linux-stable.git/tools/perf, branch v5.8.7

perf record/stat: Explicitly call out event modifiers in the documentation

2020-09-05T09:24:02+00:00

commit e48a73a312ebf19cc3d72aa74985db25c30757c1 upstream.

Event modifiers are not mentioned in the perf record or perf stat
manpages.  Add them to orient new users more effectively by pointing
them to the perf list manpage for details.

Fixes: 2055fdaf8703 ("perf list: Document precise event sampling for AMD IBS")
Signed-off-by: Kim Phillips 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Alexey Budankov 
Cc: Ian Rogers 
Cc: Jin Yao 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Paul Clarke 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: Tony Jones 
Cc: stable@vger.kernel.org
Link: http://lore.kernel.org/lkml/20200901215853.276234-1-kim.phillips@amd.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf bench mem: Always memset source before memcpy

2020-08-21T11:15:19+00:00

[ Upstream commit 1beaef29c34154ccdcb3f1ae557f6883eda18840 ]

For memcpy, the source pages are memset to zero only when --cycles is
used.  This leads to wildly different results with or without --cycles,
since all sources pages are likely to be mapped to the same zero page
without explicit writes.

Before this fix:

$ export cmd="./perf stat -e LLC-loads -- ./perf bench \
  mem memcpy -s 1024MB -l 100 -f default"
$ $cmd

         2,935,826      LLC-loads
       3.821677452 seconds time elapsed

$ $cmd --cycles

       217,533,436      LLC-loads
       8.616725985 seconds time elapsed

After this fix:

$ $cmd

       214,459,686      LLC-loads
       8.674301124 seconds time elapsed

$ $cmd --cycles

       214,758,651      LLC-loads
       8.644480006 seconds time elapsed

Fixes: 47b5757bac03c338 ("perf bench mem: Move boilerplate memory allocation to the infrastructure")
Signed-off-by: Vincent Whitchurch 
Cc: Alexander Shishkin 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: kernel@axis.com
Link: http://lore.kernel.org/lkml/20200810133404.30829-1-vincent.whitchurch@axis.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf record: Skip side-band event setup if HAVE_LIBBPF_SUPPORT is not set

2020-08-21T11:15:16+00:00

[ Upstream commit 1101c872c8c7869c78dc106ae820040f36807eda ]

We received an error report that perf-record caused 'Segmentation fault'
on a newly system (e.g. on the new installed ubuntu).

  (gdb) backtrace
  #0  __read_once_size (size=4, res=, p=0x14) at /root/0-jinyao/acme/tools/include/linux/compiler.h:139
  #1  atomic_read (v=0x14) at /root/0-jinyao/acme/tools/include/asm/../../arch/x86/include/asm/atomic.h:28
  #2  refcount_read (r=0x14) at /root/0-jinyao/acme/tools/include/linux/refcount.h:65
  #3  perf_mmap__read_init (map=map@entry=0x0) at mmap.c:177
  #4  0x0000561ce5c0de39 in perf_evlist__poll_thread (arg=0x561ce68584d0) at util/sideband_evlist.c:62
  #5  0x00007fad78491609 in start_thread (arg=) at pthread_create.c:477
  #6  0x00007fad7823c103 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

The root cause is, evlist__add_bpf_sb_event() just returns 0 if
HAVE_LIBBPF_SUPPORT is not defined (inline function path). So it will
not create a valid evsel for side-band event.

But perf-record still creates BPF side band thread to process the
side-band event, then the error happpens.

We can reproduce this issue by removing the libelf-dev. e.g.
1. apt-get remove libelf-dev
2. perf record -a -- sleep 1

  root@test:~# ./perf record -a -- sleep 1
  perf: Segmentation fault
  Obtained 6 stack frames.
  ./perf(+0x28eee8) [0x5562d6ef6ee8]
  /lib/x86_64-linux-gnu/libc.so.6(+0x46210) [0x7fbfdc65f210]
  ./perf(+0x342e74) [0x5562d6faae74]
  ./perf(+0x257e39) [0x5562d6ebfe39]
  /lib/x86_64-linux-gnu/libpthread.so.0(+0x9609) [0x7fbfdc990609]
  /lib/x86_64-linux-gnu/libc.so.6(clone+0x43) [0x7fbfdc73b103]
  Segmentation fault (core dumped)

To fix this issue,

1. We either install the missing libraries to let HAVE_LIBBPF_SUPPORT
   be defined.
   e.g. apt-get install libelf-dev and install other related libraries.

2. Use this patch to skip the side-band event setup if HAVE_LIBBPF_SUPPORT
   is not set.

Committer notes:

The side band thread is not used just with BPF, it is also used with
--switch-output-event, so narrow the ifdef to the BPF specific part.

Fixes: 23cbb41c939a ("perf record: Move side band evlist setup to separate routine")
Signed-off-by: Jin Yao 
Acked-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Jin Yao 
Cc: Kan Liang 
Cc: Peter Zijlstra 
Link: http://lore.kernel.org/lkml/20200805022937.29184-1-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf evsel: Don't set sample_regs_intr/sample_regs_user for dummy event

2020-08-21T11:15:14+00:00

[ Upstream commit c4735d990268399da9133b0ad445e488ece009ad ]

Since commit 0a892c1c9472 ("perf record: Add dummy event during system wide synthesis"),
a dummy event is added to capture mmaps.

But if we run perf-record as,

 # perf record -e cycles:p -IXMM0 -a -- sleep 1
 Error:
 dummy:HG: PMU Hardware doesn't support sampling/overflow-interrupts. Try 'perf stat'

The issue is, if we enable the extended regs (-IXMM0), but the
pmu->capabilities is not set with PERF_PMU_CAP_EXTENDED_REGS, the kernel
will return -EOPNOTSUPP error.

See following code:

/* in kernel/events/core.c */
static int perf_try_init_event(struct pmu *pmu, struct perf_event *event)

{
        ....
        if (!(pmu->capabilities & PERF_PMU_CAP_EXTENDED_REGS) &&
            has_extended_regs(event))
                ret = -EOPNOTSUPP;
        ....
}

For software dummy event, the PMU should not be set with
PERF_PMU_CAP_EXTENDED_REGS. But unfortunately now, the dummy
event has possibility to be set with PERF_REG_EXTENDED_MASK bit.

In evsel__config, /* tools/perf/util/evsel.c */

if (opts->sample_intr_regs) {
        attr->sample_regs_intr = opts->sample_intr_regs;
}

If we use -IXMM0, the attr>sample_regs_intr will be set with
PERF_REG_EXTENDED_MASK bit.

It doesn't make sense to set attr->sample_regs_intr for a
software dummy event.

This patch adds dummy event checking before setting
attr->sample_regs_intr and attr->sample_regs_user.

After:
  # ./perf record -e cycles:p -IXMM0 -a -- sleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.413 MB perf.data (45 samples) ]

Committer notes:

Adrian said this when providing his Acked-by:

"
This is fine.  It will not break PT.

no_aux_samples is useful for evsels that have been added by the code rather
than requested by the user.  For old kernels PT adds sched_switch tracepoint
to track context switches (before the current context switch event was
added) and having auxiliary sample information unnecessarily uses up space
in the perf buffer.
"

Fixes: 0a892c1c9472 ("perf record: Add dummy event during system wide synthesis")
Signed-off-by: Jin Yao 
Acked-by: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Ian Rogers 
Cc: Jin Yao 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Peter Zijlstra 
Link: http://lore.kernel.org/lkml/20200720010013.18238-1-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf tools: Fix term parsing for raw syntax

2020-08-21T11:15:12+00:00

[ Upstream commit 4929e95a1400e45b4b5a87fd3ce10273444187d4 ]

Jin Yao reported issue with possible conflict between raw events and
term values in pmu event syntax.

Currently following syntax is resolved as raw event with 0xead value:

  uncore_imc_free_running/read/

instead of using 'read' term from uncore_imc_free_running pmu, because
'read' is correct raw event syntax with 0xead value.

To solve this issue we do following:

  - check existing terms during rXXXX syntax processing
    and make them priority in case of conflict

  - allow pmu/r0x1234/ syntax to be able to specify conflicting
    raw event (implemented in previous patch)

Also add automated tests for this and perf_pmu__parse_cleanup call to
parse_events_terms, so the test gets properly cleaned up.

Fixes: 3a6c51e4d66c ("perf parser: Add support to specify rXXX event with pmu")
Reported-by: Jin Yao 
Signed-off-by: Jiri Olsa 
Tested-by: Jin Yao 
Acked-by: Ian Rogers 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Michael Petlan 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: Thomas Richter 
Link: http://lore.kernel.org/lkml/20200726075244.1191481-2-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf intel-pt: Fix duplicate branch after CBR

2020-08-21T11:15:02+00:00

commit a58a057ce65b52125dd355b7d8b0d540ea267a5f upstream.

CBR events can result in a duplicate branch event, because the state
type defaults to a branch. Fix by clearing the state type.

Example: trace 'sleep' and hope for a frequency change

 Before:

   $ perf record -e intel_pt//u sleep 0.1
   [ perf record: Woken up 1 times to write data ]
   [ perf record: Captured and wrote 0.034 MB perf.data ]
   $ perf script --itrace=bpe > before.txt

 After:

   $ perf script --itrace=bpe > after.txt
   $ diff -u before.txt after.txt
#  --- before.txt  2020-07-07 14:42:18.191508098 +0300
#  +++ after.txt   2020-07-07 14:42:36.587891753 +0300
   @@ -29673,7 +29673,6 @@
               sleep 93431 [007] 15411.619905:          1  branches:u:                 0 [unknown] ([unknown]) =>     7f0818abb2e0 clock_nanosleep@@GLIBC_2.17+0x0 (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
               sleep 93431 [007] 15411.619905:          1  branches:u:      7f0818abb30c clock_nanosleep@@GLIBC_2.17+0x2c (/usr/lib/x86_64-linux-gnu/libc-2.31.so) =>                0 [unknown] ([unknown])
               sleep 93431 [007] 15411.720069:         cbr:  cbr: 15 freq: 1507 MHz ( 56%)         7f0818abb30c clock_nanosleep@@GLIBC_2.17+0x2c (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
   -           sleep 93431 [007] 15411.720069:          1  branches:u:      7f0818abb30c clock_nanosleep@@GLIBC_2.17+0x2c (/usr/lib/x86_64-linux-gnu/libc-2.31.so) =>                0 [unknown] ([unknown])
               sleep 93431 [007] 15411.720076:          1  branches:u:                 0 [unknown] ([unknown]) =>     7f0818abb30e clock_nanosleep@@GLIBC_2.17+0x2e (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
               sleep 93431 [007] 15411.720077:          1  branches:u:      7f0818abb323 clock_nanosleep@@GLIBC_2.17+0x43 (/usr/lib/x86_64-linux-gnu/libc-2.31.so) =>     7f0818ac0eb7 __nanosleep+0x17 (/usr/lib/x86_64-linux-gnu/libc-2.31.so)
               sleep 93431 [007] 15411.720077:          1  branches:u:      7f0818ac0ebf __nanosleep+0x1f (/usr/lib/x86_64-linux-gnu/libc-2.31.so) =>     55cb7e4c2827 rpl_nanosleep+0x97 (/usr/bin/sleep)

Fixes: 91de8684f1cff ("perf intel-pt: Cater for CBR change in PSB+")
Fixes: abe5a1d3e4bee ("perf intel-pt: Decoder to output CBR changes immediately")
Signed-off-by: Adrian Hunter 
Reviewed-by: Andi Kleen 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Jiri Olsa 
Cc: stable@vger.kernel.org
Link: http://lore.kernel.org/lkml/20200710151104.15137-3-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf intel-pt: Fix FUP packet state

2020-08-21T11:15:02+00:00

commit 401136bb084fd021acd9f8c51b52fe0a25e326b2 upstream.

While walking code towards a FUP ip, the packet state is
INTEL_PT_STATE_FUP or INTEL_PT_STATE_FUP_NO_TIP. That was mishandled
resulting in the state becoming INTEL_PT_STATE_IN_SYNC prematurely.  The
result was an occasional lost EXSTOP event.

Signed-off-by: Adrian Hunter 
Reviewed-by: Andi Kleen 
Cc: Jiri Olsa 
Cc: stable@vger.kernel.org
Link: http://lore.kernel.org/lkml/20200710151104.15137-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf probe: Fix memory leakage when the probe point is not found

2020-08-21T11:15:02+00:00

commit 12d572e785b15bc764e956caaa8a4c846fd15694 upstream.

Fix the memory leakage in debuginfo__find_trace_events() when the probe
point is not found in the debuginfo. If there is no probe point found in
the debuginfo, debuginfo__find_probes() will NOT return -ENOENT, but 0.

Thus the caller of debuginfo__find_probes() must check the tf.ntevs and
release the allocated memory for the array of struct probe_trace_event.

The current code releases the memory only if the debuginfo__find_probes()
hits an error but not checks tf.ntevs. In the result, the memory allocated
on *tevs are not released if tf.ntevs == 0.

This fixes the memory leakage by checking tf.ntevs == 0 in addition to
ret < 0.

Fixes: ff741783506c ("perf probe: Introduce debuginfo to encapsulate dwarf information")
Signed-off-by: Masami Hiramatsu 
Reviewed-by: Srikar Dronamraju 
Cc: Andi Kleen 
Cc: Oleg Nesterov 
Cc: stable@vger.kernel.org
Link: http://lore.kernel.org/lkml/159438668346.62703.10887420400718492503.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf probe: Fix wrong variable warning when the probe point is not found

2020-08-21T11:15:01+00:00

commit 11fd3eb874e73ee8069bcfd54e3c16fa7ce56fe6 upstream.

Fix a wrong "variable not found" warning when the probe point is not
found in the debuginfo.

Since the debuginfo__find_probes() can return 0 even if it does not find
given probe point in the debuginfo, fill_empty_trace_arg() can be called
with tf.ntevs == 0 and it can emit a wrong warning.  To fix this, reject
ntevs == 0 in fill_empty_trace_arg().

E.g. without this patch;

  # perf probe -x /lib64/libc-2.30.so -a "memcpy arg1=%di"
  Failed to find the location of the '%di' variable at this address.
   Perhaps it has been optimized out.
   Use -V with the --range option to show '%di' location range.
  Added new events:
    probe_libc:memcpy    (on memcpy in /usr/lib64/libc-2.30.so with arg1=%di)
    probe_libc:memcpy    (on memcpy in /usr/lib64/libc-2.30.so with arg1=%di)

  You can now use it in all perf tools, such as:

  	perf record -e probe_libc:memcpy -aR sleep 1

With this;

  # perf probe -x /lib64/libc-2.30.so -a "memcpy arg1=%di"
  Added new events:
    probe_libc:memcpy    (on memcpy in /usr/lib64/libc-2.30.so with arg1=%di)
    probe_libc:memcpy    (on memcpy in /usr/lib64/libc-2.30.so with arg1=%di)

  You can now use it in all perf tools, such as:

  	perf record -e probe_libc:memcpy -aR sleep 1

Fixes: cb4027308570 ("perf probe: Trace a magic number if variable is not found")
Reported-by: Andi Kleen 
Signed-off-by: Masami Hiramatsu 
Reviewed-by: Srikar Dronamraju 
Tested-by: Andi Kleen 
Cc: Oleg Nesterov 
Cc: stable@vger.kernel.org
Link: http://lore.kernel.org/lkml/159438667364.62703.2200642186798763202.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf tools: Fix record failure when mixed with ARM SPE event

2020-07-31T12:29:01+00:00

When recording with cache-misses and arm_spe_x event, I found that it
will just fail without showing any error info if i put cache-misses
after 'arm_spe_x' event.

  [root@localhost 0620]# perf record -e cache-misses \
				-e arm_spe_0/ts_enable=1,pct_enable=1,pa_enable=1,load_filter=1,jitter=1,store_filter=1,min_latency=0/ sleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.067 MB perf.data ]
  [root@localhost 0620]#
  [root@localhost 0620]# perf record -e arm_spe_0/ts_enable=1,pct_enable=1,pa_enable=1,load_filter=1,jitter=1,store_filter=1,min_latency=0/ \
				     -e  cache-misses sleep 1
  [root@localhost 0620]#

The current code can only work if the only event to be traced is an
'arm_spe_x', or if it is the last event to be specified. Otherwise the
last event type will be checked against all the arm_spe_pmus[i]->types,
none will match and an out of bound 'i' index will be used in
arm_spe_recording_init().

We don't support concurrent multiple arm_spe_x events currently, that
is checked in arm_spe_recording_options(), and it will show the relevant
info. So add the check and record of the first found 'arm_spe_pmu' to
fix this issue here.

Fixes: ffd3d18c20b8 ("perf tools: Add ARM Statistical Profiling Extensions (SPE) support")
Signed-off-by: Wei Li 
Reviewed-by: Mathieu Poirier 
Tested-by-by: Leo Yan 
Cc: Alexander Shishkin 
Cc: Hanjun Guo 
Cc: Jiri Olsa 
Cc: Kim Phillips 
Cc: Mark Rutland 
Cc: Mike Leach 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Suzuki Poulouse 
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lore.kernel.org/lkml/20200724071111.35593-2-liwei391@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo