From patchwork Wed Jun 28 01:56:22 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexei Starovoitov X-Patchwork-Id: 13295157 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 063ACC0015E for ; Wed, 28 Jun 2023 01:56:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231214AbjF1B4p (ORCPT ); Tue, 27 Jun 2023 21:56:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54908 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231200AbjF1B4o (ORCPT ); Tue, 27 Jun 2023 21:56:44 -0400 Received: from mail-pl1-x629.google.com (mail-pl1-x629.google.com [IPv6:2607:f8b0:4864:20::629]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C319E297B; Tue, 27 Jun 2023 18:56:42 -0700 (PDT) Received: by mail-pl1-x629.google.com with SMTP id d9443c01a7336-1b801e6ce85so3325215ad.1; Tue, 27 Jun 2023 18:56:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1687917402; x=1690509402; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=tnvjt/gAeB7s5ArRb1iRUdzehhXE3naKGVtPVDLMicQ=; b=WYtjcQf8YgZ72CYD/aEhu6in5okZ+zc61H9TSvTaZMX0L40lFfNTVvpSXpAeceEfdH Rfr3mqrXxlOUwFTSD9potOda1dJdDbH1aALmuTlRUenjVutYzBau5UpufXxUsnyJgece x/W6i6r2smYYIXpezttWlVtrT9R+0PMq2dDaJhWnSJXrnt4lJGmGnv50itLYtz6ENMSB FfLLBQrHKm4MMloc/MdcMx1eU+mq8JHmDRGlnueStvyHzRsdl4tTTDFF2ZFUl7bZjvwl Hvm5ZtmCJreQn+w5RSIqEU5bAvnJhuZ1UIqImxDgW2x4B3f9ldLZyeJmLBH3HeVGy38R sBhQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687917402; x=1690509402; 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:message-id:reply-to; bh=tnvjt/gAeB7s5ArRb1iRUdzehhXE3naKGVtPVDLMicQ=; b=FQksV1+7cuecULQE8retOBZbLBnZTgjTULTYJjuvU9IszBesL0H0+qtVPvgNrI47kF gx9/O7i8oqEUHz+/NTLbZBPeZ/Bvtm4MHhw8DRxsUlx+aEK0Hsfr+mvrqbN3M0bSXDTE pmPhw9aLJgonjUwo8DVkIgQzS+tIP9idXYzoteKRy+o1+jym0/drhVGvcjTVp74bazN6 hbeaVEsZoG/AR9bf61VkXI/sUp4EC3QIKg5YoJfm6p4605EOPFmqVYAieVrPImoRoE9t 9ayxDkn7NbFzq9OcXDLDl8xaJ8usz8R07vJaGTNGWf/YGYHK5zacXV6iju0ojFBsPHHP +xlw== X-Gm-Message-State: AC+VfDxRdN5pwSb+8ebhHgkKIWx4p7lR6LuQxC0dk0ISvzbxZD1SGZ/c enCH2aE1Z05hClpm32w3WHw= X-Google-Smtp-Source: ACHHUZ78cnzX9BDqTo0MHYJSfppOTXt+zu9AxlG/4MtV9Rmj61/WPypownx0DfOZFWllfazUPutLrw== X-Received: by 2002:a17:902:ea0b:b0:1b2:676d:1143 with SMTP id s11-20020a170902ea0b00b001b2676d1143mr14533404plg.15.1687917401890; Tue, 27 Jun 2023 18:56:41 -0700 (PDT) Received: from localhost.localdomain ([2620:10d:c090:400::5:6420]) by smtp.gmail.com with ESMTPSA id k13-20020a170902ba8d00b001b69303db54sm6577289pls.91.2023.06.27.18.56.40 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Tue, 27 Jun 2023 18:56:41 -0700 (PDT) From: Alexei Starovoitov To: daniel@iogearbox.net, andrii@kernel.org, void@manifault.com, houtao@huaweicloud.com, paulmck@kernel.org Cc: tj@kernel.org, rcu@vger.kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, kernel-team@fb.com Subject: [PATCH v3 bpf-next 01/13] bpf: Rename few bpf_mem_alloc fields. Date: Tue, 27 Jun 2023 18:56:22 -0700 Message-Id: <20230628015634.33193-2-alexei.starovoitov@gmail.com> X-Mailer: git-send-email 2.39.2 (Apple Git-143) In-Reply-To: <20230628015634.33193-1-alexei.starovoitov@gmail.com> References: <20230628015634.33193-1-alexei.starovoitov@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org From: Alexei Starovoitov Rename: - struct rcu_head rcu; - struct llist_head free_by_rcu; - struct llist_head waiting_for_gp; - atomic_t call_rcu_in_progress; + struct llist_head free_by_rcu_ttrace; + struct llist_head waiting_for_gp_ttrace; + struct rcu_head rcu_ttrace; + atomic_t call_rcu_ttrace_in_progress; ... - static void do_call_rcu(struct bpf_mem_cache *c) + static void do_call_rcu_ttrace(struct bpf_mem_cache *c) to better indicate intended use. The 'tasks trace' is shortened to 'ttrace' to reduce verbosity. No functional changes. Later patches will add free_by_rcu/waiting_for_gp fields to be used with normal RCU. Signed-off-by: Alexei Starovoitov Acked-by: Hou Tao --- kernel/bpf/memalloc.c | 57 ++++++++++++++++++++++--------------------- 1 file changed, 29 insertions(+), 28 deletions(-) diff --git a/kernel/bpf/memalloc.c b/kernel/bpf/memalloc.c index 0668bcd7c926..cc5b8adb4c83 100644 --- a/kernel/bpf/memalloc.c +++ b/kernel/bpf/memalloc.c @@ -99,10 +99,11 @@ struct bpf_mem_cache { int low_watermark, high_watermark, batch; int percpu_size; - struct rcu_head rcu; - struct llist_head free_by_rcu; - struct llist_head waiting_for_gp; - atomic_t call_rcu_in_progress; + /* list of objects to be freed after RCU tasks trace GP */ + struct llist_head free_by_rcu_ttrace; + struct llist_head waiting_for_gp_ttrace; + struct rcu_head rcu_ttrace; + atomic_t call_rcu_ttrace_in_progress; }; struct bpf_mem_caches { @@ -165,18 +166,18 @@ static void alloc_bulk(struct bpf_mem_cache *c, int cnt, int node) old_memcg = set_active_memcg(memcg); for (i = 0; i < cnt; i++) { /* - * free_by_rcu is only manipulated by irq work refill_work(). + * free_by_rcu_ttrace is only manipulated by irq work refill_work(). * IRQ works on the same CPU are called sequentially, so it is * safe to use __llist_del_first() here. If alloc_bulk() is * invoked by the initial prefill, there will be no running * refill_work(), so __llist_del_first() is fine as well. * - * In most cases, objects on free_by_rcu are from the same CPU. + * In most cases, objects on free_by_rcu_ttrace are from the same CPU. * If some objects come from other CPUs, it doesn't incur any * harm because NUMA_NO_NODE means the preference for current * numa node and it is not a guarantee. */ - obj = __llist_del_first(&c->free_by_rcu); + obj = __llist_del_first(&c->free_by_rcu_ttrace); if (!obj) { /* Allocate, but don't deplete atomic reserves that typical * GFP_ATOMIC would do. irq_work runs on this cpu and kmalloc @@ -232,10 +233,10 @@ static void free_all(struct llist_node *llnode, bool percpu) static void __free_rcu(struct rcu_head *head) { - struct bpf_mem_cache *c = container_of(head, struct bpf_mem_cache, rcu); + struct bpf_mem_cache *c = container_of(head, struct bpf_mem_cache, rcu_ttrace); - free_all(llist_del_all(&c->waiting_for_gp), !!c->percpu_size); - atomic_set(&c->call_rcu_in_progress, 0); + free_all(llist_del_all(&c->waiting_for_gp_ttrace), !!c->percpu_size); + atomic_set(&c->call_rcu_ttrace_in_progress, 0); } static void __free_rcu_tasks_trace(struct rcu_head *head) @@ -254,32 +255,32 @@ static void enque_to_free(struct bpf_mem_cache *c, void *obj) struct llist_node *llnode = obj; /* bpf_mem_cache is a per-cpu object. Freeing happens in irq_work. - * Nothing races to add to free_by_rcu list. + * Nothing races to add to free_by_rcu_ttrace list. */ - __llist_add(llnode, &c->free_by_rcu); + __llist_add(llnode, &c->free_by_rcu_ttrace); } -static void do_call_rcu(struct bpf_mem_cache *c) +static void do_call_rcu_ttrace(struct bpf_mem_cache *c) { struct llist_node *llnode, *t; - if (atomic_xchg(&c->call_rcu_in_progress, 1)) + if (atomic_xchg(&c->call_rcu_ttrace_in_progress, 1)) return; - WARN_ON_ONCE(!llist_empty(&c->waiting_for_gp)); - llist_for_each_safe(llnode, t, __llist_del_all(&c->free_by_rcu)) - /* There is no concurrent __llist_add(waiting_for_gp) access. + WARN_ON_ONCE(!llist_empty(&c->waiting_for_gp_ttrace)); + llist_for_each_safe(llnode, t, __llist_del_all(&c->free_by_rcu_ttrace)) + /* There is no concurrent __llist_add(waiting_for_gp_ttrace) access. * It doesn't race with llist_del_all either. - * But there could be two concurrent llist_del_all(waiting_for_gp): + * But there could be two concurrent llist_del_all(waiting_for_gp_ttrace): * from __free_rcu() and from drain_mem_cache(). */ - __llist_add(llnode, &c->waiting_for_gp); + __llist_add(llnode, &c->waiting_for_gp_ttrace); /* Use call_rcu_tasks_trace() to wait for sleepable progs to finish. * If RCU Tasks Trace grace period implies RCU grace period, free * these elements directly, else 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); + call_rcu_tasks_trace(&c->rcu_ttrace, __free_rcu_tasks_trace); } static void free_bulk(struct bpf_mem_cache *c) @@ -307,7 +308,7 @@ static void free_bulk(struct bpf_mem_cache *c) /* and drain free_llist_extra */ llist_for_each_safe(llnode, t, llist_del_all(&c->free_llist_extra)) enque_to_free(c, llnode); - do_call_rcu(c); + do_call_rcu_ttrace(c); } static void bpf_mem_refill(struct irq_work *work) @@ -441,13 +442,13 @@ static void drain_mem_cache(struct bpf_mem_cache *c) /* No progs are using this bpf_mem_cache, but htab_map_free() called * bpf_mem_cache_free() for all remaining elements and they can be in - * free_by_rcu or in waiting_for_gp lists, so drain those lists now. + * free_by_rcu_ttrace or in waiting_for_gp_ttrace lists, so drain those lists now. * - * Except for waiting_for_gp list, there are no concurrent operations + * Except for waiting_for_gp_ttrace list, there are no concurrent operations * on these lists, so it is safe to use __llist_del_all(). */ - free_all(__llist_del_all(&c->free_by_rcu), percpu); - free_all(llist_del_all(&c->waiting_for_gp), percpu); + free_all(__llist_del_all(&c->free_by_rcu_ttrace), percpu); + free_all(llist_del_all(&c->waiting_for_gp_ttrace), percpu); free_all(__llist_del_all(&c->free_llist), percpu); free_all(__llist_del_all(&c->free_llist_extra), percpu); } @@ -462,7 +463,7 @@ static void free_mem_alloc_no_barrier(struct bpf_mem_alloc *ma) static void free_mem_alloc(struct bpf_mem_alloc *ma) { - /* waiting_for_gp lists was drained, but __free_rcu might + /* waiting_for_gp_ttrace lists was drained, but __free_rcu might * still execute. Wait for it now before we freeing percpu caches. * * rcu_barrier_tasks_trace() doesn't imply synchronize_rcu_tasks_trace(), @@ -535,7 +536,7 @@ void bpf_mem_alloc_destroy(struct bpf_mem_alloc *ma) */ irq_work_sync(&c->refill_work); drain_mem_cache(c); - rcu_in_progress += atomic_read(&c->call_rcu_in_progress); + rcu_in_progress += atomic_read(&c->call_rcu_ttrace_in_progress); } /* objcg is the same across cpus */ if (c->objcg) @@ -550,7 +551,7 @@ void bpf_mem_alloc_destroy(struct bpf_mem_alloc *ma) c = &cc->cache[i]; irq_work_sync(&c->refill_work); drain_mem_cache(c); - rcu_in_progress += atomic_read(&c->call_rcu_in_progress); + rcu_in_progress += atomic_read(&c->call_rcu_ttrace_in_progress); } } if (c->objcg)