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References: <20240109095637.35934-1-alessandro.carminati@gmail.com>
In-Reply-To: <20240109095637.35934-1-alessandro.carminati@gmail.com>
From: Song Liu <song@kernel.org>
Date: Tue, 9 Jan 2024 09:45:20 -0800
Message-ID: <CAPhsuW4vDX70-n3n0wk4XsX7+-kmG=GZZ5PHBr=EO3A7Ju2kZg@mail.gmail.com>
Subject: Re: [RFC PATCH] find_vma BPF test: increase length CPU computation
To: "Alessandro Carminati (Red Hat)" <alessandro.carminati@gmail.com>
Cc: Andrii Nakryiko <andrii@kernel.org>, Shuah Khan <shuah@kernel.org>, Mykola Lysenko <mykolal@fb.com>, 
	Alexei Starovoitov <ast@kernel.org>, Daniel Borkmann <daniel@iogearbox.net>, 
	Martin KaFai Lau <martin.lau@linux.dev>, Yonghong Song <yonghong.song@linux.dev>, 
	John Fastabend <john.fastabend@gmail.com>, KP Singh <kpsingh@kernel.org>, 
	Stanislav Fomichev <sdf@google.com>, Hao Luo <haoluo@google.com>, Jiri Olsa <jolsa@kernel.org>, 
	bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, 
	linux-kernel@vger.kernel.org
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On Tue, Jan 9, 2024 at 1:57=E2=80=AFAM Alessandro Carminati (Red Hat)
<alessandro.carminati@gmail.com> wrote:
>
> Some aarch64 systems running a PREEMPT_RT patched kernel, needs
> more time to complete the test.
> This change mirrors:
> commit ba83af059153 ("Improve stability of find_vma BPF test")
> addressing similar requirements and allowing the QTI SA8775P based
> systems, and others, to complete the test when running RT kernel.
>
> Signed-off-by: Alessandro Carminati (Red Hat) <alessandro.carminati@gmail=
com>
> ---
>  tools/testing/selftests/bpf/prog_tests/find_vma.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/find_vma.c b/tools/te=
sting/selftests/bpf/prog_tests/find_vma.c
> index 5165b38f0e59..43d62db8d57b 100644
> --- a/tools/testing/selftests/bpf/prog_tests/find_vma.c
> +++ b/tools/testing/selftests/bpf/prog_tests/find_vma.c
> @@ -51,7 +51,7 @@ static void test_find_vma_pe(struct find_vma *skel)
>         struct bpf_link *link =3D NULL;
>         volatile int j =3D 0;
>         int pfd, i;
> -       const int one_bn =3D 1000000000;
> +       const int dummy_wait =3D 2500000000;

2500000000 is bigger than INT_MAX.

>
>         pfd =3D open_pe();
>         if (pfd < 0) {
> @@ -68,10 +68,10 @@ static void test_find_vma_pe(struct find_vma *skel)
>         if (!ASSERT_OK_PTR(link, "attach_perf_event"))
>                 goto cleanup;
>
> -       for (i =3D 0; i < one_bn && find_vma_pe_condition(skel); ++i)
> +       for (i =3D 0; i < dummy_wait && find_vma_pe_condition(skel); ++i)
>                 ++j;

So we will skip this loop. Right?

Thanks,
Song


>
> -       test_and_reset_skel(skel, -EBUSY /* in nmi, irq_work is busy */, =
i =3D=3D one_bn);
> +       test_and_reset_skel(skel, -EBUSY /* in nmi, irq_work is busy */, =
i =3D=3D dummy_wait);
>  cleanup:
>         bpf_link__destroy(link);
>         close(pfd);
> --
> 2.34.1
>