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=-7.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 2D0D0C433E0 for ; Tue, 23 Jun 2020 15:42:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 039B42072E for ; Tue, 23 Jun 2020 15:42:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=joelfernandes.org header.i=@joelfernandes.org header.b="FPBrUaqD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733065AbgFWPmR (ORCPT ); Tue, 23 Jun 2020 11:42:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37620 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732951AbgFWPmQ (ORCPT ); Tue, 23 Jun 2020 11:42:16 -0400 Received: from mail-qv1-xf44.google.com (mail-qv1-xf44.google.com [IPv6:2607:f8b0:4864:20::f44]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 79155C061755 for ; Tue, 23 Jun 2020 08:42:16 -0700 (PDT) Received: by mail-qv1-xf44.google.com with SMTP id m9so3403172qvx.5 for ; Tue, 23 Jun 2020 08:42:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=joelfernandes.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=k9npaZkB/RX+A77Mjxy8tZOLesXDgVyirFfZLx7RsY8=; b=FPBrUaqD+INXJNZq97GAZ8wt0va9XMksIvOQgUMsCLh5PhfHnsz+Efu5Na78VXWJDy 1XGzChK2G0CNZjY7N2MBk7hQmzSCtWqq7r6C/3RhPhMC7Ezb5WuUmKtWAZG5o1xssGYG JfuM2ZMrklYBBVcoZO2EY1qioMp/UBzxm+s4I= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=k9npaZkB/RX+A77Mjxy8tZOLesXDgVyirFfZLx7RsY8=; b=YchcdYorqgZGysL/U6qLsvHTHTQeXYfsSloirDPNpFRwMec41g1gh1aih2hnqHwVEB BDSLSECPWqq8VpsQNGSGP2wWVAhKSNL/Rtsjn7qVdOde6Y7PMa20MxL/Z9mbs4EwpOnw RhJcmLy34wZOQe7rgcmzsVm539o+ah98AlH23dvURBFbw3ea/Vttfs6VRgKJ8qgwB388 QOm99OAa0f3Uhdoo/sm3af9gre5fARG+EkZAO/oyofn1UX8yxwhX3MSlcDNmI9/FWiXN Er3rovuFByTHDpdrZeISGDCr8viw+lH6kvp/7bgEXVz1dbltEiVw/gagGGgfNz3K0vWe xu3Q== X-Gm-Message-State: AOAM533qHWEJTrHzdXsdfmRkU5axZdBatAcGIcQCnkWT3bgiKaBs1H0v Jmcor0p5xpciFbHX8Wb58egCpCzADTo= X-Google-Smtp-Source: ABdhPJzCnBPX85hWbeFdqNNPtt+wSv9RuuKhMXclYBSr+NMQYCtrb2esRWUO8PeTG4ifuFQWlIHL7g== X-Received: by 2002:ad4:4f23:: with SMTP id fc3mr27529525qvb.25.1592926935691; Tue, 23 Jun 2020 08:42:15 -0700 (PDT) Received: from localhost ([2620:15c:6:12:9c46:e0da:efbf:69cc]) by smtp.gmail.com with ESMTPSA id g4sm843079qka.97.2020.06.23.08.42.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Jun 2020 08:42:14 -0700 (PDT) Date: Tue, 23 Jun 2020 11:42:14 -0400 From: Joel Fernandes To: Neeraj Upadhyay Cc: paulmck@kernel.org, josh@joshtriplett.org, rostedt@goodmis.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, rcu@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] rcu/tree: Force quiescent state on callback overload Message-ID: <20200623154214.GE9005@google.com> References: <1592764647-2452-1-git-send-email-neeraju@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1592764647-2452-1-git-send-email-neeraju@codeaurora.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 22, 2020 at 12:07:27AM +0530, Neeraj Upadhyay wrote: > On callback overload, we want to force quiescent state immediately, > for the first and second fqs. Enforce the same, by including > RCU_GP_FLAG_OVLD flag, in fqsstart check. > > Signed-off-by: Neeraj Upadhyay > --- Reviewed-by: Joel Fernandes (Google) And I think needs fixes tag: Fixes: 1fca4d12f4637 ("rcu: Expedite first two FQS scans under callback-overload conditions") thanks, - Joel > kernel/rcu/tree.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c > index d0988a1..6226bfb 100644 > --- a/kernel/rcu/tree.c > +++ b/kernel/rcu/tree.c > @@ -1865,7 +1865,7 @@ static void rcu_gp_fqs_loop(void) > break; > /* If time for quiescent-state forcing, do it. */ > if (!time_after(rcu_state.jiffies_force_qs, jiffies) || > - (gf & RCU_GP_FLAG_FQS)) { > + (gf & (RCU_GP_FLAG_FQS | RCU_GP_FLAG_OVLD))) { > trace_rcu_grace_period(rcu_state.name, rcu_state.gp_seq, > TPS("fqsstart")); > rcu_gp_fqs(first_gp_fqs); > -- > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, > a Linux Foundation Collaborative Project >