From patchwork Fri May 29 07:54:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrii Nakryiko X-Patchwork-Id: 1300514 Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=reject dis=none) header.from=fb.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=fb.com header.i=@fb.com header.a=rsa-sha256 header.s=facebook header.b=ShjcekY3; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 49YH0S2y70z9sSn for ; Fri, 29 May 2020 17:54:48 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725777AbgE2Hyr (ORCPT ); Fri, 29 May 2020 03:54:47 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:7464 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725355AbgE2Hyq (ORCPT ); Fri, 29 May 2020 03:54:46 -0400 Received: from pps.filterd (m0044010.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 04T7oqd5009279 for ; Fri, 29 May 2020 00:54:45 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : mime-version : content-type : content-transfer-encoding; s=facebook; bh=50VC0B8LeA2ntIfCcJ6QrFPLpJZw7hHFVsX7VYW2LTY=; b=ShjcekY3ul5HpTuvmbbcuIPU4Ns+0eic7y0PJqjNfQtKpoZx5kwTa2QY3d48DbkqhN3t W7PqOetckTIup6bP6+fOYJKssrsjoa72mRQ7C5G6K1Q3VQ+oIpXccGWX4Tmegdz5MHV0 W/zqsGQNOZTFddp0JdjmY4w9PZRBbYYNPow= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com with ESMTP id 31ajbjp50y-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Fri, 29 May 2020 00:54:45 -0700 Received: from intmgw001.08.frc2.facebook.com (2620:10d:c085:108::8) by mail.thefacebook.com (2620:10d:c085:11d::4) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Fri, 29 May 2020 00:54:44 -0700 Received: by devbig012.ftw2.facebook.com (Postfix, from userid 137359) id 7AC6B2EC3747; Fri, 29 May 2020 00:54:36 -0700 (PDT) Smtp-Origin-Hostprefix: devbig From: Andrii Nakryiko Smtp-Origin-Hostname: devbig012.ftw2.facebook.com To: , , , CC: , , Andrii Nakryiko , "Paul E . McKenney" , Jonathan Lemon Smtp-Origin-Cluster: ftw2c04 Subject: [PATCH v4 bpf-next 0/5] BPF ring buffer Date: Fri, 29 May 2020 00:54:19 -0700 Message-ID: <20200529075424.3139988-1-andriin@fb.com> X-Mailer: git-send-email 2.24.1 MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.216,18.0.687 definitions=2020-05-29_02:2020-05-28,2020-05-29 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 adultscore=0 spamscore=0 cotscore=-2147483648 bulkscore=0 impostorscore=0 mlxlogscore=999 lowpriorityscore=0 suspectscore=2 phishscore=0 priorityscore=1501 malwarescore=0 mlxscore=0 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2005290062 X-FB-Internal: deliver Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Implement a new BPF ring buffer, as presented at BPF virtual conference ([0]). It presents an alternative to perf buffer, following its semantics closely, but allowing sharing same instance of ring buffer across multiple CPUs efficiently. Most patches have extensive commentary explaining various aspects, so I'll keep cover letter short. Overall structure of the patch set: - patch #1 adds BPF ring buffer implementation to kernel and necessary verifier support; - patch #2 adds libbpf consumer implementation for BPF ringbuf; - patch #3 adds selftest, both for single BPF ring buf use case, as well as using it with array/hash of maps; - patch #4 adds extensive benchmarks and provide some analysis in commit message, it builds upon selftests/bpf's bench runner. - patch #5 adds most of patch #1 commit message as a doc under Documentation/bpf/ringbuf.rst. Litmus tests, validating consumer/producer protocols and memory orderings, were moved out as discussed in [1] and are going to be posted against -rcu tree and put under Documentation/litmus-tests/bpf-rb. [0] https://docs.google.com/presentation/d/18ITdg77Bj6YDOH2LghxrnFxiPWe0fAqcmJY95t_qr0w [1] https://lkml.org/lkml/2020/5/22/1011 v3->v4: - fix ringbuf freeing (vunmap, __free_page); verified with a trivial loop creating and closing ringbuf map endlessly (Daniel); v2->v3: - dropped unnecessary smp_wmb() (Paul); - verifier reference type enhancement patch was dropped (Alexei); - better verifier message for various memory access checks (Alexei); - clarified a bit roundup_len() bit shifting (Alexei); - converted doc to .rst (Alexei); - fixed warning on 32-bit arches regarding tautological ring area size check. v1->v2: - commit()/discard()/output() accept flags (NO_WAKEUP/FORCE_WAKEUP) (Stanislav); - bpf_ringbuf_query() added, returning available data size, ringbuf size, consumer/producer positions, needed to implement smarter notification policy (Stanislav); - added ringbuf UAPI constants to include/uapi/linux/bpf.h (Jonathan); - fixed sample size check, added proper ringbuf size check (Jonathan, Alexei); - wake_up_all() is done through irq_work (Alexei); - consistent use of smp_load_acquire/smp_store_release, no READ_ONCE/WRITE_ONCE (Alexei); - added Documentation/bpf/ringbuf.txt (Stanislav); - updated litmus test with smp_load_acquire/smp_store_release changes; - added ring_buffer__consume() API to libbpf for busy-polling; - ring_buffer__poll() on success returns number of records consumed; - fixed EPOLL notifications, don't assume available data, done similarly to perfbuf's implementation; - both ringbuf and perfbuf now have --rb-sampled mode, instead of pb-raw/pb-custom mode, updated benchmark results; - extended ringbuf selftests to validate epoll logic/manual notification logic, as well as bpf_ringbuf_query(). Cc: Paul E. McKenney Cc: Jonathan Lemon Andrii Nakryiko (5): bpf: implement BPF ring buffer and verifier support for it libbpf: add BPF ring buffer support selftests/bpf: add BPF ringbuf selftests bpf: add BPF ringbuf and perf buffer benchmarks docs/bpf: add BPF ring buffer design notes Documentation/bpf/ringbuf.rst | 209 +++++++ include/linux/bpf.h | 13 + include/linux/bpf_types.h | 1 + include/linux/bpf_verifier.h | 4 + include/uapi/linux/bpf.h | 84 ++- kernel/bpf/Makefile | 2 +- kernel/bpf/helpers.c | 10 + kernel/bpf/ringbuf.c | 501 ++++++++++++++++ kernel/bpf/syscall.c | 12 + kernel/bpf/verifier.c | 195 ++++-- kernel/trace/bpf_trace.c | 10 + tools/include/uapi/linux/bpf.h | 84 ++- tools/lib/bpf/Build | 2 +- tools/lib/bpf/libbpf.h | 21 + tools/lib/bpf/libbpf.map | 5 + tools/lib/bpf/libbpf_probes.c | 5 + tools/lib/bpf/ringbuf.c | 285 +++++++++ tools/testing/selftests/bpf/Makefile | 5 +- tools/testing/selftests/bpf/bench.c | 16 + .../selftests/bpf/benchs/bench_ringbufs.c | 566 ++++++++++++++++++ .../bpf/benchs/run_bench_ringbufs.sh | 75 +++ .../selftests/bpf/prog_tests/ringbuf.c | 211 +++++++ .../selftests/bpf/prog_tests/ringbuf_multi.c | 102 ++++ .../selftests/bpf/progs/perfbuf_bench.c | 33 + .../selftests/bpf/progs/ringbuf_bench.c | 60 ++ .../selftests/bpf/progs/test_ringbuf.c | 78 +++ .../selftests/bpf/progs/test_ringbuf_multi.c | 77 +++ tools/testing/selftests/bpf/verifier/and.c | 4 +- .../selftests/bpf/verifier/array_access.c | 4 +- tools/testing/selftests/bpf/verifier/bounds.c | 6 +- tools/testing/selftests/bpf/verifier/calls.c | 2 +- .../bpf/verifier/direct_value_access.c | 4 +- .../bpf/verifier/helper_access_var_len.c | 2 +- .../bpf/verifier/helper_value_access.c | 6 +- .../selftests/bpf/verifier/value_ptr_arith.c | 8 +- 35 files changed, 2630 insertions(+), 72 deletions(-) create mode 100644 Documentation/bpf/ringbuf.rst create mode 100644 kernel/bpf/ringbuf.c create mode 100644 tools/lib/bpf/ringbuf.c create mode 100644 tools/testing/selftests/bpf/benchs/bench_ringbufs.c create mode 100755 tools/testing/selftests/bpf/benchs/run_bench_ringbufs.sh create mode 100644 tools/testing/selftests/bpf/prog_tests/ringbuf.c create mode 100644 tools/testing/selftests/bpf/prog_tests/ringbuf_multi.c create mode 100644 tools/testing/selftests/bpf/progs/perfbuf_bench.c create mode 100644 tools/testing/selftests/bpf/progs/ringbuf_bench.c create mode 100644 tools/testing/selftests/bpf/progs/test_ringbuf.c create mode 100644 tools/testing/selftests/bpf/progs/test_ringbuf_multi.c