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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 137B8C433F4 for ; Thu, 30 Aug 2018 18:36:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B418520837 for ; Thu, 30 Aug 2018 18:36:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B418520837 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.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 S1728149AbeH3Wju (ORCPT ); Thu, 30 Aug 2018 18:39:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:42088 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726592AbeH3Wju (ORCPT ); Thu, 30 Aug 2018 18:39:50 -0400 Received: from gandalf.local.home (cpe-66-24-56-78.stny.res.rr.com [66.24.56.78]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4A85420835; Thu, 30 Aug 2018 18:36:19 +0000 (UTC) Date: Thu, 30 Aug 2018 14:36:17 -0400 From: Steven Rostedt 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, peterz@infradead.org, dhowells@redhat.com, edumazet@google.com, fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org, Tejun Heo Subject: Re: [PATCH tip/core/rcu 3/3] srcu: Make early-boot call_srcu() reuse workqueue lists Message-ID: <20180830143617.2fb85e23@gandalf.local.home> In-Reply-To: <20180830173742.GA17677@linux.vnet.ibm.com> References: <20180829212036.GA22033@linux.vnet.ibm.com> <20180829212313.22903-3-paulmck@linux.vnet.ibm.com> <20180829215616.1c10e476@vmware.local.home> <20180830020701.GE4225@linux.vnet.ibm.com> <20180829224609.5ffdc9ec@vmware.local.home> <20180830032315.GG4225@linux.vnet.ibm.com> <20180830124444.6bb9faac@gandalf.local.home> <20180830173509.GL4225@linux.vnet.ibm.com> <20180830173742.GA17677@linux.vnet.ibm.com> X-Mailer: Claws Mail 3.16.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 30 Aug 2018 10:37:42 -0700 "Paul E. McKenney" wrote: > > > But still triggered the following: > > > > > > WARNING: CPU: 0 PID: 0 at /work/git/linux-trace.git/kernel/rcu/srcutree.c:242 check_init_srcu_struct+0x85/0x90 > > > > Gah!!! I needed to have removed that WARN_ON_ONCE(), didn't I? > > In fact, I should have removed that once I started using workqueues, > > quite some time back. > > As in the below patch. > > Thanx, Paul > > ------------------------------------------------------------------------ > > diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c > index 75571ff09c62..a8846ed7f352 100644 > --- a/kernel/rcu/srcutree.c > +++ b/kernel/rcu/srcutree.c > @@ -239,7 +239,6 @@ static void check_init_srcu_struct(struct srcu_struct *sp) > { > unsigned long flags; > > - WARN_ON_ONCE(rcu_scheduler_active == RCU_SCHEDULER_INIT); Well it boots without warning ;-) Tested-by: Steven Rostedt (VMware) -- Steve > /* The smp_load_acquire() pairs with the smp_store_release(). */ > if (!rcu_seq_state(smp_load_acquire(&sp->srcu_gp_seq_needed))) /*^^^*/ > return; /* Already initialized. */