linux.git/tools/perf/tests/code-reading.c, branch v6.18.21

perf tests: Don't retest sections in "Object code reading"

2025-10-06T19:59:11+00:00

We already only test each kcore map once, but on slow systems
(particularly with network filesystems) even the non-kcore maps are
slow.

The test can test the same objdump output over and over which only wastes
time. Generalize the skipping mechanism to track all DSOs and addresses
so that each section is only tested once.

On a fully loaded ARM Juno (simulating a parallel 'perf test' run) with
a network filesystem, the original runtime is:

  real  1m51.126s
  user  0m19.445s
  sys   1m15.431s

And the new runtime is:

  real  0m48.873s
  user  0m8.031s
  sys   0m32.353s

Committer testing:

  # perf test "code read"
   22: Object code reading          : Ok
  #

Reviewed-by: Ian Rogers 
Signed-off-by: James Clark 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Signed-off-by: Arnaldo Carvalho de Melo

perf machine: Explicitly pass in host perf_env

2025-07-25T17:37:57+00:00

When creating a machine for the host explicitly pass in a scoped
perf_env. This removes a use of the global perf_env.

Signed-off-by: Ian Rogers 
Link: https://lore.kernel.org/r/20250724163302.596743-17-irogers@google.com
Signed-off-by: Namhyung Kim

perf test: Avoid use perf_env

2025-07-25T17:37:57+00:00

The perf_env global variable holds the host perf_env data but its use
is hit and miss. Switch to using local perf_env variables and ensure
scoped perf_env__init and perf_env__exit. This loses command line
setting of the perf_env, but this doesn't matter for tests. So the
perf_env is fully initialized, clear it with memset in perf_env__init.

Signed-off-by: Ian Rogers 
Link: https://lore.kernel.org/r/20250724163302.596743-13-irogers@google.com
Signed-off-by: Namhyung Kim

perf test code-reading: Avoid a leak of cpus and threads

2025-07-03T02:05:26+00:00

The perf_evlist__set_maps does the necessary gets on the arguments
passed, so the reference count bumping isn't necessary and creates a
memory leak.

Signed-off-by: Ian Rogers 
Link: https://lore.kernel.org/r/20250624190326.2038704-3-irogers@google.com
Signed-off-by: Namhyung Kim

perf sample: Make user_regs and intr_regs optional

2025-02-13T04:06:11+00:00

The struct dump_regs contains 512 bytes of cache_regs, meaning the two
values in perf_sample contribute 1088 bytes of its total 1384 bytes
size. Initializing this much memory has a cost reported by Tavian
Barnes  as about 2.5% when running `perf
script --itrace=i0`:
https://lore.kernel.org/lkml/d841b97b3ad2ca8bcab07e4293375fb7c32dfce7.1736618095.git.tavianator@tavianator.com/

Adrian Hunter  replied that the zero
initialization was necessary and couldn't simply be removed.

This patch aims to strike a middle ground of still zeroing the
perf_sample, but removing 79% of its size by make user_regs and
intr_regs optional pointers to zalloc-ed memory. To support the
allocation accessors are created for user_regs and intr_regs. To
support correct cleanup perf_sample__init and perf_sample__exit
functions are created and added throughout the code base.

Signed-off-by: Ian Rogers 
Link: https://lore.kernel.org/r/20250113194345.1537821-1-irogers@google.com
Signed-off-by: Namhyung Kim

perf tests code-reading: Handle change in objdump output from binutils >= 2.41 on riscv

2025-01-08T20:20:42+00:00

After binutils commit e43d876 which was first included in binutils 2.41,
riscv no longer supports dumping in the middle of instructions.

Increase the objdump window by 2-bytes to ensure that any instruction
that sits on the boundary of the specified stop-address is not cut in
half.

Signed-off-by: Charlie Jenkins 
Cc: Adrian Hunter 
Cc: Albert Ou 
Cc: Alexander Shishkin 
Cc: Bill Wendling 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Justin Stitt 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Nathan Chancellor 
Cc: Nick Desaulniers 
Cc: Palmer Dabbelt 
Cc: Paul Walmsley 
Cc: Peter Zijlstra 
Cc: linux-riscv@lists.infradead.org
Link: https://lore.kernel.org/r/20241219-perf_fix_riscv_obj_reading-v3-1-a7d644dcfa50@rivosinc.com
Signed-off-by: Arnaldo Carvalho de Melo

perf dso: Add reference count checking and accessor functions

2024-05-06T18:28:49+00:00

Add reference count checking to struct dso, this can help with
implementing correct reference counting discipline. To avoid
RC_CHK_ACCESS everywhere, add accessor functions for the variables in
struct dso.

The majority of the change is mechanical in nature and not easy to
split up.

Committer testing:

'perf test' up to this patch shows no regressions.

But:

  util/symbol.c: In function ‘dso__load_bfd_symbols’:
  util/symbol.c:1683:9: error: too few arguments to function ‘dso__set_adjust_symbols’
   1683 |         dso__set_adjust_symbols(dso);
        |         ^~~~~~~~~~~~~~~~~~~~~~~
  In file included from util/symbol.c:21:
  util/dso.h:268:20: note: declared here
    268 | static inline void dso__set_adjust_symbols(struct dso *dso, bool val)
        |                    ^~~~~~~~~~~~~~~~~~~~~~~
  make[6]: *** [/home/acme/git/perf-tools-next/tools/build/Makefile.build:106: /tmp/tmp.ZWHbQftdN6/util/symbol.o] Error 1
    MKDIR   /tmp/tmp.ZWHbQftdN6/tests/workloads/
  make[6]: *** Waiting for unfinished jobs....

This was updated:

  -       symbols__fixup_end(&dso->symbols, false);
  -       symbols__fixup_duplicate(&dso->symbols);
  -       dso->adjust_symbols = 1;
  +       symbols__fixup_end(dso__symbols(dso), false);
  +       symbols__fixup_duplicate(dso__symbols(dso));
  +       dso__set_adjust_symbols(dso);

But not build tested with BUILD_NONDISTRO and libbfd devel files installed
(binutils-devel on fedora).

Add the missing argument:

   	symbols__fixup_end(dso__symbols(dso), false);
   	symbols__fixup_duplicate(dso__symbols(dso));
  -	dso__set_adjust_symbols(dso);
  +	dso__set_adjust_symbols(dso, true);

Signed-off-by: Ian Rogers 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Adrian Hunter 
Cc: Ahelenia Ziemiańska 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Athira Rajeev 
Cc: Ben Gainey 
Cc: Changbin Du 
Cc: Chengen Du 
Cc: Colin Ian King 
Cc: Dima Kogan 
Cc: Ilkka Koskinen 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: K Prateek Nayak 
Cc: Kan Liang 
Cc: Leo Yan 
Cc: Li Dong 
Cc: Mark Rutland 
Cc: Masami Hiramatsu 
Cc: Namhyung Kim 
Cc: Paran Lee 
Cc: Peter Zijlstra 
Cc: Song Liu 
Cc: Sun Haiyong 
Cc: Thomas Richter 
Cc: Tiezhu Yang 
Cc: Yanteng Si 
Cc: zhaimingbing 
Link: https://lore.kernel.org/r/20240504213803.218974-6-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tests: Apply attributes to all events in object code reading test

2024-04-12T15:02:05+00:00

PERF_PMU_CAP_EXTENDED_HW_TYPE results in multiple events being opened on
heterogeneous systems. Currently this test only sets its required
attributes on the first event. Not disabling enable_on_exec on the other
events causes the test to fail because the forked objdump processes are
sampled. No tracking event is opened so Perf only knows about its own
mappings causing the objdump samples to give the following error:

  $ perf test -vvv "object code reading"

  Reading object code for memory address: 0xffff9aaa55ec
  thread__find_map failed
  ---- end(-1) ----
  24: Object code reading              : FAILED!

Fixes: 251aa040244a3b17 ("perf parse-events: Wildcard most "numeric" events")
Reviewed-by: Ian Rogers 
Signed-off-by: James Clark 
Acked-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Athira Rajeev 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Peter Zijlstra 
Cc: Spoorthy S 
Link: https://lore.kernel.org/r/20240410103458.813656-3-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo

libperf cpumap: Replace usage of perf_cpu_map__new(NULL) with perf_cpu_map__new_online_cpus()

2023-12-12T17:55:13+00:00

Passing NULL to perf_cpu_map__new() performs
perf_cpu_map__new_online_cpus(), just directly call
perf_cpu_map__new_online_cpus() to be more intention revealing.

Reviewed-by: James Clark 
Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Alexandre Ghiti 
Cc: Andrew Jones 
Cc: André Almeida 
Cc: Athira Jajeev 
Cc: Atish Patra 
Cc: Changbin Du 
Cc: Darren Hart 
Cc: Davidlohr Bueso 
Cc: Huacai Chen 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: John Garry 
Cc: K Prateek Nayak 
Cc: Kajol Jain 
Cc: Kan Liang 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Mike Leach 
Cc: Namhyung Kim 
Cc: Nick Desaulniers 
Cc: Paolo Bonzini 
Cc: Paran Lee 
Cc: Peter Zijlstra 
Cc: Ravi Bangoria 
Cc: Sandipan Das 
Cc: Sean Christopherson 
Cc: Steinar H. Gunderson 
Cc: Suzuki Poulouse 
Cc: Thomas Gleixner 
Cc: Will Deacon 
Cc: Yang Jihong 
Cc: Yang Li 
Cc: Yanteng Si 
Cc: bpf@vger.kernel.org
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20231129060211.1890454-5-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf test: Add option to change objdump binary

2023-11-09T16:49:33+00:00

All of the other Perf subcommands that use objdump have an option to
specify the binary, so add the same option to 'perf test'.

This is useful if you have built the kernel with a different toolchain
to the system one, where the system objdump may fail to disassemble
vmlinux.

Now this can be fixed with something like this:

  $ perf test --objdump llvm-objdump "object code reading"

Reviewed-by: Ian Rogers 
Signed-off-by: James Clark 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Athira Jajeev 
Cc: Fangrui Song 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Kajol Jain 
Cc: Kan Liang 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Nathan Chancellor 
Cc: Nick Desaulniers 
Cc: Peter Zijlstra 
Cc: Ravi Bangoria 
Cc: Tom Rix 
Cc: Yang Jihong 
Cc: llvm@lists.linux.dev
Link: https://lore.kernel.org/r/20231106151051.129440-2-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo