A number of builtin commands process some user args and then pass the rest to
cmd_record. cmd_record then saves argc/argv that it receives into the header of
the perf data file. But this loses the arguments handled by the first command
-- ie., the real command line from the user. This patch saves the command line
as typed by the user rather than what was passed to cmd_record.

As an example consider the command:
$ perf kvm --guest --host --guestmount=/tmp/guest-mount record
    -fo /tmp/perf.data -ag -- sleep 10

Currently the command saved to the header is:
    cmdline : /tmp/p3.5/perf record -o perf.data.kvm -fo /tmp/perf.data -ag -- sleep 1

(ignore the duplicated -o -- the first would be yet another bug with perf-kvm).

With this patch the command line saved to the header is:
cmdline : /tmp/p3.5/perf kvm --guest --host --guestmount=/tmp/guest-mount
    record -fo /tmp/perf.data -ag -- sleep 1

v2: simplified to saving the command in parse_options per Stephane's suggestion
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1343616831-6408-1-git-send-email-dsahern@gmail.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Removing perf_session->id_hdr_size, as it can be obtained from the
evsel/evlist.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-1nwc2kslu7gsfblu98xbqbll@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

So that we don't use global variables that could make us misreport event
names when having a multi window top, for instance.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-mccancovi1u0wdkg8ncth509@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

There were places where use ui__warning (or even fprintf) to show
critical messages. This patch converts them to ui__error so that the
front-end code can implement appropriate behavior.
Signed-off-by: NNamhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1338265382-6872-3-git-send-email-namhyung@gmail.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Quoting Ingo:

"While at it I'd also suggest increasing the default sampling frequency,
from 1000 Hz per CPU to at least 4Khz auto-freq or so - this should work
well all across the board I think. CPUs are getting faster and command/app
run times are getting shorter, 1Khz is a bit low IMO."
Requested-by: NIngo Molnar <mingo@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-2jafa6mkrufyekny9ei59lpu@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To match the PERF_RECORD_HEADER_TRACING_DATA record type.

This is the same info as the one used for pipe mode whereas the other
one is for regular file output. This will help in the later patch to add
meta-data infos in pipe mode.
Signed-off-by: NStephane Eranian <eranian@google.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1337081295-10303-4-git-send-email-eranian@google.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

If perf doesn't mmap on event (like perf stat), it should not create
per-task-per-cpu events. So just use a dummy cpu map to create a
per-task event for this case.
Signed-off-by: NNamhyung Kim <namhyung.kim@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1337161549-9870-3-git-send-email-namhyung.kim@lge.com
[ committer note: renamed .need_mmap to .uses_mmap ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

perf-record defaults to the H/W cycles event and if it is not supported
falls back to cpu-clock. Reset the event name as well.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Link: http://lkml.kernel.org/r/1336495811-58461-1-git-send-email-dsahern@gmail.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

perf-record on PPC is not falling back to cpu-clock:

$ perf record -ag -fo /tmp/perf.data -- sleep 1

  Error: sys_perf_event_open() syscall returned with 6 (No such device or address).  /bin/dmesg may provide additional information.

  Fatal: No CONFIG_PERF_EVENTS=y kernel support configured?

The problem is that until 2.6.37 (behavior changed with commit b0a873eb)
perf on PPC returns ENXIO when hw_perf_event_init() fails. With this
patch we get the expected behavior:

$ perf record -ag -fo /tmp/perf.data -v -- sleep 1
Old kernel, cannot exclude guest or host samples.
The cycles event is not supported, trying to fall back to cpu-clock-ticks
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.151 MB /tmp/perf.data (~6592 samples) ]
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1336490937-57106-1-git-send-email-dsahern@gmail.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

There are places that check whether target task/cpu is given or not and
some of them didn't check newly introduced uid or cpu list. Add and use
three of helper functions to treat them properly.
Signed-off-by: NNamhyung Kim <namhyung.kim@lge.com>
Reviewed-by: NDavid Ahern <dsahern@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1336367344-28071-7-git-send-email-namhyung.kim@lge.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The perf_target__strerror() sets @buf to a string that describes the
(perf_target-specific) error condition that is passed via @errnum.

This is similar to strerror_r() and does same thing if @errnum has a
standard errno value.
Signed-off-by: NNamhyung Kim <namhyung.kim@lge.com>
Suggested-by: NArnaldo Carvalho de Melo <acme@ghostprotocols.net>
Reviewed-by: NDavid Ahern <dsahern@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1336367344-28071-6-git-send-email-namhyung.kim@lge.com
[ committer note: No need to use PERF_ERRNO_TARGET__SUCCESS, use shorter idiom ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Add and use the modern perf_target__parse_uid() and get rid of the old
parse_target_uid().
Signed-off-by: NNamhyung Kim <namhyung.kim@lge.com>
Reviewed-by: NDavid Ahern <dsahern@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1336367344-28071-5-git-send-email-namhyung.kim@lge.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Now we have all information that needed to create cpu/thread maps in
struct perf_target, it'd be better using it as an argument.
Signed-off-by: NNamhyung Kim <namhyung.kim@lge.com>
Reviewed-by: NDavid Ahern <dsahern@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1335417327-11796-6-git-send-email-namhyung.kim@lge.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The perf_target__validate function is used to check given PID/TID/UID/CPU
target options and warn if some combination is impossible. Also this can
make some arguments of parse_target_uid() function useless as it is checked
before the call via our new helper.
Signed-off-by: NNamhyung Kim <namhyung.kim@lge.com>
Reviewed-by: NDavid Ahern <dsahern@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1335417327-11796-5-git-send-email-namhyung.kim@lge.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The perf_target struct will be used for taking care of cpu/thread maps
based on user's input. Since it is used on various subcommands it'd
better factoring it out.

Thanks to Arnaldo for suggesting the better name.
Signed-off-by: NNamhyung Kim <namhyung.kim@lge.com>
Reviewed-by: NDavid Ahern <dsahern@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1335417327-11796-2-git-send-email-namhyung.kim@lge.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Use cpu-clock-tick sw counter for cpu-cycles only if there is no hw
pmu available. This is the case if the syscall reports ENOENT. In
other cases (e.g. invalid attributes) we don't want the sw counter to
be used.

Cc: Ingo Molnar <mingo@kernel.org>
Link: http://lkml.kernel.org/r/1333643188-26895-5-git-send-email-robert.richter@amd.comSigned-off-by: NRobert Richter <robert.richter@amd.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

This patch adds a new feature bit, namely,
HEADER_BRANCH_STACK.  When present, it indicates
that sample records may contain branch stack.

This could be useful to a viewer to switch to
branch mode without having to parse all the
samples or without a specific cmdline option.

This will be used in a subsequent patch to
enhance perf report with branch stacks.
Signed-off-by: NStephane Eranian <eranian@google.com>
Cc: peterz@infradead.org
Cc: acme@redhat.com
Cc: asharma@fb.com
Cc: ravitillo@lbl.gov
Cc: vweaver1@eecs.utk.edu
Cc: khandual@linux.vnet.ibm.com
Cc: dsahern@gmail.com
Link: http://lkml.kernel.org/r/1331246868-19905-3-git-send-email-eranian@google.comSigned-off-by: NIngo Molnar <mingo@elte.hu>

This patch chanegs the logic of the -b, --branch-stack options
of perf record.

Based on users' request, the patch provides a default filter
mode with the -b (or --branch-any) option.  With the option,
any type of taken branches is sampled.

With -j (or --branch-filter), the user can specify any
valid combination of branch types and privilege levels
if supported by the underlying hardware.

The -b (--branch any) is a shortcut for: --branch-filter any.

 $ perf record -b foo

or:

 $ perf record --branch-filter any foo

For more specific filtering:

 $ perf record --branch-filter ind_call,u foo
Signed-off-by: NStephane Eranian <eranian@google.com>
Cc: peterz@infradead.org
Cc: acme@redhat.com
Cc: asharma@fb.com
Cc: ravitillo@lbl.gov
Cc: vweaver1@eecs.utk.edu
Cc: khandual@linux.vnet.ibm.com
Cc: dsahern@gmail.com
Link: http://lkml.kernel.org/r/1331246868-19905-2-git-send-email-eranian@google.comSigned-off-by: NIngo Molnar <mingo@elte.hu>

This patch adds a new option to enable taken branch stack
sampling, i.e., leverage the PERF_SAMPLE_BRANCH_STACK feature
of perf_events.

There is a new option to active this mode: -b.
It is possible to pass a set of filters to select the type of
branches to sample.

The following filters are available:

 - any : any type of branches
 - any_call : any function call or system call
 - any_ret : any function return or system call return
 - any_ind : any indirect branch
 - u:  only when the branch target is at the user level
 - k: only when the branch target is in the kernel
 - hv: only when the branch target is in the hypervisor

Filters can be combined by passing a comma separated list
to the option:

$ perf record -b any_call,u -e cycles:u branchy
Signed-off-by: NRoberto Agostino Vitillo <ravitillo@lbl.gov>
Signed-off-by: NStephane Eranian <eranian@google.com>
Cc: peterz@infradead.org
Cc: acme@redhat.com
Cc: robert.richter@amd.com
Cc: ming.m.lin@intel.com
Cc: andi@firstfloor.org
Cc: asharma@fb.com
Cc: vweaver1@eecs.utk.edu
Cc: khandual@linux.vnet.ibm.com
Cc: dsahern@gmail.com
Link: http://lkml.kernel.org/r/1328826068-11713-13-git-send-email-eranian@google.comSigned-off-by: NIngo Molnar <mingo@elte.hu>

Just fall back to resetting those fields, if set, warning the user that
that feature is not available.

If guest samples appear they will just be discarded because no struct
machine will be found and thus the event will be accounted as not
handled and dropped, see 0c095715.
Reported-by: NNamhyung Kim <namhyung@gmail.com>
Tested-by: NJoerg Roedel <joerg.roedel@amd.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Joerg Roedel <joerg.roedel@amd.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>
Link: http://lkml.kernel.org/n/tip-vuwxig36mzprl5n7nzvnxxsh@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

A recent refactoring of perf-record introduced the following:

perf record -a -B
Couldn't generating buildids. Use --no-buildid to profile anyway.
sleep: Terminated

I believe the triple negative was meant to be only a double negative.
:-) While I'm there, fixed the grammar on the error message.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1328567272-13190-1-git-send-email-dsahern@gmail.comSigned-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Instead of requiring that users of perf_record_opts set
.sample_id_all_avail to true, just invert the logic, using
.sample_id_all_missing, that doesn't need to be explicitely initialized
since gcc will zero members ommitted in a struct initialization.

Just like the newly introduced .exclude_{guest,host} feature test.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic 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>
Link: http://lkml.kernel.org/n/tip-ab772uzk78cwybihf0vt7kxw@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Just fall back to resetting those fields, if set, warning the user that
that feature is not available.

If guest samples appear they will just be discarded because no struct
machine will be found and thus the event will be accounted as not
handled and dropped, see 0c095715.
Reported-by: NNamhyung Kim <namhyung@gmail.com>
Tested-by: NJoerg Roedel <joerg.roedel@amd.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Joerg Roedel <joerg.roedel@amd.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>
Link: http://lkml.kernel.org/n/tip-vuwxig36mzprl5n7nzvnxxsh@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Allow a user to collect events for multiple threads or processes
using a comma separated list.

e.g., collect data on a VM and its vhost thread:
  perf top -p 21483,21485
  perf stat -p 21483,21485 -ddd
  perf record -p 21483,21485

or monitoring vcpu threads
  perf top -t 21488,21489
  perf stat -t 21488,21489 -ddd
  perf record -t 21488,21489

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1328718772-16688-1-git-send-email-dsahern@gmail.comSigned-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

A recent refactoring of perf-record introduced the following:

perf record -a -B
Couldn't generating buildids. Use --no-buildid to profile anyway.
sleep: Terminated

I believe the triple negative was meant to be only a double negative.
:-) While I'm there, fixed the grammar on the error message.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1328567272-13190-1-git-send-email-dsahern@gmail.comSigned-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Loop over all features to enable it instead of explicitly enabling every
single feature. Reducing duplicate code and making it more robust to
later changes e.g. when adding more features.

Cc: Ingo Molnar <mingo@elte.hu>
Link: http://lkml.kernel.org/r/1323966762-8574-3-git-send-email-robert.richter@amd.comSigned-off-by: NRobert Richter <robert.richter@amd.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The new --uid command line option will show only the tasks for a given
user, using the proc interface to figure out the existing tasks.

Kernel work is needed to close races at startup, but this should already
be useful in many use cases.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic 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>
Link: http://lkml.kernel.org/n/tip-bdnspm000gw2l984a2t53o8z@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The features HEADER_TRACE_INFO and HEADER_BUILD_ID are handled
different when writing the feature section. All other features are
simply disabled on failure and writing the section goes on without
returning an error. There is no reason for these special cases. This
patch unifies handling of the features.

This should be ok since all features can be parsed independently.
Offset and size of a feature's block is stored in struct perf_file_
section right after the data block of perf.data (see perf_session__
write_header()). Thus, if a feature does not exist then other features
can be processed anyway.

Also moving special code for HEADER_BUILD_ID out to write_build_id().

v2:
* perf record throws an error now if buildids may not be generated,
  which can be disabled with the --no-buildid option.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1323248577-11268-6-git-send-email-robert.richter@amd.comSigned-off-by: NRobert Richter <robert.richter@amd.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Now that we automatically point users at it, let's provide them some
guidance so that they hopefully don't just get mysterious EINVAL's
from the kernel.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1324301972-22740-4-git-send-email-nelhage@nelhage.comSigned-off-by: NNelson Elhage <nelhage@nelhage.com>
[ committer note: Made it work after 50a682ce ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

This failure is most likely due to running up against the
kernel.perf_event_mlock_kb sysctl, so we can tell the user what to do to
fix the issue.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1324301972-22740-3-git-send-email-nelhage@nelhage.comSigned-off-by: NNelson Elhage <nelhage@nelhage.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The problem is that when SAMPLE_PERIOD is not set, the kernel generates
a number of samples in proportion to an event's period. Number of these
samples may be too big and the kernel throttles all samples above a
defined limit.

E.g.: I want to trace when a process sleeps. I created a process which
sleeps for 1ms and for 4ms.  perf got 100 events in both cases.

swapper 0 [000] 1141.371830: sched_stat_sleep: comm=foo pid=1801 delay=1386750 [ns]
swapper 0 [000] 1141.369444: sched_stat_sleep: comm=foo pid=1801 delay=4499585 [ns]

In the first case a kernel want to send 4499585 events and in the second
case it wants to send 1386750 events.  perf-reports shows that process
sleeps in both places equal time.

Instead of this we can get only one sample with an attribute period. As
result we have less data transferring between kernel and user-space and
we avoid throttling of samples.

The patch "events: Don't divide events if it has field period" added a
kernel part of this functionality.
Acked-by: NArun Sharma <asharma@fb.com>
Cc: Arun Sharma <asharma@fb.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: devel@openvz.org
Link: http://lkml.kernel.org/r/1324391565-1369947-1-git-send-email-avagin@openvz.orgSigned-off-by: NAndrew Vagin <avagin@openvz.org>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

At first tools were required to do that, but while writing the python
bindings to simplify the API I made them auto-allocate when needed.

This just makes record, stat and top use that auto allocation,
simplifying them a bit.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic 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>
Link: http://lkml.kernel.org/n/tip-iokhcvkzzijr3keioubx8hlq@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To better reflect that it became the base class for all tools, that must
be in each tool struct and where common stuff will be put.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic 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>
Link: http://lkml.kernel.org/n/tip-qgpc4msetqlwr8y2k7537cxe@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Reducing the exposure of perf_session further, so that we can use the
classes in cases where no perf.data file is created.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic 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>
Link: http://lkml.kernel.org/n/tip-stua66dcscsezzrcdugvbmvd@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

So that we don't need to have that many globals.

Next steps will remove the 'session' pointer, that in most cases is
not needed.

Then we can rename perf_event_ops to 'perf_tool' that better describes
this class hierarchy.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic 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>
Link: http://lkml.kernel.org/n/tip-wp4djox7x6w1i2bab1pt4xxp@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Will be used in other tools to share the command line parsing code.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic 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>
Link: http://lkml.kernel.org/n/tip-8x0yr77r6lrd2t699s499m8n@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Tools being developed will need this to allow the user to override this
value.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic 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>
Link: http://lkml.kernel.org/n/tip-zydc1yhxfm0z35fuy95bsn1l@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Every tool that calls this and allows the user to override the value
needs this logic.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic 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>
Link: http://lkml.kernel.org/n/tip-lwscxpg57xfzahz5dmdfp9uz@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

So that we can easily start a workload in other tools.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic 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>
Link: http://lkml.kernel.org/n/tip-zdsksd4aphu0nltg2lpwsw3x@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Out of the code in 'perf record', so that we can share option parsing,
etc. Eventually will be used by 'perf top', but first 'trace' will use
it.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic 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>
Link: http://lkml.kernel.org/n/tip-hzjqsgnte1esk90ytq0ap98v@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>