The callchains are fed with an array of a fixed size.
As a result we iterate over each callchains three times:

- 1st to resolve symbols
- 2nd to filter out context boundaries
- 3rd for the insertion into the tree

This also involves some pairs of memory allocation/deallocation
everytime we insert a callchain, for the filtered out array of
addresses and for the array of symbols that comes along.

Instead, feed the callchains through a linked list with persistent
allocations. It brings several pros like:

- Merge the 1st and 2nd iterations in one. That was possible before
but in a way that would involve allocating an array slightly taller
than necessary because we don't know in advance the number of context
boundaries to filter out.

- Much lesser allocations/deallocations. The linked list keeps
persistent empty entries for the next usages and is extendable at
will.

- Makes it easier for multiple sources of callchains to feed a
stacktrace together. This is deemed to pave the way for cfi based
callchains wherein traditional frame pointer based kernel
stacktraces will precede cfi based user ones, producing an overall
callchain which size is hardly predictable. This requirement
makes the static array obsolete and makes a linked list based
iterator a much more flexible fit.

Basic testing on a big perf file containing callchains (~ 176 MB)
has shown a throughput gain of about 11% with perf report.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1294977121-5700-2-git-send-email-fweisbec@gmail.com>
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Not really something to be exported from session.c. Rename it to
'readn' as others did in the past.

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 are running the new perf on an old kernel without support for
sample_id_all, we should fall back to the old unordered processing of
events. If we didn't than we would *always* process events without
timestamps out of order, whether or not we hit a reordering race. In
other words, instead of there being a chance of not attributing samples
correctly, we would guarantee that samples would not be attributed.

While processing all events without timestamps before events with
timestamps may seem like an intuitive solution, it falls down as
PERF_RECORD_EXIT events would also be processed before any samples.
Even with a workaround for that case, samples before/after an exec would
not be attributed correctly.

This patch allows commands to indicate whether they need to fall back to
unordered processing, so that commands that do not care about timestamps
on every event will not be affected. If we do fallback, this will print
out a warning if report -D was invoked.

This patch adds the test in perf_session__new so that we only need to
test once per session. Commands that do not use an event_ops (such as
record and top) can simply pass NULL in it's place.
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <1291951882-sup-6069@au1.ibm.com>
Signed-off-by: NIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

So that we can use -T == --timestamp, asking for PERF_SAMPLE_TIME:

  $ perf record -aT
  $ perf report -D | grep PERF_RECORD_
  <SNIP>
   3   5951915425 0x47530 [0x58]: PERF_RECORD_SAMPLE(IP, 1): 16811/16811: 0xffffffff8138c1a2 period: 215979 cpu:3
   3   5952026879 0x47588 [0x90]: PERF_RECORD_SAMPLE(IP, 1): 16811/16811: 0xffffffff810cb480 period: 215979 cpu:3
   3   5952059959 0x47618 [0x38]: PERF_RECORD_FORK(6853:6853):(16811:16811)
   3   5952138878 0x47650 [0x78]: PERF_RECORD_SAMPLE(IP, 1): 16811/16811: 0xffffffff811bac35 period: 431478 cpu:3
   3   5952375068 0x476c8 [0x30]: PERF_RECORD_COMM: find:6853
   3   5952395923 0x476f8 [0x50]: PERF_RECORD_MMAP 6853/6853: [0x400000(0x25000) @ 0]: /usr/bin/find
   3   5952413756 0x47748 [0xa0]: PERF_RECORD_SAMPLE(IP, 1): 6853/6853: 0xffffffff810d080f period: 859332 cpu:3
   3   5952419837 0x477e8 [0x58]: PERF_RECORD_MMAP 6853/6853: [0x3f44600000(0x21d000) @ 0]: /lib64/ld-2.5.so
   3   5952437929 0x47840 [0x48]: PERF_RECORD_MMAP 6853/6853: [0x7fff7e1c9000(0x1000) @ 0x7fff7e1c9000]: [vdso]
   3   5952570127 0x47888 [0x58]: PERF_RECORD_MMAP 6853/6853: [0x3f46200000(0x218000) @ 0]: /lib64/libselinux.so.1
   3   5952623637 0x478e0 [0x58]: PERF_RECORD_MMAP 6853/6853: [0x3f44a00000(0x356000) @ 0]: /lib64/libc-2.5.so
   3   5952675720 0x47938 [0x58]: PERF_RECORD_MMAP 6853/6853: [0x3f44e00000(0x204000) @ 0]: /lib64/libdl-2.5.so
   3   5952710080 0x47990 [0x58]: PERF_RECORD_MMAP 6853/6853: [0x3f45a00000(0x246000) @ 0]: /lib64/libsepol.so.1
   3   5952847802 0x479e8 [0x58]: PERF_RECORD_SAMPLE(IP, 1): 6853/6853: 0xffffffff813897f0 period: 1142536 cpu:3
  <SNIP>

First column is the cpu and the second the timestamp.

That way we can investigate problems in the event stream.

If the new perf binary is run on an older kernel, it will disable this feature
automatically.
Tested-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NIan Munsie <imunsie@au1.ibm.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Ian Munsie <imunsie@au1.ibm.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: <1291318772-30880-5-git-send-email-acme@infradead.org>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

At perf_session__process_event, so that we reduce the number of lines in eache
tool sample processing routine that now receives a sample_data pointer already
parsed.

This will also be useful in the next patch, where we'll allow sample the
identity fields in MMAP, FORK, EXIT, etc, when it will be possible to see (cpu,
timestamp) just after before every event.

Also validate callchains in perf_session__process_event, i.e. as early as
possible, and keep a counter of the number of events discarded due to invalid
callchains, warning the user about it if it happens.

There is an assumption that was kept that all events have the same sample_type,
that will be dealt with in the future, when this preexisting limitation will be
removed.
Tested-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NIan Munsie <imunsie@au1.ibm.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Ian Munsie <imunsie@au1.ibm.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: <1291318772-30880-4-git-send-email-acme@infradead.org>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The ordered sample code allocates singular reference objects struct
sample_queue which have 48byte size on 64bit and 20 bytes on 32bit. That's
silly. Allocate ~64k sized chunks and hand them out.

Performance gain: ~ 15%

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20101130163820.398713983@linutronix.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

When the sample queue is flushed we free the sample reference objects. Though
we need to malloc new objects when we process further. Stop the malloc/free
orgy and cache the already allocated object for resuage. Only allocate when
the cache is empty.

Performance gain: ~ 10%

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20101130163820.338488630@linutronix.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The homebrewn sort algorithm fails to sort in time order. One of the problem
spots is that it fails to deal with equal timestamps correctly.

My first gut reaction was to replace the fancy list with an rbtree, but the
performance is 3 times worse.

Rewrite it so it works.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20101130163819.908482530@linutronix.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Move them to a session->dead_threads list just like we do with maps that
are replaced, because we may have hist_entries pointing to them.

This fixes a bug when inserting maps for a new thread that reused the
TID, mixing maps for two different threads, causing an endless loop.

The code for insering maps should be made more robust but for .35 this
is the minimalistic patch.
Reported-by: NIngo Molnar <mingo@elte.hu>
Cc: David S. Miller <davem@davemloft.net>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
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>

The changes made to support host and guest machines in a session, that
started when the 'perf kvm' tool was introduced ended up introducing a
bug where the host_machine was not having its DSOs traversed for
build-id processing.

Fix it by moving some methods to the right classes and considering the
host_machine when processing build-ids.
Reported-by: NTom Zanussi <tzanussi@gmail.com>
Reported-by: NStephane Eranian <eranian@google.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
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>

This is one more thing that started global but are more useful per hist
or per session.

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

Those are really not specific to the newt code, can be used by other UI
frontends.

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

In cbbc79a5 we introduced support for multiple events by introducing a
new "event_stat_id" struct and then made several perf_session methods
receive a point to it instead of a pointer to perf_session, and kept the
event_stats and hists rb_tree in perf_session.

While working on the new newt based browser, I realised that it would be
better to introduce a new class, "hists" (short for "histograms"),
renaming the "event_stat_id" struct and the perf_session methods that
were really "hists" methods, as they manipulate only struct hists
members, not touching anything in the other perf_session members.

Other optimizations, such as calculating the maximum lenght of a symbol
name present in an hists instance will be possible as we add them,
avoiding a re-traversal just for finding that information.

The rationale for the name "hists" to replace "event_stat_id" is that we
may have multiple sets of hists for the same event_stat id, as, for
instance, the 'perf diff' tool has, so event stat id is not what
characterizes what this struct and the functions that manipulate it do.

Cc: Eric B Munson <ebmunson@us.ibm.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

We have just one host on a given session, and that is the most common
setup right now, so embed a ->host_machine struct machine instance
directly in the perf_session class, check if we're looking for it before
going to the rb_tree.

This also fixes a problem found when we try to process old perf.data
files where we didn't have MMAP events for the kernel and modules and
thus don't create the kernel maps, do it in event__preprocess_sample if
it wasn't already.
Reported-by: NIngo Molnar <mingo@elte.hu>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Zhang, Yanmin <yanmin_zhang@linux.intel.com>
LKML-Reference: <new-submission>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The current events reordering algorithm is based on a heuristic that
gets broken once we deal with a very fast flow of events.

Indeed the time period based flushing is not suitable anymore
in the following case, assuming we have a flush period of two
seconds.

    CPU 0           |        CPU 1
                    |
  cnt1 timestamps   |      cnt1 timestamps
                    |
    0               |         0
    1               |         1
    2               |         2
    3               |         3
    [...]           |        [...]
    4 seconds later

If we spend too much time to read the buffers (case of a lot of
events to record in each buffers or when we have a lot of CPU buffers
to read), in the next pass the CPU 0 buffer could contain a slice
of several seconds of events. We'll read them all and notice we've
reached the period to flush. In the above example we flush the first
half of the CPU 0 buffer, then we read the CPU 1 buffer where we
have events that were on the flush slice and then the reordering
fails.

It's simple to reproduce with:

	perf lock record perf bench sched messaging

To solve this, we use a new solution that doesn't rely on an
heuristical time slice period anymore but on a deterministic basis
based on how perf record does its job.

perf record saves the buffers through passes. A pass is a tour
on every buffers from every CPUs. This is made in order: for
each CPU we read the buffers of every counters. So the more
buffers we visit, the later will be the timstamps of their events.

When perf record finishes a pass it records a
PERF_RECORD_FINISHED_ROUND pseudo event.
We record the max timestamp t found in the pass n. Assuming these
timestamps are monotonic across cpus, we know that if a buffer
still has events with timestamps below t, they will be all available
and then read in the pass n + 1.
Hence when we start to read the pass n + 2, we can safely flush every
events with timestamps below t.

      ============ PASS n =================
         CPU 0         |   CPU 1
                       |
      cnt1 timestamps  |   cnt2 timestamps
            1          |         2
            2          |         3
            -          |         4  <--- max recorded

      ============ PASS n + 1 ==============
         CPU 0         |   CPU 1
                       |
      cnt1 timestamps  |   cnt2 timestamps
            3          |         5
            4          |         6
            5          |         7 <---- max recorded

        Flush every events below timestamp 4

      ============ PASS n + 2 ==============
         CPU 0         |   CPU 1
                       |
      cnt1 timestamps  |   cnt2 timestamps
            6          |         8
            7          |         9
            -          |         10

        Flush every events below timestamp 7
        etc...

It also works on perf.data versions that don't have
PERF_RECORD_FINISHED_ROUND pseudo events. The difference is that
the events will be only flushed in the end of the perf.data
processing. It will then consume more memory and scale less with
large perf.data files.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>

Currently, perf 'live mode' writes build-ids at the end of the
session, which isn't actually useful for processing live mode events.

What would be better would be to have the build-ids sent before any of
the samples that reference them, which can be done by processing the
event stream and retrieving the build-ids on the first hit.  Doing
that in perf-record itself, however, is off-limits.

This patch introduces perf-inject, which does the same job while
leaving perf-record untouched.  Normal mode perf still records the
build-ids at the end of the session as it should, but for live mode,
perf-inject can be injected in between the record and report steps
e.g.:

perf record -o - ./hackbench 10 | perf inject -v -b | perf report -v -i -

perf-inject reads a perf-record event stream and repipes it to stdout.
At any point the processing code can inject other events into the
event stream - in this case build-ids (-b option) are read and
injected as needed into the event stream.

Build-ids are just the first user of perf-inject - potentially
anything that needs userspace processing to augment the trace stream
with additional information could make use of this facility.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1272696080-16435-3-git-send-email-tzanussi@gmail.com>
Signed-off-by: NTom Zanussi <tzanussi@gmail.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Now those methods don't operate on a global list of dsos, but on lists
of machines, so make this clear by renaming the functions.

Cc: Avi Kivity <avi@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zhang, Yanmin <yanmin_zhang@linux.intel.com>
LKML-Reference: <new-submission>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

struct kernel_info and kerninfo__ are too vague, what they really
describe are machines, virtual ones or hosts.

There are more changes to introduce helpers to shorten function calls
and to make more clear what is really being done, but I left that for
subsequent patches.

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>
Cc: Zhang, Yanmin <yanmin_zhang@linux.intel.com>
LKML-Reference: <new-submission>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The sample events recorded by perf record are not time ordered
because we have one buffer per cpu for each event (even demultiplexed
per task/per cpu for task bound events). But when we read trace events
we want them to be ordered by time because many state machines are
involved.

There are currently two ways perf tools deal with that:

- use -M to multiplex every buffers (perf sched, perf kmem)
  But this creates a lot of contention in SMP machines on
  record time.

- use a post-processing time reordering (perf timechart, perf lock)
  The reordering used by timechart is simple but doesn't scale well
  with huge flow of events, in terms of performance and memory use
  (unusable with perf lock for example).
  Perf lock has its own samples reordering that flushes its memory
  use in a regular basis and that uses a sorting based on the
  previous event queued (a new event to be queued is close to the
  previous one most of the time).

This patch proposes to export perf lock's samples reordering facility
to the session layer that reads the events. So if a tool wants to
get ordered sample events, it needs to set its
struct perf_event_ops::ordered_samples to true and that's it.

This prepares tracing based perf tools to get rid of the need to
use buffers multiplexing (-M) or to implement their own
reordering.

Also lower the flush period to 2 as it's sufficient already.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Tom Zanussi <tzanussi@gmail.com>

Here is the patch of userspace perf tool.
Signed-off-by: NZhang Yanmin <yanmin_zhang@linux.intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Bypasses the build_id perf header code and replaces it with a
synthesized event and processing function that accomplishes the
same thing, used when reading/writing perf data to/from a pipe.
Signed-off-by: NTom Zanussi <tzanussi@gmail.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Cc: fweisbec@gmail.com
Cc: rostedt@goodmis.org
Cc: k-keiichi@bx.jp.nec.com
Cc: acme@ghostprotocols.net
LKML-Reference: <1270184365-8281-9-git-send-email-tzanussi@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Bypasses the tracing_data perf header code and replaces it with
a synthesized event and processing function that accomplishes
the same thing, used when reading/writing perf data to/from a
pipe.

The tracing data is pretty large, and this patch doesn't attempt
to break it down into component events.  The tracing_data event
itself doesn't actually contain the tracing data, rather it
arranges for the event processing code to skip over it after
it's read, using the skip return value added to the event
processing loop in a previous patch.
Signed-off-by: NTom Zanussi <tzanussi@gmail.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Cc: fweisbec@gmail.com
Cc: rostedt@goodmis.org
Cc: k-keiichi@bx.jp.nec.com
Cc: acme@ghostprotocols.net
LKML-Reference: <1270184365-8281-8-git-send-email-tzanussi@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Bypasses the event type perf header code and replaces it with a
synthesized event and processing function that accomplishes the
same thing, used when reading/writing perf data to/from a pipe.
Signed-off-by: NTom Zanussi <tzanussi@gmail.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Cc: fweisbec@gmail.com
Cc: rostedt@goodmis.org
Cc: k-keiichi@bx.jp.nec.com
Cc: acme@ghostprotocols.net
LKML-Reference: <1270184365-8281-7-git-send-email-tzanussi@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Bypasses the attr perf header code and replaces it with a
synthesized event and processing function that accomplishes the
same thing, used when reading/writing perf data to/from a pipe.

Making the attrs into events allows them to be streamed over a
pipe along with the rest of the header data (in later patches).
It also paves the way to allowing events to be added and removed
from perf sessions dynamically.
Signed-off-by: NTom Zanussi <tzanussi@gmail.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Cc: fweisbec@gmail.com
Cc: rostedt@goodmis.org
Cc: k-keiichi@bx.jp.nec.com
Cc: acme@ghostprotocols.net
LKML-Reference: <1270184365-8281-6-git-send-email-tzanussi@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This patch makes several changes to allow the perf event stream
to be sent and received over a pipe:

- adds pipe-specific versions of the header read/write code

- adds pipe-specific version of the event processing code

- adds a range of event types to be used for header or other
  pseudo events, above the range used by the kernel

- checks the return value of event handlers, which they can use
  to skip over large events during event processing rather than actually
  reading them into event objects.

- unifies the multiple do_read() functions and updates its
  users.

Note that none of these changes affect the existing perf data
file format or processing - this code only comes into play if
perf output is sent to stdout (or is read from stdin).
Signed-off-by: NTom Zanussi <tzanussi@gmail.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Cc: fweisbec@gmail.com
Cc: rostedt@goodmis.org
Cc: k-keiichi@bx.jp.nec.com
Cc: acme@ghostprotocols.net
LKML-Reference: <1270184365-8281-2-git-send-email-tzanussi@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

So that it can use it in the 'perf annotate' command line, otherwise
it'll use the default and not the specified -i filename passed to 'perf
report'.

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: <new-submission>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Due to the assumption in perf_session__new that the kernel maps would be
created using the fake PERF_RECORD_MMAP event in a perf.data file 'perf
kmem --stat caller', that doesn't have such event, ends up not being
able to resolve the kernel addresses.

Fix it by calling perf_session__create_kernel_maps() in __cmd_kmem().

LKML-Reference: <new-submission>
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>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

For when we are processing the events and inserting the entries in the
browser.

Experimentation here: naming "ui_something" we may be treading into
creating a TUI/GUI set of routines that can then be implemented in terms
of multiple backends.

Also the time it takes for adding things to the "browser" takes, visually
(I guess I should do some profiling here ;-) ), more time than for
processing the events...

That means we probably need to create a custom hist_entry browser, so
that we reuse the structures we have in place instead of duplicating
them in newt.

But progress was made and at least we can see something while long files
are being loaded, that must be one of UI 101 bullet points :-)

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>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

We need this to know where a symbol in a callchain came from,
for various reasons, among them precise annotation from a
TUI/GUI tool.
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: <1269459619-982-5-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>

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>

We want to stream events as fast as possible to perf.data, and
also in the future we want to have splice working, when no
interception will be possible.

Using build_id__mark_dso_hit_ops to create the list of DSOs that
back MMAPs we also optimize disk usage in the build-id cache by
only caching DSOs that had hits.
Suggested-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1265223128-11786-6-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

I noticed while writing the first test in 'perf regtest' that to
just test the symbol handling routines one needs to create a
perf session, that is a layer centered on a perf.data file,
events, etc, so I untied these layers.

This reduces the complexity for the users as the number of
parameters to most of the symbols and session APIs now was
reduced while not adding more state to all the map instances by
only having data that is needed to split the kernel (kallsyms
and ELF symtab sections) maps and do vmlinux relocation on the
main kernel map.
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: <1265223128-11786-1-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

There are still some problems related to loading vmlinux files,
but those are unrelated to the feature implemented in this
patch, so will get fixed in the next patches, but here are some
results:

1. collect perf.data file on a Fedora 12 machine, x86_64, 64-bit
userland

2. transfer it to a Debian Testing machine, PARISC64, 32-bit
userland

  acme@parisc:~/git/linux-2.6-tip$ perf buildid-list | head -5
  74f9930ee94475b6b3238caf3725a50d59cb994b [kernel.kallsyms]
  55fdd56670453ea66c011158c4b9d30179c1d049 /lib/modules/2.6.33-rc4-tip+/kernel/net/ipv4/netfilter/ipt_MASQUERADE.ko
  41adff63c730890480980d5d8ba513f1c216a858 /lib/modules/2.6.33-rc4-tip+/kernel/net/ipv4/netfilter/iptable_nat.ko
  90a33def1077bb8e97b8a78546dc96c2de62df46 /lib/modules/2.6.33-rc4-tip+/kernel/net/ipv4/netfilter/nf_nat.ko
  984c7bea90ce1376d5c8e7ef43a781801286e62d /lib/modules/2.6.33-rc4-tip+/kernel/drivers/net/tun.ko

  acme@parisc:~/git/linux-2.6-tip$ perf buildid-list | tail -5
  22492f3753c6a67de5c7ccbd6b863390c92c0723 /usr/lib64/libXt.so.6.0.0
  353802bb7e1b895ba43507cc678f951e778e4c6f /usr/lib64/libMagickCore.so.2.0.0
  d10c2897558595efe7be8b0584cf7e6398bc776c /usr/lib64/libfprint.so.0.0.0
  a83ecfb519a788774a84d5ddde633c9ba56c03ab /home/acme/bin/perf
  d3ca765a8ecf257d263801d7ad8c49c189082317 /usr/lib64/libdwarf.so.0.0
  acme@parisc:~/git/linux-2.6-tip$

  acme@parisc:~/git/linux-2.6-tip$ perf report --sort comm
  The file [kernel.kallsyms] cannot be used, trying to use /proc/kallsyms...

  ^^^^ The problem related to vmlinux handling, it shouldn't be trying this
  ^^^^ rather alien /proc/kallsyms at all...

  /lib64/libpthread-2.10.2.so with build id 5c68f7afeb33309c78037e374b0deee84dd441f6 not found, continuing without symbols
  /lib64/libc-2.10.2.so with build id eb4ec8fa8b2a5eb18cad173c92f27ed8887ed1c1 not found, continuing without symbols
  /home/acme/bin/perf with build id a83ecfb519a788774a84d5ddde633c9ba56c03ab not found, continuing without symbols
  /usr/sbin/openvpn with build id f2037a091ef36b591187a858d75e203690ea9409 not found, continuing without symbols
  Failed to open /lib/modules/2.6.33-rc4-tip+/kernel/drivers/net/e1000e/e1000e.ko, continuing without symbols
  Failed to open /lib/modules/2.6.33-rc4-tip+/kernel/drivers/net/wireless/iwlwifi/iwlcore.ko, continuing without symbols

  <SNIP more complaints about not finding the right build-ids,
        those will have to wait for 'perf archive' or plain
        copying what was collected by 'perf record' on the x86_64,
        source machine, see further below for an example of this >

  # Samples: 293085637
  #
  # Overhead          Command
  # ........  ...............
  #
      61.70%             find
      23.50%             perf
       5.86%          swapper
       3.12%             sshd
       2.39%             init
       0.87%             bash
       0.86%            sleep
       0.59%      dbus-daemon
       0.25%             hald
       0.24%   NetworkManager
       0.19%  hald-addon-rfki
       0.15%          openvpn
       0.07%             phy0
       0.07%         events/0
       0.05%          iwl3945
       0.05%         events/1
       0.03%      kondemand/0
  acme@parisc:~/git/linux-2.6-tip$

Which matches what we get when running the same command for the
same perf.data file on the F12, x86_64, source machine:

  [root@doppio linux-2.6-tip]# perf report --sort comm
  # Samples: 293085637
  #
  # Overhead          Command
  # ........  ...............
  #
      61.70%             find
      23.50%             perf
       5.86%          swapper
       3.12%             sshd
       2.39%             init
       0.87%             bash
       0.86%            sleep
       0.59%      dbus-daemon
       0.25%             hald
       0.24%   NetworkManager
       0.19%  hald-addon-rfki
       0.15%          openvpn
       0.07%             phy0
       0.07%         events/0
       0.05%          iwl3945
       0.05%         events/1
       0.03%      kondemand/0
  [root@doppio linux-2.6-tip]#

The other modes work as well, modulo the problem with vmlinux:

  acme@parisc:~/git/linux-2.6-tip$ perf report --sort comm,dso 2> /dev/null | head -15
  # Samples: 293085637
  #
  # Overhead          Command                      Shared Object
  # ........  ...............  .................................
  #
      35.11%             find                   ffffffff81002b5a
      18.25%             perf                   ffffffff8102235f
      16.17%             find  libc-2.10.2.so
       9.07%             find  find
       5.80%          swapper                   ffffffff8102235f
       3.95%             perf  libc-2.10.2.so
       2.33%             init                   ffffffff810091b9
       1.65%             sshd  libcrypto.so.0.9.8k
       1.35%             find  [e1000e]
       0.68%            sleep  libc-2.10.2.so
  acme@parisc:~/git/linux-2.6-tip$

And the lack of the right buildids:

  acme@parisc:~/git/linux-2.6-tip$ perf report --sort comm,dso,symbol 2> /dev/null | head -15
  # Samples: 293085637
  #
  # Overhead          Command                      Shared Object  Symbol
  # ........  ...............  .................................  ......
  #
      35.11%             find                   ffffffff81002b5a  [k] 0xffffffff81002b5a
      18.25%             perf                   ffffffff8102235f  [k] 0xffffffff8102235f
      16.17%             find  libc-2.10.2.so                     [.] 0x00000000045782
       9.07%             find  find                               [.] 0x0000000000fb0e
       5.80%          swapper                   ffffffff8102235f  [k] 0xffffffff8102235f
       3.95%             perf  libc-2.10.2.so                     [.] 0x0000000007f398
       2.33%             init                   ffffffff810091b9  [k] 0xffffffff810091b9
       1.65%             sshd  libcrypto.so.0.9.8k                [.] 0x00000000105440
       1.35%             find  [e1000e]                           [k] 0x00000000010948
       0.68%            sleep  libc-2.10.2.so                     [.] 0x0000000011ad5b
  acme@parisc:~/git/linux-2.6-tip$

But if we:

  acme@parisc:~/git/linux-2.6-tip$ ls ~/.debug
  ls: cannot access /home/acme/.debug: No such file or directory
  acme@parisc:~/git/linux-2.6-tip$ mkdir -p ~/.debug/lib64/libc-2.10.2.so/
  acme@parisc:~/git/linux-2.6-tip$ scp doppio:.debug/lib64/libc-2.10.2.so/* ~/.debug/lib64/libc-2.10.2.so/
  acme@doppio's password:
  eb4ec8fa8b2a5eb18cad173c92f27ed8887ed1c1	             100% 1783KB 714.7KB/s   00:02
  acme@parisc:~/git/linux-2.6-tip$ mkdir -p ~/.debug/.build-id/eb
  acme@parisc:~/git/linux-2.6-tip$ ln -s ../../lib64/libc-2.10.2.so/eb4ec8fa8b2a5eb18cad173c92f27ed8887ed1c1 ~/.debug/.build-id/eb/4ec8fa8b2a5eb18cad173c92f27ed8887ed1c1
  acme@parisc:~/git/linux-2.6-tip$ perf report --dsos libc-2.10.2.so 2> /dev/null
  # dso: libc-2.10.2.so
  # Samples: 64281170
  #
  # Overhead          Command  Symbol
  # ........  ...............  ......
  #
      14.98%             perf  [.] __GI_strcmp
      12.30%             find  [.] __GI_memmove
       9.25%             find  [.] _int_malloc
       7.60%             find  [.] _IO_vfprintf_internal
       6.10%             find  [.] _IO_new_file_xsputn
       6.02%             find  [.] __GI_close
       3.08%             find  [.] _IO_file_overflow_internal
       3.08%             find  [.] malloc_consolidate
       3.08%             find  [.] _int_free
       3.08%             find  [.] __strchrnul
       3.08%             find  [.] __getdents64
       3.08%             find  [.] __write_nocancel
       3.08%            sleep  [.] __GI__dl_addr
       3.08%             sshd  [.] __libc_select
       3.08%             find  [.] _IO_new_file_write
       3.07%             find  [.] _IO_new_do_write
       3.06%             find  [.] __GI___errno_location
       3.05%             find  [.] __GI___libc_malloc
       3.04%             perf  [.] __GI_memcpy
       1.71%             find  [.] __fprintf_chk
       1.29%             bash  [.] __gconv_transform_utf8_internal
       0.79%      dbus-daemon  [.] __GI_strlen
  #
  # (For a higher level overview, try: perf report --sort comm,dso)
  #
  acme@parisc:~/git/linux-2.6-tip$

Which matches what we get on the source, F12, x86_64 machine:

  [root@doppio linux-2.6-tip]# perf report --dsos libc-2.10.2.so
  # dso: libc-2.10.2.so
  # Samples: 64281170
  #
  # Overhead          Command  Symbol
  # ........  ...............  ......
  #
      14.98%             perf  [.] __GI_strcmp
      12.30%             find  [.] __GI_memmove
       9.25%             find  [.] _int_malloc
       7.60%             find  [.] _IO_vfprintf_internal
       6.10%             find  [.] _IO_new_file_xsputn
       6.02%             find  [.] __GI_close
       3.08%             find  [.] _IO_file_overflow_internal
       3.08%             find  [.] malloc_consolidate
       3.08%             find  [.] _int_free
       3.08%             find  [.] __strchrnul
       3.08%             find  [.] __getdents64
       3.08%             find  [.] __write_nocancel
       3.08%            sleep  [.] __GI__dl_addr
       3.08%             sshd  [.] __libc_select
       3.08%             find  [.] _IO_new_file_write
       3.07%             find  [.] _IO_new_do_write
       3.06%             find  [.] __GI___errno_location
       3.05%             find  [.] __GI___libc_malloc
       3.04%             perf  [.] __GI_memcpy
       1.71%             find  [.] __fprintf_chk
       1.29%             bash  [.] __gconv_transform_utf8_internal
       0.79%      dbus-daemon  [.] __GI_strlen
  #
  # (For a higher level overview, try: perf report --sort comm,dso)
  #
  [root@doppio linux-2.6-tip]#

So I think this is really, really nice in that it demonstrates
the portability of perf.data files and the use of build-ids
accross such aliens worlds :-)

There are some things to fix tho, like the bitmap on the header,
but things are looking good.
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: <1263478990-8200-2-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

DSOs don't have this problem because the kernel emits a
PERF_MMAP for each new executable mapping it performs on
monitored threads.

To fix the kernel case we simulate the same behaviour, by having
'perf record' to synthesize a PERF_MMAP for the kernel, encoded
like this:

[root@doppio ~]# perf record -a -f sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.344 MB perf.data (~15038 samples) ]
[root@doppio ~]# perf report -D | head -10

0xd0 [0x40]: event: 1
.
. ... raw event: size 64 bytes
.  0000:  01 00 00 00 00 00 40 00 00 00 00 00 00 00 00 00 ......@........
.  0010:  00 00 00 81 ff ff ff ff 00 00 00 00 00 00 00 00 ...............
.  0020:  00 00 00 00 00 00 00 00 5b 6b 65 72 6e 65 6c 2e ........  [kernel
.  0030:  6b 61 6c 6c 73 79 6d 73 2e 5f 74 65 78 74 5d 00  kallsyms._text]
.  0xd0
[0x40]: PERF_RECORD_MMAP 0/0: [0xffffffff81000000((nil)) @ (nil)]: [kernel.kallsyms._text]

I.e. we identify such event as having:

 .pid      = 0
 .filename = [kernel.kallsyms.REFNAME]
 .start    = REFNAME addr in /proc/kallsyms at 'perf record' time

and use now a hardcoded value of '.text' for REFNAME.

Then, later, in 'perf report', if there are any kernel hits and
thus we need to resolve kernel symbols, we search for REFNAME
and if its address changed, relocation happened and we thus must
change the kernel mapping routines to one that uses .pgoff as
the relocation to apply.

This way we use the same mechanism used for the other DSOs and
don't have to do a two pass in all the kernel symbols.
Reported-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
LKML-Reference: <1262717431-1246-1-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

So that tools such as 'perf probe' don't have to lookup
'[kernel.kallsyms]' but instead access them directly after
perf_session__create_kernel_maps or
map_groups__create_kernel_maps.
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Masami 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: <1262629169-22797-4-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Since now all that we have are perf event handlers, leave just
the name of the event.
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: <1261957026-15580-9-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Now perf_event_ops has just that, event handlers.
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: <1261957026-15580-8-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

As this is a session property, not belonging to perf_event_ops,
that can be shared by many perf_session instances.
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: <1261957026-15580-7-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This is really something tools need to do before asking for the
events to be processed, leaving perf_session__process_events to
do just that, process events.

Also add a msg parameter to perf_session__has_traces() so that
the right message can be printed, fixing a regression added by
me in the previous cset (right timechart message) and also
fixing 'perf kmem', that was not asking if 'perf kmem record'
was ran.
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: <1261957026-15580-6-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>