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=-2.1 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, USER_AGENT_MUTT 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 8351AC43142 for ; Tue, 26 Jun 2018 17:44:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2592B268B5 for ; Tue, 26 Jun 2018 17:44:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="M6r8Fe+n" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2592B268B5 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754639AbeFZRoo (ORCPT ); Tue, 26 Jun 2018 13:44:44 -0400 Received: from merlin.infradead.org ([205.233.59.134]:52778 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754619AbeFZRon (ORCPT ); Tue, 26 Jun 2018 13:44:43 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=aLWR/usDDFr41rmAa4XuO+UBc83YZTmcKS8kpV9VQ4k=; b=M6r8Fe+njxuSA8eFrQ1nJgCtI IIQafm88vnBFo0GhH4Nen6VkV6ZaN2Tfm+y/bCMxIvIH5MfO40vLpl4XYToyiIPN1JMjHqllIKImT H6am5sZUmo5kAARuxf7NF88+jUghfhCR1OYKTtSGWXQNEWBHMUVEVd/akS+yqxdRNsQCxNTxAEi9O t79fgqqj4egwf9yPwSe4sqwRVNZ8zXAb2JB51EbPioIAk/zZSNwEY0kAeWD3a7b6JFZZp5V4Fxfeg iMS74O+gOBEcxQZlj45h1WRjn0hdcQ9oJOuzjceyALfxONUrbg+ihxYC/5PnqGT5utH+cUm5bqGnm 8qVaHWWnQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1fXs0w-0004Sd-9r; Tue, 26 Jun 2018 17:44:26 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id A28FA2029F1DB; Tue, 26 Jun 2018 19:44:24 +0200 (CEST) Date: Tue, 26 Jun 2018 19:44:24 +0200 From: Peter Zijlstra To: "Paul E. McKenney" Cc: linux-kernel@vger.kernel.org, mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org Subject: Re: [PATCH tip/core/rcu 13/22] rcu: Fix grace-period hangs due to race with CPU offline Message-ID: <20180626174424.GK2494@hirez.programming.kicks-ass.net> References: <20180626002052.GA24146@linux.vnet.ibm.com> <20180626171048.2181-13-paulmck@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180626171048.2181-13-paulmck@linux.vnet.ibm.com> User-Agent: Mutt/1.10.0 (2018-05-17) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 26, 2018 at 10:10:39AM -0700, Paul E. McKenney wrote: > diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h > index 3def94fc9c74..6683da6e4ecc 100644 > --- a/kernel/rcu/tree.h > +++ b/kernel/rcu/tree.h > @@ -363,6 +363,10 @@ struct rcu_state { > const char *name; /* Name of structure. */ > char abbr; /* Abbreviated name. */ > struct list_head flavors; /* List of RCU flavors. */ > + > + spinlock_t ofl_lock ____cacheline_internodealigned_in_smp; Are you really sure you didn't mean to use ____cacheline_aligned_in_smp ? This internode crap gives you full page alignment under certain rare configs.