From patchwork Wed Aug 17 21:04:18 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexei Starovoitov X-Patchwork-Id: 12946468 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 B2D48C2BB41 for ; Wed, 17 Aug 2022 21:05:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242276AbiHQVFG (ORCPT ); Wed, 17 Aug 2022 17:05:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32896 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242278AbiHQVFF (ORCPT ); Wed, 17 Aug 2022 17:05:05 -0400 Received: from mail-pf1-x435.google.com (mail-pf1-x435.google.com [IPv6:2607:f8b0:4864:20::435]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CCA9CAB4ED for ; Wed, 17 Aug 2022 14:05:03 -0700 (PDT) Received: by mail-pf1-x435.google.com with SMTP id f30so13070566pfq.4 for ; Wed, 17 Aug 2022 14:05:03 -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; bh=eyosi/ApRDmJH06E2mfAg4K+Gs7C6ov+wMXDcYoXgiA=; b=TBY+PoFfGdsg0yomLDUoAOGXLF9qjczt9cp0q1IiM/33m0YWNLrsV+Zbulc7dEckwd cO8pG7g6UMuWrw/EqWsVbyrwYIEsU+fnO8RVKKCa5iAq9EESd4TGuRszWSbOWpbyu1lU PmfbskvdzlxfWOaMtSzXO+DybRcIg4cf/htmkFRUUHLBBcCs0ixbHqmSVMswiqOd5SwO SMYeNvcUmLX2TmCB2PsmQ99VrrWyVJiAZZaRvq2azixp+l9J/tZVQ72Jh3w8xXdE7GDv emSmbNxl72zQYAJ2RXy0A1FMAEJQBSLKvwGO6xd7rVSTYaijbis6necH/stR9FTslGqZ a1ZA== 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; bh=eyosi/ApRDmJH06E2mfAg4K+Gs7C6ov+wMXDcYoXgiA=; b=WGunUkWtcdz2StEMVv86fyqG8HooNexIMYFJvXm4ikPfwTbtOfnvogwjxNvvxIdEVg gs9LY48qS1smKBVAWuq+ziWZinDuH7Zqoqs1ZVQXmqFaJl1EmhE6PpLLXMpmldWilsEL y9XIh9bUbigEfmPmAHck6lZ2B5qnqsXhP35orDUjqI2ciJv06zi9venEpj+AdQQiFwVc 4SZuaB0rPFvmsmLxjK+2P+EpwvozSD1zi2zj8RO4gJOLOCKb18Vot7nbkLZ++hG1rxXE v0AT2BvmQtA2lZGnSJN/W7AzjaDjgoQEN2ZYQOcuQnuyo+//+/rHPBn0wEFsqySDyUAc /u+w== X-Gm-Message-State: ACgBeo27VlCYmERyrwi9o0ETb1PqGfZ1vJPYYHZOsZg4KARdw7rH3xkv ycgMksquK6/MHtQ9diqf3dw= X-Google-Smtp-Source: AA6agR6XP65/0jbYH/wPxm3Z4T7RTZCVbt+m8h5jlW0+bxnCjWSMWGeInm1BbOsq3aGVfxvPUFZaUg== X-Received: by 2002:a65:60d4:0:b0:419:9871:9cf with SMTP id r20-20020a6560d4000000b00419987109cfmr74148pgv.214.1660770303230; Wed, 17 Aug 2022 14:05:03 -0700 (PDT) Received: from localhost.localdomain ([2620:10d:c090:500::1:ccd6]) by smtp.gmail.com with ESMTPSA id d6-20020a170902654600b0016a33177d3csm348261pln.160.2022.08.17.14.05.01 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Wed, 17 Aug 2022 14:05:02 -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 v2 bpf-next 11/12] bpf: Convert percpu hash map to per-cpu bpf_mem_alloc. Date: Wed, 17 Aug 2022 14:04:18 -0700 Message-Id: <20220817210419.95560-12-alexei.starovoitov@gmail.com> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220817210419.95560-1-alexei.starovoitov@gmail.com> References: <20220817210419.95560-1-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 Convert dynamic allocations in percpu hash map from alloc_percpu() to bpf_mem_cache_alloc() from per-cpu bpf_mem_alloc. Since bpf_mem_alloc frees objects after RCU gp the call_rcu() is removed. Signed-off-by: Alexei Starovoitov --- kernel/bpf/hashtab.c | 38 ++++++++++++++++---------------------- 1 file changed, 16 insertions(+), 22 deletions(-) diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c index bf20c45002fe..921f6fa9dc1b 100644 --- a/kernel/bpf/hashtab.c +++ b/kernel/bpf/hashtab.c @@ -94,6 +94,7 @@ struct bucket { struct bpf_htab { struct bpf_map map; struct bpf_mem_alloc ma; + struct bpf_mem_alloc pcpu_ma; struct bucket *buckets; void *elems; union { @@ -121,14 +122,14 @@ struct htab_elem { struct { void *padding; union { - struct bpf_htab *htab; struct pcpu_freelist_node fnode; struct htab_elem *batch_flink; }; }; }; union { - struct rcu_head rcu; + /* pointer to per-cpu pointer */ + void *ptr_to_pptr; struct bpf_lru_node lru_node; }; u32 hash; @@ -439,8 +440,6 @@ static int htab_map_alloc_check(union bpf_attr *attr) bool zero_seed = (attr->map_flags & BPF_F_ZERO_SEED); int numa_node = bpf_map_attr_numa_node(attr); - BUILD_BUG_ON(offsetof(struct htab_elem, htab) != - offsetof(struct htab_elem, hash_node.pprev)); BUILD_BUG_ON(offsetof(struct htab_elem, fnode.next) != offsetof(struct htab_elem, hash_node.pprev)); @@ -601,6 +600,12 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr) err = bpf_mem_alloc_init(&htab->ma, htab->elem_size, false); if (err) goto free_map_locked; + if (percpu) { + err = bpf_mem_alloc_init(&htab->pcpu_ma, + round_up(htab->map.value_size, 8), true); + if (err) + goto free_map_locked; + } } return &htab->map; @@ -611,6 +616,7 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr) for (i = 0; i < HASHTAB_MAP_LOCK_COUNT; i++) free_percpu(htab->map_locked[i]); bpf_map_area_free(htab->buckets); + bpf_mem_alloc_destroy(&htab->pcpu_ma); bpf_mem_alloc_destroy(&htab->ma); free_htab: lockdep_unregister_key(&htab->lockdep_key); @@ -886,19 +892,11 @@ static int htab_map_get_next_key(struct bpf_map *map, void *key, void *next_key) static void htab_elem_free(struct bpf_htab *htab, struct htab_elem *l) { if (htab->map.map_type == BPF_MAP_TYPE_PERCPU_HASH) - free_percpu(htab_elem_get_ptr(l, htab->map.key_size)); + bpf_mem_cache_free(&htab->pcpu_ma, l->ptr_to_pptr); check_and_free_fields(htab, l); bpf_mem_cache_free(&htab->ma, l); } -static void htab_elem_free_rcu(struct rcu_head *head) -{ - struct htab_elem *l = container_of(head, struct htab_elem, rcu); - struct bpf_htab *htab = l->htab; - - htab_elem_free(htab, l); -} - static void htab_put_fd_value(struct bpf_htab *htab, struct htab_elem *l) { struct bpf_map *map = &htab->map; @@ -944,12 +942,7 @@ static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l) __pcpu_freelist_push(&htab->freelist, &l->fnode); } else { dec_elem_count(htab); - if (htab->map.map_type == BPF_MAP_TYPE_PERCPU_HASH) { - l->htab = htab; - call_rcu(&l->rcu, htab_elem_free_rcu); - } else { - htab_elem_free(htab, l); - } + htab_elem_free(htab, l); } } @@ -1051,18 +1044,18 @@ static struct htab_elem *alloc_htab_elem(struct bpf_htab *htab, void *key, memcpy(l_new->key, key, key_size); if (percpu) { - size = round_up(size, 8); if (prealloc) { pptr = htab_elem_get_ptr(l_new, key_size); } else { /* alloc_percpu zero-fills */ - pptr = bpf_map_alloc_percpu(&htab->map, size, 8, - GFP_NOWAIT | __GFP_NOWARN); + pptr = bpf_mem_cache_alloc(&htab->pcpu_ma); if (!pptr) { bpf_mem_cache_free(&htab->ma, l_new); l_new = ERR_PTR(-ENOMEM); goto dec_count; } + l_new->ptr_to_pptr = pptr; + pptr = *(void **)pptr; } pcpu_init_value(htab, pptr, value, onallcpus); @@ -1554,6 +1547,7 @@ static void htab_map_free(struct bpf_map *map) bpf_map_free_kptr_off_tab(map); free_percpu(htab->extra_elems); bpf_map_area_free(htab->buckets); + bpf_mem_alloc_destroy(&htab->pcpu_ma); bpf_mem_alloc_destroy(&htab->ma); if (htab->use_percpu_counter) percpu_counter_destroy(&htab->pcount);