linux-stable.git/tools/perf, branch v5.1.7

perf intel-pt: Fix sample timestamp wrt non-taken branches

2019-05-25T16:16:39+00:00

commit 1b6599a9d8e6c9f7e9b0476012383b1777f7fc93 upstream.

The sample timestamp is updated to ensure that the timestamp represents
the time of the sample and not a branch that the decoder is still
walking towards. The sample timestamp is updated when the decoder
returns, but the decoder does not return for non-taken branches. Update
the sample timestamp then also.

Note that commit 3f04d98e972b5 ("perf intel-pt: Improve sample
timestamp") was also a stable fix and appears, for example, in v4.4
stable tree as commit a4ebb58fd124 ("perf intel-pt: Improve sample
timestamp").

Signed-off-by: Adrian Hunter 
Cc: Jiri Olsa 
Cc: stable@vger.kernel.org # v4.4+
Fixes: 3f04d98e972b ("perf intel-pt: Improve sample timestamp")
Link: http://lkml.kernel.org/r/20190510124143.27054-4-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf intel-pt: Fix improved sample timestamp

2019-05-25T16:16:39+00:00

commit 61b6e08dc8e3ea80b7485c9b3f875ddd45c8466b upstream.

The decoder uses its current timestamp in samples. Usually that is a
timestamp that has already passed, but in some cases it is a timestamp
for a branch that the decoder is walking towards, and consequently
hasn't reached.

The intel_pt_sample_time() function decides which is which, but was not
handling TNT packets exactly correctly.

In the case of TNT, the timestamp applies to the first branch, so the
decoder must first walk to that branch.

That means intel_pt_sample_time() should return true for TNT, and this
patch makes that change. However, if the first branch is a non-taken
branch (i.e. a 'N'), then intel_pt_sample_time() needs to return false
for subsequent taken branches in the same TNT packet.

To handle that, introduce a new state INTEL_PT_STATE_TNT_CONT to
distinguish the cases.

Note that commit 3f04d98e972b5 ("perf intel-pt: Improve sample
timestamp") was also a stable fix and appears, for example, in v4.4
stable tree as commit a4ebb58fd124 ("perf intel-pt: Improve sample
timestamp").

Signed-off-by: Adrian Hunter 
Cc: Jiri Olsa 
Cc: stable@vger.kernel.org # v4.4+
Fixes: 3f04d98e972b5 ("perf intel-pt: Improve sample timestamp")
Link: http://lkml.kernel.org/r/20190510124143.27054-3-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf intel-pt: Fix instructions sampling rate

2019-05-25T16:16:38+00:00

commit 7ba8fa20e26eb3c0c04d747f7fd2223694eac4d5 upstream.

The timestamp used to determine if an instruction sample is made, is an
estimate based on the number of instructions since the last known
timestamp. A consequence is that it might go backwards, which results in
extra samples. Change it so that a sample is only made when the
timestamp goes forwards.

Note this does not affect a sampling period of 0 or sampling periods
specified as a count of instructions.

Example:

 Before:

 $ perf script --itrace=i10us
 ls 13812 [003] 2167315.222583:       3270 instructions:u:      7fac71e2e494 __GI___tunables_init+0xf4 (/lib/x86_64-linux-gnu/ld-2.28.so)
 ls 13812 [003] 2167315.222667:      30902 instructions:u:      7fac71e2da0f _dl_cache_libcmp+0x2f (/lib/x86_64-linux-gnu/ld-2.28.so)
 ls 13812 [003] 2167315.222667:         10 instructions:u:      7fac71e2d9ff _dl_cache_libcmp+0x1f (/lib/x86_64-linux-gnu/ld-2.28.so)
 ls 13812 [003] 2167315.222667:          8 instructions:u:      7fac71e2d9ea _dl_cache_libcmp+0xa (/lib/x86_64-linux-gnu/ld-2.28.so)
 ls 13812 [003] 2167315.222667:         14 instructions:u:      7fac71e2d9ea _dl_cache_libcmp+0xa (/lib/x86_64-linux-gnu/ld-2.28.so)
 ls 13812 [003] 2167315.222667:          6 instructions:u:      7fac71e2d9ff _dl_cache_libcmp+0x1f (/lib/x86_64-linux-gnu/ld-2.28.so)
 ls 13812 [003] 2167315.222667:         14 instructions:u:      7fac71e2d9ff _dl_cache_libcmp+0x1f (/lib/x86_64-linux-gnu/ld-2.28.so)
 ls 13812 [003] 2167315.222667:          4 instructions:u:      7fac71e2dab2 _dl_cache_libcmp+0xd2 (/lib/x86_64-linux-gnu/ld-2.28.so)
 ls 13812 [003] 2167315.222728:      16423 instructions:u:      7fac71e2477a _dl_map_object_deps+0x1ba (/lib/x86_64-linux-gnu/ld-2.28.so)
 ls 13812 [003] 2167315.222734:      12731 instructions:u:      7fac71e27938 _dl_name_match_p+0x68 (/lib/x86_64-linux-gnu/ld-2.28.so)
 ...

 After:
 $ perf script --itrace=i10us
 ls 13812 [003] 2167315.222583:       3270 instructions:u:      7fac71e2e494 __GI___tunables_init+0xf4 (/lib/x86_64-linux-gnu/ld-2.28.so)
 ls 13812 [003] 2167315.222667:      30902 instructions:u:      7fac71e2da0f _dl_cache_libcmp+0x2f (/lib/x86_64-linux-gnu/ld-2.28.so)
 ls 13812 [003] 2167315.222728:      16479 instructions:u:      7fac71e2477a _dl_map_object_deps+0x1ba (/lib/x86_64-linux-gnu/ld-2.28.so)
 ...

Signed-off-by: Adrian Hunter 
Cc: Jiri Olsa 
Cc: stable@vger.kernel.org
Fixes: f4aa081949e7b ("perf tools: Add Intel PT decoder")
Link: http://lkml.kernel.org/r/20190510124143.27054-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf tools: Remove needless asm/unistd.h include fixing build in some places

2019-05-02T20:00:20+00:00

We were including sys/syscall.h and asm/unistd.h, since sys/syscall.h
includes asm/unistd.h, sometimes this leads to the redefinition of
defines, breaking the build.

Noticed on ARC with uCLibc.

Cc: Adrian Hunter 
Cc: Arnaldo Carvalho de Melo 
Cc: Arnd Bergmann 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Rich Felker 
Cc: Vineet Gupta 
Link: https://lkml.kernel.org/n/tip-xjpf80o64i2ko74aj2jih0qg@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

tools build: Add -ldl to the disassembler-four-args feature test

2019-05-02T20:00:20+00:00

Thomas Backlund reported that the perf build was failing on the Mageia 7
distro, that is because it uses:

  cat /tmp/build/perf/feature/test-disassembler-four-args.make.output
  /usr/bin/ld: /usr/lib64/libbfd.a(plugin.o): in function `try_load_plugin':
  /home/iurt/rpmbuild/BUILD/binutils-2.32/objs/bfd/../../bfd/plugin.c:243:
  undefined reference to `dlopen'
  /usr/bin/ld:
  /home/iurt/rpmbuild/BUILD/binutils-2.32/objs/bfd/../../bfd/plugin.c:271:
  undefined reference to `dlsym'
  /usr/bin/ld:
  /home/iurt/rpmbuild/BUILD/binutils-2.32/objs/bfd/../../bfd/plugin.c:256:
  undefined reference to `dlclose'
  /usr/bin/ld:
  /home/iurt/rpmbuild/BUILD/binutils-2.32/objs/bfd/../../bfd/plugin.c:246:
  undefined reference to `dlerror'
  as we allow dynamic linking and loading

Mageia 7 uses these linker flags:
  $ rpm --eval %ldflags
    -Wl,--as-needed -Wl,--no-undefined -Wl,-z,relro -Wl,-O1 -Wl,--build-id -Wl,--enable-new-dtags

So add -ldl to this feature LDFLAGS.

Reported-by: Thomas Backlund 
Tested-by: Thomas Backlund 
Cc: Adrian Hunter 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Song Liu 
Link: https://lkml.kernel.org/r/20190501173158.GC21436@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf cs-etm: Always allocate memory for cs_etm_queue::prev_packet

2019-05-02T20:00:20+00:00

Robert Walker reported a segmentation fault is observed when process
CoreSight trace data; this issue can be easily reproduced by the command
'perf report --itrace=i1000i' for decoding tracing data.

If neither the 'b' flag (synthesize branches events) nor 'l' flag
(synthesize last branch entries) are specified to option '--itrace',
cs_etm_queue::prev_packet will not been initialised.  After merging the
code to support exception packets and sample flags, there introduced a
number of uses of cs_etm_queue::prev_packet without checking whether it
is valid, for these cases any accessing to uninitialised prev_packet
will cause crash.

As cs_etm_queue::prev_packet is used more widely now and it's already
hard to follow which functions have been called in a context where the
validity of cs_etm_queue::prev_packet has been checked, this patch
always allocates memory for cs_etm_queue::prev_packet.

Reported-by: Robert Walker 
Suggested-by: Robert Walker 
Signed-off-by: Leo Yan 
Tested-by: Robert Walker 
Cc: Alexander Shishkin 
Cc: Jiri Olsa 
Cc: Mathieu Poirier 
Cc: Mike Leach 
Cc: Namhyung Kim 
Cc: Suzuki K Poulouse 
Cc: linux-arm-kernel@lists.infradead.org
Fixes: 7100b12cf474 ("perf cs-etm: Generate branch sample for exception packet")
Fixes: 24fff5eb2b93 ("perf cs-etm: Avoid stale branch samples when flush packet")
Link: http://lkml.kernel.org/r/20190428083228.20246-1-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo

perf cs-etm: Don't check cs_etm_queue::prev_packet validity

2019-05-02T20:00:20+00:00

Since cs_etm_queue::prev_packet is allocated for all cases, it will
never be NULL pointer; now validity checking prev_packet is pointless,
remove all of them.

Signed-off-by: Leo Yan 
Tested-by: Robert Walker 
Cc: Alexander Shishkin 
Cc: Jiri Olsa 
Cc: Mathieu Poirier 
Cc: Mike Leach 
Cc: Namhyung Kim 
Cc: Suzuki K Poulouse 
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/20190428083228.20246-2-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo

perf report: Report OOM in status line in the GTK UI

2019-05-02T20:00:20+00:00

An -ENOMEM error is not reported in the GTK GUI.  Instead this error
message pops up on the screen:

[root@m35lp76 perf]# ./perf  report -i perf.data.error68-1

	Processing events... [974K/3M]
	Error:failed to process sample

	0xf4198 [0x8]: failed to process type: 68

However when I use the same perf.data file with --stdio it works:

[root@m35lp76 perf]# ./perf  report -i perf.data.error68-1 --stdio \
		| head -12

  # Total Lost Samples: 0
  #
  # Samples: 76K of event 'cycles'
  # Event count (approx.): 99056160000
  #
  # Overhead  Command          Shared Object      Symbol
  # ........  ...............  .................  .........
  #
     8.81%  find             [kernel.kallsyms]  [k] ftrace_likely_update
     8.74%  swapper          [kernel.kallsyms]  [k] ftrace_likely_update
     8.34%  sshd             [kernel.kallsyms]  [k] ftrace_likely_update
     2.19%  kworker/u512:1-  [kernel.kallsyms]  [k] ftrace_likely_update

The sample precentage is a bit low.....

The GUI always fails in the FINISHED_ROUND event (68) and does not
indicate the reason why.

When happened is the following. Perf report calls a lot of functions and
down deep when a FINISHED_ROUND event is processed, these functions are
called:

  perf_session__process_event()
  + perf_session__process_user_event()
    + process_finished_round()
      + ordered_events__flush()
        + __ordered_events__flush()
	  + do_flush()
	    + ordered_events__deliver_event()
	      + perf_session__deliver_event()
	        + machine__deliver_event()
	          + perf_evlist__deliver_event()
	            + process_sample_event()
	              + hist_entry_iter_add() --> only called in GUI case!!!
	                + hist_iter__report__callback()
	                  + symbol__inc_addr_sample()

	                    Now this functions runs out of memory and
			    returns -ENOMEM. This is reported all the way up
			    until function

perf_session__process_event() returns to its caller, where -ENOMEM is
changed to -EINVAL and processing stops:

 if ((skip = perf_session__process_event(session, event, head)) < 0) {
      pr_err("%#" PRIx64 " [%#x]: failed to process type: %d\n",
	     head, event->header.size, event->header.type);
      err = -EINVAL;
      goto out_err;
 }

This occurred in the FINISHED_ROUND event when it has to process some
10000 entries and ran out of memory.

This patch indicates the root cause and displays it in the status line
of ther perf report GUI.

Output before (on GUI status line):

  0xf4198 [0x8]: failed to process type: 68

Output after:

  0xf4198 [0x8]: failed to process type: 68 [not enough memory]

Committer notes:

the 'skip' variable needs to be initialized to -EINVAL, so that when the
size is less than sizeof(struct perf_event_attr) we avoid this valid
compiler warning:

  util/session.c: In function ‘perf_session__process_events’:
  util/session.c:1936:7: error: ‘skip’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
     err = skip;
     ~~~~^~~~~~
  util/session.c:1874:6: note: ‘skip’ was declared here
    s64 skip;
        ^~~~
  cc1: all warnings being treated as errors

Signed-off-by: Thomas Richter 
Reviewed-by: Hendrik Brueckner 
Reviewed-by: Jiri Olsa 
Cc: Heiko Carstens 
Cc: Martin Schwidefsky 
Link: http://lkml.kernel.org/r/20190423105303.61683-1-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo

perf bench numa: Add define for RUSAGE_THREAD if not present

2019-05-02T20:00:20+00:00

While cross building perf to the ARC architecture on a fedora 30 host,
we were failing with:

      CC       /tmp/build/perf/bench/numa.o
  bench/numa.c: In function ‘worker_thread’:
  bench/numa.c:1261:12: error: ‘RUSAGE_THREAD’ undeclared (first use in this function); did you mean ‘SIGEV_THREAD’?
    getrusage(RUSAGE_THREAD, &rusage);
              ^~~~~~~~~~~~~
              SIGEV_THREAD
  bench/numa.c:1261:12: note: each undeclared identifier is reported only once for each function it appears in

[perfbuilder@60d5802468f6 perf]$ /arc_gnu_2019.03-rc1_prebuilt_uclibc_le_archs_linux_install/bin/arc-linux-gcc --version | head -1
arc-linux-gcc (ARCv2 ISA Linux uClibc toolchain 2019.03-rc1) 8.3.1 20190225
[perfbuilder@60d5802468f6 perf]$

Trying to reproduce a report by Vineet, I noticed that, with just
cross-built zlib and numactl libraries, I ended up with the above
failure.

So, since RUSAGE_THREAD is available as a define, check for that and
numactl libraries, I ended up with the above failure.

So, since RUSAGE_THREAD is available as a define in the system headers,
check if it is defined in the 'perf bench numa' sources and define it if
not.

Now it builds and I have to figure out if the problem reported by Vineet
only takes place if we have libelf or some other library available.

Cc: Arnd Bergmann 
Cc: Jiri Olsa 
Cc: linux-snps-arc@lists.infradead.org
Cc: Namhyung Kim 
Cc: Vineet Gupta 
Link: https://lkml.kernel.org/n/tip-2wb4r1gir9xrevbpq7qp0amk@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf annotate: Fix build on 32 bit for BPF annotation

2019-05-02T20:00:19+00:00

Commit 6987561c9e86 ("perf annotate: Enable annotation of BPF programs") adds
support for BPF programs annotations but the new code does not build on 32-bit.

Signed-off-by: Thadeu Lima de Souza Cascardo 
Acked-by: Song Liu 
Fixes: 6987561c9e86 ("perf annotate: Enable annotation of BPF programs")
Link: http://lkml.kernel.org/r/20190403194452.10845-1-cascardo@canonical.com
Signed-off-by: Arnaldo Carvalho de Melo