linux-stable.git/tools/perf, branch linux-4.1.y

perf tests: Decompress kernel module before objdump

2018-05-23T01:36:28+00:00

[ Upstream commit 94df1040b1e6aacd8dec0ba3c61d7e77cd695f26 ]

If a kernel modules is compressed, it should be decompressed before
running objdump to parse binary data correctly.  This fixes a failure of
object code reading test for me.

Signed-off-by: Namhyung Kim 
Acked-by: Adrian Hunter 
Acked-by: Jiri Olsa 
Cc: David Ahern 
Cc: Peter Zijlstra 
Cc: Wang Nan 
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170608073109.30699-8-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf report: Ensure the perf DSO mapping matches what libdw sees

2018-05-23T01:36:28+00:00

[ Upstream commit 2538b9e2450ae255337c04356e9e0f8cb9ec48d9 ]

In some situations the libdw unwinder stopped working properly.  I.e.
with libunwind we see:

~~~~~
heaptrack_gui  2228 135073.400112:     641314 cycles:
	            e8ed _dl_fixup (/usr/lib/ld-2.25.so)
	           15f06 _dl_runtime_resolve_sse_vex (/usr/lib/ld-2.25.so)
	           ed94c KDynamicJobTracker::KDynamicJobTracker (/home/milian/projects/compiled/kf5/lib64/libKF5KIOWidgets.so.5.35.0)
	           608f3 _GLOBAL__sub_I_kdynamicjobtracker.cpp (/home/milian/projects/compiled/kf5/lib64/libKF5KIOWidgets.so.5.35.0)
	            f199 call_init.part.0 (/usr/lib/ld-2.25.so)
	            f2a5 _dl_init (/usr/lib/ld-2.25.so)
	             db9 _dl_start_user (/usr/lib/ld-2.25.so)
~~~~~

But with libdw and without this patch this sample is not properly
unwound:

~~~~~
heaptrack_gui  2228 135073.400112:     641314 cycles:
	            e8ed _dl_fixup (/usr/lib/ld-2.25.so)
	           15f06 _dl_runtime_resolve_sse_vex (/usr/lib/ld-2.25.so)
	           ed94c KDynamicJobTracker::KDynamicJobTracker (/home/milian/projects/compiled/kf5/lib64/libKF5KIOWidgets.so.5.35.0)
~~~~~

Debug output showed me that libdw found a module for the last frame
address, but it thinks it belongs to /usr/lib/ld-2.25.so. This patch
double-checks what libdw sees and what perf knows. If the mappings
mismatch, we now report the elf known to perf. This fixes the situation
above, and the libdw unwinder produces the same stack as libunwind.

Signed-off-by: Milian Wolff 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Link: http://lkml.kernel.org/r/20170602143753.16907-1-milian.wolff@kdab.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf trace: Add mmap alias for s390

2018-05-23T01:36:27+00:00

[ Upstream commit 54265664c15a68905d8d67d19205e9a767636434 ]

The s390 architecture maps sys_mmap (nr 90) into sys_old_mmap.  For this
reason perf trace can't find the proper syscall event to get args format
from and displays it wrongly as 'continued'.

To fix that fill the "alias" field with "old_mmap" for trace's mmap record
to get the correct translation.

Before:
     0.042 ( 0.011 ms): vest/43052 fstat(statbuf: 0x3ffff89fd90                ) = 0
     0.042 ( 0.028 ms): vest/43052  ... [continued]: mmap()) = 0x3fffd6e2000
     0.072 ( 0.025 ms): vest/43052 read(buf: 0x3fffd6e2000, count: 4096        ) = 6

After:
     0.045 ( 0.011 ms): fstat(statbuf: 0x3ffff8a0930                           ) = 0
     0.057 ( 0.018 ms): mmap(arg: 0x3ffff8a0858                                ) = 0x3fffd14a000
     0.076 ( 0.025 ms): read(buf: 0x3fffd14a000, count: 4096                   ) = 6

Signed-off-by: Jiri Olsa 
Cc: David Ahern 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/20170531113557.19175-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf session: Don't rely on evlist in pipe mode

2018-05-23T01:33:45+00:00

[ Upstream commit 0973ad97c187e06aece61f685b9c3b2d93290a73 ]

Session sets a number parameters that rely on evlist. These parameters
are not used in pipe-mode and should not be set, since evlist is
unavailable. Fix that.

Signed-off-by: David Carrillo-Cisneros 
Acked-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: He Kuang 
Cc: Masami Hiramatsu 
Cc: Paul Turner 
Cc: Peter Zijlstra 
Cc: Simon Que 
Cc: Stephane Eranian 
Cc: Wang Nan 
Link: http://lkml.kernel.org/r/20170410201432.24807-6-davidcc@google.com
[ Check if file != NULL in perf_session__new(), like when used by builtin-top.c ]
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf inject: Copy events when reordering events in pipe mode

2018-05-23T01:33:45+00:00

[ Upstream commit 1e0d4f0200e4dbdfc38d818f329d8a0955f7c6f5 ]

__perf_session__process_pipe_events reuses the same memory buffer to
process all events in the pipe.

When reordering is needed (e.g. -b option), events are not immediately
flushed, but kept around until reordering is possible, causing
memory corruption.

The problem is usually observed by a "Unknown sample error" output. It
can easily be reproduced by:

  perf record -o - noploop | perf inject -b > output

Committer testing:

Before:

  $ perf record -o - stress -t 2 -c 2 | perf inject -b > /dev/null
  stress: info: [8297] dispatching hogs: 2 cpu, 0 io, 0 vm, 0 hdd
  stress: info: [8297] successful run completed in 2s
  [ perf record: Woken up 3 times to write data ]
  [ perf record: Captured and wrote 0.000 MB - ]
  Warning:
  Found 1 unknown events!

  Is this an older tool processing a perf.data file generated by a more recent tool?

  If that is not the case, consider reporting to linux-kernel@vger.kernel.org.

  $

After:

  $ perf record -o - stress -t 2 -c 2 | perf inject -b > /dev/null
  stress: info: [9027] dispatching hogs: 2 cpu, 0 io, 0 vm, 0 hdd
  stress: info: [9027] successful run completed in 2s
  [ perf record: Woken up 3 times to write data ]
  [ perf record: Captured and wrote 0.000 MB - ]
  no symbols found in /usr/bin/stress, maybe install a debug package?
  no symbols found in /usr/bin/stress, maybe install a debug package?
  $

Signed-off-by: David Carrillo-Cisneros 
Tested-by: Arnaldo Carvalho de Melo 
Acked-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: He Kuang 
Cc: Masami Hiramatsu 
Cc: Paul Turner 
Cc: Peter Zijlstra 
Cc: Simon Que 
Cc: Stephane Eranian 
Cc: Wang Nan 
Link: http://lkml.kernel.org/r/20170410201432.24807-3-davidcc@google.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf tools: Make perf_event__synthesize_mmap_events() scale

2018-05-23T01:33:43+00:00

[ Upstream commit 88b897a30c525c2eee6e7f16e1e8d0f18830845e ]

This patch significantly improves the execution time of
perf_event__synthesize_mmap_events() when running perf record on systems
where processes have lots of threads.

It just happens that cat /proc/pid/maps support uses a O(N^2) algorithm to
generate each map line in the maps file.  If you have 1000 threads, then you
have necessarily 1000 stacks.  For each vma, you need to check if it
corresponds to a thread's stack.  With a large number of threads, this can take
a very long time. I have seen latencies >> 10mn.

As of today, perf does not use the fact that a mapping is a stack, therefore we
can work around the issue by using /proc/pid/tasks/pid/maps.  This entry does
not try to map a vma to stack and is thus much faster with no loss of
functonality.

The proc-map-timeout logic is kept in case users still want some upper limit.

In V2, we fix the file path from /proc/pid/tasks/pid/maps to actual
/proc/pid/task/pid/maps, tasks -> task.  Thanks Arnaldo for catching this.

Committer note:

This problem seems to have been elliminated in the kernel since commit :
b18cb64ead40 ("fs/proc: Stop trying to report thread stacks").

Signed-off-by: Stephane Eranian 
Acked-by: Jiri Olsa 
Cc: Andy Lutomirski 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/20170315135059.GC2177@redhat.com
Link: http://lkml.kernel.org/r/1489598233-25586-1-git-send-email-eranian@google.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf bench numa: Fixup discontiguous/sparse numa nodes

2018-03-04T15:28:25+00:00

[ Upstream commit 321a7c35c90cc834851ceda18a8ee18f1d032b92 ]

Certain systems are designed to have sparse/discontiguous nodes.  On
such systems, 'perf bench numa' hangs, shows wrong number of nodes and
shows values for non-existent nodes. Handle this by only taking nodes
that are exposed by kernel to userspace.

Signed-off-by: Satheesh Rajendran 
Reviewed-by: Srikar Dronamraju 
Acked-by: Naveen N. Rao 
Link: http://lkml.kernel.org/r/1edbcd353c009e109e93d78f2f46381930c340fe.1511368645.git.sathnaga@linux.vnet.ibm.com
Signed-off-by: Balamuruhan S 
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf top: Fix window dimensions change handling

2018-03-04T15:28:25+00:00

[ Upstream commit b135e5ee1a0e325166c30b16cf5493fea44ede45 ]

The stdio perf top crashes when we change the terminal
window size. The reason is that we assumed we get the
perf_top pointer as a signal handler argument which is
not the case.

Changing the SIGWINCH handler logic to change global
resize variable, which is checked in the main thread
loop.

Signed-off-by: Jiri Olsa 
Tested-by: Arnaldo Carvalho de Melo 
Tested-by: Ravi Bangoria 
Cc: Adrian Hunter 
Cc: Andi Kleen 
Cc: David Ahern 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: http://lkml.kernel.org/n/tip-ysuzwz77oev1ftgvdscn9bpu@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf symbols: Fix symbols__fixup_end heuristic for corner cases

2018-01-17T17:55:36+00:00

[ Upstream commit e7ede72a6d40cb3a30c087142d79381ca8a31dab ]

The current symbols__fixup_end() heuristic for the last entry in the rb
tree is suboptimal as it leads to not being able to recognize the symbol
in the call graph in a couple of corner cases, for example:

 i) If the symbol has a start address (f.e. exposed via kallsyms)
    that is at a page boundary, then the roundup(curr->start, 4096)
    for the last entry will result in curr->start == curr->end with
    a symbol length of zero.

ii) If the symbol has a start address that is shortly before a page
    boundary, then also here, curr->end - curr->start will just be
    very few bytes, where it's unrealistic that we could perform a
    match against.

Instead, change the heuristic to roundup(curr->start, 4096) + 4096, so
that we can catch such corner cases and have a better chance to find
that specific symbol. It's still just best effort as the real end of the
symbol is unknown to us (and could even be at a larger offset than the
current range), but better than the current situation.

Alexei reported that he recently run into case i) with a JITed eBPF
program (these are all page aligned) as the last symbol which wasn't
properly shown in the call graph (while other eBPF program symbols in
the rb tree were displayed correctly). Since this is a generic issue,
lets try to improve the heuristic a bit.

Reported-and-Tested-by: Alexei Starovoitov 
Signed-off-by: Daniel Borkmann 
Fixes: 2e538c4a1847 ("perf tools: Improve kernel/modules symbol lookup")
Link: http://lkml.kernel.org/r/bb5c80d27743be6f12afc68405f1956a330e1bc9.1489614365.git.daniel@iogearbox.net
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf test attr: Fix ignored test case result

2018-01-17T17:55:18+00:00

[ Upstream commit 22905582f6dd4bbd0c370fe5732c607452010c04 ]

Command perf test -v 16 (Setup struct perf_event_attr test) always
reports success even if the test case fails.  It works correctly if you
also specify -F (for don't fork).

   root@s35lp76 perf]# ./perf test -v 16
   15: Setup struct perf_event_attr               :
   --- start ---
   running './tests/attr/test-record-no-delay'
   [ perf record: Woken up 1 times to write data ]
   [ perf record: Captured and wrote 0.002 MB /tmp/tmp4E1h7R/perf.data
     (1 samples) ]
   expected task=0, got 1
   expected precise_ip=0, got 3
   expected wakeup_events=1, got 0
   FAILED './tests/attr/test-record-no-delay' - match failure
   test child finished with 0
   ---- end ----
   Setup struct perf_event_attr: Ok

The reason for the wrong error reporting is the return value of the
system() library call. It is called in run_dir() file tests/attr.c and
returns the exit status, in above case 0xff00.

This value is given as parameter to the exit() function which can only
handle values 0-0xff.

The child process terminates with exit value of 0 and the parent does
not detect any error.

This patch corrects the error reporting and prints the correct test
result.

Signed-off-by: Thomas-Mich Richter 
Acked-by: Jiri Olsa 
Cc: Heiko Carstens 
Cc: Hendrik Brueckner 
Cc: Martin Schwidefsky 
Cc: Thomas-Mich Richter 
LPU-Reference: 20170913081209.39570-2-tmricht@linux.vnet.ibm.com
Link: http://lkml.kernel.org/n/tip-rdube6rfcjsr1nzue72c7lqn@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin