From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-177.mta1.migadu.com (out-177.mta1.migadu.com [95.215.58.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AAB913C0883 for ; Thu, 22 Jan 2026 21:28:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.177 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769117302; cv=none; b=Wwl2Z4dCej0g+qXB4ge0PXugzcKPPUqxAFsWvI20Vla4tS97kc5jvW2+Vk1wHpUdpQ/kGy09nwgxF8Wm+m3unmsPnzjoZZNvfml4swOA/UxVeFZGjPbvjhtAvc9OAUrn8wgYTYeqIt8exu+m/l6uYQ2pztrQTie5c7YTmHWs0KE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769117302; c=relaxed/simple; bh=lqMtq74LqEMpeRrst1Zwf/b9YGce6Q/qFp14tV0qKc4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=GNhg6QgRLq5q7g0RUeocLLxAxjIhgeqQvSaZHeCZnn0/UwQoypXdRhoMk0n++zP0uZ9d5RxaYIS5Gmx5tUQfjASY/N4JOwnS03+r2dvAl4tmdkFderpFLV0Tb3qQEubJqhh3typfzBIR6yEmz4Ri1WMjExPI6JUP9mOgw4/zFgQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=pV8c8sNA; arc=none smtp.client-ip=95.215.58.177 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="pV8c8sNA" Message-ID: <4a41cc0f-e409-478f-ad71-103de63cfacb@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1769117293; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=C1sh+9KhIreTIihfzat2Ijx895fJhZ1M1Yv78rApw7o=; b=pV8c8sNASHy2vzhH2AKUoiRbtgtzc6VATnqzCtwwjsTq/QzQi7+ejqSd4mP9/OhOz0ahLq VNAt2Vp2g4c7fks2GhM2VmN4zFjqvdlwhRzgbaOkG8spf7x+7sBNkWTDrPFDL67yTHsfhJ 2azgoYks9CkWNhJmt3MbG8elxkfi/r8= Date: Thu, 22 Jan 2026 13:28:04 -0800 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH bpf-next v2 2/2] selftests/bpf: Fix xdp_pull_data failure with 64K page Content-Language: en-GB To: Amery Hung Cc: bpf@vger.kernel.org, Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , kernel-team@fb.com, Martin KaFai Lau , Alan Maguire References: <20260122162616.3578898-1-yonghong.song@linux.dev> <20260122162621.3579387-1-yonghong.song@linux.dev> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Yonghong Song In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT On 1/22/26 1:18 PM, Amery Hung wrote: > On Thu, Jan 22, 2026 at 8:56 AM Yonghong Song wrote: >> If the argument 'pull_len' of run_test() is 'PULL_MAX' or >> 'PULL_MAX | PULL_PLUS_ONE', the eventual pull_len size >> will close to the page size. On arm64 systems with 64K pages, >> the pull_len size will be close to 64K. But the existing buffer >> will be close to 9000 which is not enough to pull. >> >> For those failed run_tests(), make buff size to >> 2 * pg_sz + (pg_sz / 2) >> This way, there will be enough buffer space to pull >> regardless of page size. >> >> Tested-by: Alan Maguire >> Cc: Amery Hung >> Signed-off-by: Yonghong Song >> --- >> .../testing/selftests/bpf/prog_tests/xdp_pull_data.c | 12 +++++++----- >> 1 file changed, 7 insertions(+), 5 deletions(-) >> >> Changelog: >> v1 -> v2: >> - v1: https://lore.kernel.org/bpf/20260120210930.2544950-1-yonghong.song@linux.dev/ >> - Use pg_sz to simplify buff_len calculation. >> >> diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_pull_data.c b/tools/testing/selftests/bpf/prog_tests/xdp_pull_data.c >> index efa350d04ec5..35f0eb5b43f3 100644 >> --- a/tools/testing/selftests/bpf/prog_tests/xdp_pull_data.c >> +++ b/tools/testing/selftests/bpf/prog_tests/xdp_pull_data.c >> @@ -114,12 +114,14 @@ static void test_xdp_pull_data_basic(void) >> { >> u32 pg_sz, max_meta_len, max_data_len; >> struct test_xdp_pull_data *skel; >> + int buff_len; >> >> skel = test_xdp_pull_data__open_and_load(); >> if (!ASSERT_OK_PTR(skel, "test_xdp_pull_data__open_and_load")) >> return; >> >> pg_sz = sysconf(_SC_PAGE_SIZE); >> + buff_len = 2 * pg_sz + pg_sz / 2; > Thanks for fixing the test. Just curious if there is an issue with 1.5 > pg_sz as suggested by Alan? Yes. It works fine with 1.5 pg_sz too. I picked '2 * pg_sz + pg_sz / 2' as for 4K page, 9000 will have 2 frags and I intend to maintain 2 frags for the tests. > >> if (find_xdp_sizes(skel, pg_sz)) >> goto out; >> @@ -140,13 +142,13 @@ static void test_xdp_pull_data_basic(void) >> run_test(skel, XDP_PASS, pg_sz, 9000, 0, 1025, 1025); >> >> /* multi-buf pkt, empty linear data area, pull requires memmove */ >> - run_test(skel, XDP_PASS, pg_sz, 9000, 0, 0, PULL_MAX); >> + run_test(skel, XDP_PASS, pg_sz, buff_len, 0, 0, PULL_MAX); >> >> /* multi-buf pkt, no headroom */ >> - run_test(skel, XDP_PASS, pg_sz, 9000, max_meta_len, 1024, PULL_MAX); >> + run_test(skel, XDP_PASS, pg_sz, buff_len, max_meta_len, 1024, PULL_MAX); >> >> /* multi-buf pkt, no tailroom, pull requires memmove */ >> - run_test(skel, XDP_PASS, pg_sz, 9000, 0, max_data_len, PULL_MAX); >> + run_test(skel, XDP_PASS, pg_sz, buff_len, 0, max_data_len, PULL_MAX); >> >> /* Test cases with invalid pull length */ >> >> @@ -154,7 +156,7 @@ static void test_xdp_pull_data_basic(void) >> run_test(skel, XDP_DROP, pg_sz, 2048, 0, 2048, 2049); >> >> /* multi-buf pkt with no space left in linear data area */ >> - run_test(skel, XDP_DROP, pg_sz, 9000, max_meta_len, max_data_len, >> + run_test(skel, XDP_DROP, pg_sz, buff_len, max_meta_len, max_data_len, >> PULL_MAX | PULL_PLUS_ONE); >> >> /* multi-buf pkt, empty linear data area */ >> @@ -165,7 +167,7 @@ static void test_xdp_pull_data_basic(void) >> PULL_MAX | PULL_PLUS_ONE); > We should also change these two cases above to use buff_len to make > sure we are testing the right logic in bpf_xdp_pull_data(). Sure. Will do. Replacing 9000 with buff_len for those two cases works okay too for both x86 and 64-page arm64. > >> /* multi-buf pkt, no tailroom */ >> - run_test(skel, XDP_DROP, pg_sz, 9000, 0, max_data_len, >> + run_test(skel, XDP_DROP, pg_sz, buff_len, 0, max_data_len, >> PULL_MAX | PULL_PLUS_ONE); >> >> out: >> -- >> 2.47.3 >> >>