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[23.128.96.34]) by mx.google.com with ESMTPS id kw7-20020a170902f90700b001b9c205a860si8058357plb.377.2023.09.12.09.29.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 12 Sep 2023 09:29:31 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.34 as permitted sender) client-ip=23.128.96.34; Authentication-Results: mx.google.com; dkim=pass header.i=@bytedance.com header.s=google header.b=Y+JY1U7c; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.34 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=bytedance.com Received: from out1.vger.email (depot.vger.email [IPv6:2620:137:e000::3:0]) by howler.vger.email (Postfix) with ESMTP id 619348220129; Tue, 12 Sep 2023 00:02:15 -0700 (PDT) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.10 at howler.vger.email Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231218AbjILHCN (ORCPT + 39 others); Tue, 12 Sep 2023 03:02:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42912 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231307AbjILHCK (ORCPT ); Tue, 12 Sep 2023 03:02:10 -0400 Received: from mail-pl1-x631.google.com (mail-pl1-x631.google.com [IPv6:2607:f8b0:4864:20::631]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3070AE7C for ; Tue, 12 Sep 2023 00:01:59 -0700 (PDT) Received: by mail-pl1-x631.google.com with SMTP id d9443c01a7336-1bf11b1c7d0so44042165ad.0 for ; Tue, 12 Sep 2023 00:01:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1694502118; x=1695106918; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=MB3Qkjjlw5hcMhrPR6LeX9MD2h80SkIGJQgP0ux+r7k=; b=Y+JY1U7cdDH6+WdhWG+jx92Z1YlgNPiheNE3JQgtfyKVrVkgSnJ511PX5YL5nP8i8o nQ3DIlKMMbA2w4TUl2BYnd/eYRH9gdNpW+72v8bxfZzZrO+fbM5lN7AutGEYeAqUN8mL vSdHjdPytTw44CodoeZDxcPenvIO94PdLFprc7zNl+q4RYjVF7UCK+FoBPlWQAooj9gu TN3jQf/ptIwE220kNWRz4SIolBl65lg8OasEf3ViB9HBbrSeigkBXJSOWzmbBA6qgbKv SG9SuS/92OGeJE3WWggBvlizgE9nyM5Oghd9Cw9QvVfZVGoyZ4rAG4rO48PQ0BdVfyFz BPPA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1694502118; x=1695106918; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=MB3Qkjjlw5hcMhrPR6LeX9MD2h80SkIGJQgP0ux+r7k=; b=ZFIdTXA1QT10mGnic+RHmqyc85uNxcfmmqJkTOzee4kI+9e2H4SB6Vv6aVysheWCcI c66jume6lupWnaVGjyJJtGodwbb5hX+7HC3JSEpWKFNodR6ybmrrvcC8DPTqWxZqW4V4 r86xX1mJ3fw1npoQ5/L7t22OteaT3w9Lnr0y1uFqDFgMBcBS1qYfFyHNsTdPHHio94yA nursPfFw/lGl5Dr9yKHwxpY6CC5OAGYEV0xVkf2yCXAYLFbeV72AsSFd5BMsVXVFQGLt EGFPPWdRj6EQHHHX+3vEkVP2dzBQH7MojLzXNNmDsgTDpeIrTOS4KOv+xKPVpN3oRXoP rrXg== X-Gm-Message-State: AOJu0YxsEyJtIDa49Dg+GwuFe6XsaRl/vyOb+OxZnkafMgky9LvgHHV6 nfGaL4TSAoUUALtc50DCPDIwEw== X-Received: by 2002:a17:903:22c8:b0:1bb:85cd:9190 with SMTP id y8-20020a17090322c800b001bb85cd9190mr2731636plg.18.1694502118654; Tue, 12 Sep 2023 00:01:58 -0700 (PDT) Received: from n37-019-243.byted.org ([180.184.84.173]) by smtp.gmail.com with ESMTPSA id b8-20020a170902d50800b001b8953365aesm7635401plg.22.2023.09.12.00.01.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 12 Sep 2023 00:01:58 -0700 (PDT) From: Chuyi Zhou To: bpf@vger.kernel.org Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@kernel.org, tj@kernel.org, linux-kernel@vger.kernel.org, Chuyi Zhou Subject: [PATCH bpf-next v2 0/6] Add Open-coded process and css iters Date: Tue, 12 Sep 2023 15:01:43 +0800 Message-Id: <20230912070149.969939-1-zhouchuyi@bytedance.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (howler.vger.email [0.0.0.0]); Tue, 12 Sep 2023 00:02:16 -0700 (PDT) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1776849960572610986 X-GMAIL-MSGID: 1776849960572610986 Hi, This is version 2 of process and css iters support. All the changes were suggested by Alexei. Thanks for your review! --- Changelog --- Changes from v1: - Add a pre-patch to make some preparations before supporting css_task iters. - Add an allowlist for css_task iters - Let bpf progs do explicit bpf_rcu_read_lock() when using process iters and css_descendant iters. --------------------- In some BPF usage scenarios, it will be useful to iterate the process and css directly in the BPF program. One of the expected scenarios is customizable OOM victim selection via BPF[1]. Inspired by Dave's task_vma iter[2], this patchset adds three types of open-coded iterator kfuncs: 1. bpf_for_each(process, p). Just like for_each_process(p) in kernel to itearing all tasks in the system. 2. bpf_for_each(css_task, task, css). It works like css_task_iter_{start, next, end} and would be used to iterating tasks/threads under a css. 3. bpf_for_each(css_{post, pre}, pos, root_css). It works like css_next_descendant_{pre, post} to iterating all descendant css. BPF programs can use these kfuncs directly or through bpf_for_each macro. link[1]: https://lore.kernel.org/lkml/20230810081319.65668-1-zhouchuyi@bytedance.com/ link[2]: https://lore.kernel.org/all/20230810183513.684836-1-davemarchevsky@fb.com/ Chuyi Zhou (6): cgroup: Prepare for using css_task_iter_*() in BPF bpf: Introduce css_task open-coded iterator kfuncs bpf: Introduce process open coded iterator kfuncs bpf: Introduce css_descendant open-coded iterator kfuncs bpf: teach the verifier to enforce css_iter and process_iter in RCU CS selftests/bpf: Add tests for open-coded task and css iter include/linux/cgroup.h | 12 +- include/uapi/linux/bpf.h | 16 ++ kernel/bpf/helpers.c | 12 ++ kernel/bpf/task_iter.c | 130 +++++++++++++++++ kernel/bpf/verifier.c | 53 ++++++- kernel/cgroup/cgroup.c | 18 ++- tools/include/uapi/linux/bpf.h | 16 ++ tools/lib/bpf/bpf_helpers.h | 24 +++ .../testing/selftests/bpf/prog_tests/iters.c | 138 ++++++++++++++++++ .../testing/selftests/bpf/progs/iters_task.c | 104 +++++++++++++ 10 files changed, 508 insertions(+), 15 deletions(-) create mode 100644 tools/testing/selftests/bpf/progs/iters_task.c