We want just the script output, not internal details about the record phase.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

If we include a newline character in the string argument to perror()
then the output will be split across two lines like so,

    Unable to read perf file descriptor
    : No space left on device

Deleting the newline character prints a much more readable error,

    Unable to read perf file descriptor: No space left on device

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <89e77b54659bc3798b23a5596c2debb7f6f4cf27.1283010281.git.matt@console-pimps.org>
Signed-off-by: NMatt Fleming <matt@console-pimps.org>
Signed-off-by: NArnaldo Carvalho de Melo <acme@felicio.ghostprotocols.net>

Where we don't have the audit.MACH_ARMEB constant.

Cc: David S. Miller <davem@davemloft.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

. Print message at script start telling how to get te summary
. Print the syscall names
. Accept both pid (if numeric) or COMM name

Now it looks like this:

[root@emilia tmp]# perf trace syscall-counts-by-pid
Press control+C to stop and show the summary
^C
syscall events by comm/pid:

comm [pid]/syscalls                            count
----------------------------------------  ----------

automount [1670]
  futex                                            2

sshd [2322]
  rt_sigprocmask                                   4
  select                                           2
  write                                            1
  read                                             1

perf [15178]
  read                                          2506
  open                                           794
  close                                          769
  write                                          240
  getdents                                       112
  lseek                                           16
  stat                                             9
  perf_counter_open                                5
  fcntl                                            5
  mmap                                             5
  statfs                                           2

perf [15179]
  read                                         56701
  open                                           499
  stat                                           176
  fstat                                          149
  close                                          109
  mmap                                            98
  brk                                             75
  rt_sigaction                                    66
  munmap                                          42
  mprotect                                        24
  lstat                                            7
  lseek                                            5
  getdents                                         4
  ioctl                                            3
  readlink                                         2
  futex                                            1
  statfs                                           1
  getegid                                          1
  geteuid                                          1
  getgid                                           1
  getuid                                           1
  getrlimit                                        1
  fcntl                                            1
  uname                                            1
  write                                            1
[root@emilia tmp]# fg
-bash: fg: current: no such job
[root@emilia tmp]# perf trace syscall-counts-by-pid 2322
Press control+C to stop and show the summary
^C
syscall events by comm/pid:

comm [pid]/syscalls                            count
----------------------------------------  ----------

sshd [2322]
  rt_sigprocmask                                   4
  select                                           2
  write                                            1
  read                                             1
[root@emilia tmp]# perf trace syscall-counts-by-pid sshd
Press control+C to stop and show the summary
^C
syscall events for sshd:

comm [pid]/syscalls                            count
----------------------------------------  ----------

sshd [2322]
  rt_sigprocmask                                   4
  select                                           2
  write                                            1
  read                                             1
[root@emilia tmp]#

Cc: David S. Miller <davem@davemloft.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

[root@emilia tmp]# perf trace sctop 1
syscall events:

event                                          count
----------------------------------------  ----------
read                                          215400
futex                                           4029
write                                            376
brk                                               33
rt_sigprocmask                                    24
select                                            17
lseek                                              2
fsync                                              1
^C[root@emilia tmp]#

Cc: David S. Miller <davem@davemloft.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

. Print message at script start telling how to get te summary
. Print the syscall name

Now it looks like this:

[root@emilia ~]# perf trace syscall-counts
Press control+C to stop and show the summary
^C
syscall events:

event                                          count
----------------------------------------  -----------
read                                          102752
open                                            1293
close                                            878
write                                            319
stat                                             185
fstat                                            149
getdents                                         116
mmap                                              98
brk                                               80
rt_sigaction                                      66
munmap                                            42
mprotect                                          24
lseek                                             21
lstat                                              7
rt_sigprocmask                                     4
futex                                              3
statfs                                             3
ioctl                                              3
readlink                                           2
select                                             2
getegid                                            1
geteuid                                            1
getgid                                             1
getuid                                             1
getrlimit                                          1
fcntl                                              1
uname                                              1
[root@emilia ~]#

Cc: David S. Miller <davem@davemloft.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

. Print message at script start telling how to get te summary
. Print the syscall name using the audit-lib-python package, if
  installed
. Print the errno string
. Accept both pid (if numeric) or COMM name

Now it looks like this:

[root@emilia ~]# perf trace failed-syscalls-by-pid
Press control+C to stop and show the summary
^C
syscall errors:

comm [pid]                           count
------------------------------  ----------

automount [1670]
  syscall: futex
    err = ETIMEDOUT                     39

irqbalance [1462]
  syscall: openat
    err = ENOENT                         4

perf [7888]
  syscall: lseek
    err = ESPIPE                         1
  syscall: open
    err = ENOENT                        24

perf [7889]
  syscall: ioctl
    err = EINVAL                         1
  syscall: readlink
    err = EINVAL                         2
  syscall: open
    err = ENOENT                       389
  syscall: stat
    err = ENOENT                       141
  syscall: lseek
    err = ESPIPE                         3
[root@emilia ~]#

[root@emilia ~]# perf trace failed-syscalls-by-pid 1670
Press control+C to stop and show the summary
^C
syscall errors:

comm [pid]                           count
------------------------------  ----------

automount [1670]
  syscall: futex
    err = ETIMEDOUT                      2
[root@emilia ~]#
[root@emilia ~]#
[root@emilia ~]#
[root@emilia ~]# perf trace failed-syscalls-by-pid automount
Press control+C to stop and show the summary
^C
syscall errors for automount:

comm [pid]                           count
------------------------------  ----------

automount [1669]
  syscall: futex
    err = ETIMEDOUT                      1

automount [1670]
  syscall: futex
    err = ETIMEDOUT                      5
[root@emilia ~]#

Cc: David S. Miller <davem@davemloft.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Fixing the following error on 32-bit arches:

util/probe-finder.c: In function ‘line_range_search_cb’:
util/probe-finder.c:1734: error: format ‘%lx’ expects type ‘long
unsigned int’, but argument 3 has type ‘Dwarf_Off’
Reported-by: NIngo Molnar <mingo@elte.hu>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
LKML-Reference: <new-submission>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The extension starts with the last dot in the name, not the first.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1286723462.2955.206.camel@localhost>
Signed-off-by: NBen Hutchings <ben@decadent.org.uk>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Set $PERF_EXEC_PATH before starting the record and report scripts, and
make them use it where necessary.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1286723403.2955.205.camel@localhost>
Signed-off-by: NBen Hutchings <ben@decadent.org.uk>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Existing documentation doesn't discuss event modifiers, so add a description of
what's currently possible to the documentation of perf-list.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Robert Richter <robert.richter@amd.com>
LKML-Reference: <1287107460-12112-1-git-send-email-sonnyrao@linux.vnet.ibm.com>
Signed-off-by: NSonny Rao <sonnyrao@linux.vnet.ibm.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

We wrap it in libslang.h because we need to deal with older slang release
where HAVE_LONG_LONG is referenced as:

So we need to define it.

Noticed when rebuilding the perf tools on a RHEL5 machine.

Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephane Eranian <eranian@google.com>
LKML-Reference: <new-submission>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Add basic module probe support on perf probe. This introduces "--module
<MODNAME>" option to perf probe for putting probes and showing lines and
variables in the given module.

Currently, this supports only probing on running modules.  Supporting off-line
module probing is the next step.

e.g.)
[show lines]
 # ./perf probe --module drm -L drm_vblank_info
<drm_vblank_info:0>
      0  int drm_vblank_info(struct seq_file *m, void *data)
      1  {
                struct drm_info_node *node = (struct drm_info_node *) m->private
      3         struct drm_device *dev = node->minor->dev;
 ...
[show vars]
 # ./perf probe --module drm -V drm_vblank_info:3
Available variables at drm_vblank_info:3
        @<drm_vblank_info+20>
                (unknown_type)  data
                struct drm_info_node*   node
                struct seq_file*        m
[put a probe]
 # ./perf probe --module drm drm_vblank_info:3 node m
Add new event:
  probe:drm_vblank_info (on drm_vblank_info:3 with node m)

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

        perf record -e probe:drm_vblank_info -aR sleep 1
[list probes]
 # ./perf probe -l
probe:drm_vblank_info (on drm_vblank_info:3@drivers/gpu/drm/drm_info.c with ...

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20101021101341.3542.71638.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Add --externs for allowing --vars to show accessible global (externally
defined) variables from a given probe point too.

This will give you a hint which globals can be accessible from the probe point.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20101021101335.3542.31003.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Just change the order of function arguments for ease of read; moving optional
bool flag to the last.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20101021101329.3542.51200.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Add -V (--vars) option for listing accessible local variables at given probe
point. This will help finding which local variables are available for event
arguments.

e.g.)
 # perf probe -V call_timer_fn:23
 Available variables at call_timer_fn:23
         @<run_timer_softirq+345>
                 function_type*  fn
                 int     preempt_count
                 long unsigned int       data
                 struct list_head        work_list
                 struct list_head*       head
                 struct timer_list*      timer
                 struct tvec_base*       base

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20101021101323.3542.40282.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Allow users to set external defined global variables as event arguments (e.g.
jiffies).

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <20101021101316.3542.1999.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Fix to check the die's address and search into the die only if it has given
address.

This will avoid finding wrong variables in wrong basic block.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <20101021101309.3542.46434.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Fix to get the actual type die of variables by using dwarf_attr_integrate()
which gets attribute from die even if the type die is connected by
DW_AT_abstract_origin.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <20101021101302.3542.38549.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

With the addition of trace_softirq_raise() the softirq tracepoint got
even more convoluted. Why the tracepoints take two pointers to assign
an integer is beyond my comprehension.

But adding an extra case which treats the first pointer as an unsigned
long when the second pointer is NULL including the back and forth
type casting is just horrible.

Convert the softirq tracepoints to take a single unsigned int argument
for the softirq vector number and fix the call sites.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
LKML-Reference: <alpine.LFD.2.00.1010191428560.6815@localhost6.localdomain6>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
Acked-by: mathieu.desnoyers@efficios.com
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>

Merge branch 'tip/perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core

The function start_func_tracer() was incorrectly added in the
 #ifdef CONFIG_FUNCTION_TRACER condition, but is still used even
when function tracing is not enabled.

The calls to register_ftrace_function() and register_ftrace_graph()
become nops (and their arguments are even ignored), thus there is
no reason to hide start_func_tracer() when function tracing is
not enabled.
Reported-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Remove a couple of pointless header file includes.
Fixes a compile bug caused by header file include dependencies with
"irq: Add tracepoint to softirq_raise" within linux-next.
Reported-by: NSachin Sant <sachinp@in.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
[ cherry-picked from the s390 tree to fix "2bf2160d: irq: Add tracepoint to softirq_raise" ]
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Ugly #include dependencies. We need to have local_softirq_pending()
defined before it gets used in <linux/interrupt.h>. But <asm/hardirq.h>
provides the definition *after* this #include chain:
  <linux/irq.h>
    <asm/irq.h>
      <asm/hw_irq.h>
        <linux/interrupt.h>
Signed-off-by: NTony Luck <tony.luck@intel.com>
[ cherry-picked from the ia64 tree to fix "2bf2160d: irq: Add tracepoint to softirq_raise" ]
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Commit c3f00c70 ("perf: Separate find_get_context() from event
initialization") changed the generic perf_event code to call
perf_event_alloc, which calls the arch-specific event_init code,
before looking up the context for the new event.  Unfortunately,
power_pmu_event_init uses event->ctx->task to see whether the
new event is a per-task event or a system-wide event, and thus
crashes since event->ctx is NULL at the point where
power_pmu_event_init gets called.

(The reason it needs to know whether it is a per-task event is
because there are some hardware events on Power systems which
only count when the processor is not idle, and there are some
fixed-function counters which count such events.  For example,
the "run cycles" event counts cycles when the processor is not
idle.  If the user asks to count cycles, we can use "run cycles"
if this is a per-task event, since the processor is running when
the task is running, by definition.  We can't use "run cycles"
if the user asks for "cycles" on a system-wide counter.)

Fortunately the information we need is in the
event->attach_state field, so we just use that instead.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20101019055535.GA10398@drongo>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Reported-by: NAlexey Kardashevskiy <aik@au1.ibm.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Merge branch 'tip/perf/recordmcount-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core

When DYNAMIC_FTRACE is enabled and we use the C version of recordmcount,
all objects are run through the recordmcount program to create a
separate section that stores all the callers of mcount.

The build process has a special file: scripts/mod/empty.o. This is
built from empty.c which is literally an empty file (except for a
single comment). This file is used to find information about the target
elf format, like endianness and word size.

The problem comes up when we need to build recordmcount. The
build process requires that empty.o is built first. The build rules
for empty.o will try to execute recordmcount on the empty.o file.
We get an error that recordmcount does not exist.

To avoid this recursion, the build file will skip running recordmcount
if the file that it is building is script/mod/empty.o.

[ extra comment Suggested-by: Sam Ravnborg <sam@ravnborg.org> ]
Reported-by: NIngo Molnar <mingo@elte.hu>
Tested-by: NIngo Molnar <mingo@elte.hu>
Cc: Michal Marek <mmarek@suse.cz>
Cc: linux-kbuild@vger.kernel.org
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

The use of the JUMP_LABEL() construct ends up creating endless silly
wrappers, create a higher level construct to reduce this clutter.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Acked-by: NFrederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Trades a call + conditional + ret for an unconditional jmp.
Acked-by: NFrederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101014203625.501657727@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Add an interface to allow usage of jump_labels with atomic counters.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NFrederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20101014203625.501657727@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Now that there's still only a few users around, rename things to make
them more consistent.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101014203625.448565169@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

hw_breakpoint creation needs to account stuff per-task to ensure there
is always sufficient hardware resources to back these things due to
ptrace.

With the perf per pmu context changes the event initialization no
longer has access to the event context, for the simple reason that we
need to first find the pmu (result of initialization) before we can
find the context.

This makes hw_breakpoints unhappy, because it can no longer do per
task accounting, cure this by frobbing a task pointer in the event::hw
bits for now...
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20101014203625.391543667@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

So that we can pass the task pointer to the event allocation, so that
we can use task associated data during event initialization.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101014203625.340789919@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Currently it looks like find_lively_task_by_vpid() takes a task ref
and relies on find_get_context() to drop it.

The problem is that perf_event_create_kernel_counter() shouldn't be
dropping task refs.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NFrederic Weisbecker <fweisbec@gmail.com>
Acked-by: NMatt Helsley <matthltc@us.ibm.com>
LKML-Reference: <20101014203625.278436085@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Matt found we trigger the WARN_ON_ONCE() in perf_group_attach() when we take
the move_group path in perf_event_open().

Since we cannot de-construct the group (we rely on it to move the events), we
have to simply ignore the double attach. The group state is context invariant
and doesn't need changing.
Reported-by: NMatt Fleming <matt@console-pimps.org>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1287135757.29097.1368.camel@twins>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Provide a mechanism that allows running code in IRQ context. It is
most useful for NMI code that needs to interact with the rest of the
system -- like wakeup a task to drain buffers.

Perf currently has such a mechanism, so extract that and provide it as
a generic feature, independent of perf so that others may also
benefit.

The IRQ context callback is generated through self-IPIs where
possible, or on architectures like powerpc the decrementer (the
built-in timer facility) is set to generate an interrupt immediately.

Architectures that don't have anything like this get to do with a
callback from the timer tick. These architectures can call
irq_work_run() at the tail of any IRQ handlers that might enqueue such
work (like the perf IRQ handler) to avoid undue latencies in
processing the work.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NKyle McMartin <kyle@mcmartin.ca>
Acked-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
[ various fixes ]
Signed-off-by: NHuang Ying <ying.huang@intel.com>
LKML-Reference: <1287036094.7768.291.camel@yhuang-dev>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The group_sched_in() function uses a transactional approach to schedule
a group of events. In a group, either all events can be scheduled or
none are. To schedule each event in, the function calls event_sched_in().
In case of error, event_sched_out() is called on each event in the group.

The problem is that event_sched_out() does not completely cancel the
effects of event_sched_in(). Furthermore event_sched_out() changes the
state of the event as if it had run which is not true is this particular
case.

Those inconsistencies impact time tracking fields and may lead to events
in a group not all reporting the same time_enabled and time_running values.
This is demonstrated with the example below:

$ task -eunhalted_core_cycles,baclears,baclears -e unhalted_core_cycles,baclears,baclears sleep 5
1946101 unhalted_core_cycles (32.85% scaling, ena=829181, run=556827)
  11423 baclears (32.85% scaling, ena=829181, run=556827)
   7671 baclears (0.00% scaling, ena=556827, run=556827)

2250443 unhalted_core_cycles (57.83% scaling, ena=962822, run=405995)
  11705 baclears (57.83% scaling, ena=962822, run=405995)
  11705 baclears (57.83% scaling, ena=962822, run=405995)

Notice that in the first group, the last baclears event does not
report the same timings as its siblings.

This issue comes from the fact that tstamp_stopped is updated
by event_sched_out() as if the event had actually run.

To solve the issue, we must ensure that, in case of error, there is
no change in the event state whatsoever. That means timings must
remain as they were when entering group_sched_in().

To do this we defer updating tstamp_running until we know the
transaction succeeded. Therefore, we have split event_sched_in()
in two parts separating the update to tstamp_running.

Similarly, in case of error, we do not want to update tstamp_stopped.
Therefore, we have split event_sched_out() in two parts separating
the update to tstamp_stopped.

With this patch, we now get the following output:

$ task -eunhalted_core_cycles,baclears,baclears -e unhalted_core_cycles,baclears,baclears sleep 5
2492050 unhalted_core_cycles (71.75% scaling, ena=1093330, run=308841)
  11243 baclears (71.75% scaling, ena=1093330, run=308841)
  11243 baclears (71.75% scaling, ena=1093330, run=308841)

1852746 unhalted_core_cycles (0.00% scaling, ena=784489, run=784489)
   9253 baclears (0.00% scaling, ena=784489, run=784489)
   9253 baclears (0.00% scaling, ena=784489, run=784489)

Note that the uneven timing between groups is a side effect of
the process spending most of its time sleeping, i.e., not enough
event rotations (but that's a separate issue).
Signed-off-by: NStephane Eranian <eranian@google.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4cb86b4c.41e9d80a.44e9.3e19@mx.google.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

PERF_COUNT_HW_CACHE_DTLB:READ:MISS had a bogus umask value of 0 which
counts nothing. Needed to be 0x7 (to count all possibilities).

PERF_COUNT_HW_CACHE_ITLB:READ:MISS had a bogus umask value of 0 which
counts nothing. Needed to be 0x3 (to count all possibilities).
Signed-off-by: NStephane Eranian <eranian@google.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Robert Richter <robert.richter@amd.com>
Cc: <stable@kernel.org> # as far back as it applies
LKML-Reference: <4cb85478.41e9d80a.44e2.3f00@mx.google.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

You can only call update_context_time() when the context
is active, i.e., the thread it is attached to is still running.

However, perf_event_read() can be called even when the context
is inactive, e.g., user read() the counters. The call to
update_context_time() must be conditioned on the status of
the context, otherwise, bogus time_enabled, time_running may
be returned. Here is an example on AMD64. The task program
is an example from libpfm4. The -p prints deltas every 1s.

$ task -p -e cpu_clk_unhalted sleep 5
    2,266,610 cpu_clk_unhalted (0.00% scaling, ena=2,158,982, run=2,158,982)
	    0 cpu_clk_unhalted (0.00% scaling, ena=2,158,982, run=2,158,982)
	    0 cpu_clk_unhalted (0.00% scaling, ena=2,158,982, run=2,158,982)
	    0 cpu_clk_unhalted (0.00% scaling, ena=2,158,982, run=2,158,982)
	    0 cpu_clk_unhalted (0.00% scaling, ena=2,158,982, run=2,158,982)
5,242,358,071 cpu_clk_unhalted (99.95% scaling, ena=5,000,359,984, run=2,319,270)

Whereas if you don't read deltas, e.g., no call to perf_event_read() until
the process terminates:

$ task -e cpu_clk_unhalted sleep 5
    2,497,783 cpu_clk_unhalted (0.00% scaling, ena=2,376,899, run=2,376,899)

Notice that time_enable, time_running are bogus in the first example
causing bogus scaling.

This patch fixes the problem, by conditionally calling update_context_time()
in perf_event_read().
Signed-off-by: NStephane Eranian <eranian@google.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: stable@kernel.org
LKML-Reference: <4cb856dc.51edd80a.5ae0.38fb@mx.google.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>