Before this patch this message would very briefly appear on the
screen and then the screen would get updates only on the top,
for number of interrupts received, etc, but no annotation would
be performed:

 [root@doppio linux-2.6-tip]# perf top -s n_tty_write > /tmp/bla
 objdump: '[kernel.kallsyms]': No such file

Now this is what the user gets:

 [root@doppio linux-2.6-tip]# perf top -s n_tty_write
 Can't annotate n_tty_write: No vmlinux file was found in the
 path: [0] vmlinux
 [1] /boot/vmlinux
 [2] /boot/vmlinux-2.6.33-rc5
 [3] /lib/modules/2.6.33-rc5/build/vmlinux
 [4] /usr/lib/debug/lib/modules/2.6.33-rc5/vmlinux
 [root@doppio linux-2.6-tip]#

This bug was introduced when we added automatic search for
vmlinux, before that time the user had to specify a vmlinux
file.
Reported-by: NDavid S. Miller <davem@davemloft.net>
Reported-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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: <stable@kernel.org>
LKML-Reference: <1268664418-28328-2-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

When forking its target, perf record can capture data from
before the target application is started.  Perf stat uses the
enable_on_exec flag in the event attributes to keep from
displaying events from before the target program starts, this
patch adds the same functionality to perf record when it is will
fork the target process.
Signed-off-by: NEric B Munson <ebmunson@us.ibm.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1268664418-28328-1-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This should turn on instruction counting on P4s, which was missing in
the first version of the new PMU driver.

It's inaccurate for now, we still need dependant event to tag mops
before we can count them precisely. The result is that the number of
instruction may be lifted up.
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: NLin Ming <ming.m.lin@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <1268629102.3355.11.camel@minggr.sh.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Ingo reported:

 |
 | There's a build failure on -tip with the P4 driver, on UP 32-bit, if
 | PERF_EVENTS is enabled but UP_APIC is disabled:
 |
 | arch/x86/built-in.o: In function `p4_pmu_handle_irq':
 | perf_event.c:(.text+0xa756): undefined reference to `apic'
 | perf_event.c:(.text+0xa76e): undefined reference to `apic'
 |

So we have to unmask LVTPC only if we're configured to have one.
Reported-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
CC: Lin Ming <ming.m.lin@intel.com>
CC: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20100313081116.GA5179@lenovo>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The use_browser needs to be in a file that is always built and
also we need a browser__show_help stub in that case.
Reported-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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>
LKML-Reference: <1268438710-32697-1-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Merge reason: The new P4 driver is stable and ready now for more
              testing.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

[root@doppio ~]# perf report -i newt.data | head -10
  # Samples: 11999679868
  #
  # Overhead  Command                  Shared Object  Symbol
  # ........  .......  .............................  ......
  #
      63.61%     perf  libslang.so.2.1.4              [.] SLsmg_write_chars
       6.30%     perf  perf                           [.] symbols__find
       2.19%     perf  libnewt.so.0.52.10             [.] newtListboxAppendEntry
       2.08%     perf  libslang.so.2.1.4              [.] SLsmg_write_chars@plt
       1.99%     perf  libc-2.10.2.so                 [.] _IO_vfprintf_internal
  [root@doppio ~]#

Not good, the newt form for report works, but slang has to eat
the cost of the additional callgraph lines everytime it prints a
line, and the callgraph doesn't appear on the screen, so move
the callgraph printing to a separate function and don't use it
in newt.c.

Newt tree widgets are being investigated to properly support
callgraphs, but till that gets merged, lets remove this huge
overhead and show at least the symbol overheads for a callgraph
rich perf.data with good performance.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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>
LKML-Reference: <1268408808-13595-2-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

For consistency, use the newt API more fully.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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>
LKML-Reference: <1268408808-13595-1-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

These are keys people expect when pressed to exit the current
widget, so have associate all of them to this semantic.
Suggested-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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>
LKML-Reference: <1268401692-9361-1-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Newt has widespread availability and provides a rather simple
API as can be seen by the size of this patch.

The work needed to support it will benefit other frontends too.

In this initial patch it just checks if the output is a tty, if
not it falls back to the previous behaviour, also if
newt-devel/libnewt-dev is not installed the previous behaviour
is maintaned.

Pressing enter on a symbol will annotate it, ESC in the
annotation window will return to the report symbol list.

More work will be done to remove the special casing in
color_fprintf, stop using fmemopen/FILE in the printing of
hist_entries, etc.

Also the annotation doesn't need to be done via spawning "perf
annotate" and then browsing its output, we can do better by
calling directly the builtin-annotate.c functions, that would
then be moved to tools/perf/util/annotate.c and shared with perf
top, etc

But lets go by baby steps, this patch already improves perf
usability by allowing to quickly do annotations on symbols from
the report screen and provides a first experimentation with
libnewt/TUI integration of tools.

Tested on RHEL5 and Fedora12 X86_64 and on Debian PARISC64 to
browse a perf.data file collected on a Fedora12 x86_64 box.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Avi Kivity <avi@redhat.com>
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>
LKML-Reference: <1268349164-5822-5-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

We need those to properly size the browser widht in the newt
TUI.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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>
LKML-Reference: <1268349164-5822-4-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Just like we do for pr_debug, so that we can have a single point
where to redirect to the currently used output system, be it
stdio or newt.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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>
LKML-Reference: <1268349164-5822-3-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Will be used by the newt code too.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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>
LKML-Reference: <1268349164-5822-2-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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>
LKML-Reference: <1268349164-5822-1-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Merge reason: We want to queue up a dependent patch.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

In case of not assigned x86_pmu and software events NULL dereference may
being hit via x86_pmu::schedule_events method.

Fix it by checking if x86_pmu is initialized at all.
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Cc: Lin Ming <ming.m.lin@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20100311215016.GG25162@lenovo>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

[acme@mica linux-2.6-tip]$ perf record -a -f
   Fatal: Permission error - are you root?
 	 Consider tweaking /proc/sys/kernel/perf_event_paranoid.

 [acme@mica linux-2.6-tip]$
Suggested-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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>
LKML-Reference: <1268333592-30872-2-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Fixing this symptom:

 [acme@mica linux-2.6-tip]$ perf record -a -f
   Fatal: Permission error - are you root?

 Bus error
 [acme@mica linux-2.6-tip]$

I.e. if for some reason no data is collected, in this case a non
root user trying to do systemwide profiling, no data will be
collected, and then we end up trying to mmap a zero sized file
and access the file header, b00m.
Reported-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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: <stable@kernel.org>
LKML-Reference: <1268333592-30872-1-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The netburst PMU is way different from the "architectural
perfomance monitoring" specification that current CPUs use.
P4 uses a tuple of ESCR+CCCR+COUNTER MSR registers to handle
perfomance monitoring events.

A few implementational details:

1) We need a separate x86_pmu::hw_config helper in struct
   x86_pmu since register bit-fields are quite different from P6,
   Core and later cpu series.

2) For the same reason is a x86_pmu::schedule_events helper
   introduced.

3) hw_perf_event::config consists of packed ESCR+CCCR values.
   It's allowed since in reality both registers only use a half
   of their size. Of course before making a real write into a
   particular MSR we need to unpack the value and extend it to
   a proper size.

4) The tuple of packed ESCR+CCCR in hw_perf_event::config
   doesn't describe the memory address of ESCR MSR register
   so that we need to keep a mapping between these tuples
   used and available ESCR (various P4 events may use same
   ESCRs but not simultaneously), for this sake every active
   event has a per-cpu map of hw_perf_event::idx <--> ESCR
   addresses.

5) Since hw_perf_event::idx is an offset to counter/control register
   we need to lift X86_PMC_MAX_GENERIC up, otherwise kernel
   strips it down to 8 registers and event armed may never be turned
   off (ie the bit in active_mask is set but the loop never reaches
   this index to check), thanks to Peter Zijlstra

Restrictions:

 - No cascaded counters support (do we ever need them?)
 - No dependent events support (so PERF_COUNT_HW_INSTRUCTIONS
   doesn't work for now)
 - There are events with same counters which can't work simultaneously
   (need to use intersected ones due to broken counter 1)
 - No PERF_COUNT_HW_CACHE_ events yet

Todo:

 - Implement dependent events
 - Need proper hashing for event opcodes (no linear search, good for
   debugging stage but not in real loads)
 - Some events counted during a clock cycle -- need to set threshold
   for them and count every clock cycle just to get summary statistics
   (ie to behave the same way as other PMUs do)
 - Need to swicth to use event_constraints
 - To support RAW events we need to encode a global list of P4 events
   into p4_templates
 - Cache events need to be added

Event support status matrix:

 Event			status
 -----------------------------
 cycles			works
 cache-references	works
 cache-misses		works
 branch-misses		works
 bus-cycles		partially (does not work on 64bit cpu with HT enabled)
 instruction		doesnt work (needs dependent event [mop tagging])
 branches		doesnt work
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: NLin Ming <ming.m.lin@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20100311165439.GB5129@lenovo>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This patch is an optimization in perf_event_task_sched_in() to avoid
scheduling the events twice in a row.

Without it, the perf_disable()/perf_enable() pair is invoked twice,
thereby pinned events counts while scheduling flexible events and we go
throuh hw_perf_enable() twice.

By encapsulating, the whole sequence into perf_disable()/perf_enable() we
ensure, hw_perf_enable() is going to be invoked only once because of the
refcount protection.
Signed-off-by: NStephane Eranian <eranian@google.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1268288765-5326-1-git-send-email-eranian@google.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Export perf_trace_regs and perf_arch_fetch_caller_regs since module will
use these.
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
[ use EXPORT_PER_CPU_SYMBOL_GPL() ]
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4B989C1B.2090407@cn.fujitsu.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

What happens is that we schedule badly like:

<...>-1987  [019]   280.252808: x86_pmu_start: event-46/1300c0: idx: 0
<...>-1987  [019]   280.252811: x86_pmu_start: event-47/1300c0: idx: 1
<...>-1987  [019]   280.252812: x86_pmu_start: event-48/1300c0: idx: 2
<...>-1987  [019]   280.252813: x86_pmu_start: event-49/1300c0: idx: 3
<...>-1987  [019]   280.252814: x86_pmu_start: event-50/1300c0: idx: 32
<...>-1987  [019]   280.252825: x86_pmu_stop: event-46/1300c0: idx: 0
<...>-1987  [019]   280.252826: x86_pmu_stop: event-47/1300c0: idx: 1
<...>-1987  [019]   280.252827: x86_pmu_stop: event-48/1300c0: idx: 2
<...>-1987  [019]   280.252828: x86_pmu_stop: event-49/1300c0: idx: 3
<...>-1987  [019]   280.252829: x86_pmu_stop: event-50/1300c0: idx: 32
<...>-1987  [019]   280.252834: x86_pmu_start: event-47/1300c0: idx: 1
<...>-1987  [019]   280.252834: x86_pmu_start: event-48/1300c0: idx: 2
<...>-1987  [019]   280.252835: x86_pmu_start: event-49/1300c0: idx: 3
<...>-1987  [019]   280.252836: x86_pmu_start: event-50/1300c0: idx: 32
<...>-1987  [019]   280.252837: x86_pmu_start: event-51/1300c0: idx: 32 *FAIL*

This happens because we only iterate the n_running events in the first
pass, and reset their index to -1 if they don't match to force a
re-assignment.

Now, in our RR example, n_running == 0 because we fully unscheduled, so
event-50 will retain its idx==32, even though in scheduling it will have
gotten idx=0, and we don't trigger the re-assign path.

The easiest way to fix this is the below patch, which simply validates
the full assignment in the second pass.
Reported-by: NStephane Eranian <eranian@google.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1268311069.5037.31.camel@laptop>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Fix:

  arch/powerpc/kernel/perf_event.c:1334: error: 'power_pmu_notifier' undeclared (first use in this function)
  arch/powerpc/kernel/perf_event.c:1334: error: (Each undeclared identifier is reported only once
  arch/powerpc/kernel/perf_event.c:1334: error: for each function it appears in.)
  arch/powerpc/kernel/perf_event.c:1334: error: implicit declaration of function 'power_pmu_notifier'
  arch/powerpc/kernel/perf_event.c:1334: error: implicit declaration of function 'register_cpu_notifier'

Due to commit 3f6da390 (perf: Rework and fix the arch CPU-hotplug hooks).
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Without this change, the install path is relative to
prefix/DESTDIR where prefix is automatically set to $HOME.

This can produce unexpected results. For example:

  make -C tools/perf DESTDIR=/home/jkacur/tmp install-man

creates the directory:		/home/jkacur/home/jkacur/tmp/share/...
instead of the expected:	/home/jkacur/tmp/share/...
Signed-off-by: NJohn Kacur <jkacur@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Kyle McMartin <kyle@redhat.com>
Cc: <stable@kernel.org>
LKML-Reference: <1268312220-12880-1-git-send-email-jkacur@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

From : Ananth N Mavinakayanahalli <ananth@in.ibm.com>

When freeing the instruction slot, the arithmetic to calculate
the index of the slot in the page needs to account for the total
size of the instruction on the various architectures.

Calculate the index correctly when freeing the out-of-line
execution slot.
Reported-by: NSachin Sant <sachinp@in.ibm.com>
Reported-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NAnanth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: NMasami Hiramatsu <mhiramat@redhat.com>
LKML-Reference: <4B9667AB.9050507@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

At present, the perf subcommands that do system-wide monitoring
(perf stat, perf record and perf top) don't work properly unless
the online cpus are numbered 0, 1, ..., N-1.  These tools ask
for the number of online cpus with sysconf(_SC_NPROCESSORS_ONLN)
and then try to create events for cpus 0, 1, ..., N-1.

This creates problems for systems where the online cpus are
numbered sparsely.  For example, a POWER6 system in
single-threaded mode (i.e. only running 1 hardware thread per
core) will have only even-numbered cpus online.

This fixes the problem by reading the /sys/devices/system/cpu/online
file to find out which cpus are online.  The code that does that is in
tools/perf/util/cpumap.[ch], and consists of a read_cpu_map()
function that sets up a cpumap[] array and returns the number of
online cpus.  If /sys/devices/system/cpu/online can't be read or
can't be parsed successfully, it falls back to using sysconf to
ask how many cpus are online and sets up an identity map in cpumap[].

The perf record, perf stat and perf top code then calls
read_cpu_map() in the system-wide monitoring case (instead of
sysconf) and uses cpumap[] to get the cpu numbers to pass to
perf_event_open.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Cc: Anton Blanchard <anton@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
LKML-Reference: <20100310093609.GA3959@brick.ozlabs.ibm.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Anton Blanchard found that he could reliably make the kernel hit a
BUG_ON in the slab allocator by taking a cpu offline and then online
while a system-wide perf record session was running.

The reason is that when the cpu comes up, we completely reinitialize
the ctx field of the struct perf_cpu_context for the cpu.  If there is
a system-wide perf record session running, then there will be a struct
perf_event that has a reference to the context, so its refcount will
be 2.  (The perf_event has been removed from the context's group_entry
and event_entry lists by perf_event_exit_cpu(), but that doesn't
remove the perf_event's reference to the context and doesn't decrement
the context's refcount.)

When the cpu comes up, perf_event_init_cpu() gets called, and it calls
__perf_event_init_context() on the cpu's context.  That resets the
refcount to 1.  Then when the perf record session finishes and the
perf_event is closed, the refcount gets decremented to 0 and the
context gets kfreed after an RCU grace period.  Since the context
wasn't kmalloced -- it's part of a per-cpu variable -- bad things
happen.

In fact we don't need to completely reinitialize the context when the
cpu comes up.  It's sufficient to initialize the context once at boot,
but we need to do it for all possible cpus.

This moves the context initialization to happen at boot time.  With
this, we don't trash the refcount and the context never gets kfreed,
and we don't hit the BUG_ON.
Reported-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Tested-by: NAnton Blanchard <anton@samba.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: <stable@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Drop the obsolete "profile" naming used by perf for trace events.
Perf can now do more than simple events counting, so generalize
the API naming.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Jason Baron <jbaron@redhat.com>

We are taking a wrong regs snapshot when a trace event triggers.
Either we use get_irq_regs(), which gives us the interrupted
registers if we are in an interrupt, or we use task_pt_regs()
which gives us the state before we entered the kernel, assuming
we are lucky enough to be no kernel thread, in which case
task_pt_regs() returns the initial set of regs when the kernel
thread was started.

What we want is different. We need a hot snapshot of the regs,
so that we can get the instruction pointer to record in the
sample, the frame pointer for the callchain, and some other
things.

Let's use the new perf_fetch_caller_regs() for that.

Comparison with perf record -e lock: -R -a -f -g
Before:

        perf  [kernel]                   [k] __do_softirq
               |
               --- __do_softirq
                  |
                  |--55.16%-- __open
                  |
                   --44.84%-- __write_nocancel

After:

            perf  [kernel]           [k] perf_tp_event
               |
               --- perf_tp_event
                  |
                  |--41.07%-- lock_acquire
                  |          |
                  |          |--39.36%-- _raw_spin_lock
                  |          |          |
                  |          |          |--7.81%-- hrtimer_interrupt
                  |          |          |          smp_apic_timer_interrupt
                  |          |          |          apic_timer_interrupt

The old case was producing unreliable callchains. Now having
right frame and instruction pointers, we have the trace we
want.

Also syscalls and kprobe events already have the right regs,
let's use them instead of wasting a retrieval.

v2: Follow the rename perf_save_regs() -> perf_fetch_caller_regs()
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Archs <linux-arch@vger.kernel.org>

Events that trigger overflows by interrupting a context can
use get_irq_regs() or task_pt_regs() to retrieve the state
when the event triggered. But this is not the case for some
other class of events like trace events as tracepoints are
executed in the same context than the code that triggered
the event.

It means we need a different api to capture the regs there,
namely we need a hot snapshot to get the most important
informations for perf: the instruction pointer to get the
event origin, the frame pointer for the callchain, the code
segment for user_mode() tests (we always use __KERNEL_CS as
trace events always occur from the kernel) and the eflags
for further purposes.

v2: rename perf_save_regs to perf_fetch_caller_regs as per
Masami's suggestion.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Archs <linux-arch@vger.kernel.org>

We were using the frame pointer based stack walker on every
contexts in x86-32, but not in x86-64 where we only use the
seven-league boots on the exception stacks.

Use it also on irq and process stacks. This utterly accelerate
the captures.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>

There are rcu locked read side areas in the path where we submit
a trace event. And these rcu_read_(un)lock() trigger lock events,
which create recursive events.

One pair in do_perf_sw_event:

__lock_acquire
      |
      |--96.11%-- lock_acquire
      |          |
      |          |--27.21%-- do_perf_sw_event
      |          |          perf_tp_event
      |          |          |
      |          |          |--49.62%-- ftrace_profile_lock_release
      |          |          |          lock_release
      |          |          |          |
      |          |          |          |--33.85%-- _raw_spin_unlock

Another pair in perf_output_begin/end:

__lock_acquire
      |--23.40%-- perf_output_begin
      |          |          __perf_event_overflow
      |          |          perf_swevent_overflow
      |          |          perf_swevent_add
      |          |          perf_swevent_ctx_event
      |          |          do_perf_sw_event
      |          |          perf_tp_event
      |          |          |
      |          |          |--55.37%-- ftrace_profile_lock_acquire
      |          |          |          lock_acquire
      |          |          |          |
      |          |          |          |--37.31%-- _raw_spin_lock

The problem is not that much the trace recursion itself, as we have a
recursion protection already (though it's always wasteful to recurse).
But the trace events are outside the lockdep recursion protection, then
each lockdep event triggers a lock trace, which will trigger two
other lockdep events. Here the recursive lock trace event won't
be taken because of the trace recursion, so the recursion stops there
but lockdep will still analyse these new events:

To sum up, for each lockdep events we have:

	lock_*()
	     |
             trace lock_acquire
                  |
                  ----- rcu_read_lock()
                  |          |
                  |          lock_acquire()
                  |          |
                  |          trace_lock_acquire() (stopped)
                  |          |
		  |          lockdep analyze
                  |
                  ----- rcu_read_unlock()
                             |
                             lock_release
                             |
                             trace_lock_release() (stopped)
                             |
                             lockdep analyze

And you can repeat the above two times as we have two rcu read side
sections when we submit an event.

This is fixed in this patch by moving the lock trace event under
the lockdep recursion protection.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Jens Axboe <jens.axboe@oracle.com>

If -vv is used just the map table will be printed, -vvv will
print the symbol table too, with it we can see that we have a
bug where some samples are not being resolved to a map when we
get them in the perf.data stream, but after we have it all
processed, we can find the right map, some reordering probably
is happening.

Upcoming patches will provide ways to ask for most PERF_SAMPLE_
conditional samples to be taken for !PERF_RECORD_SAMPLE events
too, then we'll be able to ask for PERF_SAMPLE_TIME and
PERF_SAMPLE_CPU to help diagnose this.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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>
LKML-Reference: <1268161097-17761-1-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Perf report does not handle multiple events being reported, even
though perf record stores them properly on disk.  This patch
addresses that issue by adding the logic to perf report to use
the event stream id that is saved by record and the new data
structures to seperate the event streams and report them
individually.
Signed-off-by: NEric B Munson <ebmunson@us.ibm.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1267804269-22660-6-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Now that report can store historgrams for multiple events we
need to be able to do the post processing work for each
histogram. This patch changes the post processing functions so
that they can be called individually for each event's histogram.
Signed-off-by: NEric B Munson <ebmunson@us.ibm.com>
[ Guarantee bisectabilty by fixing up builtin-report.c ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1267804269-22660-5-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This patch adds the structures necessary to count each event
type independently in perf report.
Signed-off-by: NEric B Munson <ebmunson@us.ibm.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1267804269-22660-4-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

In order to minimize the impact of storing multiple events in a
report this function will now take the root of the histogram
tree so that the logic for selecting the proper tree can be
inserted before the call.
Signed-off-by: NEric B Munson <ebmunson@us.ibm.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1267804269-22660-3-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Currently perf record does not write the ID or the to disk for
events. This doesn't allow report to tell if an event stream
contains one or more types of events.  This patch adds this
entry to the list of data that record will write to disk if more
than one event was requested.
Signed-off-by: NEric B Munson <ebmunson@us.ibm.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1267804269-22660-2-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

cc1: warnings being treated as errors
 util/probe-finder.c: In function 'find_line_range':
 util/probe-finder.c:172: warning: 'src' may be used
 uninitialized in this function make: *** [util/probe-finder.o]
 Error 1
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: NMasami Hiramatsu <mhiramat@redhat.com>
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>
LKML-Reference: <1267804269-22660-1-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
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>
LKML-Reference: <1267800842-22324-1-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>