This patch supports the addition to the kernel of AUX area buffers that
can be mmapped separately from the perf-events buffer.

The AUX buffer can be configured to contain hardware-produced trace
information. The first implementation will support Intel BTS and Intel
PT.

One auxtrace buffer is mmapped per perf-events buffer.  If the requested
auxtrace buffer size is zero, which it will be until further support is
added, then no auxtrace mmapping is attempted.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1428594864-29309-3-git-send-email-adrian.hunter@intel.com
[ Fixed conflict in evlist.h ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Add a feature to indicate that a perf.data file contains AUX area data.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1428594864-29309-2-git-send-email-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

When converting int values, perf first extractes it to a ulonglong, then
feeds it to babeltrace as a signed value.

For negative 32 bit values (for example, return values of failed
syscalls), the extracted data should be something like 0xfffffffe (-2).
It becomes a large int64 value.

Babeltrace denies to insert it with bt_ctf_field_signed_integer_set_value()
because it is larger than 0x7fffffff, the largest positive value a
 32 bit int can be.

This patch introduces adjust_signedness(), which fills high bits of
ulonglong with 1 if the value is negative.
Signed-off-by: NWang Nan <wangnan0@huawei.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jeremie Galarneau <jgalar@efficios.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Tom Zanussi <tzanussi@gmail.com>
Link: http://lkml.kernel.org/r/1429372220-6406-8-git-send-email-jolsa@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>
[ s/signess/signedness/g ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Some parameters of syscall tracepoints named as 'nr', 'event', etc.
When dealing with them, perf convert to ctf meets some problem:

 1. If a parameter with name 'nr', it will duplicate syscall's
    common field 'nr'. One such syscall is io_submit().

 2. If a parameter with name 'event', it is denied to be inserted
    because 'event' is a CTF spec keyword[1]. One such syscall is
    epoll_ctl.

This patch appends '_dupl_X' suffix to avoid problem 1, prepend a '_'
prefix to avoid problem 2.

[1] http://diamon.org/docs/ctf/v1.8.2/#specC.1.2Signed-off-by: NWang Nan <wangnan0@huawei.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jeremie Galarneau <jgalar@efficios.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Tom Zanussi <tzanussi@gmail.com>
Link: http://lkml.kernel.org/r/1429372220-6406-7-git-send-email-jolsa@kernel.org
[ changed to use format_file::alias ]
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Adding support to limit the size of ordered_events queue, so we could
control allocation size of perf data files without proper finished round
events.
Reviewed-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Acked-by: NNamhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jeremie Galarneau <jgalar@efficios.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1429372220-6406-5-git-send-email-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

For big data files the size of data allocated for stream instance could
get really high. It's needed to flush the data out of the stream once in
a while.

Unfortunately there's no size indication in the stream object, so we
govern the flush based on the number of stored events. Current flush
limit is set ot 100000 events.
Reviewed-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Acked-by: NNamhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jeremie Galarneau <jgalar@efficios.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1429372220-6406-4-git-send-email-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Currently we store the data into single data strea/file. The cpu if data
is stored within the event sample. The lttng puts the CPU number that
belongs to the event into the packet context instead into the event.

This patch makes sure that the trace produce by perf does look the same
way. We now use one stream per-CPU. Having it all in one stream
increased the total size of the resulting file. The test went from
416KiB (with perf_cpu event member) to 24MiB due to the required (and
pointless) flush. With the per-cpu streams the total size went up to
588KiB.
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jeremie Galarneau <jgalar@efficios.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1429372220-6406-3-git-send-email-jolsa@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Adding build tests for following make commands:
  $ make -C <kernelsrc> tools/perf
  $ make -C <kernelsrc>/tools perf
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: linux-kbuild@vger.kernel.org
Link: http://lkml.kernel.org/r/1429389280-18720-4-git-send-email-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Several fixes were needed to allow following builds:
  $ make tools/tmon
  $ make -C <kernelsrc> tools/perf
  $ make -C <kernelsrc>/tools perf

 - some of the tools (perf) use same make variables as in
   kernel build, unsetting srctree and objtree
 - using original $(O) for O variable
 - perf build does not follow the descend function setup
   invoking it via it's own make rule

I tried the rest of the tools/Makefile targets and they
seem to work now.
Reported-by: NBrian Norris <computersforpeace@gmail.com>
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: linux-kbuild@vger.kernel.org
Link: http://lkml.kernel.org/r/1429389280-18720-3-git-send-email-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The perf build handles its dependencies by itself.

Also renaming libapi libapikfs to libapi as it got
changed just recently.
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: linux-kbuild@vger.kernel.org
Link: http://lkml.kernel.org/r/1429389280-18720-2-git-send-email-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Introduce an 'alias' field to 'struct format_field' to be able
to use alternative name for the field.

It is initialized with same string pointer as 'name' field.
The free logic checks the 'alias' pointer being reset by user
and frees it.

This will be handy when converting data into CTF, where each
field within event needs to have a unique name (while this
is not required for tracepoint). Converter can easily assign
unique name into the format_field struct.
Suggested-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Acked-by: NSteven Rostedt <rostedt@goodmis.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jeremie Galarneau <jgalar@efficios.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-qwyq8blnfkg6s5vlbrvn1en3@git.kernel.org
Link: http://lkml.kernel.org/r/1429372220-6406-6-git-send-email-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Show message when errors occurred during conversion setup and conversion
process.

Before this patch:
  $ ./perf data convert --to-ctf=ctf
  $ echo $?
  255

After this patch:
  $ ./perf data convert --to-ctf=ctf
  Error during conversion setup.
Signed-off-by: NHe Kuang <hekuang@huawei.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jeremie Galarneau <jgalar@efficios.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-xvhr1vf7zav9kkeo9w1hv4uk@git.kernel.org
Link: http://lkml.kernel.org/r/1429372220-6406-2-git-send-email-jolsa@kernel.orgSigned-off-by: NJiri Olsa <jolsa@kernel.org>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The period_ratio_delta, period_ratio and wdiff are never by used at the
same time.  Instead, Just one of them is accessed according to a
comparison method.  So make it union to reduce memory footprint.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1429416255-12070-3-git-send-email-namhyung@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

It's not used anywhere, let's get rid of it.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1429416255-12070-2-git-send-email-namhyung@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

0d68bc92 breaks compiles on RHEL6/OL6:
    cc1: warnings being treated as errors
    builtin-kmem.c: In function ‘search_page_alloc_stat’:
    builtin-kmem.c:322: error: declaration of ‘stat’ shadows a global declaration
                            node = &parent->rb_left;
    /usr/include/sys/stat.h:455: error: shadowed declaration is here
    builtin-kmem.c: In function ‘perf_evsel__process_page_alloc_event’:
    builtin-kmem.c:378: error: declaration of ‘stat’ shadows a global declaration
    /usr/include/sys/stat.h:455: error: shadowed declaration is here
    builtin-kmem.c: In function ‘perf_evsel__process_page_free_event’:
    builtin-kmem.c:431: error: declaration of ‘stat’ shadows a global declaration
    /usr/include/sys/stat.h:455: error: shadowed declaration is here

Rename local variable to pstat to avoid the name conflict.
Signed-off-by: NDavid Ahern <david.ahern@oracle.com>
Link: http://lkml.kernel.org/r/1429033773-31383-1-git-send-email-david.ahern@oracle.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Merge tag 'perf-core-for-mingo-2' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:

New features:

  - Analyze page allocator events in 'perf kmem' (Namhyung Kim)

User visible changes:

  - Fix retprobe 'perf probe' handling when failing to find needed debuginfo (He Kuang)

  - lazy_line probe fixes in 'perf probe' (Naohiro Aota, He Kuang)

Infrastructure changes:

  - Record pfn instead of pointer to struct page in tracepoints (Namhyung Kim)
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NIngo Molnar <mingo@kernel.org>

The first argument passed to find_probe_point_lazy() should be CU die,
which will be passed to die_walk_lines() when lazy_line matches.
Currently, when we probe with lazy_line pattern to file without function
name, NULL pointer is passed and causes a segment fault.

Can be reproduced as following:

  $ perf probe -k vmlinux --add='fs/super.c;s->s_count=1;'
  [ 1958.984658] perf[1020]: segfault at 10 ip 00007fc6e10d8c71 sp
  00007ffcbfaaf900 error 4 in libdw-0.161.so[7fc6e10ce000+34000]
  Segmentation fault

After this patch:

  $ perf probe -k vmlinux --add='fs/super.c;s->s_count=1;'
  Added new event:
  probe:_stext         (on @fs/super.c)

  You can now use it in all perf tools, such as:
    perf record -e probe:_stext -aR sleep 1
Signed-off-by: NHe Kuang <hekuang@huawei.com>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1428925290-5623-3-git-send-email-hekuang@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

If we use lazy matching, it failed to open a souce file if perf command
is invoked outside of compilation directory:

$ perf probe -a '__schedule;clear_*'
Failed to open kernel/sched/core.c: No such file or directory
  Error: Failed to add events. (-2)

OTOH, other commands like "probe -L" can solve the souce directory by
themselves. Let's make it possible for lazy matching too!
Signed-off-by: NNaohiro Aota <naota@elisp.net>
Acked-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1426223923-1493-1-git-send-email-naota@elisp.netSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

When perf probe searched in a debuginfo file and failed, it tried with
an alternative, in function get_alternative_probe_event():

        memcpy(tmp, &pev->point, sizeof(*tmp));
        memset(&pev->point, 0, sizeof(pev->point));

In this case, it drops the retprobe flag and forgets to set it back in
find_alternative_probe_point(), so the problem occurs.

Can be reproduced as following:

  $ perf probe -v -k vmlinux --add='sys_write%return'
  ...
  Added new event:
  Writing event: p:probe/sys_write _stext+1584952
    probe:sys_write      (on sys_write%return)

  $ cat /sys/kernel/debug/tracing/kprobe_events
  p:probe/sys_write _stext+1584952

After this patch:

  $ perf probe -v -k vmlinux --add='sys_write%return'
  Added new event:
  Writing event: r:probe/sys_write SyS_write+0
    probe:sys_write      (on sys_write%return)

  $ cat /sys/kernel/debug/tracing/kprobe_events
  r:probe/sys_write SyS_write
Signed-off-by: NHe Kuang <hekuang@huawei.com>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1428925290-5623-1-git-send-email-hekuang@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The perf kmem command records and analyze kernel memory allocation only
for SLAB objects.  This patch implement a simple page allocator analyzer
using kmem:mm_page_alloc and kmem:mm_page_free events.

It adds two new options of --slab and --page.  The --slab option is for
analyzing SLAB allocator and that's what perf kmem currently does.

The new --page option enables page allocator events and analyze kernel
memory usage in page unit.  Currently, 'stat --alloc' subcommand is
implemented only.

If none of these --slab nor --page is specified, --slab is implied.

First run 'perf kmem record' to generate a suitable perf.data file:

  # perf kmem record --page sleep 5

Then run 'perf kmem stat' to postprocess the perf.data file:

  # perf kmem stat --page --alloc --line 10

  -------------------------------------------------------------------------------
   PFN              | Total alloc (KB) | Hits     | Order | Mig.type | GFP flags
  -------------------------------------------------------------------------------
            4045014 |               16 |        1 |     2 |  RECLAIM |  00285250
            4143980 |               16 |        1 |     2 |  RECLAIM |  00285250
            3938658 |               16 |        1 |     2 |  RECLAIM |  00285250
            4045400 |               16 |        1 |     2 |  RECLAIM |  00285250
            3568708 |               16 |        1 |     2 |  RECLAIM |  00285250
            3729824 |               16 |        1 |     2 |  RECLAIM |  00285250
            3657210 |               16 |        1 |     2 |  RECLAIM |  00285250
            4120750 |               16 |        1 |     2 |  RECLAIM |  00285250
            3678850 |               16 |        1 |     2 |  RECLAIM |  00285250
            3693874 |               16 |        1 |     2 |  RECLAIM |  00285250
   ...              | ...              | ...      | ...   | ...      | ...
  -------------------------------------------------------------------------------

  SUMMARY (page allocator)
  ========================
  Total allocation requests     :           44,260   [          177,256 KB ]
  Total free requests           :              117   [              468 KB ]

  Total alloc+freed requests    :               49   [              196 KB ]
  Total alloc-only requests     :           44,211   [          177,060 KB ]
  Total free-only requests      :               68   [              272 KB ]

  Total allocation failures     :                0   [                0 KB ]

  Order     Unmovable   Reclaimable       Movable      Reserved  CMA/Isolated
  -----  ------------  ------------  ------------  ------------  ------------
      0            32             .        44,210             .             .
      1             .             .             .             .             .
      2             .            18             .             .             .
      3             .             .             .             .             .
      4             .             .             .             .             .
      5             .             .             .             .             .
      6             .             .             .             .             .
      7             .             .             .             .             .
      8             .             .             .             .             .
      9             .             .             .             .             .
     10             .             .             .             .             .
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/1428298576-9785-4-git-send-email-namhyung@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The struct page is opaque for userspace tools, so it'd be better to save
pfn in order to identify page frames.

The textual output of $debugfs/tracing/trace file remains unchanged and
only raw (binary) data format is changed - but thanks to libtraceevent,
userspace tools which deal with the raw data (like perf and trace-cmd)
can parse the format easily.  So impact on the userspace will also be
minimal.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Based-on-patch-by: NJoonsoo Kim <js1304@gmail.com>
Acked-by: NIngo Molnar <mingo@kernel.org>
Acked-by: NSteven Rostedt <rostedt@goodmis.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/1428298576-9785-3-git-send-email-namhyung@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Dan Carpenter pointed out that the control flow in pt_pmu_hw_init()
is a bit messy: for example the kfree(de_attrs) is entirely
superfluous.

Another problem is the inconsistent mixing of label based and
direct return error handling.

Add modern, label based error handling instead and clean up the code
a bit as well.

Note that we'll still do a kfree(NULL) in the normal case - this does
not matter as this is an init path and kfree() returns early if it
sees a NULL.
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20150409090805.GG17605@mwandaSigned-off-by: NIngo Molnar <mingo@kernel.org>

Merge tag 'perf-core-for-mingo' 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:

New user visible features:

  - Support multiple probes on different binaries on the same command line (Masami Hiramatsu)

User visible changes:

  - Fix synthesizing fork_event.ppid for non-main thread (David Ahern)

  - Fix cross-endian analysis (David Ahern)

  - Fix segfault in 'perf buildid-list' when show DSOs with hits (He Kuang)

Infrastructure changes:

  - Fix type for references to data_head/tail (David Ahern)

  - Fix error path to do closedir() when synthesizing threads (Arnaldo Carvalho de Melo)
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NIngo Molnar <mingo@kernel.org>

The data_head and data_tail fields are defined as __u64 in
linux/perf_event.h, but perf userspace uses int and unsigned int.

Convert all references to u64 for consistency.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1428420037-26599-1-git-send-email-dsahern@gmail.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To avoid probing in unintended binary, the orphaned -x option must be
checked and warned.

Without this patch, following command sets up the probe in the kernel.

  -----
  # perf probe -a strcpy -x ./perf
  Added new event:
    probe:strcpy         (on strcpy)

  You can now use it in all perf tools, such as:

          perf record -e probe:strcpy -aR sleep 1
  -----

But in this case, it seems that the user may want to probe in the perf
binary. With this patch, perf-probe correctly handles the orphaned -x.

  -----
  # perf probe -a strcpy -x ./perf
    Error: -x/-m must follow the probe definitions.
  ...
  -----
Reported-by: NJiri Olsa <jolsa@redhat.com>
Acked-by: NJiri Olsa <jolsa@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150401102541.17137.75477.stgit@localhost.localdomainSigned-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Support multiple probes on different binaries with just
one command.

In the result, this example sets up the probes on icmp_rcv in
kernel, on main and set_target in perf, and on pcspkr_event
in pcspker.ko driver.
  -----
  # perf probe -a icmp_rcv -x ./perf -a main -a set_target \
   -m /lib/modules/4.0.0-rc5+/kernel/drivers/input/misc/pcspkr.ko \
   -a pcspkr_event
  Added new event:
    probe:icmp_rcv       (on icmp_rcv)

  You can now use it in all perf tools, such as:

          perf record -e probe:icmp_rcv -aR sleep 1

  Added new event:
    probe_perf:main      (on main in /home/mhiramat/ksrc/linux-3/tools/perf/perf)

  You can now use it in all perf tools, such as:

          perf record -e probe_perf:main -aR sleep 1

  Added new event:
    probe_perf:set_target (on set_target in /home/mhiramat/ksrc/linux-3/tools/perf/perf)

  You can now use it in all perf tools, such as:

          perf record -e probe_perf:set_target -aR sleep 1

  Added new event:
    probe:pcspkr_event   (on pcspkr_event in pcspkr)

  You can now use it in all perf tools, such as:

          perf record -e probe:pcspkr_event -aR sleep 1
  -----
Reported-by: NArnaldo Carvalho de Melo <acme@infradead.org>
Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150401102539.17137.46454.stgit@localhost.localdomainSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

commit: f3b623b8 ("perf tools: Reference count struct thread")
appends every thread->node to dead_threads in machine__remove_thread()
and list_del_init() this node in thread__put().

perf_event__exit_del_thread() releases thread wihout using
machine__remove_thread(), and causes a NULL pointer crash when
list_del_init(&thread->node) is called. Fix this by using
machine_remove_thread() instead of using thread__put() directly.

This problem can be reproduced as following:

  $ perf record ls
  $ perf buildid-list --with-hits
  [ 3874.195070] perf[1018]: segfault at 0 ip 00000000004b0b15 sp
  00007ffc35b44780 error 6 in perf[400000+166000]
  Segmentation fault

After this patch:
  $ perf record ls
  $ perf buildid-list --with-hits
  bc23e7c3281e542650ba4324421d6acf78f4c23e /proc/kcore
  643324cb0e969f30c56d660f167f84a150845511 [vdso]
  0000000000000000000000000000000000000000 /bin/busybox
  ...
Signed-off-by: NHe Kuang <hekuang@huawei.com>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1428658500-6483-1-git-send-email-hekuang@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Trying to analyze a big endian data file on little endian system fails
with the error:

  0xa9b40 [0x70]: failed to process type: 9

The problem is that header parsing is not done correctly because the
file attributes are not swapped. Make it so. With this patch able to
analyze a sparc64 data file on x86_64.
Signed-off-by: NDavid Ahern <david.ahern@oracle.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1428610546-178789-1-git-send-email-david.ahern@oracle.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

When traversing /proc to synthesize the PERF_RECORD_FORK et al events we
were bailing out on errors without calling closedir(), fix it.
Reported-by: NDavid Ahern <dsahern@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-vxtp593rfztgbi8noy0m967p@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Commit ca6c41c5 sets the ppid based on what is read from the
/proc/pid/status file when synthesizing fork events.

This is correct thing to do for new processes but not threads of a
process.

Fix ppid for threads to be the main thread when synthesizing fork events
(ie., assume main thread spawned all sub-threads in a process).
Reported-by: NArnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
Signed-off-by: NDavid Ahern <david.ahern@oracle.com>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: NDon Zickus <dzickus@redhat.com>
Link: http://lkml.kernel.org/r/1428598107-178999-1-git-send-email-david.ahern@oracle.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Merge tag 'perf-core-for-mingo' 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:

User visible changes:

  - Teach 'perf record' about perf_event_attr.clockid (Peter Zijlstra)

  - Improve 'perf sched replay' on high CPU core count machines (Yunlong Song)

  - 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)

  - Add 'I' event modifier for perf_event_attr.exclude_idle bit (Jiri Olsa)

  - Respect -i option 'in perf kmem' (Jiri Olsa)

Infrastructure changes:

  - Honor operator priority in libtraceevent (Namhyung Kim)

  - Merge all perf_event_attr print functions (Peter Zijlstra)

  - Check kmaps access to make code more robust (Wang Nan)

  - Fix inverted logic in perf_mmap__empty() (He Kuang)

  - Fix ARM 32 'perf probe' building error (Wang Nan)

  - Fix perf_event_attr tests (Jiri Olsa)
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Adding 'I' event modifier to have complete set of modifiers for
perf_event_attr:exclude_* bits.

Any event specified with 'I' modifier will have the
perf_event_attr:exclude_idle bit set.

  $ perf record -e cycles:I -vv ls 2>&1 | grep exclude_idle
  exclude_hv          0    exclude_idle        1

Adding automated tests.
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: William Cohen <wcohen@redhat.com>
Link: http://lkml.kernel.org/r/1428441919-23099-2-git-send-email-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

report__warn_kptr_restrict() calls map__kmap(kernel_map) before checking
kernel_map againest NULL.

Which is dangerous, since map__kmap() will return a invalid and not NULL
address.

It will trigger a warning message in map__kmap() after the patch "perf:
kmaps: enforce usage of kmaps to protect futher bugs." was applied.

This patch fixes it by adding the missing checking.
Signed-off-by: NWang Nan <wangnan0@huawei.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1428490772-135393-1-git-send-email-wangnan0@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Following commit:
  1a594131 perf: Add wakeup watermark control to the AUX area

enlarged perf_event_attr, but did not updated attr tests.
Reported-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Kaixu Xia <kaixu.xia@linaro.org>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robert Richter <rric@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Markus T Metzger <markus.t.metzger@intel.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: http://lkml.kernel.org/n/20150407171715.GA22603@krava.redhat.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Commit 9b118aca ("perf probe: Fix to
handle aliased symbols in glibc") uses an absolute format '%lx' to
print u64 argument, which causes compiling error on ARM 32.

This patch replaces it with PRIx64.
Signed-off-by: NWang Nan <wangnan0@huawei.com>
Acked-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1428459274-138470-1-git-send-email-wangnan0@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Currently there's 3 (that I found) different and incomplete
implementations of printing perf_event_attr.

This is quite silly. Merge the lot.

While this patch does not retain the exact form all printing that I
found is debug output and thus it should not be critical.

Also, I cannot find a single print_event_desc() caller.

Pre:

 $ perf record -vv -e cycles -- sleep 1
 ------------------------------------------------------------
 perf_event_attr:
  type                0
  size                104
  config              0
  sample_period       4000
  sample_freq         4000
  sample_type         0x107
  read_format         0
  disabled            1    inherit             1
  pinned              0    exclusive           0
  exclude_user        0    exclude_kernel      0
  exclude_hv          0    exclude_idle        0
  mmap                1    comm                1
  mmap2               1    comm_exec           1
  freq                1    inherit_stat        0
  enable_on_exec      1    task                1
  watermark           0    precise_ip          0
  mmap_data           0    sample_id_all       1
  exclude_host        0    exclude_guest       1
  excl.callchain_kern 0    excl.callchain_user 0
  wakeup_events       0
  wakeup_watermark    0
  bp_type             0
  bp_addr             0
  config1             0
  bp_len              0
  config2             0
  branch_sample_type  0
  sample_regs_user    0
  sample_stack_user   0
  sample_regs_intr    0
 ------------------------------------------------------------

 $ perf evlist  -vv
 cycles: sample_freq=4000, size: 104, sample_type: IP|TID|TIME|PERIOD,
 disabled: 1, inherit: 1, mmap: 1, mmap2: 1, comm: 1, comm_exec: 1,
 freq: 1, enable_on_exec: 1, task: 1, sample_id_all: 1, exclude_guest: 1

 Post:

 $ ./perf record -vv -e cycles -- sleep 1
 ------------------------------------------------------------
 perf_event_attr:
  size                             112
  { sample_period, sample_freq }   4000
  sample_type                      IP|TID|TIME|PERIOD
  disabled                         1
  inherit                          1
  mmap                             1
  comm                             1
  freq                             1
  enable_on_exec                   1
  task                             1
  sample_id_all                    1
  exclude_guest                    1
  mmap2                            1
  comm_exec                        1
------------------------------------------------------------

 $ ./perf evlist  -vv
 cycles: size: 112, { sample_period, sample_freq }: 4000, sample_type:
 IP|TID|TIME|PERIOD, disabled: 1, inherit: 1, mmap: 1, comm: 1, freq:
 1, enable_on_exec: 1, task: 1, sample_id_all: 1, exclude_guest: 1,
 mmap2: 1, comm_exec: 1
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: NAdrian Hunter <adrian.hunter@intel.com>
Acked-by: NIngo Molnar <mingo@kernel.org>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150407091150.644238729@infradead.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Teach perf-record about the new perf_event_attr::{use_clockid, clockid}
fields. Add a simple parameter to set the clock (if any) to be used for
the events to be recorded into the data file.

Since we store the entire perf_event_attr in the EVENT_DESC section we
also already store the used clockid in the data file.
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yunlong Song <yunlong.song@huawei.com>
Link: http://lkml.kernel.org/r/20150407154851.GR23123@twins.programming.kicks-ass.net
[ Conditionally define CLOCK_BOOTTIME, at least rhel6 doesn't have it - dsahern
  Ditto for CLOCK_MONOTONIC_RAW, sles11sp2 doesn't have it - yunlong.song ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

perf sched replay: Use replay_repeat to calculate the runavg of cpu usage instead of the default value 10

Since sched->replay_repeat is set to 10 as default, the sched->run_avg,
sched->runavg_cpu_usage, and sched->runavg_parent_cpu_usage all use
10 to calculate their value.

However, the replay_repeat can be changed to other value by using -r
option, so the calculation above should use replay_repeat to achieve
more accurate results instead of the default value 10.
Signed-off-by: NYunlong Song <yunlong.song@huawei.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1427809596-29559-10-git-send-email-yunlong.song@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Enable to use perf.data when it is not owned by current user or root.

Example:

 $ ls -al perf.data
 -rw------- 1 Yunlong.Song Yunlong.Song 5321918 Mar 25 15:14 perf.data
 $ sudo id
 uid=0(root) gid=0(root) groups=0(root),64(pkcs11)

Before this patch:

 $ sudo perf sched replay -f
 run measurement overhead: 98 nsecs
 sleep measurement overhead: 52909 nsecs
 the run test took 1000015 nsecs
 the sleep test took 1054253 nsecs
 File perf.data not owned by current user or root (use -f to override)

As shown above, the -f option does not work at all.

After this patch:

 $ sudo perf sched replay -f
 run measurement overhead: 221 nsecs
 sleep measurement overhead: 40514 nsecs
 the run test took 1000003 nsecs
 the sleep test took 1056098 nsecs
 nr_run_events:        10
 nr_sleep_events:      1562
 nr_wakeup_events:     5
 task      0 (                  :1:         1), nr_events: 1
 task      1 (                  :2:         2), nr_events: 1
 task      2 (                  :3:         3), nr_events: 1
 ...
 ...
 task   1549 (             :163132:    163132), nr_events: 1
 task   1550 (             :163540:    163540), nr_events: 1
 task   1551 (           <unknown>:         0), nr_events: 10
 ------------------------------------------------------------
 #1  : 50.198, ravg: 50.20, cpu: 2335.18 / 2335.18
 #2  : 219.099, ravg: 67.09, cpu: 2835.11 / 2385.17
 #3  : 238.626, ravg: 84.24, cpu: 3278.26 / 2474.48
 #4  : 200.364, ravg: 95.85, cpu: 2977.41 / 2524.77
 #5  : 176.882, ravg: 103.96, cpu: 2801.35 / 2552.43
 #6  : 191.093, ravg: 112.67, cpu: 2813.70 / 2578.56
 #7  : 189.448, ravg: 120.35, cpu: 2809.21 / 2601.62
 #8  : 200.637, ravg: 128.38, cpu: 2849.91 / 2626.45
 #9  : 248.338, ravg: 140.37, cpu: 4380.61 / 2801.87
 #10 : 511.139, ravg: 177.45, cpu: 3077.73 / 2829.45

As shown above, the -f option really works now.

Besides for replay, -f option can also work for latency and map.
Signed-off-by: NYunlong Song <yunlong.song@huawei.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1427809596-29559-9-git-send-email-yunlong.song@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The soft maximum number of open files for a calling process is 1024,
which is defined as INR_OPEN_CUR in include/uapi/linux/fs.h, and the
hard maximum number of open files for a calling process is 4096, which
is defined as INR_OPEN_MAX in include/uapi/linux/fs.h.

Both INR_OPEN_CUR and INR_OPEN_MAX are used to limit the value of
RLIMIT_NOFILE in include/asm-generic/resource.h.

And the soft maximum number finally decides the limitation of the
maximum files which are allowed to be opened.

That is to say a process can use at most 1024 file descriptors for its
o pened files, or an EMFILE error will happen.

This error can be fixed by increasing the soft maximum number, under the
constraint that the soft maximum number can not exceed the hard maximum
number, or both soft and hard maximum number should be increased
simultaneously with privilege.

For perf sched replay, it uses sys_perf_event_open to create the file
descriptor for each of the tasks in order to handle information of perf
events.

That is to say each task needs a unique file descriptor. In x86_64,
there may be over 1024 or 4096 tasks correspoinding to the record in
perf.data, which causes that no enough file descriptors can be used.

As a result, EMFILE error happens and stops the replay process. To solve
this problem, we adaptively increase the soft and hard maximum number of
open files with a '-f' option.

Example:

Test environment: x86_64 with 160 cores

 $ cat /proc/sys/kernel/pid_max
 163840
 $ cat /proc/sys/fs/file-max
 6815744
 $ ulimit -Sn
 1024
 $ ulimit -Hn
 4096

Before this patch:

 $ perf sched replay
 ...
 task   1549 (             :163132:    163132), nr_events: 1
 task   1550 (             :163540:    163540), nr_events: 1
 task   1551 (           <unknown>:         0), nr_events: 10
 Error: sys_perf_event_open() syscall returned with -1 (Too many open
 files)

After this patch:

 $ perf sched replay
 ...
 task   1549 (             :163132:    163132), nr_events: 1
 task   1550 (             :163540:    163540), nr_events: 1
 task   1551 (           <unknown>:         0), nr_events: 10
 Error: sys_perf_event_open() syscall returned with -1 (Too many open
 files)
 Have a try with -f option

 $ perf sched replay -f
 ...
 task   1549 (             :163132:    163132), nr_events: 1
 task   1550 (             :163540:    163540), nr_events: 1
 task   1551 (           <unknown>:         0), nr_events: 10
 ------------------------------------------------------------
 #1  : 54.401, ravg: 54.40, cpu: 3285.21 / 3285.21
 #2  : 199.548, ravg: 68.92, cpu: 4999.65 / 3456.66
 #3  : 170.483, ravg: 79.07, cpu: 1349.94 / 3245.99
 #4  : 192.034, ravg: 90.37, cpu: 1322.88 / 3053.67
 #5  : 182.929, ravg: 99.62, cpu: 1406.51 / 2888.96
 #6  : 152.974, ravg: 104.96, cpu: 1167.54 / 2716.82
 #7  : 155.579, ravg: 110.02, cpu: 2992.53 / 2744.39
 #8  : 130.557, ravg: 112.08, cpu: 1126.43 / 2582.59
 #9  : 138.520, ravg: 114.72, cpu: 1253.22 / 2449.65
 #10 : 134.328, ravg: 116.68, cpu: 1587.95 / 2363.48
Signed-off-by: NYunlong Song <yunlong.song@huawei.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1427809596-29559-8-git-send-email-yunlong.song@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>