From patchwork Fri Sep 2 21:10:55 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexei Starovoitov X-Patchwork-Id: 12964676 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EB510C6FA82 for ; Fri, 2 Sep 2022 21:11:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230458AbiIBVLw (ORCPT ); Fri, 2 Sep 2022 17:11:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53888 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229649AbiIBVLv (ORCPT ); Fri, 2 Sep 2022 17:11:51 -0400 Received: from mail-pf1-x429.google.com (mail-pf1-x429.google.com [IPv6:2607:f8b0:4864:20::429]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A3A34DB7C5 for ; Fri, 2 Sep 2022 14:11:50 -0700 (PDT) Received: by mail-pf1-x429.google.com with SMTP id y127so3078446pfy.5 for ; Fri, 02 Sep 2022 14:11:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date; bh=7zZUv+wUiLTbSdfVlnRTA9LoEPz96HdCoAnAM60zCkc=; b=NwS+9ZK2eKTx+aaMOQ7GdHd0ONySpdNTqKHMSj9KKgWrBRR8iXt8Df/fwP/LvFm+10 D1EWQA+KOVMQrFsTbYkppw0sjJqjbiJ8xgDT/caLNdqxKR3ulJItoGLuoFfkewGl4GVj WooLniQWrCHe2zNrOzblGJtjrYvUfDWJTZG1kajIikXP6grHGph1/wguaa33stHepzJ+ L2ZiXeHpJwK8aDdwIawyaJ8Ex9mjGH+9bWT/TAU3ij0sM/l57nR4efX65CHBrZzq/NiT 6ZDREUOVgpQFhfiMnmg/RieFkpIfvfPUn9Bw2snvhhpFPoUHuljnJnBJuQFM1RWMjNxA 19EQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date; bh=7zZUv+wUiLTbSdfVlnRTA9LoEPz96HdCoAnAM60zCkc=; b=TldccwNyKZg+Iz/ycMkP1a8pTaUz/gVAdW9e/tvpLMz5MriO77pNVIKH7s2M39YrJT nVX3B+hZjvETsqo6+RBVhA4G6S/JTsgr8KXkQg+9g9VQwwmwN6U3RYzF8SqEhgCswY3S fzzoaGc2fwS+3JMdyUE2qpWHnQSyqa4Tdgtln3pdq7fC3ql7cPjlbOG+uha2pw5ag+fC 2eZ6695AeXbvMf86SjTjO2yKcTWs/tYukBbVYvuSR/kZbNrdgRKzTQWZOjEpSPCeCA3C gkh0cZ5qJSFXsD+E+dQg2Ep2RU2zMO3BbnydI9NbvnYaOwzv0443YRG/3wpCYIuJmG5v BTvg== X-Gm-Message-State: ACgBeo31Udi+OV63iEb66E1GYR5gTUbKUj5GtSLM+eZxCzQo3+laVzmC ZFx4g3pVmjOjiFe9Fv0um7k= X-Google-Smtp-Source: AA6agR5uPuVHb59iNf+oddnsd3ubEx/z1NYbz1Rk4wngjEXEteRwU+dblj5OPnu6zTdC6eXF++2rNA== X-Received: by 2002:a63:2048:0:b0:41c:daad:450d with SMTP id r8-20020a632048000000b0041cdaad450dmr31330653pgm.240.1662153110141; Fri, 02 Sep 2022 14:11:50 -0700 (PDT) Received: from localhost.localdomain ([2620:10d:c090:500::c978]) by smtp.gmail.com with ESMTPSA id c18-20020a170902d49200b0017315b11bb8sm2124526plg.213.2022.09.02.14.11.48 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Fri, 02 Sep 2022 14:11:49 -0700 (PDT) From: Alexei Starovoitov To: davem@davemloft.net Cc: daniel@iogearbox.net, andrii@kernel.org, tj@kernel.org, memxor@gmail.com, delyank@fb.com, linux-mm@kvack.org, bpf@vger.kernel.org, kernel-team@fb.com Subject: [PATCH v6 bpf-next 13/16] bpf: Prepare bpf_mem_alloc to be used by sleepable bpf programs. Date: Fri, 2 Sep 2022 14:10:55 -0700 Message-Id: <20220902211058.60789-14-alexei.starovoitov@gmail.com> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220902211058.60789-1-alexei.starovoitov@gmail.com> References: <20220902211058.60789-1-alexei.starovoitov@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net From: Alexei Starovoitov Use call_rcu_tasks_trace() to wait for sleepable progs to finish. Then use call_rcu() to wait for normal progs to finish and finally do free_one() on each element when freeing objects into global memory pool. Acked-by: Kumar Kartikeya Dwivedi Acked-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov --- kernel/bpf/memalloc.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/memalloc.c b/kernel/bpf/memalloc.c index f7b07787581b..8895c016dcdb 100644 --- a/kernel/bpf/memalloc.c +++ b/kernel/bpf/memalloc.c @@ -230,6 +230,13 @@ static void __free_rcu(struct rcu_head *head) atomic_set(&c->call_rcu_in_progress, 0); } +static void __free_rcu_tasks_trace(struct rcu_head *head) +{ + struct bpf_mem_cache *c = container_of(head, struct bpf_mem_cache, rcu); + + call_rcu(&c->rcu, __free_rcu); +} + static void enque_to_free(struct bpf_mem_cache *c, void *obj) { struct llist_node *llnode = obj; @@ -255,7 +262,11 @@ static void do_call_rcu(struct bpf_mem_cache *c) * from __free_rcu() and from drain_mem_cache(). */ __llist_add(llnode, &c->waiting_for_gp); - call_rcu(&c->rcu, __free_rcu); + /* Use call_rcu_tasks_trace() to wait for sleepable progs to finish. + * Then use call_rcu() to wait for normal progs to finish + * and finally do free_one() on each element. + */ + call_rcu_tasks_trace(&c->rcu, __free_rcu_tasks_trace); } static void free_bulk(struct bpf_mem_cache *c) @@ -457,6 +468,7 @@ void bpf_mem_alloc_destroy(struct bpf_mem_alloc *ma) /* c->waiting_for_gp list was drained, but __free_rcu might * still execute. Wait for it now before we free 'c'. */ + rcu_barrier_tasks_trace(); rcu_barrier(); free_percpu(ma->cache); ma->cache = NULL; @@ -471,6 +483,7 @@ void bpf_mem_alloc_destroy(struct bpf_mem_alloc *ma) } if (c->objcg) obj_cgroup_put(c->objcg); + rcu_barrier_tasks_trace(); rcu_barrier(); free_percpu(ma->caches); ma->caches = NULL;