From mboxrd@z Thu Jan 1 00:00:00 1970 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 05953C433DF for ; Fri, 21 Aug 2020 15:02:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D5830207DE for ; Fri, 21 Aug 2020 15:02:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="gXewPaOP" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728125AbgHUPCL (ORCPT ); Fri, 21 Aug 2020 11:02:11 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:49518 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728079AbgHUPBp (ORCPT ); Fri, 21 Aug 2020 11:01:45 -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 07LExm3p019716 for ; Fri, 21 Aug 2020 08:01:45 -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-transfer-encoding : content-type; s=facebook; bh=93YUqiKcCsH6d2x0Oo79WQel4Zy29asOn7HtCcmmMQ0=; b=gXewPaOPtjdK7n8g8ihd6vb1Jxm47rBv6ovwaAZN7NCEwUhT/GHxcCo2lF1KIJ+E1Jek ri4NNz5eULQTNokkSSexOlwMmP7fvAUL6cbCS0cIjboz3SVyHVdUuDWjZid6tc0OlYBB GewXTwVoae9xr7U+JyC0pE2PQq/7Dyfgi8o= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 3304m3da81-3 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Fri, 21 Aug 2020 08:01:45 -0700 Received: from intmgw001.06.prn3.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::4) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Fri, 21 Aug 2020 08:01:40 -0700 Received: by devvm1096.prn0.facebook.com (Postfix, from userid 111017) id 225B23441045; Fri, 21 Aug 2020 08:01:35 -0700 (PDT) Smtp-Origin-Hostprefix: devvm From: Roman Gushchin Smtp-Origin-Hostname: devvm1096.prn0.facebook.com To: CC: , Alexei Starovoitov , Daniel Borkmann , , , Johannes Weiner , Shakeel Butt , , Roman Gushchin Smtp-Origin-Cluster: prn0c01 Subject: [PATCH bpf-next v4 00/30] bpf: switch to memcg-based memory accounting Date: Fri, 21 Aug 2020 08:01:04 -0700 Message-ID: <20200821150134.2581465-1-guro@fb.com> X-Mailer: git-send-email 2.24.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-08-21_08:2020-08-21,2020-08-21 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 mlxlogscore=999 impostorscore=0 mlxscore=0 bulkscore=0 suspectscore=13 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-2008210141 X-FB-Internal: deliver Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Currently bpf is using the memlock rlimit for the memory accounting. This approach has its downsides and over time has created a significant amount of problems: 1) The limit is per-user, but because most bpf operations are performed as root, the limit has a little value. 2) It's hard to come up with a specific maximum value. Especially because the counter is shared with non-bpf users (e.g. memlock() users). Any specific value is either too low and creates false failures or too high and useless. 3) Charging is not connected to the actual memory allocation. Bpf code should manually calculate the estimated cost and precharge the counter= , and then take care of uncharging, including all fail paths. It adds to the code complexity and makes it easy to leak a charge. 4) There is no simple way of getting the current value of the counter. We've used drgn for it, but it's far from being convenient. 5) Cryptic -EPERM is returned on exceeding the limit. Libbpf even had a function to "explain" this case for users. In order to overcome these problems let's switch to the memcg-based memory accounting of bpf objects. With the recent addition of the percpu memory accounting, now it's possible to provide a comprehensive accountin= g of the memory used by bpf programs and maps. This approach has the following advantages: 1) The limit is per-cgroup and hierarchical. It's way more flexible and a= llows a better control over memory usage by different workloads. Of course, = it requires enabled cgroups and kernel memory accounting and properly con= figured cgroup tree, but it's a default configuration for a modern Linux syste= m. 2) The actual memory consumption is taken into account. It happens automa= tically on the allocation time if __GFP_ACCOUNT flags is passed. Uncharging is= also performed automatically on releasing the memory. So the code on the bp= f side becomes simpler and safer. 3) There is a simple way to get the current value and statistics. In general, if a process performs a bpf operation (e.g. creates or update= s a map), it's memory cgroup is charged. However map updates performed from an interrupt context are charged to the memory cgroup which contained the process, which created the map. Providing a 1:1 replacement for the rlimit-based memory accounting is a non-goal of this patchset. Users and memory cgroups are completely orthogonal, so it's not possible even in theory. Memcg-based memory accounting requires a properly configured cgroup tree to be actually useful. However, it's the way how the memory is managed on a modern Linux system. The patchset consists of the following parts: 1) an auxiliary patch by Johanness, which adds an ability to charge a custom memory cgroup from an interrupt context 2) memcg-based accounting for various bpf objects: progs and maps 3) removal of the rlimit-based accounting 4) removal of rlimit adjustments in userspace samples v4: - covered allocations made from an interrupt context, by Daniel - added some clarifications to the cover letter v3: - droped the userspace part for further discussions/refinements, by Andrii and Song v2: - fixed build issue, caused by the remaining rlimit-based accounting for sockhash maps Johannes Weiner (1): mm: support nesting memalloc_use_memcg() Roman Gushchin (29): bpf: memcg-based memory accounting for bpf progs bpf: memcg-based memory accounting for bpf maps bpf: refine memcg-based memory accounting for arraymap maps bpf: refine memcg-based memory accounting for cpumap maps bpf: memcg-based memory accounting for cgroup storage maps bpf: refine memcg-based memory accounting for devmap maps bpf: refine memcg-based memory accounting for hashtab maps bpf: memcg-based memory accounting for lpm_trie maps bpf: memcg-based memory accounting for bpf ringbuffer bpf: memcg-based memory accounting for socket storage maps bpf: refine memcg-based memory accounting for sockmap and sockhash maps bpf: refine memcg-based memory accounting for xskmap maps bpf: eliminate rlimit-based memory accounting for arraymap maps bpf: eliminate rlimit-based memory accounting for bpf_struct_ops maps bpf: eliminate rlimit-based memory accounting for cpumap maps bpf: eliminate rlimit-based memory accounting for cgroup storage maps bpf: eliminate rlimit-based memory accounting for devmap maps bpf: eliminate rlimit-based memory accounting for hashtab maps bpf: eliminate rlimit-based memory accounting for lpm_trie maps bpf: eliminate rlimit-based memory accounting for queue_stack_maps maps bpf: eliminate rlimit-based memory accounting for reuseport_array maps bpf: eliminate rlimit-based memory accounting for bpf ringbuffer bpf: eliminate rlimit-based memory accounting for sockmap and sockhash maps bpf: eliminate rlimit-based memory accounting for stackmap maps bpf: eliminate rlimit-based memory accounting for socket storage maps bpf: eliminate rlimit-based memory accounting for xskmap maps bpf: eliminate rlimit-based memory accounting infra for bpf maps bpf: eliminate rlimit-based memory accounting for bpf progs bpf: samples: do not touch RLIMIT_MEMLOCK fs/buffer.c | 6 +- fs/notify/fanotify/fanotify.c | 5 +- fs/notify/inotify/inotify_fsnotify.c | 5 +- include/linux/bpf.h | 27 +-- include/linux/sched/mm.h | 28 +-- kernel/bpf/arraymap.c | 30 +-- kernel/bpf/bpf_struct_ops.c | 19 +- kernel/bpf/core.c | 20 +- kernel/bpf/cpumap.c | 20 +- kernel/bpf/devmap.c | 23 +-- kernel/bpf/hashtab.c | 33 +--- kernel/bpf/helpers.c | 37 +++- kernel/bpf/local_storage.c | 38 +--- kernel/bpf/lpm_trie.c | 17 +- kernel/bpf/queue_stack_maps.c | 16 +- kernel/bpf/reuseport_array.c | 12 +- kernel/bpf/ringbuf.c | 33 +--- kernel/bpf/stackmap.c | 16 +- kernel/bpf/syscall.c | 177 ++++-------------- mm/memcontrol.c | 6 +- net/core/bpf_sk_storage.c | 23 +-- net/core/sock_map.c | 40 +--- net/xdp/xskmap.c | 13 +- samples/bpf/map_perf_test_user.c | 11 -- samples/bpf/offwaketime_user.c | 2 - samples/bpf/sockex2_user.c | 2 - samples/bpf/sockex3_user.c | 2 - samples/bpf/spintest_user.c | 2 - samples/bpf/syscall_tp_user.c | 2 - samples/bpf/task_fd_query_user.c | 5 - samples/bpf/test_lru_dist.c | 3 - samples/bpf/test_map_in_map_user.c | 9 - samples/bpf/test_overhead_user.c | 2 - samples/bpf/trace_event_user.c | 2 - samples/bpf/tracex2_user.c | 6 - samples/bpf/tracex3_user.c | 6 - samples/bpf/tracex4_user.c | 6 - samples/bpf/tracex5_user.c | 3 - samples/bpf/tracex6_user.c | 3 - samples/bpf/xdp1_user.c | 6 - samples/bpf/xdp_adjust_tail_user.c | 6 - samples/bpf/xdp_monitor_user.c | 6 - samples/bpf/xdp_redirect_cpu_user.c | 6 - samples/bpf/xdp_redirect_map_user.c | 6 - samples/bpf/xdp_redirect_user.c | 6 - samples/bpf/xdp_router_ipv4_user.c | 6 - samples/bpf/xdp_rxq_info_user.c | 6 - samples/bpf/xdp_sample_pkts_user.c | 6 - samples/bpf/xdp_tx_iptunnel_user.c | 6 - samples/bpf/xdpsock_user.c | 7 - .../selftests/bpf/progs/map_ptr_kern.c | 5 - 51 files changed, 180 insertions(+), 602 deletions(-) --=20 2.26.2