linux.git/tools/perf/util/Build, branch vsnprintf

perf dwarf-regs: Move powerpc dwarf-regs out of arch

2024-11-09T16:39:13+00:00

Move arch/powerpc/util/dwarf-regs.c to util/dwarf-regs-powerpc.c and
compile in unconditionally. get_arch_regstr is redundant when EM_NONE
is treated as EM_HOST so remove and update dwarf-regs.c conditions.
Make get_powerpc_regs unconditionally available whwn libdw is.

Reviewed-by: Masami Hiramatsu (Google) 
Signed-off-by: Ian Rogers 
Cc: Anup Patel 
Cc: Yang Jihong 
Cc: Palmer Dabbelt 
Cc: David S. Miller 
Cc: Albert Ou 
Cc: Shenlin Liang 
Cc: Nick Terrell 
Cc: Guilherme Amadio 
Cc: Steinar H. Gunderson 
Cc: Changbin Du 
Cc: Alexander Lobakin 
Cc: Przemek Kitszel 
Cc: Huacai Chen 
Cc: Guo Ren 
Cc: Masahiro Yamada 
Cc: Will Deacon 
Cc: James Clark 
Cc: Mike Leach 
Cc: Chen Pei 
Cc: Leo Yan 
Cc: Oliver Upton 
Cc: Aditya Gupta 
Cc: Kajol Jain 
Cc: Athira Rajeev 
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-riscv@lists.infradead.org
Cc: Bibo Mao 
Cc: John Garry 
Cc: Atish Patra 
Cc: Dima Kogan 
Cc: Paul Walmsley 
Cc: Dr. David Alan Gilbert 
Cc: linux-csky@vger.kernel.org
Link: https://lore.kernel.org/r/20241108234606.429459-14-irogers@google.com
Signed-off-by: Namhyung Kim

perf dwarf-regs: Move csky dwarf-regs out of arch

2024-11-09T16:39:13+00:00

Move arch/csky/util/dwarf-regs.c to util/dwarf-regs-csky.c and compile
in unconditionally. To avoid get_arch_regstr being duplicated, rename
to get_csky_regstr and add to get_dwarf_regstr switch.

Update #ifdefs to allow ABI V1 and V2 tables at the same
time. Determine the table from the ELF flags.

Reviewed-by: Masami Hiramatsu (Google) 
Signed-off-by: Ian Rogers 
Cc: Anup Patel 
Cc: Yang Jihong 
Cc: Palmer Dabbelt 
Cc: David S. Miller 
Cc: Albert Ou 
Cc: Shenlin Liang 
Cc: Nick Terrell 
Cc: Guilherme Amadio 
Cc: Steinar H. Gunderson 
Cc: Changbin Du 
Cc: Alexander Lobakin 
Cc: Przemek Kitszel 
Cc: Huacai Chen 
Cc: Guo Ren 
Cc: Masahiro Yamada 
Cc: Will Deacon 
Cc: James Clark 
Cc: Mike Leach 
Cc: Chen Pei 
Cc: Leo Yan 
Cc: Oliver Upton 
Cc: Aditya Gupta 
Cc: Kajol Jain 
Cc: Athira Rajeev 
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-riscv@lists.infradead.org
Cc: Bibo Mao 
Cc: John Garry 
Cc: Atish Patra 
Cc: Dima Kogan 
Cc: Paul Walmsley 
Cc: Dr. David Alan Gilbert 
Cc: linux-csky@vger.kernel.org
Link: https://lore.kernel.org/r/20241108234606.429459-11-irogers@google.com
Signed-off-by: Namhyung Kim

perf dwarf-regs: Move x86 dwarf-regs out of arch

2024-11-09T16:39:13+00:00

Move arch/x86/util/dwarf-regs.c to util/dwarf-regs-x86.c and compile
in unconditionally. To avoid get_arch_regnum being duplicated, rename
to get_x86_regnum and add to get_dwarf_regnum switch.

For get_arch_regstr, this was unused on x86 unless the machine type
was EM_NONE. Map that case to EM_HOST and remove get_arch_regstr from
dwarf-regs-x86.c.

Reviewed-by: Masami Hiramatsu (Google) 
Signed-off-by: Ian Rogers 
Cc: Anup Patel 
Cc: Yang Jihong 
Cc: Palmer Dabbelt 
Cc: David S. Miller 
Cc: Albert Ou 
Cc: Shenlin Liang 
Cc: Nick Terrell 
Cc: Guilherme Amadio 
Cc: Steinar H. Gunderson 
Cc: Changbin Du 
Cc: Alexander Lobakin 
Cc: Przemek Kitszel 
Cc: Huacai Chen 
Cc: Guo Ren 
Cc: Masahiro Yamada 
Cc: Will Deacon 
Cc: James Clark 
Cc: Mike Leach 
Cc: Chen Pei 
Cc: Leo Yan 
Cc: Oliver Upton 
Cc: Aditya Gupta 
Cc: Kajol Jain 
Cc: Athira Rajeev 
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-riscv@lists.infradead.org
Cc: Bibo Mao 
Cc: John Garry 
Cc: Atish Patra 
Cc: Dima Kogan 
Cc: Paul Walmsley 
Cc: Dr. David Alan Gilbert 
Cc: linux-csky@vger.kernel.org
Link: https://lore.kernel.org/r/20241108234606.429459-8-irogers@google.com
Signed-off-by: Namhyung Kim

perf hwmon_pmu: Add hwmon filename parser

2024-11-09T16:26:53+00:00

hwmon filenames have a specific encoding that will be used to give a
config value. The encoding is described in:
Documentation/hwmon/sysfs-interface.rst
Add a function to parse the filename into consituent enums/ints that
will then be amenable to config encoding.

Note, things are done this way to allow mapping names to config and
back without the use of hash/dynamic lookup tables.

Signed-off-by: Ian Rogers 
Cc: Ravi Bangoria 
Cc: Yoshihiro Furudera 
Cc: Howard Chu 
Cc: Ze Gao 
Cc: Changbin Du 
Cc: Junhao He 
Cc: Weilin Wang 
Cc: James Clark 
Cc: Oliver Upton 
Cc: Athira Jajeev 
[namhyung: add #include  for strlcpy()]
Link: https://lore.kernel.org/r/20241109003759.473460-3-irogers@google.com
Signed-off-by: Namhyung Kim

perf build: Rename CONFIG_DWARF to CONFIG_LIBDW

2024-10-18T17:17:40+00:00

In Makefile.config for unwinding the name dwarf implies either
libunwind or libdw. Make it clearer that CONFIG_DWARF is really just
defined when libdw is present by renaming to CONFIG_LIBDW.

Signed-off-by: Ian Rogers 
Acked-by: Namhyung Kim 
Tested-by: Leo Yan 
Cc: Anup Patel 
Cc: Yang Jihong 
Cc: Palmer Dabbelt 
Cc: David S. Miller 
Cc: Albert Ou 
Cc: Shenlin Liang 
Cc: Nick Terrell 
Cc: Guilherme Amadio 
Cc: Steinar H. Gunderson 
Cc: Changbin Du 
Cc: Alexander Lobakin 
Cc: Przemek Kitszel 
Cc: Huacai Chen 
Cc: Guo Ren 
Cc: Masahiro Yamada 
Cc: Masami Hiramatsu (Google) 
Cc: Will Deacon 
Cc: James Clark 
Cc: Mike Leach 
Cc: Chen Pei 
Cc: Leo Yan 
Cc: Oliver Upton 
Cc: Aditya Gupta 
Cc: Kajol Jain 
Cc: Athira Rajeev 
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-riscv@lists.infradead.org
Cc: Bibo Mao 
Cc: John Garry 
Cc: Atish Patra 
Cc: Dima Kogan 
Cc: Paul Walmsley 
Cc: Dr. David Alan Gilbert 
Cc: linux-csky@vger.kernel.org
Link: https://lore.kernel.org/r/20241017001354.56973-12-irogers@google.com
Signed-off-by: Namhyung Kim

perf tool_pmu: Factor tool events into their own PMU

2024-10-11T06:40:32+00:00

Rather than treat tool events as a special kind of event, create a
tool only PMU where the events/aliases match the existing
duration_time, user_time and system_time events. Remove special
parsing and printing support for the tool events, but add function
calls for when PMU functions are called on a tool_pmu.

Move the tool PMU code in evsel into tool_pmu.c to better encapsulate
the tool event behavior in that file.

Signed-off-by: Ian Rogers 
Acked-by: Namhyung Kim 
Link: https://lore.kernel.org/r/20241002032016.333748-5-irogers@google.com
Signed-off-by: Namhyung Kim

perf report: Support LLVM for addr2line()

2024-09-03T13:15:16+00:00

In addition to the existing support for libbfd and calling out to
an external addr2line command, add support for using libllvm directly.

This is both faster than libbfd, and can be enabled in distro builds
(the LLVM license has an explicit provision for GPLv2 compatibility).

Thus, it is set as the primary choice if available.

As an example, running 'perf report' on a medium-size profile with
DWARF-based backtraces took 58 seconds with LLVM, 78 seconds with
libbfd, 153 seconds with external llvm-addr2line, and I got tired and
aborted the test after waiting for 55 minutes with external bfd
addr2line (which is the default for perf as compiled by distributions
today).

Evidently, for this case, the bfd addr2line process needs 18 seconds (on
a 5.2 GHz Zen 3) to load the .debug ELF in question, hits the 1-second
timeout and gets killed during initialization, getting restarted anew
every time. Having an in-process addr2line makes this much more robust.

As future extensions, libllvm can be used in many other places where
we currently use libbfd or other libraries:

 - Symbol enumeration (in particular, for PE binaries).
 - Demangling (including non-Itanium demangling, e.g. Microsoft
   or Rust).
 - Disassembling (perf annotate).

However, these are much less pressing; most people don't profile PE
binaries, and perf has non-bfd paths for ELF. The same with demangling;
the default _cxa_demangle path works fine for most users, and while bfd
objdump can be slow on large binaries, it is possible to use
--objdump=llvm-objdump to get the speed benefits.  (It appears
LLVM-based demangling is very simple, should we want that.)

Tested with LLVM 14, 15, 16, 18 and 19. For some reason, LLVM 12 was not
correctly detected using feature_check, and thus was not tested.

Committer notes:

 Added the name and a __maybe_unused to address:

   1    13.50 almalinux:8                   : FAIL gcc version 8.5.0 20210514 (Red Hat 8.5.0-22) (GCC)
    util/srcline.c: In function 'dso__free_a2l':
    util/srcline.c:184:20: error: parameter name omitted
     void dso__free_a2l(struct dso *)
                        ^~~~~~~~~~~~
    make[3]: *** [/git/perf-6.11.0-rc3/tools/build/Makefile.build:158: util] Error 2

Signed-off-by: Steinar H. Gunderson 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Ian Rogers 
Link: https://lore.kernel.org/r/20240803152008.2818485-1-sesse@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf bpf-filter: Add build dependency to header files

2024-08-28T21:21:24+00:00

The flex and bison files need to be recompiled when one of these header
filters are changed.

 * util/bpf-filter.h
 * util/bpf_skel/sample-filter.h

Signed-off-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: https://lore.kernel.org/r/20240826221045.1202305-3-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf cap: Tidy up and improve capability testing

2024-08-20T20:53:12+00:00

Remove dependence on libcap. libcap is only used to query whether a
capability is supported, which is just 1 capget system call.

If the capget system call fails, fall back on root permission
checking. Previously if libcap fails then the permission is assumed
not present which may be pessimistic/wrong.

Add a used_root out argument to perf_cap__capable to say whether the
fall back root check was used. This allows the correct error message,
"root" vs "users with the CAP_PERFMON or CAP_SYS_ADMIN capability", to
be selected.

Tidy uses of perf_cap__capable so that tests aren't repeated if capget
isn't supported.

Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Athira Rajeev 
Cc: Changbin Du 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Oliver Upton 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20240806220614.831914-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf stat: Fork and launch 'perf record' when 'perf stat' needs to get retire latency value for a metric.

2024-08-13T18:24:48+00:00

When retire_latency value is used in a metric formula, evsel would fork
a 'perf record' process with "-e" and "-W" options. 'perf record' will
collect required retire_latency values in parallel while 'perf stat' is
collecting counting values.

At the point of time that 'perf stat' stops counting, evsel would stop
'perf record' by sending sigterm signal to 'perf record' process.
Sampled data will be processed to get retire latency value. Another
thread is required to synchronize between 'perf stat' and 'perf record'
when we pass data through pipe.

Retire_latency evsel is not opened for 'perf stat' so that there is no
counter wasted on it. This commit includes code suggested by Namhyung to
adjust reading size for groups that include retire_latency evsels.

In current :R parsing implementation, the parser would recognize events
with retire_latency modifier and insert them into the evlist like a
normal event.  Ideally, we need to avoid counting these events.

In this commit, at the time when a retire_latency evsel is read, set the
retire latency value processed from the sampled data to count value.
This sampled retire latency value will be used for metric calculation
and final event count print out. No special metric calculation and event
print out code required for retire_latency events.

Reviewed-by: Namhyung Kim 
Signed-off-by: Weilin Wang 
Acked-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Caleb Biggers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Perry Taylor 
Cc: Peter Zijlstra 
Cc: Samantha Alt 
Link: https://lore.kernel.org/r/20240720062102.444578-4-weilin.wang@intel.com
[ Squashed the 3rd and 4th commit in the series to keep it building patch by patch ]
[ Constified the 'struct perf_tool' pointer in process_sample_event() ]
[ Use perf_tool__init(&tool, false) to address a segfault I reported and Ian/Weilin diagnosed ]
Signed-off-by: Arnaldo Carvalho de Melo