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>

In __dsos__read_build_ids if the dso already had its build-id read,
don't try again.

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>

Should be there for the sake of RAW events.
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
CC: Lin Ming <ming.m.lin@intel.com>
CC: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20100518212439.354345151@openvz.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This snippet somehow escaped the commit:

 | commit 137351e0
 | Author: Cyrill Gorcunov <gorcunov@openvz.org>
 | Date:   Sat May 8 15:25:52 2010 +0400
 |
 |    x86, perf: P4 PMU -- protect sensible procedures from preemption

so bring it eventually back. It helps to catch
preemption issue (if there will be, rule of thumb --
don't use raw_ if you can).
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Cc: Lin Ming <ming.m.lin@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20100518212439.167259349@openvz.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

To prevent from clashes in future code modifications
do a real check for ESCR address being in hash. At
moment the callers are known to pass sane values but
better to be on a safe side.

And comment fix.
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
CC: Lin Ming <ming.m.lin@intel.com>
CC: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20100518212439.004503600@openvz.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

All the functions that call this can handle the equivalent, non
panic'ing wrapped routines.

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>

Functions that were calling xzalloc also returned -1 when, for other
reasons, it could fail, and the calleds are coping with failures, so
stop using die() and xzalloc().

Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Masami Hiramatsu <mhiramat@redhat.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>

That could leave filedescriptors open and leak memory. Also stop using
xmalloc, use malloc and handle results just like other error cases in
the same routine that used it.

Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Masami Hiramatsu <mhiramat@redhat.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>

Without the bloated cplus_demangle from binutils, i.e building with:

$ make NO_DEMANGLE=1 O=~acme/git/build/perf -j3 -C tools/perf/ install

Before:

   text	   data	    bss	    dec	    hex	filename
 471851	  29280	4025056	4526187	 45106b	/home/acme/bin/perf

After:

[acme@doppio linux-2.6-tip]$ size ~/bin/perf
   text	   data	    bss	    dec	    hex	filename
 446886	  29232	4008576	4484694	 446e56	/home/acme/bin/perf

So its a 5.3% size reduction in code, but the interesting part is in the git
diff --stat output:

 19 files changed, 20 insertions(+), 1909 deletions(-)

If we ever need some of the things we got from git but weren't using, we just
have to go to the git repo and get fresh, uptodate source code bits.

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>

It is hard to read very large numbers so provide an option to perf stat
to separate thousands using a separator. The patch leverages the locale
support of stdio. You need to set your LC_NUMERIC appropriately, for
instance LC_NUMERIC=en_US.UTF8. You need to pass -B to activate this
feature. This way existing scripts parsing the output do not need to be
changed. Here is an example.

$ perf stat noploop 2
noploop for 2 seconds

 Performance counter stats for 'noploop 2':

        1998.347031  task-clock-msecs         #      0.998 CPUs
                 61  context-switches         #      0.000 M/sec
                  0  CPU-migrations           #      0.000 M/sec
                118  page-faults              #      0.000 M/sec
      4,138,410,900  cycles                   #   2070.917 M/sec  (scaled from 70.01%)
      2,062,650,268  instructions             #      0.498 IPC    (scaled from 70.01%)
      2,057,653,466  branches                 #   1029.678 M/sec  (scaled from 70.01%)
             40,267  branch-misses            #      0.002 %      (scaled from 30.04%)
      2,055,961,348  cache-references         #   1028.831 M/sec  (scaled from 30.03%)
             53,725  cache-misses             #      0.027 M/sec  (scaled from 30.02%)

        2.001393933  seconds time elapsed

$ perf stat -B  noploop 2
noploop for 2 seconds

 Performance counter stats for 'noploop 2':

        1998.297883  task-clock-msecs         #      0.998 CPUs
                 59  context-switches         #      0.000 M/sec
                  0  CPU-migrations           #      0.000 M/sec
                119  page-faults              #      0.000 M/sec
      4,131,380,160  cycles                   #   2067.450 M/sec  (scaled from 70.01%)
      2,059,096,507  instructions             #      0.498 IPC    (scaled from 70.01%)
      2,054,681,303  branches                 #   1028.216 M/sec  (scaled from 70.01%)
             25,650  branch-misses            #      0.001 %      (scaled from 30.05%)
      2,056,283,014  cache-references         #   1029.017 M/sec  (scaled from 30.03%)
             47,097  cache-misses             #      0.024 M/sec  (scaled from 30.02%)

        2.001391016  seconds time elapsed

Cc: David S. Miller <davem@davemloft.net>
Cc: Frédéric 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: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <4bf28fe8.914ed80a.01ca.fffff5f5@mx.google.com>
Signed-off-by: NStephane Eranian <eranian@google.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Convert to the transactional PMU API and remove the duplication of
group_sched_in().

[cross build only]
Signed-off-by: NLin Ming <ming.m.lin@intel.com>
Acked-by: NDavid Miller <davem@davemloft.net>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1272002193.5707.65.camel@minggr.sh.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Since the x86 XCHG ins implies LOCK, avoid the use by
using a sequence count instead.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Since there is now only a single writer, we can use
local_t instead and avoid all these pesky LOCK insn.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Since we can now assume there is only a single writer
to each buffer, we can remove per-cpu lock thingy and
use a simply nest-count to the same effect.

This removes the need to disable IRQs.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Since we now have working per-task-per-cpu events for
a while, disallow mmap() on per-task inherited
events. Those things were a performance problem
anyway, and doing away with it allows us to optimize
the buffer somewhat by assuming there is only a
single writer.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Ensure cpu bound buffers live on the right NUMA node.
Suggested-by: NStephane Eranian <eranian@google.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1274114880.5605.5236.camel@twins>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

In case the sampling buffer has no "payload" pages,
nr_pages is 0. The problem is that the error path in
perf_output_begin() skips to a label which assumes
perf_output_lock() has been issued which is not the
case. That triggers a WARN_ON() in
perf_output_unlock().

This patch fixes the problem by skipping
perf_output_unlock() in case data->nr_pages is 0.
Signed-off-by: NStephane Eranian <eranian@google.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4bf13674.014fd80a.6c82.ffffb20c@mx.google.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

When we've got but a single event per tracepoint
there is no reason to try and multiplex it so don't.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: NIngo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Tested-by: NLin Ming <ming.m.lin@intel.com>
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
LKML-Reference: <1274174954.22793.17.camel@minggr.sh.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

It might happen that an event can overflow without
the proper overflow flag set. Check the sign bit in
the raw counter value to solve this problem.
Tested-by: NLin Ming <ming.m.lin@intel.com>
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: fweisbec@gmail.com
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <1274083984.6540.15.camel@minggr.sh.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

slang versions <= 2.0.6 have a "#if HAVE_LONG_LONG" that breaks the
build if it isn't defined. Use the equivalent one that glibc has on
features.h.
Reported-by: NSteven Rostedt <rostedt@goodmis.org>
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: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Check elfutils version, and if it is old don't compile CFI analysis code. This
allows to compile perf with old elfutils.
Signed-off-by: NMasami Hiramatsu <mhiramat@redhat.com>
Tested-by: NStephane Eranian <eranian@google.com>
Reported-by: NRobert Richter <robert.richter@amd.com>
Cc: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <20100510171207.26029.97604.stgit@localhost6.localdomain6>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

make NO_NEWT=1

Will avoid building the newt (tui) support.
Suggested-by: NIngo Molnar <mingo@elte.hu>
LKML-Reference: <new-submission>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

That happened for an old perf.data file that had no fake MMAP events for
the kernel modules, but even then it should warn once for each module,
not one time for every symbol in every module not found.
Reported-by: NIngo Molnar <mingo@elte.hu>
LKML-Reference: <new-submission>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

At least on rawhide using -lnewt is not enough if we use SLang routines
directly, so add an explicit -lslang since we use SLang routines.
Reported-by: NIngo Molnar <mingo@elte.hu>
Tested-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

OPT_SET_INT was renamed to OPT_SET_UINT since the only use in these
tools is to set something that has an enum type, that is builtin
compatible with unsigned int.

Several string constifications were done to make OPT_STRING require a
const char * type.

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>

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>

To avoid problems like the one fixed by Stephane Eranian in 3de29cab, now
we'll got this instead:

	bench/sched-messaging.c:259: error: negative width in bit-field ‘<anonymous>’
	bench/sched-messaging.c:261: error: negative width in bit-field ‘<anonymous>’

Which is rather cryptic, but is how BUILD_BUG_ON_ZERO works, so kernel
hackers should be already used to this.

With it in place found some problems, fixed by changing the affected
variables to sensible types or changed some OPT_INTEGER to OPT_UINTEGER.

Next csets will go thru converting each of the remaining OPT_ so that
review can be made easier by grouping changes per type per patch.

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>

For unsigned int options to be parsed, next patches will make use of it.

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>

Older versions of the slang library didn't used the 'const' specifier,
causing problems with modern compilers of this kind:

util/newt.c:252: error: passing argument 1 of ‘SLsmg_printf’ discards
qualifiers from pointer target type

Fix it by using some wrappers that when needed const the affected
parameters back to plain (char *).
Reported-by: NLin Ming <ming.m.lin@intel.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Lin Ming <ming.m.lin@intel.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: <20100517145421.GD29052@ghostprotocols.net>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The -c option defines the user requested sampling period. It was implemented
using an unsigned int variable but the type of the option was OPT_LONG. Thus,
the option parser was overwriting memory belonging to other variables, namely
the mmap_pages leading to a zero page sampling buffer. The bug was exposed only
when compiling at -O0, probably because the compiler was padding variables at
higher optimization levels.

This patch fixes this problem by declaring user_interval as u64. This also
avoids wrap-around issues for large period on 32-bit systems.

Commiter note:

Made it use OPT_U64(user_interval) after implementing OPT_U64 in the
previous patch.

Cc: David S. Miller <davem@davemloft.net>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <4bf11ae9.e88cd80a.06b0.ffffa8e3@mx.google.com>
Signed-off-by: NStephane Eranian <eranian@google.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

We have things like user_interval (-c/--count) in 'perf record' that
needs this.

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>

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

In fact it is now added to the hot key list when newt_form__new is used,
allowing us to remove the explicit assignment in all its users.

The visible change is that <- will exit the menu that pops up when -> is
pressed (and Enter when callchains are not being used).
Suggested-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>
LKML-Reference: <new-submission>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

'D'/'d' for zooming into the DSO in the current highlighted hist entry,
'T'/'t' for zooming into the current thread.
Suggested-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>
LKML-Reference: <new-submission>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

ESC still asks for confirmation.
Suggested-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>
LKML-Reference: <new-submission>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

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

Right now that means that pressing the left arrow willl make the symbol
annotation window to exit back to the main symbol histogram browser.

This is another improvement on the UI fastpath, i.e. just the arrows and
enter are enough for most browsing.
Suggested-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>
LKML-Reference: <new-submission>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Jaswinder reported this #GP:

 |
 | Message from syslogd@ht at May 14 09:39:32 ...
 | kernel:[  314.908612] EIP: [<c100ccca>]
 | x86_perf_event_set_period+0x19d/0x1b2 SS:ESP 0068:edac3d70
 |

Ming has narrowed it down to a comparision issue
between arguments with different sizes and
signs. As result event index reached a wrong
value which in turn led to a GP fault.

At the same time it was found that p4_next_cntr
has broken logic and should return the counter
index only if it was not yet borrowed for
another event.
Reported-by: NJaswinder Singh Rajput <jaswinderlinux@gmail.com>
Reported-by: NLin Ming <ming.m.lin@intel.com>
Bisected-by: NLin Ming <ming.m.lin@intel.com>
Tested-by: NJaswinder Singh Rajput <jaswinderlinux@gmail.com>
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
CC: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20100514190815.GG13509@lenovo>
Signed-off-by: NIngo Molnar <mingo@elte.hu>