From patchwork Tue Oct 11 07:11:28 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hou Tao X-Patchwork-Id: 13003708 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 EA12AC433FE for ; Tue, 11 Oct 2022 06:45:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229797AbiJKGpt (ORCPT ); Tue, 11 Oct 2022 02:45:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48602 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229631AbiJKGpt (ORCPT ); Tue, 11 Oct 2022 02:45:49 -0400 Received: from dggsgout12.his.huawei.com (dggsgout12.his.huawei.com [45.249.212.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4644377544; Mon, 10 Oct 2022 23:45:41 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.153]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTP id 4MmmSs65bPz6PmnJ; Tue, 11 Oct 2022 14:43:25 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP4 (Coremail) with SMTP id gCh0CgD39sgQEUVj3FxfAA--.20636S7; Tue, 11 Oct 2022 14:45:40 +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 , "David S . Miller" , Jakub Kicinski , Stanislav Fomichev , Jiri Olsa , John Fastabend , "Paul E . McKenney" , Delyan Kratunov , rcu@vger.kernel.org, houtao1@huawei.com Subject: [PATCH bpf-next 3/3] bpf: Free trace program array after one RCU-tasks-trace grace period Date: Tue, 11 Oct 2022 15:11:28 +0800 Message-Id: <20221011071128.3470622-4-houtao@huaweicloud.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20221011071128.3470622-1-houtao@huaweicloud.com> References: <20221011071128.3470622-1-houtao@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: gCh0CgD39sgQEUVj3FxfAA--.20636S7 X-Coremail-Antispam: 1UD129KBjvJXoW7Xry5uFW8Xw13CryrAr15XFb_yoW8JF1rpF yDGFyqkF48Cr4Fkw1DAFy2k3y5J397Wr1fKa4rC3ySkw45X34kW343CFWruF1YgrZ5KryI vas8Krn3JanFvFDanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUBYb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUWw A2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxS w2x7M28EF7xvwVC0I7IYx2IY67AKxVW7JVWDJwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxV W8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v2 6rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMc Ij6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_ Jr0_Gr1lF7xvr2IYc2Ij64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1l42xK82IYc2Ij64 vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8G jcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r4a6rW5MIIYrxkI7VAKI48JMIIF0xvE2I x0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14v26F4j6r4UJwCI42IY6xAI w20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x 0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7IU1c4S7UUUUU== X-CM-SenderInfo: xkrx3t3r6k3tpzhluzxrxghudrp/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org From: Hou Tao To support sleepable uprobe bpf program, the freeing of trace program array chains a RCU-tasks-trace grace period with a normal RCU grace period. But considering in the current implementation of RCU-tasks-trace that one RCU-tasks-trace grace period implies one normal RCU grace period, so it is not need for such chaining and it is safe to free the array in the callback of call_rcu_tasks_trace(). Signed-off-by: Hou Tao --- kernel/bpf/core.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 711fd293b6de..f943620b55b0 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -2247,12 +2247,15 @@ void bpf_prog_array_free(struct bpf_prog_array *progs) kfree_rcu(progs, rcu); } +/* Now RCU Tasks grace period implies RCU grace period, so no need to call + * kfree_rcu(), just call kfree() directly. + */ static void __bpf_prog_array_free_sleepable_cb(struct rcu_head *rcu) { struct bpf_prog_array *progs; progs = container_of(rcu, struct bpf_prog_array, rcu); - kfree_rcu(progs, rcu); + kfree(progs); } void bpf_prog_array_free_sleepable(struct bpf_prog_array *progs)