When an IP with an unresolved symbol occurs in the callchain more than
once (ie. recursion), then duplicate symbols can be created because
the callchain nodes are never updated after they are first created.

To fix this issue we call dso__find_symbol whenever we encounter a NULL
symbol, in case we already added a symbol at that IP since we started
traversing the callchain.

This change prevents duplicate symbols from being exported when duplicate
IPs are present in the callchain.
Signed-off-by: NChris Phlipot <cphlipot0@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1462937209-6032-5-git-send-email-cphlipot0@gmail.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Remove the call to map_ip() to adjust al.addr, because it has already
been called when assembling the callchain, in:

  thread__resolve_callchain_sample(perf_sample)
      add_callchain_ip(ip = perf_sample->callchain->ips[j])
          thread__find_addr_location(addr = ip)
              thread__find_addr_map(addr) {
                  al->addr = addr
                  if (al->map)
                      al->addr = al->map->map_ip(al->map, al->addr);
              }

Calling it a second time can result in incorrect addresses being used.
This can have effects such as duplicate symbols being created and
exported.
Signed-off-by: NChris Phlipot <cphlipot0@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1462937209-6032-4-git-send-email-cphlipot0@gmail.com
[ Show the callchain where it is done, to help reviewing this change down the line ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Use the dso__insert_symbol function instead of symbols__insert() in
order to properly update the dso symbol cache.

If the cache is not updated, then duplicate symbols can be
unintentionally created, inserted, and exported.

This change prevents duplicate symbols from being exported due to
dso__find_symbol() using a stale symbol cache.
Signed-off-by: NChris Phlipot <cphlipot0@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1462937209-6032-3-git-send-email-cphlipot0@gmail.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The exported sample now contains a reference to the call_path_id that
represents its callchain.

While callchains themselves are nice to have, being able to associate
them with samples makes them much more useful, and can allow for such
things as determining how much cumulative time is spent in a particular
function. This information is normally possible to get from the call
return processor. However, when doing normal sampling, call/return
information is not available, thus necessitating the need for
associating samples directly with call paths.

This commit include changes to db-export layer to make this information
available for subsequent patches in this change set, but by itself, does
not make any changes visible to the user.
Signed-off-by: NChris Phlipot <cphlipot0@gmail.com>
Acked-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1461831551-12213-5-git-send-email-cphlipot0@gmail.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

This change enables the db export api to export callchains. This is
accomplished by adding callchains obtained from samples to the
call_path_root structure and exporting them via the current call path
export API.

While the current API does support exporting call paths, this is not
supported when sampling. This commit addresses that missing feature by
allowing the export of call paths when callchains are present in
samples.

Summary:

- This feature is activated by initializing the call_path_root member
  inside the db_export structure to a non-null value.

- Callchains are resolved with thread__resolve_callchain() and then stored
  and exported by adding a call path under call path root.
- Symbol and DSO for each callchain node are exported via db_ids_from_al()

This commit puts in place infrastructure to be used by subsequent commits,
and by itself, does not introduce any user-visible changes.
Signed-off-by: NChris Phlipot <cphlipot0@gmail.com>
Acked-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1461831551-12213-4-git-send-email-cphlipot0@gmail.com
[ Made adjustments suggested by Adrian Hunter, see thread via this cset's Link: tag ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Move the call path handling code out of thread-stack.c and
thread-stack.h to allow other components that are not part of
thread-stack to create call paths.

Summary:

- Create call-path.c and call-path.h and add them to the build.

- Move all call path related code out of thread-stack.c and thread-stack.h
  and into call-path.c and call-path.h.

- A small subset of structures and functions are now visible through
  call-path.h, which is required for thread-stack.c to continue to
  compile.

This change is a prerequisite for subsequent patches in this change set
and by itself contains no user-visible changes.
Signed-off-by: NChris Phlipot <cphlipot0@gmail.com>
Acked-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1461831551-12213-3-git-send-email-cphlipot0@gmail.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Since none of the perf_event fields are used anymore, just the
perf_sample ones, and since this resolves to (map, symbol) from data
structures within struct thread, rename it to thread__resolve and make
the argument ordering similar to the one in machine__resolve().

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-2b33hs9bp550tezzlhl4kejh@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Thread ref-counting was not done for get_main_thread() meaning that
there was a thread__get() from machine__find_thread() that was not being
paired with thread__put(). Fix that.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1432906425-9911-2-git-send-email-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

In addition to using refcounts for the struct thread lifetime
management, we need to protect access to machine->threads from
concurrent access.

That happens in 'perf top', where a thread processes events, inserting
and deleting entries from that rb_tree while another thread decays
hist_entries, that end up dropping references and ultimately deleting
threads from the rb_tree and releasing its resources when no further
hist_entry (or other data structures, like in 'perf sched') references
it.

So the rule is the same for refcounts + protected trees in the kernel,
get the tree lock, find object, bump the refcount, drop the tree lock,
return, use object, drop the refcount if no more use of it is needed,
keep it if storing it in some other data structure, drop when releasing
that data structure.

I.e. pair "t = machine__find(new)_thread()" with a "thread__put(t)", and
"perf_event__preprocess_sample(&al)" with "addr_location__put(&al)".

The addr_location__put() one is because as we return references to
several data structures, we may end up adding more reference counting
for the other data structures and then we'll drop it at
addr_location__put() time.
Acked-by: NDavid Ahern <dsahern@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-bs9rt4n0jw3hi9f3zxyy3xln@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

As it comes from address_location->thread, that is already stored as
export_sample->al, where the thread can be obtained.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/20150402141542.GA9630@kernel.org
Link: http://lkml.kernel.org/n/tip-bzotbl4epoztw0jd6sm2stpf@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

As it is available via another parameter, address_location->thread.
Acked-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: lkml.kernel.org/r/551D08F8.3040706@intel.com
Link: http://lkml.kernel.org/n/tip-6dbn0tcm9hyv92g7h3zj2dbt@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Tracing for a workload begins before the comm event is seen, which
results in the initial comm having a string of the form ":<pid>" (e.g.
":12345").

In order to export the correct string, defer the export until the new
script 'flush' callback.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
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/r/1414678188-14946-8-git-send-email-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Make it possible for the database export API to use the enhanced thread
stack and export detailed information about paired calls and returns.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
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/r/1414678188-14946-6-git-send-email-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Add the ability to export branch types through the database export
facility.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
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/r/1414678188-14946-3-git-send-email-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

This patch introduces an abstraction for exporting sample data in a
database-friendly way.  The abstraction does not implement the actual
output.  A subsequent patch takes this facility into use for extending
the script interface.

The abstraction is needed because static data like symbols, dsos, comms
etc need to be exported only once.  That means allocating them a unique
identifier and recording it on each structure.  The member 'db_id' is
used for that.  'db_id' is just a 64-bit sequence number.

Exporting centres around the db_export__sample() function which exports
the associated data structures if they have not yet been allocated a
db_id.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
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/r/1414061124-26830-6-git-send-email-adrian.hunter@intel.com
[ committer note: Stash db_id using symbol_conf.priv_size + symbol__priv() and foo->priv areas ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>