Received-SPF: softfail (google.com: domain of transitioning linux-kernel-owner@vger.kernel.org does not designate 23.128.96.19 as permitted sender) client-ip=23.128.96.19;
MIME-Version: 1.0
References: <1645114959-119064-1-git-send-email-john.garry@huawei.com>
 <CANpmjNOO6yxF+xXoatR==uvSaEwsWyZ=n7ExEM_=OJaDYBCeSw@mail.gmail.com> <f7782f09-7f12-b957-a1b2-d0673ec1304c@huawei.com>
In-Reply-To: <f7782f09-7f12-b957-a1b2-d0673ec1304c@huawei.com>
From:   Marco Elver <elver@google.com>
Date:   Thu, 17 Feb 2022 18:40:45 +0100
Message-ID: <CANpmjNOO-fsU7PP_PqeT53_N=xmNruiT3mvE0e1y=EtKJUfFGg@mail.gmail.com>
Subject: Re: [PATCH] perf test: Skip Sigtrap test for arm+aarch64
To:     John Garry <john.garry@huawei.com>
Cc:     peterz@infradead.org, mingo@redhat.com, acme@kernel.org,
        mark.rutland@arm.com, jolsa@kernel.org, namhyung@kernel.org,
        leo.yan@linaro.org, dvyukov@google.com, will@kernel.org,
        linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux@armlinux.org.uk,
        irogers@google.com, Thomas Richter <tmricht@linux.ibm.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Thu, 17 Feb 2022 at 18:34, John Garry <john.garry@huawei.com> wrote:
[...]
> >> -#if defined(__powerpc__) || defined(__s390x__)
> >> +#if defined(__powerpc__) || defined(__s390x__) || \
> >> +       defined(__arm__) || defined(__aarch64__)
> >>   #define BP_ACCOUNT_IS_SUPPORTED 0
> >>   #else
> >>   #define BP_ACCOUNT_IS_SUPPORTED 1
> >
> > This is now equivalent to BP_SIGNAL_IS_SUPPORTED
> > tools/perf/tests/tests.h -- and different from the original
> > BP_ACCOUNT_IS_SUPPORTED (and makes me wonder why
> > BP_SIGNAL_IS_SUPPORTED wasn't just used from the beginning). Perhaps
> > just use BP_SIGNAL_IS_SUPPORTED.
> >
>
> We currently have BP_ACCOUNT_IS_SUPPORTED defined now in 2x locations:
>
> tests/sigtrap.c
> tests/bp_account.c
>
> bp_account works for arm64, and we don't want to skip that test. So, as
> long as the macro meaning is appropriate, we can reuse
> BP_SIGNAL_IS_SUPPORTED for sigtrap.c

BP_ACCOUNT seems to say something about the "breakpoint accounting /
measuring" test. BP_SIGNAL is about the tests that want to use
breakpoints to generate signals.

So it's very much appropriate to use BP_SIGNAL here if, as we have
discovered regardless how they're generated in response to
breakpoints, are broken on arm/arm64. On the day arm/arm64 decides to
fix signals, I'm assuming all tests being skipped with
BP_SIGNAL_IS_SUPPORTED can be re-enabled (or so we hope).

Thanks,
-- Marco