linux-stable.git/tools/perf/util/intel-pt-decoder, branch v4.12.4

perf intel-pt: Clear FUP flag on error

2017-07-27T22:10:05+00:00

commit 6a558f12dbe85437acbdec5e149ea07b5554eced upstream.

Sometimes a FUP packet is associated with a TSX transaction and a flag is
set to indicate that. Ensure that flag is cleared on any error condition
because at that point the decoder can no longer assume it is correct.

Signed-off-by: Adrian Hunter 
Cc: Andi Kleen 
Link: http://lkml.kernel.org/r/1495786658-18063-9-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf intel-pt: Use FUP always when scanning for an IP

2017-07-27T22:10:05+00:00

commit 622b7a47b843c78626f40c1d1aeef8483383fba2 upstream.

The decoder will try to use branch packets to find an IP to start decoding
or to recover from errors. Currently the FUP packet is used only in the
case of an overflow, however there is no reason for that to be a special
case. So just use FUP always when scanning for an IP.

Signed-off-by: Adrian Hunter 
Cc: Andi Kleen 
Link: http://lkml.kernel.org/r/1495786658-18063-8-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf intel-pt: Ensure never to set 'last_ip' when packet 'count' is zero

2017-07-27T22:10:05+00:00

commit f952eaceb089b691eba7c4e13686e742a8f26bf5 upstream.

Intel PT uses IP compression based on the last IP. For decoding purposes,
'last IP' is not updated when a branch target has been suppressed, which is
indicated by IPBytes == 0. IPBytes is stored in the packet 'count', so
ensure never to set 'last_ip' when packet 'count' is zero.

Signed-off-by: Adrian Hunter 
Cc: Andi Kleen 
Link: http://lkml.kernel.org/r/1495786658-18063-7-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf intel-pt: Fix last_ip usage

2017-07-27T22:10:04+00:00

commit ee14ac0ef6827cd6f9a572cc83dd0191ea17812c upstream.

Intel PT uses IP compression based on the last IP. For decoding
purposes, 'last IP' is considered to be reset to zero whenever there is
a synchronization packet (PSB). The decoder wasn't doing that, and was
treating the zero value to mean that there was no last IP, whereas
compression can be done against the zero value. Fix by setting last_ip
to zero when a PSB is received and keep track of have_last_ip.

Signed-off-by: Adrian Hunter 
Cc: Andi Kleen 
Link: http://lkml.kernel.org/r/1495786658-18063-6-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf intel-pt: Ensure IP is zero when state is INTEL_PT_STATE_NO_IP

2017-07-27T22:10:04+00:00

commit ad7167a8cd174ba7d8c0d0ed8d8410521206d104 upstream.

A value of zero is used to indicate that there is no IP. Ensure the
value is zero when the state is INTEL_PT_STATE_NO_IP.

Signed-off-by: Adrian Hunter 
Cc: Andi Kleen 
Link: http://lkml.kernel.org/r/1495786658-18063-5-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf intel-pt: Fix missing stack clear

2017-07-27T22:10:04+00:00

commit 12b7080609097753fd8198cc1daf589be3ec1cca upstream.

The return compression stack must be cleared whenever there is a PSB. Fix
one case where that was not happening.

Signed-off-by: Adrian Hunter 
Cc: Andi Kleen 
Link: http://lkml.kernel.org/r/1495786658-18063-4-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf intel-pt: Improve sample timestamp

2017-07-27T22:10:04+00:00

commit 3f04d98e972b59706bd43d6cc75efac91f8fba50 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. Improve that situation by using the pkt_state to
determine when to use the current or previous timestamp.

Signed-off-by: Adrian Hunter 
Cc: Andi Kleen 
Link: http://lkml.kernel.org/r/1495786658-18063-3-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf intel-pt: Move decoder error setting into one condition

2017-07-27T22:10:04+00:00

commit 22c06892332d8916115525145b78e606e9cc6492 upstream.

Move decoder error setting into one condition.

Cc'ed to stable because later fixes depend on it.

Signed-off-by: Adrian Hunter 
Cc: Andi Kleen 
Link: http://lkml.kernel.org/r/1495786658-18063-2-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'perf-core-for-mingo-4.12-20170316' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

2017-03-16T16:29:23+00:00

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

New features:

 - Add 'brstackinsn' field in 'perf script' to reuse the x86 instruction
   decoder used in the Intel PT code to study hot paths to samples (Andi Kleen)

Kernel changes:

 - Default UPROBES_EVENTS to Y (Alexei Starovoitov)

 - Fix check for kretprobe offset within function entry (Naveen N. Rao)

Infrastructure changes:

 - Introduce util func is_sdt_event() (Ravi Bangoria)

 - Make perf_event__synthesize_mmap_events() scale on older kernels where
   reading /proc/pid/maps is way slower than reading /proc/pid/task/pid/maps (Stephane Eranian)

Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Ingo Molnar

perf script: Add 'brstackinsn' for branch stacks

2017-03-16T12:24:35+00:00

Implement printing instruction sequences as hex dump for branch stacks.

This relies on the x86 instruction decoder used by the PT decoder to
find the lengths of instructions to dump them individually.

This is good enough for pattern matching.

This allows to study hot paths for individual samples, together with
branch misprediction and cycle count / IPC information if available (on
Skylake systems).

  % perf record -b ...
  % perf script -F brstackinsn
  ...
    read_hpet+67:
          ffffffff9905b843        insn: 74 ea                     # PRED
          ffffffff9905b82f        insn: 85 c9
          ffffffff9905b831        insn: 74 12
          ffffffff9905b833        insn: f3 90
          ffffffff9905b835        insn: 48 8b 0f
          ffffffff9905b838        insn: 48 89 ca
          ffffffff9905b83b        insn: 48 c1 ea 20
          ffffffff9905b83f        insn: 39 f2
          ffffffff9905b841        insn: 89 d0
          ffffffff9905b843        insn: 74 ea                     # PRED

Only works when no special branch filters are specified.

Occasionally the path does not reach up to the sample IP, as the LBRs
may be frozen before executing a final jump. In this case we print a
special message.

The instruction dumper piggy backs on the existing infrastructure from
the IP PT decoder.

An earlier iteration of this patch relied on a disassembler, but this
version only uses the existing instruction decoder.

Committer note:

Added hint about how to get suitable perf.data files for use with
'-F brstackinsm':

  $ perf record usleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.018 MB perf.data (8 samples) ]
  $
  $ perf script -F brstackinsn
  Display of branch stack assembler requested, but non all-branch filter set
  Hint: run 'perf record -b ...'
  $

Signed-off-by: Andi Kleen 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Jiri Olsa 
Cc: Michael Ellerman 
Link: http://lkml.kernel.org/r/20170223234634.583-1-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo