From patchwork Tue Aug 18 22:23:09 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yonghong Song X-Patchwork-Id: 262331 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 73AF0C433DF for ; Tue, 18 Aug 2020 22:23:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3A90F20738 for ; Tue, 18 Aug 2020 22:23:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="l1a2le90" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726905AbgHRWXS (ORCPT ); Tue, 18 Aug 2020 18:23:18 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:19520 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726799AbgHRWXO (ORCPT ); Tue, 18 Aug 2020 18:23:14 -0400 Received: from pps.filterd (m0148461.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 07IMDOuF006385 for ; Tue, 18 Aug 2020 15:23:14 -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-transfer-encoding : content-type; s=facebook; bh=9c3ZuDwr2uOpTm5OWCQEezdAmZ5DrDsJbhRbj1zx6Fk=; b=l1a2le90xC/nQ0FXLfoLJcItpSIZDp5BH89uO2fEwrc8sE9FkUDHs+MjubNz0k3LA8My 1NqFlHfAG1uZKcjHjCfXX3pdpRkFXiSJ85Kd/qljV1tMHocAGyE3bniZiyGNBhGgInok ezP6ycPnohbqA3lY2p1jt1ZfuRGPwW+HBKw= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com with ESMTP id 3304m2we98-11 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 18 Aug 2020 15:23:14 -0700 Received: from intmgw005.03.ash8.facebook.com (2620:10d:c085:208::11) by mail.thefacebook.com (2620:10d:c085:21d::4) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Tue, 18 Aug 2020 15:23:13 -0700 Received: by devbig003.ftw2.facebook.com (Postfix, from userid 128203) id 7B9ED37050C9; Tue, 18 Aug 2020 15:23:09 -0700 (PDT) Smtp-Origin-Hostprefix: devbig From: Yonghong Song Smtp-Origin-Hostname: devbig003.ftw2.facebook.com To: , CC: Alexei Starovoitov , Daniel Borkmann , Smtp-Origin-Cluster: ftw2c04 Subject: [PATCH bpf v2 0/3] bpf: two fixes for bpf iterators Date: Tue, 18 Aug 2020 15:23:09 -0700 Message-ID: <20200818222309.2181236-1-yhs@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=2.50.10434:6.0.235, 18.0.687 definitions=2020-08-18_16:2020-08-18,2020-08-18 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 mlxlogscore=499 impostorscore=0 mlxscore=0 bulkscore=0 suspectscore=8 spamscore=0 phishscore=0 lowpriorityscore=0 malwarescore=0 clxscore=1015 adultscore=0 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2008180160 X-FB-Internal: deliver Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Patch #1 fixed a rcu stall warning when traversing large number of tasks/files without overflowing seq_file buffer. The method is to control the number of visited objects in bpf_seq_read() so all bpf iterators will benefit. Patch #2 calculated tid properly in a namespace in order to avoid visiting the name task multiple times. Patch #3 handled read() error code EAGAIN properly in bpftool bpf_iter userspace code to collect pids. The change is needed due to Patch #1. Yonghong Song (3): bpf: fix a rcu_sched stall issue with bpf task/task_file iterator bpf: avoid visit same object multiple times bpftool: handle EAGAIN error code properly in pids collection kernel/bpf/bpf_iter.c | 15 ++++++++++++++- kernel/bpf/task_iter.c | 3 ++- tools/bpf/bpftool/pids.c | 2 ++ 3 files changed, 18 insertions(+), 2 deletions(-)