Merge tag 'perf-core-for-mingo-20160419' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux

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

Build fixes:

- Fix 'perf trace' build when DWARF unwind isn't available (Arnaldo Carvalho de Melo)

- Remove x86 references from arch-neutral Build, fixing it in !x86 arches,
  reported as breaking the build for powerpc64le in linux-next (Arnaldo Carvalho de Melo)

Infrastructure changes:

- Do memset() variable 'st' using the correct size in the jit code (Colin Ian King)

- Fix postgresql ubuntu 'perf script' install instructions (Chris Phlipot)

- Use callchain_param more thoroughly when checking how callchains were
  configured, eventually will be the only way to look for callchain parameters
  (Arnaldo Carvalho de Melo)

- Fix some issues in the 'perf test kallsyms' entry (Arnaldo Carvalho de Melo)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

With the array aligned as per events/intel/core.c it was fairly
obvious we missed one, add it in.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Re-order the model array to match the order in events/intel/core.c,
to easier spot gaps and such.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Add Skylake client support for RAPL domains. In addition to RAPL domains
in Broadwell clients, it has support for platform domain (aka PSys). The
PSys domain controls the entire SoC instead of just a CPU package. Unlike
package domain, PSys support requires more than just processor level
implementation. The other parts in the system need additional HW level
signaling, which OEMs need to support. When not supported, the energy
counter register in PSys domain returns 0.

Also corrected error in comment for GPU counter, which previously was
DRAM counter.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com
[ Cnverted to model_match stuff. ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: bp@alien8.de
Cc: hpa@zytor.com
Cc: jacob.jun.pan@linux.intel.com
Cc: rjw@rjwysocki.net
Link: http://lkml.kernel.org/r/1460930581-29748-2-git-send-email-srinivas.pandruvada@linux.intel.comSigned-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

This patch introduces 'write_backward' bit to perf_event_attr, which
controls the direction of a ring buffer. After set, the corresponding
ring buffer is written from end to beginning. This feature is design to
support reading from overwritable ring buffer.

Ring buffer can be created by mapping a perf event fd. Kernel puts event
records into ring buffer, user tooling like perf fetch them from
address returned by mmap(). To prevent racing between kernel and tooling,
they communicate to each other through 'head' and 'tail' pointers.
Kernel maintains 'head' pointer, points it to the next free area (tail
of the last record). Tooling maintains 'tail' pointer, points it to the
tail of last consumed record (record has already been fetched). Kernel
determines the available space in a ring buffer using these two
pointers to avoid overwrite unfetched records.

By mapping without 'PROT_WRITE', an overwritable ring buffer is created.
Different from normal ring buffer, tooling is unable to maintain 'tail'
pointer because writing is forbidden. Therefore, for this type of ring
buffers, kernel overwrite old records unconditionally, works like flight
recorder. This feature would be useful if reading from overwritable ring
buffer were as easy as reading from normal ring buffer. However,
there's an obscure problem.

The following figure demonstrates a full overwritable ring buffer. In
this figure, the 'head' pointer points to the end of last record, and a
long record 'E' is pending. For a normal ring buffer, a 'tail' pointer
would have pointed to position (X), so kernel knows there's no more
space in the ring buffer. However, for an overwritable ring buffer,
kernel ignore the 'tail' pointer.

   (X)                              head
    .                                |
    .                                V
    +------+-------+----------+------+---+
    |A....A|B.....B|C........C|D....D|   |
    +------+-------+----------+------+---+

Record 'A' is overwritten by event 'E':

      head
       |
       V
    +--+---+-------+----------+------+---+
    |.E|..A|B.....B|C........C|D....D|E..|
    +--+---+-------+----------+------+---+

Now tooling decides to read from this ring buffer. However, none of these
two natural positions, 'head' and the start of this ring buffer, are
pointing to the head of a record. Even the full ring buffer can be
accessed by tooling, it is unable to find a position to start decoding.

The first attempt tries to solve this problem AFAIK can be found from
[1]. It makes kernel to maintain 'tail' pointer: updates it when ring
buffer is half full. However, this approach introduces overhead to
fast path. Test result shows a 1% overhead [2]. In addition, this method
utilizes no more tham 50% records.

Another attempt can be found from [3], which allows putting the size of
an event at the end of each record. This approach allows tooling to find
records in a backward manner from 'head' pointer by reading size of a
record from its tail. However, because of alignment requirement, it
needs 8 bytes to record the size of a record, which is a huge waste. Its
performance is also not good, because more data need to be written.
This approach also introduces some extra branch instructions to fast
path.

'write_backward' is a better solution to this problem.

Following figure demonstrates the state of the overwritable ring buffer
when 'write_backward' is set before overwriting:

       head
        |
        V
    +---+------+----------+-------+------+
    |   |D....D|C........C|B.....B|A....A|
    +---+------+----------+-------+------+

and after overwriting:
                                     head
                                      |
                                      V
    +---+------+----------+-------+---+--+
    |..E|D....D|C........C|B.....B|A..|E.|
    +---+------+----------+-------+---+--+

In each situation, 'head' points to the beginning of the newest record.
From this record, tooling can iterate over the full ring buffer and fetch
records one by one.

The only limitation that needs to be considered is back-to-back reading.
Due to the non-deterministic of user programs, it is impossible to ensure
the ring buffer keeps stable during reading. Consider an extreme situation:
tooling is scheduled out after reading record 'D', then a burst of events
come, eat up the whole ring buffer (one or multiple rounds). When the
tooling process comes back, reading after 'D' is incorrect now.

To prevent this problem, we need to find a way to ensure the ring buffer
is stable during reading. ioctl(PERF_EVENT_IOC_PAUSE_OUTPUT) is
suggested because its overhead is lower than
ioctl(PERF_EVENT_IOC_ENABLE).

By carefully verifying 'header' pointer, reader can avoid pausing the
ring-buffer. For example:

    /* A union of all possible events */
    union perf_event event;

    p = head = perf_mmap__read_head();
    while (true) {
        /* copy header of next event */
        fetch(&event.header, p, sizeof(event.header));

        /* read 'head' pointer */
        head = perf_mmap__read_head();

        /* check overwritten: is the header good? */
        if (!verify(sizeof(event.header), p, head))
            break;

        /* copy the whole event */
        fetch(&event, p, event.header.size);

        /* read 'head' pointer again */
        head = perf_mmap__read_head();

        /* is the whole event good? */
        if (!verify(event.header.size, p, head))
            break;
        p += event.header.size;
    }

However, the overhead is high because:

 a) In-place decoding is not safe.
    Copying-verifying-decoding is required.
 b) Fetching 'head' pointer requires additional synchronization.

(From Alexei Starovoitov:

Even when this trick works, pause is needed for more than stability of
reading. When we collect the events into overwrite buffer we're waiting
for some other trigger (like all cpu utilization spike or just one cpu
running and all others are idle) and when it happens the buffer has
valuable info from the past. At this point new events are no longer
interesting and buffer should be paused, events read and unpaused until
next trigger comes.)

This patch utilizes event's default overflow_handler introduced
previously. perf_event_output_backward() is created as the default
overflow handler for backward ring buffers. To avoid extra overhead to
fast path, original perf_event_output() becomes __perf_event_output()
and marked '__always_inline'. In theory, there's no extra overhead
introduced to fast path.

Performance testing:

Calling 3000000 times of 'close(-1)', use gettimeofday() to check
duration.  Use 'perf record -o /dev/null -e raw_syscalls:*' to capture
system calls. In ns.

Testing environment:

  CPU    : Intel(R) Core(TM) i7-4790 CPU @ 3.60GHz
  Kernel : v4.5.0
                    MEAN         STDVAR
 BASE            800214.950    2853.083
 PRE1           2253846.700    9997.014
 PRE2           2257495.540    8516.293
 POST           2250896.100    8933.921

Where 'BASE' is pure performance without capturing. 'PRE1' is test
result of pure 'v4.5.0' kernel. 'PRE2' is test result before this
patch. 'POST' is test result after this patch. See [4] for the detailed
experimental setup.

Considering the stdvar, this patch doesn't introduce performance
overhead to the fast path.

 [1] http://lkml.iu.edu/hypermail/linux/kernel/1304.1/04584.html
 [2] http://lkml.iu.edu/hypermail/linux/kernel/1307.1/00535.html
 [3] http://lkml.iu.edu/hypermail/linux/kernel/1512.0/01265.html
 [4] http://lkml.kernel.org/g/56F89DCD.1040202@huawei.comSigned-off-by: Wang Nan <wangnan0@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: <acme@kernel.org>
Cc: <pi3orama@163.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Zefan Li <lizefan@huawei.com>
Link: http://lkml.kernel.org/r/1459865478-53413-1-git-send-email-wangnan0@huawei.com
[ Fixed the changelog some more. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

LBR filtering is also supported on the Silvermont and Airmont
microarchitectures. The layout of MSR_LBR_SELECT is the same as Nehalem.
Signed-off-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1460706825-46163-1-git-send-email-kan.liang@intel.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Add perf core PMU support for Intel Goldmont CPU cores:

 - The init code is based on Silvermont.

 - There is a new cache event list, based on the Silvermont cache event list.

 - Goldmont has 32 LBR entries. It also uses new LBRv6 format, which
   report the cycle information using upper 16-bit of the LBR_TO.

 - It's recommended to use CPU_CLK_UNHALTED.CORE_P + NPEBS for precise cycles.

For details, please refer to the latest SDM058:

 http://www.intel.com/content/dam/www/public/us/en/documents/manuals/64-ia-32-architectures-software-developer-vol-3b-part-2-manual.pdfSigned-off-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1460706167-45320-1-git-send-email-kan.liang@intel.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Markus reported that 0 should also disable the throttling we per
Documentation/sysctl/kernel.txt.
Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Fixes: 91a612ee ("perf/core: Fix dynamic interrupt throttle")
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Added one missing Haswell model.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: bp@alien8.de
Cc: hpa@zytor.com
Link: http://lkml.kernel.org/r/1460907809-11897-1-git-send-email-srinivas.pandruvada@linux.intel.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Everything the same as base Skylake, just a new model number.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1460751933-2264-1-git-send-email-andi@firstfloor.orgSigned-off-by: Ingo Molnar <mingo@kernel.org>

One of the branches leading to an error had no debug message emitted,
fix it, the new lines are:

  # perf test -v kallsyms
<SNIP>
  0xffffffff81001000: diff name v: xen_hypercall_set_trap_table k: hypercall_page
  0xffffffff810691f0: diff name v: try_to_free_pud_page k: try_to_free_pmd_page
<SNIP>
  0xffffffff8150bb20: diff name v: wakeup_expire_count_show.part.5 k: wakeup_active_count_show.part.7
  0xffffffff816bc7f0: diff name v: phys_switch_id_show.part.11 k: phys_port_name_show.part.12
  0xffffffff817bbb90: diff name v: __do_softirq k: __softirqentry_text_start
<SNIP>

This in turn exercises another bug, still under investigation, because those
aliases _are_ in kallsyms, with the same name...

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: ab414dcd ("perf test: Fixup aliases checking in the 'vmlinux matches kallsyms' test")
Link: http://lkml.kernel.org/n/tip-5fhea7a54a54gsmagu9obpr4@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Before:

  # perf test -v kallsyms
<SNIP>
  Maps only in vmlinux:
   ffffffff81d5e000-ffffffff81ec3ac8 115e000 [kernel].init.text
   ffffffff81ec3ac8-ffffffffa0000000 12c3ac8 [kernel].exit.text
   ffffffffa0000000-ffffffffa000c000 0 [fjes]
   ffffffffa000c000-ffffffffa0017000 0 [video]
   ffffffffa0017000-ffffffffa001c000 0 [grace]
<SNIP>
   ffffffffa0a7f000-ffffffffa0ba5000 0 [xfs]
   ffffffffa0ba5000-ffffffffffffffff 0 [veth]
  Maps in vmlinux with a different name in kallsyms:
  Maps only in kallsyms:
   ffff880000100000-ffff88001000b000 80000103000 [kernel.kallsyms]
   ffff88001000b000-ffff880100000000 8001000e000 [kernel.kallsyms]
   ffff880100000000-ffffc90000000000 80100003000 [kernel.kallsyms]
<SNIP>
   ffffffffa0000000-ffffffffff600000 7fffa0003000 [kernel.kallsyms]
   ffffffffff600000-ffffffffffffffff 7fffff603000 [kernel.kallsyms]
  test child finished with -1
  ---- end ----
  vmlinux symtab matches kallsyms: FAILED!
  #

After:

  # perf test -v 1
   1: vmlinux symtab matches kallsyms                          :
  --- start ---
  test child forked, pid 7058
  Looking at the vmlinux_path (8 entries long)
  Using /lib/modules/4.6.0-rc1+/build/vmlinux for symbols
  0xffffffff81076870: diff end addr for aesni_gcm_dec v: 0xffffffff810791f2 k: 0xffffffff81076902
  0xffffffff81079200: diff end addr for aesni_gcm_enc v: 0xffffffff8107bb03 k: 0xffffffff81079292
  0xffffffff8107e8d0: diff end addr for aesni_gcm_enc_avx_gen2 v: 0xffffffff81083e76 k: 0xffffffff8107e943
  0xffffffff81083e80: diff end addr for aesni_gcm_dec_avx_gen2 v: 0xffffffff81089611 k: 0xffffffff81083ef3
  0xffffffff81089990: diff end addr for aesni_gcm_enc_avx_gen4 v: 0xffffffff8108e7c4 k: 0xffffffff81089a03
  0xffffffff8108e7d0: diff end addr for aesni_gcm_dec_avx_gen4 v: 0xffffffff810937ef k: 0xffffffff8108e843
  Maps only in vmlinux:
   ffffffff81d5e000-ffffffff81ec3ac8 115e000 [kernel].init.text
   ffffffff81ec3ac8-ffffffffa0000000 12c3ac8 [kernel].exit.text
  Maps in vmlinux with a different name in kallsyms:
  Maps only in kallsyms:
  test child finished with -1
  ---- end ----
 vmlinux symtab matches kallsyms: FAILED!
  #

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: 8e0cf965 ("perf symbols: Add support for reading from /proc/kcore")
Link: http://lkml.kernel.org/n/tip-n6vrwt9t89w8k769y349govx@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Before the support for using /proc/kcore was introduced, the kallsyms
routines used /proc/modules and the first 'perf test' entry expected
finding maps for each module in the system, which is not the case with
the kcore code. Provide a way to ignore kcore files so that the test can
have its expectations met.

Improving the test to cover kcore files as well needs to be done.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ek5urnu103dlhfk4l6pcw041@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

It will already be dealt with generating the syscalltbl.c file in the
x86 arch specific Build files, namely via 'archheaders'.

This fixes the build on !x86 arches, as reported for powerpcle
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: 1b700c99 ("perf tools: Build syscall table .c header from kernel's syscall_64.tbl")
Link: http://lkml.kernel.org/r/20160415212831.GT9056@kernel.org
[ Removed the syscalltbl.o altogether, as per Jiri's suggestion ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The current code is memsetting the 'struct stat' variable 'st' with the size of
'stat' (which turns out to be 1 byte) rather than the size of variable 'sz'.

Committer notes:

sizeof(function) isn't valid, the result depends on the compiler used, with
gcc, enabling pedantic warnings we get:

  $ cat sizeof_function.c
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <unistd.h>
  #include <stdio.h>

  int main(void)
  {
	  printf("sizeof(stat)=%zd, stat=%p\n", sizeof(stat), stat);
	  return 0;
  }
  $ readelf -sW sizeof_function | grep -w stat
      49: 0000000000400630    16 FUNC    WEAK   HIDDEN    13 stat
  $ cc -pedantic sizeof_function.c   -o sizeof_function
  sizeof_function.c: In function ‘main’:
  sizeof_function.c:8:46: warning: invalid application of ‘sizeof’ to a function type [-Wpointer-arith]
    printf("sizeof(stat)=%zd, stat=%p\n", sizeof(stat), stat);
                                              ^
  $ ./sizeof_function
  sizeof(stat)=1, stat=0x400630
  $

  Standard C, section 6.5.3.4:

  "The sizeof operator shall not be applied to an expression that has function
   type or an incomplete type, to the parenthesized name of such a type,
   or to an expression that designates a bit-field member."

  http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1256.pdfSigned-off-by: Colin Ian King <colin.king@canonical.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Fixes: 9b07e27f ("perf inject: Add jitdump mmap injection support")
Link: http://lkml.kernel.org/r/1461020838-9260-1-git-send-email-colin.king@canonical.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The current instructions for setting up an Ubuntu system for using the
export-to-postgresql.py script are incorrect.

The instructions in the script have been updated to work on newer
versions of ubuntu.

-Add missing dependencies to apt-get command:
    python-pyside.qtsql, libqt4-sql-psql
-Add '-s' option to createuser command to force the user to be a
    superuser since the command doesn't prompt as indicated in the
    current instructions.

Tested on: Ubuntu 14.04, Ubuntu 16.04(beta)
Signed-off-by: Chris Phlipot <cphlipot0@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1461056164-14914-3-git-send-email-cphlipot0@gmail.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Merge tag 'perf-urgent-for-mingo-20160418' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

Pull a perf/urgent fix from Arnaldo Carvalho de Melo:

- Fix segfault tracing transactions in Intel PT (Adrian Hunter)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

One more step in the direction of using just callchain_param for
callchain parameters.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-3b1o9kb2dc94zldz0klckti6@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-u701i6qpecgm9jiat52i8l98@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

We have callchain_param.enabled for that.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-silwqjc2t25ls42dsvg28pp5@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

We have callchain_param.enabled, so no need to have something just for
'perf report' to do the same thing.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-wbeisubpualwogwi5u8utnt1@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Trying to move in the direction of using callchain_param for all
callchain parameters, eventually ditching them from symbol_conf.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-kixllia6r26mz45ng056zq7z@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Found by code inspection, while looking at thread__resolve_callchain()
callsites, one had it, the other didn't.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-6r8i2afd3523thuuaxl39yhk@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-5i07ivw1yjsweb7gztr255jd@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Tracing a workload that uses transactions gave a seg fault as follows:

  perf record -e intel_pt// workload
  perf report
  Program received signal SIGSEGV, Segmentation fault.
  0x000000000054b58c in intel_pt_reset_last_branch_rb (ptq=0x1a36110)
  	at util/intel-pt.c:929
  929 ptq->last_branch_rb->nr = 0;
  (gdb) p ptq->last_branch_rb
  $1 = (struct branch_stack *) 0x0
  (gdb) up
  1148 intel_pt_reset_last_branch_rb(ptq);
  (gdb) l
  1143 if (ret)
  1144 pr_err("Intel Processor Trace: failed to deliver transaction event
  1145 ret);
  1146
  1147 if (pt->synth_opts.callchain)
  1148 intel_pt_reset_last_branch_rb(ptq);
  1149
  1150 return ret;
  1151 }
  1152
  (gdb) p pt->synth_opts.callchain
  $2 = true
  (gdb)
  (gdb) bt
   #0 0x000000000054b58c in intel_pt_reset_last_branch_rb (ptq=0x1a36110)
   #1 0x000000000054c1e0 in intel_pt_synth_transaction_sample (ptq=0x1a36110)
   #2 0x000000000054c5b2 in intel_pt_sample (ptq=0x1a36110)

Caused by checking the 'callchain' flag when it should have been the
'last_branch' flag.  Fix that.
Reported-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: stable@vger.kernel.org # v4.4+
Fixes: f14445ee ("perf intel-pt: Support generating branch stack")
Link: http://lkml.kernel.org/r/1460977068-11566-1-git-send-email-adrian.hunter@intel.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Pull device mapper fix from Mike Snitzer:
 "Fix for earlier 4.6-rc4 stable@ commit that introduced improper use of
  write lock in cmd_read_lock() -- due to cut-n-paste gone awry (and
  sparse didn't catch it)"

* tag 'dm-4.6-fix-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm cache metadata: fix cmd_read_lock() acquiring write lock

Commit 9567366f ("dm cache metadata: fix READ_LOCK macros and
cleanup WRITE_LOCK macros") uses down_write() instead of down_read() in
cmd_read_lock(), yet up_read() is used to release the lock in
READ_UNLOCK().  Fix it.

Fixes: 9567366f ("dm cache metadata: fix READ_LOCK macros and cleanup WRITE_LOCK macros")
Cc: stable@vger.kernel.org
Signed-off-by: Ahmed Samy <f.fallen45@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Pull char/misc fixes from Greg KH:
 "Here are some small char/misc driver fixes for 4.6-rc4.  Full details
  are in the shortlog, nothing major here.

  These have all been in linux-next for a while with no reported issues"

* tag 'char-misc-4.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  lkdtm: do not leak free page on kmalloc failure
  lkdtm: fix memory leak of base
  lkdtm: fix memory leak of val
  extcon: palmas: Drop stray IRQF_EARLY_RESUME flag

Pull misc fixes from Greg KH:
 "Here are three small fixes for 4.6-rc4.

  Two fix up some lz4 issues with big endian systems, and the remaining
  one resolves a minor debugfs issue that was reported.

  All have been in linux-next with no reported issues"

* tag 'driver-core-4.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  lib: lz4: cleanup unaligned access efficiency detection
  lib: lz4: fixed zram with lz4 on big endian machines
  debugfs: Make automount point inodes permanently empty

Pull USB driver fixes from Greg KH:
 "Here are some small USB fixes for 4.6-rc4.

  Mostly xhci fixes for reported issues, a UAS bug that has hit a number
  of people, including stable tree users, and a few other minor things.

  All have been in linux-next for a while with no reported issues"

* tag 'usb-4.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: hcd: out of bounds access in for_each_companion
  USB: uas: Add a new NO_REPORT_LUNS quirk
  USB: uas: Limit qdepth at the scsi-host level
  doc: usb: Fix typo in gadget_multi documentation
  usb: host: xhci-plat: Make enum xhci_plat_type start at a non zero value
  xhci: fix 10 second timeout on removal of PCI hotpluggable xhci controllers
  usb: xhci: fix wild pointers in xhci_mem_cleanup
  usb: host: xhci-plat: fix cannot work if R-Car Gen2/3 run on above 4GB phys
  usb: host: xhci: add a new quirk XHCI_NO_64BIT_SUPPORT
  xhci: resume USB 3 roothub first
  usb: xhci: applying XHCI_PME_STUCK_QUIRK to Intel BXT B0 host
  cdc-acm: fix crash if flushed with nothing buffered

Pull dmaengine fixes from Vinod Koul:
 "This time we have some odd fixes in hsu, edma, omap and xilinx.

  Usual fixes and nothing special"

* tag 'dmaengine-fix-4.6-rc4' of git://git.infradead.org/users/vkoul/slave-dma:
  dmaengine: dw: fix master selection
  dmaengine: edma: special case slot limit workaround
  dmaengine: edma: Remove dynamic TPTC power management feature
  dmaengine: vdma: don't crash when bad channel is requested
  dmaengine: omap-dma: Do not suppress interrupts for memcpy
  dmaengine: omap-dma: Fix polled channel completion detection and handling
  dmaengine: hsu: correct use of channel status register
  dmaengine: hsu: correct residue calculation of active descriptor
  dmaengine: hsu: set HSU_CH_MTSR to memory width

Pull locking fixlet from Ingo Molnar:
 "Fixes a build warning on certain Kconfig combinations"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/lockdep: Fix print_collision() unused warning

Pull EFI fix from Ingo Molnar:
 "An arm64 boot crash fix"

* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi/arm64: Don't apply MEMBLOCK_NOMAP to UEFI memory map mapping

The variable is initialized and then conditionally set to a different
value, but not used when DWARF unwinding is not available, bummer, write
1000 times: "Run make -C tools/perf build-test"...

  builtin-trace.c: In function ‘cmd_trace’:
  builtin-trace.c:3112:6: error: variable ‘max_stack_user_set’ set but not
  used [-Werror=unused-but-set-variable]
    bool max_stack_user_set = true;
        ^
  cc1: all warnings being treated as err

Fix it by marking it as __maybe_unused.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: 05614993 ("perf trace: Make --(min,max}-stack imply "--call-graph dwarf"")
Link: http://lkml.kernel.org/n/tip-85r40c5hhv6jnmph77l1hgsr@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>