linux.git/tools/perf, branch v4.0-rc1

perf symbols: Convert lseek + read to pread

2015-01-29T20:02:01+00:00

When dso_cache__read() is called, it reads data from the given offset
using lseek + normal read syscall.  It can be combined to a single pread
syscall.

Signed-off-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Andi Kleen 
Cc: David Ahern 
Cc: Frederic Weisbecker 
Cc: Jiri Olsa 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/r/1422518843-25818-40-git-send-email-namhyung@kernel.org
[ Fixed it up when cherry picking it from the multi threaded patchkit ]
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Use perf_data_file__fd() consistently

2015-01-29T19:58:24+00:00

Do not reference file->fd directly since we want hide the
implementation details from outside for possible future changes.

Signed-off-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Andi Kleen 
Cc: David Ahern 
Cc: Frederic Weisbecker 
Cc: Jiri Olsa 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/r/1422518843-25818-8-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Support to read compressed module from build-id cache

2015-01-29T19:56:54+00:00

The commit c00c48fc6e6e ("perf symbols: Preparation for compressed
kernel module support") added support for compressed kernel modules but
it only supports system path DSOs.  When a dso is read from build-id
cache, its filename doesn't end with ".gz" but has build-id.  In this
case, we should fallback to the original dso->name.

Signed-off-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Andi Kleen 
Cc: David Ahern 
Cc: Frederic Weisbecker 
Cc: Jiri Olsa 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/r/1422518843-25818-2-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf evsel: Set attr.task bit for a tracking event

2015-01-29T19:54:59+00:00

The perf_event_attr.task bit is to track task (fork and exit) events but
it missed to be set by perf_evsel__config().  While it was not a problem
in practice since setting other bits (comm/mmap) ended up being in same
result, it'd be good to set it explicitly anyway.

The attr->task is to track task related events (fork/exit) only but
other meta events like comm and mmap[2] also needs the task events.  So
setting attr->comm and/or attr->mmap causes the kernel emits the task
events anyway.  So the attr->task is only meaningful when other bits are
off but I'd like to set it for completeness.

Signed-off-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Andi Kleen 
Cc: David Ahern 
Cc: Frederic Weisbecker 
Cc: Jiri Olsa 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/r/1422518843-25818-6-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf header: Set header version correctly

2015-01-29T19:53:11+00:00

When check_magic_endian() is called, it checks the magic number in the
perf data file to determine version and endianness.  But if it uses a
same endian the verison number wasn't updated and makes confusion.

Signed-off-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Andi Kleen 
Cc: David Ahern 
Cc: Frederic Weisbecker 
Cc: Jiri Olsa 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/r/1422518843-25818-5-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf record: Show precise number of samples

2015-01-29T19:37:20+00:00

After perf record finishes, it prints file size and number of samples in
the file but this info is wrong since it assumes typical sample size of
24 bytes and divides file size by the value.

However as we post-process recorded samples for build-id, it can show
correct number like below.  If build-id post-processing is not requested
just omit the wrong number of samples.

  $ perf record noploop 1
    [ perf record: Woken up 1 times to write data ]
    [ perf record: Captured and wrote 0.159 MB perf.data (3989 samples) ]

  $ perf report --stdio -n
  # To display the perf.data header info, please use --header/--header-only options.
  #
  # Samples: 3K of event 'cycles'
  # Event count (approx.): 3771330663
  #
  # Overhead       Samples  Command  Shared Object     Symbol
  # ........  ............  .......  ................  ..........................
  #
      99.90%          3982  noploop  noploop           [.] main
       0.09%             1  noploop  ld-2.17.so        [.] _dl_check_map_versions
       0.01%             1  noploop  [kernel.vmlinux]  [k] setup_arg_pages
       0.00%             5  noploop  [kernel.vmlinux]  [k] intel_pmu_enable_all

Reported-by: Milian Wolff 
Signed-off-by: Namhyung Kim 
Reviewed-by: Jiri Olsa 
Cc: Adrian Hunter 
Cc: Andi Kleen 
Cc: David Ahern 
Cc: Frederic Weisbecker 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/r/1422518843-25818-4-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Do not use __perf_session__process_events() directly

2015-01-29T19:36:32+00:00

It's only used for perf record to process build-id because its file size
it's not fixed at this time due to remaining header features.

However data offset and size is available so that we can use the
perf_session__process_events() once we set the file size as the current
offset like for now.

Signed-off-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Andi Kleen 
Cc: David Ahern 
Cc: Frederic Weisbecker 
Cc: Jiri Olsa 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/r/1422518843-25818-3-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf callchain: Cache eh/debug frame offset for dwarf unwind

2015-01-29T19:20:42+00:00

When libunwind tries to resolve callchains it needs to know the offset
of .eh_frame_hdr or .debug_frame to access the dso.

Since it will always return the same result for a given DSO, just cache
the result as an optimization.

Signed-off-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Andi Kleen 
Cc: David Ahern 
Cc: Frederic Weisbecker 
Cc: Jiri Olsa 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/r/1422518843-25818-41-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Provide stub for missing pthread_attr_setaffinity_np

2015-01-28T15:43:32+00:00

uClibc Linuxthreads.old doesn't support the pthread_attr_setaffinity_np()
functioo:

   ----------------->8-----------------------
  CC       bench/futex-hash.o
  CC       bench/futex-wake.o
bench/futex-hash.c: In function 'bench_futex_hash':
bench/futex-hash.c:161:3: error: implicit declaration of function
'pthread_attr_setaffinity_np' [-Werror=implicit-function-declaration]
   ret = pthread_attr_setaffinity_np(&thread_attr, sizeof(cpu_set_t),
&cpu);
   ^
bench/futex-hash.c:161:3: error: nested extern declaration of
'pthread_attr_setaffinity_np' [-Werror=nested-externs]
   ----------------->8-----------------------

So introduce a test to check that and if not available provide a stub.

Signed-off-by: Vineet Gupta 
Acked-by: Jiri Olsa 
Cc: Alexey Brodkin 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1421156604-30603-6-git-send-email-vgupta@synopsys.com
Signed-off-by: Arnaldo Carvalho de Melo

perf evsel: Don't rely on malloc working for sz 0

2015-01-28T15:43:32+00:00

When running perf on ARC (uClibc based userspace), ran into this issue
   ------------->8----------------
	[ARCLinux]$ ./perf record ls
	bin             etc             perf            sys
	debug           init            perf.data       tmp
	[ perf record: Woken up 1 times to write data ]
	[ perf record: Captured and wrote 0.001 MB perf.data (~24 samples) ]

	[ARCLinux]$ ./perf report
	incompatible file format (rerun with -v to learn more)
   ------------->8----------------

The problem happens in the following call stack when zalloc is called
with size zero

glibc default / uClibc with MALLOC_GLIBC_COMPAT are OK, but not if that
config option is not enabled.

  cmd_report
     perf_session__new
	perf_session__open
	    perf_session__read_header
		read_attr(fd, header, &f_attr)
		nr_ids = f_attr.ids.size / sizeof(u64); <-- 0
		perf_evsel__alloc_id(vsel, 1, nr_ids)
			zalloc(ncpus * nthreads * sizeof(u64)) <-- 0

header.c: read_attr()

(gdb) p *f_attr
$17 = {
  attr = {
    type = 0,
    size = 96,
    config = 0,
    {
      sample_period = 4000,
      sample_freq = 4000
    },
...
  ids = {
    offset = 104,
    size = 0      <------
  }
}

Signed-off-by: Vineet Gupta 
Suggested-by: Namhyung Kim 
Acked-by: Jiri Olsa 
Cc: Alexey Brodkin 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1421156604-30603-5-git-send-email-vgupta@synopsys.com
Signed-off-by: Arnaldo Carvalho de Melo