Reducing the size of symbol.h by removing things that are better placed
somewhere else.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-edenkmjt1oe5fks2s6umd30b@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To be compliant with XDG user directory layout, the user's plugin
directory is changed from ~/.traceevent/plugins to
~/.local/lib/traceevent/plugins/
Suggested-by: NPatrick McLean <chutzpah@gentoo.org>
Signed-off-by: NTzvetomir Stoyanov <tstoyanov@vmware.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Patrick McLean <chutzpah@gentoo.org>
Cc: linux-trace-devel@vger.kernel.org
Link: https://lore.kernel.org/linux-trace-devel/20190313144206.41e75cf8@patrickm/
Link: http://lore.kernel.org/linux-trace-devel/20190801074959.22023-4-tz.stoyanov@gmail.com
Link: http://lore.kernel.org/lkml/20190805204355.344622683@goodmis.orgSigned-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The tep_register_trace_clock() API is used to instruct the traceevent
library how to print the event time stamps. As event print interface if
redesigned, this API is not needed any more.  The new event print API is
flexible and the user can specify how the time stamps are printed.
Signed-off-by: NTzvetomir Stoyanov <tstoyanov@vmware.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Patrick McLean <chutzpah@gentoo.org>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/linux-trace-devel/20190801074959.22023-3-tz.stoyanov@gmail.com
Link: http://lore.kernel.org/lkml/20190805204355.195042846@goodmis.orgSigned-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Libtraceevent APIs for printing various trace events information are
complicated, there are complex extra parameters. To control the way
event information is printed, the user should call a set of functions in
a specific sequence.

These APIs are reimplemented to provide a more simple interface for
printing event information.

Removed APIs:

 	tep_print_event_task()
	tep_print_event_time()
	tep_print_event_data()
	tep_event_info()
	tep_is_latency_format()
	tep_set_latency_format()
	tep_data_latency_format()
	tep_set_print_raw()

A new API for printing event information is introduced:
   void tep_print_event(struct tep_handle *tep, struct trace_seq *s,
		        struct tep_record *record, const char *fmt, ...);
where "fmt" is a printf-like format string, followed by the event
fields to be printed. Supported fields:
 TEP_PRINT_PID, "%d" - event PID
 TEP_PRINT_CPU, "%d" - event CPU
 TEP_PRINT_COMM, "%s" - event command string
 TEP_PRINT_NAME, "%s" - event name
 TEP_PRINT_LATENCY, "%s" - event latency
 TEP_PRINT_TIME, %d - event time stamp. A divisor and precision
   can be specified as part of this format string:
   "%precision.divisord". Example:
   "%3.1000d" - divide the time by 1000 and print the first 3 digits
   before the dot. Thus, the time stamp "123456000" will be printed as
   "123.456"
 TEP_PRINT_INFO, "%s" - event information.
 TEP_PRINT_INFO_RAW, "%s" - event information, in raw format.

Example:
  tep_print_event(tep, s, record, "%16s-%-5d [%03d] %s %6.1000d %s %s",
		  TEP_PRINT_COMM, TEP_PRINT_PID, TEP_PRINT_CPU,
		  TEP_PRINT_LATENCY, TEP_PRINT_TIME, TEP_PRINT_NAME, TEP_PRINT_INFO);
Output:
	ls-11314 [005] d.h. 185207.366383 function __wake_up
Signed-off-by: NTzvetomir Stoyanov <tstoyanov@vmware.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-trace-devel@vger.kernel.org
Cc: Patrick McLean <chutzpah@gentoo.org>
Link: http://lore.kernel.org/linux-trace-devel/20190801074959.22023-2-tz.stoyanov@gmail.com
Link: http://lore.kernel.org/lkml/20190805204355.041132030@goodmis.orgSigned-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

bpf.h and build-id.h are not needed at all in event.h, remove them.

And fixup the fallout of files that were getting needed stuff from this
now pruned include.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-rdm3dgtlrndmmnlc4bafsg3b@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

And fixup the fallout of c files not building due to now missing
headers.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-sw8k3kpla98pr3rqypbjk9hf@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

All we need there is a forward declaration for 'union perf_event', so
remove it from there and add missing header directives in places using
things from this indirect include.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-7ftk0ztstqub1tirjj8o8xbl@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

And fix the fallout, adding it to places that must have it since they
use its definitions.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-1s3jel4i26chq2g0lydoz7i3@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

With the movement of lots of stuff out of perf.h to other headers we
ended up not needing it in lots of places, remove it from those places.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-c718m0sxxwp73lp9d8vpihb4@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Its not needed there, add it to the places that need it and were getting
it via those headers.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-5yulx1u16vyd0zmrbg1tjhju@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Seems to be a better place for this function to live, further shrinking
the hodge-podge that perf.h was.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-0zzt1u9rpyjukdy1ccr2u5r9@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

And remove unneeded include directives from perf-sys.h to prune the
header dependency tree.

Fixup the fallout in places where definitions were being used without
the needed include directives that were being satisfied because they
were in perf-sys.h.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-7b1zvugiwak4ibfa3j6ott7f@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To reduce perf-sys.h and eventually nuke it.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-ars2j5m3if3gypsvkbbijucq@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Remove traceevent/event-parse.h and traceevent/trace-seq.h from places
where it is not needed.

Should avoid rebuilding those files when these traceevent headers get
changed.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Tzvetomir Stoyanov <tstoyanov@vmware.com>
Link: https://lkml.kernel.org/n/tip-26hn75jn9rdealn4uqtzend6@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Display a warning when attempting to profile more than MAX_NR_CPU CPUs.
This patch should not change any behavior.
Signed-off-by: NKyle Meyer <kyle.meyer@hpe.com>
Reviewed-by: NJiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russ Anderson <russ.anderson@hpe.com>
Link: http://lore.kernel.org/lkml/20190827214352.94272-8-meyerk@stormcage.eag.rdlabs.hpecorp.netSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The function cpu__max_cpu() returns the possible number of CPUs as
defined in the sysfs and can be used as an alternative for MAX_NR_CPUS
in write_cache.

MAX_CACHES is replaced by cpu__max_cpu() * MAX_CACHE_LVL.
Signed-off-by: NKyle Meyer <kyle.meyer@hpe.com>
Reviewed-by: NJiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russ Anderson <russ.anderson@hpe.com>
Link: http://lore.kernel.org/lkml/20190827214352.94272-7-meyerk@stormcage.eag.rdlabs.hpecorp.netSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

nr_cpus, the number of CPUs online during a record session bound by
MAX_NR_CPUS, can be used as a dynamic alternative for MAX_NR_CPUS in
__machine__synthesize_threads and machine__set_current_tid.
Signed-off-by: NKyle Meyer <kyle.meyer@hpe.com>
Reviewed-by: NJiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russ Anderson <russ.anderson@hpe.com>
Link: http://lore.kernel.org/lkml/20190827214352.94272-6-meyerk@stormcage.eag.rdlabs.hpecorp.netSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

nr_cpus, the number of CPUs online during a record session bound by
MAX_NR_CPUS, can be used as a dynamic alternative for MAX_NR_CPUS in
perf_session__cpu_bitmap.
Signed-off-by: NKyle Meyer <kyle.meyer@hpe.com>
Reviewed-by: NJiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russ Anderson <russ.anderson@hpe.com>
Link: http://lore.kernel.org/lkml/20190827214352.94272-5-meyerk@stormcage.eag.rdlabs.hpecorp.netSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The function cpu__max_cpu() returns the possible number of CPUs as
defined in the sysfs and can be used as an alternative for MAX_NR_CPUS
in zero_per_pkg() and check_per_pkg().
Signed-off-by: NKyle Meyer <kyle.meyer@hpe.com>
Reviewed-by: NJiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russ Anderson <russ.anderson@hpe.com>
Link: http://lore.kernel.org/lkml/20190827214352.94272-4-meyerk@stormcage.eag.rdlabs.hpecorp.netSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

'nr_cpus', the number of CPUs online during a record session bound by
MAX_NR_CPUS, can be used as a dynamic alternative for MAX_NR_CPUS in
svg_build_topology_map().

The value of nr_cpus can be passed into str_to_bitmap(),
scan_core_topology(), and svg_build_topology_map() to replace
MAX_NR_CPUS as well.
Signed-off-by: NKyle Meyer <kyle.meyer@hpe.com>
Reviewed-by: NJiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russ Anderson <russ.anderson@hpe.com>
Link: http://lore.kernel.org/lkml/20190827214352.94272-3-meyerk@stormcage.eag.rdlabs.hpecorp.netSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Exchange the parameters of svg_build_topology_map() with 'struct
perf_env *env' and adjust the function accordingly.

This patch should not change any behavior, it is merely refactoring for
the following patch.

Committer notes:

No need to include env.h from svghelper.h, all it needs is a forward
declaration for 'struct perf_env', so move the include directive to
svghelper.c, where it is really needed.
Signed-off-by: NKyle Meyer <kyle.meyer@hpe.com>
Reviewed-by: NJiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russ Anderson <russ.anderson@hpe.com>
Link: http://lore.kernel.org/lkml/20190827214352.94272-2-meyerk@stormcage.eag.rdlabs.hpecorp.netSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

There's wrong bitmap considered when checking for cpu count of specific
node.

We do the needed computation for 'set' variable, but at the end we use
the 'c2c_he->cpuset' weight, which shows misleading numbers.

Fixes: 1e181b92 ("perf c2c report: Add 'node' sort key")
Reported-by: NJoe Mario <jmario@redhat.com>
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20190820140219.28338-1-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Merge tag 'perf-core-for-mingo-5.4-20190829' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:

perf top:

  Namhyung Kim:

  - Decay all events in the evlist, we were decaying just the first event
    in a group.

  - Fix linking of histograms in different evsels in a event group with more
    than two events.

  With the two fixes above a command line such as:

    # perf top -e '{cycles,instructions,cache-misses,cache-references}

    Should work as expected, with four columns and with all of them being
    decayed over time, i.e. less weight is given for older samples.

perf record:

  Arnaldo Carvalho de Melo:

  - Fix collection of build-ids when using setns() to get into namespaces,
    which had been broken with the introduction of the extra thread to
    react to PERF_RECORD_BPF_EVENT, i.e. to collect extra info for BPF
    programs. We need to unshare(CLONE_FS) in that thread so that the
    main one can do the setns(CLONE_NEWNS) when collectingthe build-ids.
    Without that symbol resolution gets more difficult and potentially
    misresolves symbols.

core:

  Igor Lubashev:

  - Further alignment in permission checking via capabilities to how the
    kernel checks what tooling tries to do.

PowerPC:

  Naveen N. Rao:

  - Sync powerpc syscall.tbl, so that 'perf trace' gets the definitions
    for recent syscalls.

libperf:

  Jiri Olsa:

  - Move the rest of the PERF_RECORD_ metadata struct definitions so that
    we can use 'union perf_event'.

libtraceevent:

  Steven Rostedt (VMware):

  - Do not free tep->cmdlines in add_new_comm() on failure.

  - Remove unneeded qsort and uses memmove instead
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NIngo Molnar <mingo@kernel.org>

While reading a trace data file that had 100,000s of tasks, the process
took an extremely long time. I profiled it down to add_new_comm(), which
was doing a qsort() call on an array that was pretty much already sorted
(all but the last element. qsort() isn't very efficient when dealing
with mostly sorted arrays, and this definitely showed its issues.

When adding a new task to the task list, instead of using qsort(), do
another bsearch() with a function that will find the element before
where the new task will be inserted in. Then simply shift the rest of
the array, and insert the task where it belongs.

Fixes: f7d82350 ("tools/events: Add files to create libtraceevent.a")
Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lkml.kernel.org/r/20190828191820.127233764@goodmis.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

If the re-allocation of tep->cmdlines succeeds, then the previous
allocation of tep->cmdlines will be freed. If we later fail in
add_new_comm(), we must not free cmdlines, and also should assign
tep->cmdlines to the new allocation. Otherwise when freeing tep, the
tep->cmdlines will be pointing to garbage.

Fixes: a6d2a61a ("tools lib traceevent: Remove some die() calls")
Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-trace-devel@vger.kernel.org
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20190828191819.970121417@goodmis.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

When we started using a thread to catch the PERF_RECORD_BPF_EVENT meta
data events to then ask the kernel for further info (BTF, etc) for BPF
programs shortly after they get loaded, we forgot to use
unshare(CLONE_FS) as was done in:

  868a8329 ("perf top: Support lookup of symbols in other mount namespaces.")

Do it so that we can enter the namespaces to read the build-ids at the
end of a 'perf record' session for the DSOs that had hits.

Before:

Starting a 'stress-ng --cpus 8' inside a container and then, outside the
container running:

  # perf record -a --namespaces sleep 5
  # perf buildid-list | grep stress-ng
  #

We would end up with a 'perf.data' file that had no entry in its
build-id table for the /usr/bin/stress-ng binary inside the container
that got tons of PERF_RECORD_SAMPLEs.

After:

  # perf buildid-list | grep stress-ng
  f2ed02c68341183a124b9b0f6e2e6c493c465b29 /usr/bin/stress-ng
  #

Then its just a matter of making sure that that binary debuginfo package
gets available in a place that 'perf report' will look at build-id keyed
ELF files, which, in my case, on a f30 notebook, was a matter of
installing the debuginfo file for the distro used in the container,
fedora 31:

  # rpm -ivh http://fedora.c3sl.ufpr.br/linux/development/31/Everything/x86_64/debug/tree/Packages/s/stress-ng-debuginfo-0.07.29-10.fc31.x86_64.rpm

Then, because perf currently looks for those debuginfo files (richer ELF
symtab) inside that namespace (look at the setns calls):

  openat(AT_FDCWD, "/proc/self/ns/mnt", O_RDONLY) = 137
  openat(AT_FDCWD, "/proc/13169/ns/mnt", O_RDONLY) = 139
  setns(139, CLONE_NEWNS)                 = 0
  stat("/usr/bin/stress-ng", {st_mode=S_IFREG|0755, st_size=3065416, ...}) = 0
  openat(AT_FDCWD, "/usr/bin/stress-ng", O_RDONLY) = 140
  fcntl(140, F_GETFD)                     = 0
  fstat(140, {st_mode=S_IFREG|0755, st_size=3065416, ...}) = 0
  mmap(NULL, 3065416, PROT_READ, MAP_PRIVATE, 140, 0) = 0x7ff2fdc5b000
  munmap(0x7ff2fdc5b000, 3065416)         = 0
  close(140)                              = 0
  stat("stress-ng-0.07.29-10.fc31.x86_64.debug", 0x7fff45d71260) = -1 ENOENT (No such file or directory)
  stat("/usr/bin/stress-ng-0.07.29-10.fc31.x86_64.debug", 0x7fff45d71260) = -1 ENOENT (No such file or directory)
  stat("/usr/bin/.debug/stress-ng-0.07.29-10.fc31.x86_64.debug", 0x7fff45d71260) = -1 ENOENT (No such file or directory)
  stat("/usr/lib/debug/usr/bin/stress-ng-0.07.29-10.fc31.x86_64.debug", 0x7fff45d71260) = -1 ENOENT (No such file or directory)
  stat("/root/.debug/.build-id/f2/ed02c68341183a124b9b0f6e2e6c493c465b29", 0x7fff45d711e0) = -1 ENOENT (No such file or directory)

To only then go back to the "host" namespace to look just in the users's
~/.debug cache:

  setns(137, CLONE_NEWNS)                 = 0
  chdir("/root")                          = 0
  close(137)                              = 0
  close(139)                              = 0
  stat("/root/.debug/.build-id/f2/ed02c68341183a124b9b0f6e2e6c493c465b29/elf", 0x7fff45d732e0) = -1 ENOENT (No such file or directory)

It continues to fail to resolve symbols:

  # perf report | grep stress-ng | head -5
     9.50%  stress-ng-cpu    stress-ng    [.] 0x0000000000021ac1
     8.58%  stress-ng-cpu    stress-ng    [.] 0x0000000000021ab4
     8.51%  stress-ng-cpu    stress-ng    [.] 0x0000000000021489
     7.17%  stress-ng-cpu    stress-ng    [.] 0x00000000000219b6
     3.93%  stress-ng-cpu    stress-ng    [.] 0x0000000000021478
  #

To overcome that we use:

  # perf buildid-cache -v --add /usr/lib/debug/usr/bin/stress-ng-0.07.29-10.fc31.x86_64.debug
  Adding f2ed02c68341183a124b9b0f6e2e6c493c465b29 /usr/lib/debug/usr/bin/stress-ng-0.07.29-10.fc31.x86_64.debug: Ok
  #
  # ls -la /root/.debug/.build-id/f2/ed02c68341183a124b9b0f6e2e6c493c465b29/elf
  -rw-r--r--. 3 root root 2401184 Jul 27 07:03 /root/.debug/.build-id/f2/ed02c68341183a124b9b0f6e2e6c493c465b29/elf
  # file /root/.debug/.build-id/f2/ed02c68341183a124b9b0f6e2e6c493c465b29/elf
  /root/.debug/.build-id/f2/ed02c68341183a124b9b0f6e2e6c493c465b29/elf: ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), dynamically linked, interpreter \004, BuildID[sha1]=f2ed02c68341183a124b9b0f6e2e6c493c465b29, for GNU/Linux 3.2.0, with debug_info, not stripped, too many notes (256)
  #

Now it finally works:

  # perf report | grep stress-ng | head -5
    23.59%  stress-ng-cpu    stress-ng    [.] ackermann
    23.33%  stress-ng-cpu    stress-ng    [.] is_prime
    17.36%  stress-ng-cpu    stress-ng    [.] stress_cpu_sieve
     6.08%  stress-ng-cpu    stress-ng    [.] stress_cpu_correlate
     3.55%  stress-ng-cpu    stress-ng    [.] queens_try
  #

I'll make sure that it looks for the build-id keyed files in both the
"host" namespace (the namespace the user running 'perf record' was a the
time of the recording) and in the container namespace, as it shouldn't
matter where a content based key lookup finds the ELF file to use in
resolving symbols, etc.
Reported-by: NKarl Rister <krister@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Krister Johansen <kjlx@templeofstupid.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stanislav Fomichev <sdf@google.com>
Cc: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Fixes: 657ee553 ("perf evlist: Introduce side band thread")
Link: https://lkml.kernel.org/n/tip-g79k0jz41adiaeuqud742t2l@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

So it's available for libperf's users.
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190828135717.7245-24-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Even more, to have a "perf_record_" prefix, so that they match the
PERF_RECORD_ enum they map to.
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190828135717.7245-23-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

So it's available for libperf's users.
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190828135717.7245-22-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Move the PERF_RECORD_COMPRESSED event definition to libperf's event.h.

In order to keep libperf simple, we switch 'u64/u32/u16/u8' types used
events to their generic '__u*' versions.
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190828135717.7245-21-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Move the PERF_RECORD_HEADER_FEATURE event definition to libperf's
event.h.

In order to keep libperf simple, we switch 'u64/u32/u16/u8' types used
events to their generic '__u*' versions.
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190828135717.7245-20-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Move the PERF_RECORD_TIME_CONV event definition to libperf's event.h.

In order to keep libperf simple, we switch 'u64/u32/u16/u8' types used
events to their generic '__u*' versions.
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190828135717.7245-19-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Move the PERF_RECORD_STAT_ROUND event definition to libperf's event.h.

In order to keep libperf simple, we switch 'u64/u32/u16/u8' types used
events to their generic '__u*' versions.
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190828135717.7245-18-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Move the PERF_RECORD_STAT event definition to libperf's event.h.

In order to keep libperf simple, we switch 'u64/u32/u16/u8' types used
events to their generic '__u*' versions.
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190828135717.7245-17-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Move the PERF_RECORD_STAT_CONFIG event definition to libperf's event.h.

In order to keep libperf simple, we switch 'u64/u32/u16/u8' types used
events to their generic '__u*' versions.
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190828135717.7245-16-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Move the PERF_RECORD_THREAD_MAP event definition to libperf's event.h.

In order to keep libperf simple, we switch 'u64/u32/u16/u8' types used
events to their generic '__u*' versions.
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190828135717.7245-15-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Move the PERF_RECORD_SWITCH event definition to libperf's event.h.

In order to keep libperf simple, we switch 'u64/u32/u16/u8' types used
events to their generic '__u*' versions.
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190828135717.7245-14-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Move the PERF_RECORD_ITRACE_START event definition to libperf's event.h.

In order to keep libperf simple, we switch 'u64/u32/u16/u8' types used
events to their generic '__u*' versions.
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190828135717.7245-13-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Move the PERF_RECORD_AUX event definition to libperf's event.h.

In order to keep libperf simple, we switch 'u64/u32/u16/u8' types used
events to their generic '__u*' versions.
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190828135717.7245-12-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Move the PERF_RECORD_AUXTRACE_ERROR event definition to libperf's
event.h.

In order to keep libperf simple, we switch 'u64/u32/u16/u8' types used
events to their generic '__u*' versions.
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190828135717.7245-11-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>