then leak it and create a new cpu map
with the correct data.

Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Fixes: daeecbc0c431 ("perf tools: Add event_update event scale type")
Link: http://lkml.kernel.org/n/tip-lukcf9hdj092ax2914ss95at@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf util: Add more debug message on failure path

2017-01-26T14:43:00+00:00

It's helpful for debugging on tracing features.

Signed-off-by: Namhyung Kim 
Tested-by: Masami Hiramatsu 
Cc: Frederic Weisbecker 
Cc: Jeremy Eder 
Cc: Jiri Olsa ,
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: Steven Rostedt 
Link: http://lkml.kernel.org/n/tip-rjysr9ljiesymgk4qblteaty@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Move two variables usied in libperf from perf.c

2017-01-17T14:36:45+00:00

The use_browser and perf_version_string variables are both declared in
perf.c but they are also referenced by other functions of libperf.a.

Therefore a user linking an own main() with libperf.a must declare those
two variables in their files even if the files never use the browser or
the version information.

This patch fixes this issue by moving use_browser and
perf_version_string out of perf.c to some other files.

Signed-off-by: Soramichi Akiyama 
Cc: Alexander Shishkin 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/20170117002237.c1aec0ce3b4d675dca018deb@m.soramichi.jp
Signed-off-by: Arnaldo Carvalho de Melo

perf header: Display feature name on write failure

2016-10-24T14:07:34+00:00

Display name of feature instead of just the number
during recording data.

Before:
  failed to write feature 13

Now:
  failed to write feature HEADER_CPU_TOPOLOGY

Signed-off-by: Jiri Olsa 
Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: http://lkml.kernel.org/n/tip-k9d9trozi5kkx737cy8n5xh5@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf header: Display missing features

2016-10-24T14:07:34+00:00

Display missing features in header info, like:

  $ perf report --header-only
  # ========
  # captured on: Mon Oct 10 09:39:47 2016
  ...
  # missing features: HEADER_TRACING_DATA HEADER_CPU_TOPOLOGY ...

To help in diagnosing problems.

Signed-off-by: Jiri Olsa 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: http://lkml.kernel.org/n/tip-bh5gp84gobdmyl345dcp64se@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf report: Move captured info to generic header info

2016-10-24T14:07:33+00:00

It's not displayed in TUI now, putting it into generic part.

Signed-off-by: Jiri Olsa 
Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: http://lkml.kernel.org/n/tip-5fk88kejqgi50ye7xdkhiloz@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf header: Set nr_numa_nodes only when we parsed all the data

2016-10-13T14:12:29+00:00

Sukadev reported segfault on releasing perf env's numa data.  It's due
to nr_numa_nodes being set no matter if the numa data gets parsed
properly. The perf_env__exit crash the on releasing non existed data.

Setting nr_numa_nodes only when data are parsed out properly.

Signed-off-by: Jiri Olsa 
Reported-by: Sukadev Bhattiprolu 
Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: http://lkml.kernel.org/n/tip-dt9c0zgkt4hybn2cr4xiawta@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Use __weak definition from linux/compiler.h

2016-08-23T18:37:33+00:00

Replace __attribute__((weak)) with __weak definition

Signed-off-by: Rui Teng 
Cc: Alexander Shishkin 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1469671557-2256-2-git-send-email-rui.teng@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo