From patchwork Fri Dec 30 04:11:50 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hou Tao X-Patchwork-Id: 13084064 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 092D5C10F1B for ; Fri, 30 Dec 2022 04:12:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234095AbiL3EMQ (ORCPT ); Thu, 29 Dec 2022 23:12:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37674 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234204AbiL3EMJ (ORCPT ); Thu, 29 Dec 2022 23:12:09 -0500 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 597D4DFC6; Thu, 29 Dec 2022 20:12:07 -0800 (PST) Received: from mail02.huawei.com (unknown [172.30.67.153]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4NjsKF32Yfz4f3lXl; Fri, 30 Dec 2022 12:12:01 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP4 (Coremail) with SMTP id gCh0CgAHcLMPZa5j3H4SAw--.35465S9; Fri, 30 Dec 2022 12:12:04 +0800 (CST) From: Hou Tao To: bpf@vger.kernel.org Cc: Martin KaFai Lau , Andrii Nakryiko , Song Liu , Hao Luo , Yonghong Song , Alexei Starovoitov , Daniel Borkmann , KP Singh , Stanislav Fomichev , Jiri Olsa , John Fastabend , "Paul E . McKenney" , rcu@vger.kernel.org, houtao1@huawei.com Subject: [RFC PATCH bpf-next 5/6] bpf: Use BPF_MA_NO_REUSE in htab map Date: Fri, 30 Dec 2022 12:11:50 +0800 Message-Id: <20221230041151.1231169-6-houtao@huaweicloud.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20221230041151.1231169-1-houtao@huaweicloud.com> References: <20221230041151.1231169-1-houtao@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: gCh0CgAHcLMPZa5j3H4SAw--.35465S9 X-Coremail-Antispam: 1UD129KBjvdXoWrur4DAr1fGr4rAF1xJw1kXwb_yoWkWrb_Cr 4fXFs0krsxC3yI9F1DGFsagr1FgFWSgF15urn5trZrtry5Jas5J3WUuFnxZ3yrGan7G39r X3ZI9rsFg3yaqjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbSxYFVCjjxCrM7AC8VAFwI0_Wr0E3s1l1xkIjI8I6I8E6xAIw20E Y4v20xvaj40_Wr0E3s1l1IIY67AEw4v_Jr0_Jr4l82xGYIkIc2x26280x7IE14v26r126s 0DM28IrcIa0xkI8VCY1x0267AKxVW5JVCq3wA2ocxC64kIII0Yj41l84x0c7CEw4AK67xG Y2AK021l84ACjcxK6xIIjxv20xvE14v26w1j6s0DM28EF7xvwVC0I7IYx2IY6xkF7I0E14 v26r4UJVWxJr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAF wI0_GcCE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2 WlYx0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkE bVWUJVW8JwACjcxG0xvY0x0EwIxGrwACI402YVCY1x02628vn2kIc2xKxwCF04k20xvY0x 0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E 7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcV C0I7IYx2IY67AKxVWUCVW8JwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Cr0_Gr1UMIIF0xvE 42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJVW8JwCI42IY6I8E87Iv6x kF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjxUFgAwUUUUU X-CM-SenderInfo: xkrx3t3r6k3tpzhluzxrxghudrp/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org From: Hou Tao Use BPF_MA_NO_REUSE in htab map to disable the immediate reuse of free elements, so the lookup procedure will not return incorrect result. After the change, the performance of "./map_perf_test 4 18 8192" will drop from 520K to 330K events per sec on one CPU. Signed-off-by: Hou Tao --- kernel/bpf/hashtab.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c index 623111d4276d..e1636c5d0051 100644 --- a/kernel/bpf/hashtab.c +++ b/kernel/bpf/hashtab.c @@ -574,14 +574,14 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr) goto free_prealloc; } } else { - err = bpf_mem_alloc_init(&htab->ma, htab->elem_size, 0, + err = bpf_mem_alloc_init(&htab->ma, htab->elem_size, BPF_MA_NO_REUSE, htab_elem_ctor); if (err) goto free_map_locked; if (percpu) { err = bpf_mem_alloc_init(&htab->pcpu_ma, round_up(htab->map.value_size, 8), - BPF_MA_PERCPU, NULL); + BPF_MA_PERCPU | BPF_MA_NO_REUSE, NULL); if (err) goto free_map_locked; }