From patchwork Wed Jul 24 16:57:57 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Brian Vazquez X-Patchwork-Id: 1136417 Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.b="FQTT+XyX"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 45v1kl5xpMz9sBF for ; Thu, 25 Jul 2019 02:58:23 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728334AbfGXQ6T (ORCPT ); Wed, 24 Jul 2019 12:58:19 -0400 Received: from mail-pg1-f202.google.com ([209.85.215.202]:42980 "EHLO mail-pg1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726148AbfGXQ6T (ORCPT ); Wed, 24 Jul 2019 12:58:19 -0400 Received: by mail-pg1-f202.google.com with SMTP id q10so5500096pgi.9 for ; Wed, 24 Jul 2019 09:58:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=6m5pZYRwQ/VLImDzwYssdUybUrVH4MZ+xdF6UGNAnzQ=; b=FQTT+XyX/59gFXT1uGFwGXtgUyjKf4iPsM32Sk9G7dinmYGnLj5i3YxJQtU8tzbl3K fwhzXeFXWn0VIXqHMCinq/2BuSH08UCWzLV1RhNs2sLV3K6hH4jBQs/6fNwFi/g+EKXR edlGI5m6uMpv4ChVdLz3GNY/yAFrgF63w7bCSpQpduHIbJ8i4GKo67HwDYWtHVc30uH2 cHuLWQEAtdudgD5RySbzOO2htsNdMFjzNb5sD0lRZwmVsGSKHhc+cjH/B0sFOU6XO4MB 0uVmd0DQzCI7Nlg93wUgjZRchVV0sPjtemJxHS6WjwuQVp1T4K0c/o2K1wYsWPyE4XZD OPxw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=6m5pZYRwQ/VLImDzwYssdUybUrVH4MZ+xdF6UGNAnzQ=; b=ozccNynn+hI6qGzChh3uidagLbpojxDxB3fILvm4hQeNVc1T6dy6dxXd6RRpGqB3DI pLerh4/jtJaSuS4ZkddRGPmncldgs2C/dAkDMEI7igxYudD0mwBHpBGlyUDSvIyvIvKu /thnpuVxyUAxCsKNxAsAQtEB0zluXXBqUOmT1P1P2az3CrPPYnEig9O/LX1nUAHGi4E5 EJ79A2sfoxjp/lb0T3rIRT6qSb2/63fGClW331hJDbkxsDPqPWo0WeA7XV1JFgoexDbk U90GpRk9yt7n8zEqqgQsb96pOv8QcolHSvgTues3nqQXMrMIxdv2QDIIiefZQ7S5pUyv 3VCQ== X-Gm-Message-State: APjAAAXXy/t3fGaxtkRuxkDdsHK/B1DHzJGKdyJtNc8AA+82klRpahT1 nslTQHMY4O3+Nurl5rg85toZYb/a7TdW X-Google-Smtp-Source: APXvYqz+p+xcj+020H6PKH7tPE0RHUStQ5VIaTQ18W/SgvXCVq97XWVBm/0xcPcAITrs8Or7z49zx7jJypgy X-Received: by 2002:a63:a35e:: with SMTP id v30mr23431447pgn.129.1563987497938; Wed, 24 Jul 2019 09:58:17 -0700 (PDT) Date: Wed, 24 Jul 2019 09:57:57 -0700 Message-Id: <20190724165803.87470-1-brianvv@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.22.0.657.g960e92d24f-goog Subject: [PATCH bpf-next 0/6] bpf: add BPF_MAP_DUMP command to dump more than one entry per call From: Brian Vazquez To: Brian Vazquez , Alexei Starovoitov , Daniel Borkmann , "David S . Miller" Cc: Stanislav Fomichev , Willem de Bruijn , Petar Penkov , linux-kernel@vger.kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, Brian Vazquez Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org This introduces a new command to retrieve multiple number of entries from a bpf map. This new command can be executed from the existing BPF syscall as follows: err = bpf(BPF_MAP_DUMP, union bpf_attr *attr, u32 size) using attr->dump.map_fd, attr->dump.prev_key, attr->dump.buf, attr->dump.buf_len returns zero or negative error, and populates buf and buf_len on succees This implementation is wrapping the existing bpf methods: map_get_next_key and map_lookup_elem Note that this implementation can be extended later to do dump and delete by extending map_lookup_and_delete_elem (currently it only works for bpf queue/stack maps) and either use a new flag in map_dump or a new command map_dump_and_delete. Results show that even with a 1-elem_size buffer, it runs ~40 faster than the current implementation, improvements of ~85% are reported when the buffer size is increased, although, after the buffer size is around 5% of the total number of entries there's no huge difference in increasing it. Tested: Tried different size buffers to handle case where the bulk is bigger, or the elements to retrieve are less than the existing ones, all runs read a map of 100K entries. Below are the results(in ns) from the different runs: buf_len_1: 69038725 entry-by-entry: 112384424 improvement 38.569134 buf_len_2: 40897447 entry-by-entry: 111030546 improvement 63.165590 buf_len_230: 13652714 entry-by-entry: 111694058 improvement 87.776687 buf_len_5000: 13576271 entry-by-entry: 111101169 improvement 87.780263 buf_len_73000: 14694343 entry-by-entry: 111740162 improvement 86.849542 buf_len_100000: 13745969 entry-by-entry: 114151991 improvement 87.958187 buf_len_234567: 14329834 entry-by-entry: 114427589 improvement 87.476941 The series of patches are split as follows: - First patch move some map_lookup_elem logic into 2 fucntions to deduplicate code: bpf_map_value_size and bpf_map_copy_value - Second patch introduce map_dump function - Third patch syncs tools linux headers - Fourth patch adds libbpf support - Last two patches adds tests RFC Changelog: - remove wrong usage of attr.flags - move map_fd to remove hole after it v3: - add explanation of the API in the commit message - fix masked errors and return them to user - copy last_key from return buf into prev_key if it was provided - run perf test with kpti and retpoline mitigations v2: - use proper bpf-next tag Brian Vazquez (6): bpf: add bpf_map_value_size and bp_map_copy_value helper functions bpf: add BPF_MAP_DUMP command to dump more than one entry per call bpf: keep bpf.h in sync with tools/ libbpf: support BPF_MAP_DUMP command selftests/bpf: test BPF_MAP_DUMP command on a bpf hashmap selftests/bpf: add test to measure performance of BPF_MAP_DUMP include/uapi/linux/bpf.h | 9 + kernel/bpf/syscall.c | 251 ++++++++++++++++++------ tools/include/uapi/linux/bpf.h | 9 + tools/lib/bpf/bpf.c | 28 +++ tools/lib/bpf/bpf.h | 4 + tools/lib/bpf/libbpf.map | 2 + tools/testing/selftests/bpf/test_maps.c | 148 +++++++++++++- 7 files changed, 388 insertions(+), 63 deletions(-)