From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 89BC4C433E7 for ; Thu, 15 Oct 2020 01:39:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 327E122257 for ; Thu, 15 Oct 2020 01:39:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=joelfernandes.org header.i=@joelfernandes.org header.b="KHZxHPt6" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389276AbgJOBjx (ORCPT ); Wed, 14 Oct 2020 21:39:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50624 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389203AbgJOBjj (ORCPT ); Wed, 14 Oct 2020 21:39:39 -0400 Received: from mail-il1-x141.google.com (mail-il1-x141.google.com [IPv6:2607:f8b0:4864:20::141]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AA649C0F26DF for ; Wed, 14 Oct 2020 17:23:13 -0700 (PDT) Received: by mail-il1-x141.google.com with SMTP id k1so2022061ilc.10 for ; Wed, 14 Oct 2020 17:23:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=joelfernandes.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=r29xpTf6pvYM7gD58XVxOmq2IxwCczlKKPsLjfq0wY8=; b=KHZxHPt6wIS2EIC6+g6Kc2+u9s6sj9IprZGUn/lUToLDA0H9JPuf68sgMH615RcYV5 2KPQ53rnHBPMIyEcqXIwDoAqJAoUwR6YvYeTUsmqwh8Trv4v5MYa+KBCJrJtYp4Qd8DO 7xQqxM2quYkYjDou9hx3Gc0fm2RcgCe5XSlmc= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=r29xpTf6pvYM7gD58XVxOmq2IxwCczlKKPsLjfq0wY8=; b=gmCgEf6+anU2vfgdxIwmCvTA/hHmi6hUnRCMAdaSECQh3aRmsm5zxWl9UniZ1irV3F XTX9oywrbhOZly/QWRf0wKSCvWeAxP0XvNEczvOcEgyTkjmkEe+SYXc4Swn9haNdGnld iOR2X+7ACWKYtev+hgvkvB/peQHxEZ4APXp6GSZhPajOWQrXS7rCQ8FYbTTjqmZowDjF MPxW+0olPAnL9DvJis84M42FdpCT70/X2vG2cSqAUs+5UTyH6qljc0gik+cLEbQar3s9 jftJ4QRCFiu3yTgrJnchCWglPlwp2srPoSwVCQCgIXes5ZOP+SPZWVeUjK5jYYIzBQH6 fNqw== X-Gm-Message-State: AOAM533F5lC3BUUdlPj1YJdK98lj09162XSJs44mwRjwOYQ0lgyUn6zJ WlB+KaoiKv/Uw64/AMneFjia5/ubVDyN0Q== X-Google-Smtp-Source: ABdhPJzpXsMpawpBva537F45BAEL+dWfZtKhDdPmyxDV30In3qYw4avOkfAgI8DUhD6kF+BknXSCyg== X-Received: by 2002:a92:c213:: with SMTP id j19mr1288001ilo.205.1602721392906; Wed, 14 Oct 2020 17:23:12 -0700 (PDT) Received: from joelaf.cam.corp.google.com ([2620:15c:6:12:cad3:ffff:feb3:bd59]) by smtp.gmail.com with ESMTPSA id r4sm1075622ilc.32.2020.10.14.17.23.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 14 Oct 2020 17:23:12 -0700 (PDT) From: "Joel Fernandes (Google)" To: linux-kernel@vger.kernel.org Cc: "Joel Fernandes (Google)" , Ingo Molnar , Josh Triplett , Lai Jiangshan , Marco Elver , Mathieu Desnoyers , "Paul E. McKenney" , rcu@vger.kernel.org, Steven Rostedt , "Uladzislau Rezki (Sony)" , fweisbec@gmail.com, neeraj.iitr10@gmail.com Subject: [PATCH v7 5/6] rcu/tree: Remove redundant smp_mb() in rcu_do_batch Date: Wed, 14 Oct 2020 20:23:00 -0400 Message-Id: <20201015002301.101830-6-joel@joelfernandes.org> X-Mailer: git-send-email 2.28.0.1011.ga647a8990f-goog In-Reply-To: <20201015002301.101830-1-joel@joelfernandes.org> References: <20201015002301.101830-1-joel@joelfernandes.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This memory barrier is not needed as rcu_segcblist_add_len() already includes a memory barrier. Signed-off-by: Joel Fernandes (Google) --- kernel/rcu/tree.c | 1 - 1 file changed, 1 deletion(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 346a05506935..6c6d3c7036e6 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2525,7 +2525,6 @@ static void rcu_do_batch(struct rcu_data *rdp) /* Update counts and requeue any remaining callbacks. */ rcu_segcblist_insert_done_cbs(&rdp->cblist, &rcl); - smp_mb(); /* List handling before counting for rcu_barrier(). */ rcu_segcblist_add_len(&rdp->cblist, -count); /* Reinstate batch limit if we have worked down the excess. */ -- 2.28.0.1011.ga647a8990f-goog