Em Thu, May 26, 2022 at 12:44:33PM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Mon, May 09, 2022 at 03:42:52PM +0100, James Clark escreveu:
> > Architectures can detect availability of extra registers at
> > runtime so use this more complete set for unwinding. This
> > will include the VG register on arm64 in a later commit.
> >
> > If the function isn't implemented then PERF_REGS_MASK is
> > returned and there is no change.
>
> Committer notes:
>
> Added util/perf_regs.c to tools/perf/util/python-ext-sources so that
> 'perf test python' passes, i.e. the perf python binding has all the
> symbols it needs, addressing:
>
> $ perf test -v python
> 19: 'import perf' in python :
> --- start ---
> test child forked, pid 2037817
> python usage test: "echo "import sys ; sys.path.append('/tmp/build/perf/python'); import perf" | '/usr/bin/python3' "
> Traceback (most recent call last):
> File "<stdin>", line 1, in <module>
> ImportError: /tmp/build/perf/python/perf.cpython-310-x86_64-linux-gnu.so: undefined symbol: arch__user_reg_mask
> test child finished with -1
> ---- end ----
> 'import perf' in python: FAILED!
> $
Too old to support?
69 7.19 ubuntu:16.04-x-arm64 : FAIL gcc version 5.4.0 20160609 (Ubuntu/Linaro 5.4.0-6ubuntu1~16.04.9)
arch/arm64/util/perf_regs.c: In function 'arch__user_reg_mask':
arch/arm64/util/perf_regs.c:151:28: error: 'HWCAP_SVE' undeclared (first use in this function)
if (getauxval(AT_HWCAP) & HWCAP_SVE)
^
arch/arm64/util/perf_regs.c:151:28: note: each undeclared identifier is reported only once for each function it appears in
/git/perf-5.18.0/tools/build/Makefile.build:139: recipe for target 'util' failed
make[5]: *** [util] Error 2
/git/perf-5.18.0/tools/build/Makefile.build:139: recipe for target 'arm64' failed
make[4]: *** [arm64] Error 2
/git/perf-5.18.0/tools/build/Makefile.build:139: recipe for target 'arch' failed
make[3]: *** [arch] Error 2
⬢[acme@toolbox perf]$ find . -name "*.h" | xargs grep -w HWCAP_SVE
./arch/arm64/include/uapi/asm/hwcap.h:#define HWCAP_SVE (1 << 22)
⬢[acme@toolbox perf]$
> > Signed-off-by: James Clark <james.clark@xxxxxxx>
> > ---
> > tools/perf/util/evsel.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> > index d38722560e80..a881784da966 100644
> > --- a/tools/perf/util/evsel.c
> > +++ b/tools/perf/util/evsel.c
> > @@ -875,7 +875,7 @@ static void __evsel__config_callchain(struct evsel *evsel, struct record_opts *o
> > "specifying a subset with --user-regs may render DWARF unwinding unreliable, "
> > "so the minimal registers set (IP, SP) is explicitly forced.\n");
> > } else {
> > - attr->sample_regs_user |= PERF_REGS_MASK;
> > + attr->sample_regs_user |= arch__user_reg_mask();
> > }
> > attr->sample_stack_user = param->dump_size;
> > attr->exclude_callchain_user = 1;
> > --
> > 2.28.0
>
> --
>
> - Arnaldo
--
- Arnaldo
