From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from 69-171-232-180.mail-mxout.facebook.com (69-171-232-180.mail-mxout.facebook.com [69.171.232.180]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8D487366DDA for ; Tue, 13 Jan 2026 06:10:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=69.171.232.180 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768284637; cv=none; b=Ojh8Vfm5w7HjT7GCcBvustARTAIeRgp410q/5QgEzlSnKQKznqh+1QAyx0c64EZkLniSoxIWbNVYqLV5A1uTGe65ghMpk68OcxIg0BXiU1YpXCykNoMn50TNyRiwvKyKQQudyRVS4dExaoGRbGsf4OWb4t/AUPRe6NX1eIu3G6Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768284637; c=relaxed/simple; bh=zIqXCU23yyFgh6nxfs9EingDx5He8xEjte0JfRI+SiA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=JBWnpYxY7TRVkQHZd7zkqVt7DN4IGPX4hWoqUFtXyJeIJJTJOP5vzppEiAzISYYJx/wRiZARJY1jtWQ3CC3FYuBQVZIXeg2Bx6abrV2XkvY0cWadkHqbbEPlsj9O9xUqZoezqxAriVRCMRqmE7ofdEkxAQxjkxg7iBQCbGmwA+4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.dev; spf=fail smtp.mailfrom=linux.dev; arc=none smtp.client-ip=69.171.232.180 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=linux.dev Received: by devvm16039.vll0.facebook.com (Postfix, from userid 128203) id 7841A18C4C5FB; Mon, 12 Jan 2026 22:10:23 -0800 (PST) From: Yonghong Song To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , kernel-team@fb.com, Martin KaFai Lau , "T.J. Mercier" Subject: [PATCH bpf-next 1/3] selftests/bpf: Fix dmabuf_iter/lots_of_buffers failure with 64K page Date: Mon, 12 Jan 2026 22:10:23 -0800 Message-ID: <20260113061023.3798085-1-yonghong.song@linux.dev> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260113061018.3797051-1-yonghong.song@linux.dev> References: <20260113061018.3797051-1-yonghong.song@linux.dev> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable On arm64 with 64K page , I observed the following test failure: ... subtest_dmabuf_iter_check_lots_of_buffers:FAIL:total_bytes_read unexpec= ted total_bytes_read: actual 4696 <=3D expected 65536 #97/3 dmabuf_iter/lots_of_buffers:FAIL With 4K page on x86, the total_bytes_read is 4593. With 64K page on arm64, the total_byte_read is 4696. In progs/dmabuf_iter.c, for each iteration, the output is BPF_SEQ_PRINTF(seq, "%lu\n%llu\n%s\n%s\n", inode, size, name, exporter)= ; The only difference between 4K and 64K page is 'size' in the above BPF_SEQ_PRINTF. The 4K page will output '4096' and the 64K page will output '65536'. So the total_bytes_read with 64K page is slighter greater than 4K page. Adjusting the total_bytes_read from 65536 to 4096 fixed the issue. Cc: T.J. Mercier Signed-off-by: Yonghong Song --- tools/testing/selftests/bpf/prog_tests/dmabuf_iter.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/bpf/prog_tests/dmabuf_iter.c b/tools= /testing/selftests/bpf/prog_tests/dmabuf_iter.c index e442be9dde7e..fb2cea710db3 100644 --- a/tools/testing/selftests/bpf/prog_tests/dmabuf_iter.c +++ b/tools/testing/selftests/bpf/prog_tests/dmabuf_iter.c @@ -233,7 +233,7 @@ static void subtest_dmabuf_iter_check_lots_of_buffers= (struct dmabuf_iter *skel) while ((bytes_read =3D read(iter_fd, buf, sizeof(buf))) > 0) total_bytes_read +=3D bytes_read; =20 - ASSERT_GT(total_bytes_read, getpagesize(), "total_bytes_read"); + ASSERT_GT(total_bytes_read, 4096, "total_bytes_read"); =20 close(iter_fd); } --=20 2.47.3