linux-stable.git/tools/perf/Documentation, branch v6.1.2

perf tools: Make quiet mode consistent between tools

2022-12-31T12:33:07+00:00

[ Upstream commit a527c2c1e2d43e9f145f5d0c5d6ac0bdf5220e22 ]

Use the global quiet variable everywhere so that all tools hide warnings
in quiet mode and update the documentation to reflect this.

'perf probe' claimed that errors are not printed in quiet mode but I
don't see this so remove it from the docs.

Signed-off-by: James Clark 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20221018094137.783081-3-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo 
Stable-dep-of: 8b269b755512 ("perf probe: Check -v and -q options in the right place")
Signed-off-by: Sasha Levin

perf docs: Fix man page build wrt perf-arm-coresight.txt

2022-10-25T20:40:48+00:00

perf build assumes documentation files starting with "perf-" are man
pages but perf-arm-coresight.txt is not a man page:

  asciidoc: ERROR: perf-arm-coresight.txt: line 2: malformed manpage title
  asciidoc: ERROR: perf-arm-coresight.txt: line 3: name section expected
  asciidoc: FAILED: perf-arm-coresight.txt: line 3: section title expected
  make[3]: *** [Makefile:266: perf-arm-coresight.xml] Error 1
  make[3]: *** Waiting for unfinished jobs....
  make[2]: *** [Makefile.perf:895: man] Error 2

Fix by renaming it.

Fixes: dc2e0fb00bb2b24f ("perf test coresight: Add relevant documentation about ARM64 CoreSight testing")
Reported-by: Christian Borntraeger 
Reported-by: Sven Schnelle 
Reviewed-by: Leo Yan 
Signed-off-by: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Carsten Haitzler 
Cc: coresight@lists.linaro.org
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Mathieu Poirier 
Cc: Mike Leach 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Suzuki Poulouse 
Link: https://lore.kernel.org/r/a176a3e1-6ddc-bb63-e41c-15cda8c2d5d2@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf mem/c2c: Add load store event mappings for AMD

2022-10-06T19:30:06+00:00

The 'perf mem' and 'perf c2c' tools are wrappers around 'perf record'
with mem load/ store events. IBS tagged load/store sample provides most
of the information needed for these tools. Wire in the "ibs_op//" event
as mem-ldst event for AMD.

There are some limitations though: Only load/store micro-ops provide
mem/c2c information. Whereas, IBS does not have a way to choose a
particular type of micro-op to tag. This results in many non-LS
micro-ops being tagged which appear as N/A in the perf report. IBS,
being an uncore pmu from kernel point of view[1], does not support per
process monitoring. Thus, perf mem/c2c on AMD are currently supported in
per-cpu mode only.

Example:

  $ sudo perf mem record -- -c 10000
  ^C[ perf record: Woken up 227 times to write data ]
  [ perf record: Captured and wrote 58.760 MB perf.data (836978 samples) ]

  $ sudo perf mem report -F mem,sample,snoop
  Samples: 836K of event 'ibs_op//', Event count (approx.): 8418762
  Memory access                  Samples  Snoop
  N/A                             700620  N/A
  L1 hit                          126675  N/A
  L2 hit                             424  N/A
  L3 hit                             664  HitM
  L3 hit                              10  N/A
  Local RAM hit                        2  N/A
  Remote RAM (1 hop) hit            8558  N/A
  Remote Cache (1 hop) hit             3  N/A
  Remote Cache (1 hop) hit             2  HitM
  Remote Cache (2 hops) hit           10  HitM
  Remote Cache (2 hops) hit            6  N/A
  Uncached hit                         4  N/A
  $

[1]: https://lore.kernel.org/lkml/20220829113347.295-1-ravi.bangoria@amd.com

Signed-off-by: Ravi Bangoria 
Acked-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Ali Saidi 
Cc: Ananth Narayan 
Cc: Andi Kleen 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: H. Peter Anvin 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Joe Mario 
Cc: Kan Liang 
Cc: Kim Phillips 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Sandipan Das 
Cc: Santosh Shukla 
Cc: Stephane Eranian 
Cc: Thomas Gleixner 
Cc: x86@kernel.org
Link: https://lore.kernel.org/r/20221006153946.7816-6-ravi.bangoria@amd.com
Signed-off-by: Arnaldo Carvalho de Melo

perf mem/c2c: Set PERF_SAMPLE_WEIGHT for LOAD_STORE events

2022-10-06T19:29:32+00:00

Currently perf sets PERF_SAMPLE_WEIGHT flag only for mem load events.
Set it for combined load-store event as well which will enable recording
of load latency by default on arch that does not support independent
mem load event.

Also document missing -W in perf-record man page.

Signed-off-by: Ravi Bangoria 
Acked-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Ali Saidi 
Cc: Ananth Narayan 
Cc: Andi Kleen 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: H. Peter Anvin 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Joe Mario 
Cc: Kan Liang 
Cc: Kim Phillips 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Sandipan Das 
Cc: Santosh Shukla 
Cc: Stephane Eranian 
Cc: Thomas Gleixner 
Cc: x86@kernel.org
Link: https://lore.kernel.org/r/20221006153946.7816-5-ravi.bangoria@amd.com
Signed-off-by: Arnaldo Carvalho de Melo

perf test coresight: Add relevant documentation about ARM64 CoreSight testing

2022-10-06T17:50:55+00:00

Add/improve documentation helping people get started with CoreSight and
perf as well as describe the testing and how it works.

Reviewed-by: James Clark 
Signed-off-by: Carsten Haitzler 
Cc: Leo Yan 
Cc: Mathieu Poirier 
Cc: Mike Leach 
Cc: Suzuki Poulouse 
Cc: coresight@lists.linaro.org
Cc: linux-doc@vger.kernel.org
Link: https://lore.kernel.org/r/20220909152803.2317006-14-carsten.haitzler@foss.arm.com
Signed-off-by: Arnaldo Carvalho de Melo

perf lock: Add -q/--quiet option to suppress header and debug messages

2022-10-04T11:55:23+00:00

Like in 'perf report', this option is to suppress header and debug messages.

Signed-off-by: Namhyung Kim 
Acked-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20220924004221.841024-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf lock: Add -E/--entries option

2022-10-04T11:55:23+00:00

Like in 'perf top', the -E option can limit number of entries to print.

It can be useful when users want to see top N contended locks only.

Signed-off-by: Namhyung Kim 
Acked-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20220924004221.841024-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Add 'addr' sort key

2022-10-04T11:55:22+00:00

Sometimes users want to see actual (virtual) address of sampled instructions.
Add a new 'addr' sort key to display the raw addresses.

  $ perf record -o- true | perf report -i- -s addr
  # To display the perf.data header info, please use --header/--header-only options.
  #
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.000 MB - ]
  #
  # Total Lost Samples: 0
  #
  # Samples: 12  of event 'cycles:u'
  # Event count (approx.): 252512
  #
  # Overhead  Address
  # ........  ..................
  #
      42.96%  0x7f96f08443d7
      29.55%  0x7f96f0859b50
      14.76%  0x7f96f0852e02
       8.30%  0x7f96f0855028
       4.43%  0xffffffff8de01087

Note that it just compares and displays the sample ip.  Each process can
have a different memory layout and the ip will be different even if they run
the same binary.  So this sort key is mostly meaningful for per-process
profile data.

Signed-off-by: Namhyung Kim 
Acked-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: https://lore.kernel.org/r/20220923173142.805896-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf inject: Clarify build-id options a little bit

2022-10-04T11:55:22+00:00

Update the documentation of --build-id and --buildid-all options to
clarify the difference between them.  The former requires full sample
processing to find which DSOs are actually used.  While the latter simply
injects every DSO's build-id from MMAP{,2} records, skipping SAMPLEs.

Reviewed-by: Adrian Hunter 
Signed-off-by: Namhyung Kim 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: https://lore.kernel.org/r/20220923173142.805896-3-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf lock contention: Allow to change stack depth and skip

2022-10-04T11:55:22+00:00

It needs stack traces to find callers of locks.  To minimize the
performance overhead it only collects up to 8 entries for each stack
trace.  And it skips first 3 entries as they came from BPF, tracepoint
and lock functions which are not interested for most users.

But it turned out that those numbers are different in some
configuration.  Using fixed number can result in non meaningful caller
names.  Let's make them adjustable with --stack-depth and --skip-stack
options.

On my setup, the default output is like below:

  # /perf lock con -ab -F contended,wait_total sleep 3
   contended   total wait         type   caller

          28      4.55 ms     rwlock:W   __bpf_trace_contention_begin+0xb
          33      1.67 ms     rwlock:W   __bpf_trace_contention_begin+0xb
          12    580.28 us     spinlock   __bpf_trace_contention_begin+0xb
          60    240.54 us      rwsem:R   __bpf_trace_contention_begin+0xb
          27     64.45 us     spinlock   __bpf_trace_contention_begin+0xb

If I change the stack skip to 5, the result will be like:

  # perf lock con -ab -F contended,wait_total --stack-skip 5 sleep 3
   contended   total wait         type   caller

          32    715.45 us     spinlock   folio_lruvec_lock_irqsave+0x61
          26    550.22 us     spinlock   folio_lruvec_lock_irqsave+0x61
          15    486.93 us      rwsem:R   mmap_read_lock+0x13
          12    139.66 us      rwsem:W   vm_mmap_pgoff+0x93
           1      7.04 us     spinlock   tick_do_update_jiffies64+0x25

Signed-off-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Peter Zijlstra 
Cc: Song Liu 
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20220912055314.744552-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo