[PATCH v7 7/9] perf: arm64: Add test for userspace counter access on heterogeneous systems

[Rob Herring]

On Fri, Apr 30, 2021 at 1:17 PM Rob Herring <robh at kernel.org> wrote:
>
> On Fri, Apr 30, 2021 at 11:46 AM Masayoshi Mizuma <msys.mizuma at gmail.com> wrote:
> >
> > On Mon, Apr 19, 2021 at 10:15:09PM -0500, Rob Herring wrote:
> > > Userspace counter access only works on heterogeneous systems with some
> > > restrictions. The userspace process must be pinned to a homogeneous
> > > subset of CPUs and must open the corresponding PMU for those CPUs. This
> > > commit adds a test implementing these requirements.
> > >
> > > Signed-off-by: Rob Herring <robh at kernel.org>
> > > ---
> > > v6:
> > >  - Add a check on cap_user_rdpmc
> > > v5:
> > >  - Adapt to libperf mmap API changes
> > > v4:
> > >  - Update perf_evsel__mmap params
> > > v2:
> > >  - Drop all but heterogeneous test as others covered by libperf tests
> > >  - Rework to use libperf
> > > ---
> > >  tools/perf/arch/arm64/include/arch-tests.h |   7 +
> > >  tools/perf/arch/arm64/tests/Build          |   1 +
> > >  tools/perf/arch/arm64/tests/arch-tests.c   |   4 +
> > >  tools/perf/arch/arm64/tests/user-events.c  | 177 +++++++++++++++++++++
> > >  4 files changed, 189 insertions(+)
> > >  create mode 100644 tools/perf/arch/arm64/tests/user-events.c
> > >
> > > diff --git a/tools/perf/arch/arm64/include/arch-tests.h b/tools/perf/arch/arm64/include/arch-tests.h
> > > index 90ec4c8cb880..380ad34a3f09 100644
> > > --- a/tools/perf/arch/arm64/include/arch-tests.h
> > > +++ b/tools/perf/arch/arm64/include/arch-tests.h
> > > @@ -2,11 +2,18 @@
> > >  #ifndef ARCH_TESTS_H
> > >  #define ARCH_TESTS_H
> > >
> > > +#include <linux/compiler.h>
> > > +
> > >  #ifdef HAVE_DWARF_UNWIND_SUPPORT
> > >  struct thread;
> > >  struct perf_sample;
> > > +int test__arch_unwind_sample(struct perf_sample *sample,
> > > +                          struct thread *thread);
> > >  #endif
> >
> > Hello,
> >
> > I got the following compile error with aarch64 on Fedora33.
> >
> >     # make tools/perf
> >     ...
> >     In file included from arch/arm64/tests/arch-tests.c:4:
> >     /root//libperf_v7/tools/perf/arch/arm64/include/arch-tests.h:10:5: error: redundant redeclaration of ‘test__arch_unwind_sample’ [-Werror=redundant-decls]
> >        10 | int test__arch_unwind_sample(struct perf_sample *sample,
> >           |     ^~~~~~~~~~~~~~~~~~~~~~~~
> >     In file included from arch/arm64/tests/arch-tests.c:3:
> >     /root//libperf_v7/tools/perf/tests/tests.h:140:5: note: previous declaration of ‘test__arch_unwind_sample’ was here
> >       140 | int test__arch_unwind_sample(struct perf_sample *sample,
> >           |     ^~~~~~~~~~~~~~~~~~~~~~~~
> >     cc1: all warnings being treated as errors
> >     make[8]: *** [/root//libperf_v7/tools/build/Makefile.build:97: /root/libperf_v7/tools/perf/arch/arm64/tests/arch-tests.o] Error 1
> >     make[8]: *** Waiting for unfinished jobs....
> >     In file included from arch/arm64/tests/user-events.c:13:
> >     /root//libperf_v7/tools/perf/arch/arm64/include/arch-tests.h:10:5: error: redundant redeclaration of ‘test__arch_unwind_sample’ [-Werror=redundant-decls]
> >        10 | int test__arch_unwind_sample(struct perf_sample *sample,
> >           |     ^~~~~~~~~~~~~~~~~~~~~~~~
> >     In file included from arch/arm64/tests/user-events.c:12:
> >     /root//libperf_v7/tools/perf/tests/tests.h:140:5: note: previous declaration of ‘test__arch_unwind_sample’ was here
> >       140 | int test__arch_unwind_sample(struct perf_sample *sample,
> >           |     ^~~~~~~~~~~~~~~~~~~~~~~~
> >     cc1: all warnings being treated as errors
> >     ...
> >
> > The error is gone after the following patch is applied.
>
> Thanks. Honestly, I'm not sure why it was there in the first place.
> Looking at the git history and this series history doesn't give any
> clues.

Well, except that both x86 and powerpc have the same hunk in their
arch-tests.h. Do you see errors on those arches?

Rob